Claymore Solar Basics

8/6/2019 Claymore Solar Basics

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If you are visiting these pages you are obviously interested in what solar power can do for you. . . . .

If you intend fitting solar, wind or grid (MAINS) backup power, it is essential for you to understand how solarelectricity works and what it will do for you. It is really pretty simple!

We have compiled some information to give you the knowledge to design your own solar power system. Once upona time solar design was the realm of rocket scientists. These people thought they possessed special knowledge, butas you will see, anyone with a calculator, two halves on their brain intact and an interest can design a solar powersystem.

You already have the interest otherwise you would be surfing elsewhere, so without further ado, start with the linkson the left and work through page by page by working down the links. It will help to have a pen, a calculator andsome paper ... A solar power system could look like this ... You would have some solar panels in a sunny place. These wouldgenerate electricity whenever the sun shone on them. The problem is what to do with this electricity ...We could attach something straight to the panel with a bit of wire, the trouble is whatever we attached would onlywork when the sun was shining. Since the first basic need is usually lights at night this setup would be prettyhopeless!

The next stage is to add a battery ...

The addition of a battery makes a solar system functional 24 hours per day. The electricity you generate during theday can be used at night then replenished again on the next sunny day. A consideration here is what would happenif the batteries were totally full of charge in the middle of a sunny day ...

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The next addition is a solar regulator ...

A solar regulator is a device that prevents the solar panels from over-charging the battery when it is full of charge.This also serves to protect the battery from being dangerously over-discharged.

It is likely we need some "mains type power"...

When you have a simple solar system as described above you are limited to powering your lights and appliancesstraight off the battery. This is fine for small setups needing only basic lighting and simple battery powereddevices. If you are intending to set up a solar system for a house, you will no doubt require some modernappliances straight from the electrical shop. These devices will undoubtedly need a power point to plug into. To

provide the necessary power for these appliances from your battery bank you need an inverter. An inverter is adevice that converts the electricity stored in your battery to something more useable like the 240 volts you getfrom the socket on the wall at home.

Add another generation source ...

Depending on your location and situation you may be able to add a complimentary generation source like a windgenerator. This will connect to your battery independently of the solar panels and will most probably require itsown regulator to work alongside the solar regulator. This is covered more in the information section on windgenerators.

Summary: You use solar panels in sunlight to generate electricity. You store this electricity in a battery bank. Asolar regulator prevents the battery bank from being overcharged/discharged. You convert the battery electricity tomains electricity using a device called an inverter. Later on this information section will cover stuff like how manypanels we need, how big should the battery bank be and some information on inverter selection but for themoment the next step to understanding all this stuff is a basic e lectricity lesson which is next!

Progress on to the next section which is simple electricity by using the side navigation bar.

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I would describe it as an invisible substance that came out of wires and made things like lights and the stereo andTV and stuff work and that it could be a bit shocking if you touched it. Basically it can be described as a bunch of things called electrons that flow through wires. These things can do a bitof work for us.

For our purposes we need to know that: Electricity is stuff that flows to appliances through wires. Electricity has two characteristics called voltage and current . Some examples of voltage are:

12 volts - A common car electrical voltage and small solar system voltage24 volts - A common small house or large motorhome voltage48 volts - A more serious voltage for medium - large household solar power systems96 Volts and above - Serious voltage from a large battery bank for a larger installation.Mains type voltage - This varies depending on what part of the world you come from, commonly 110 or 220 -250 volts

Current - Is the amount of electricity flowing and is proportional to the amount of power being used. A definitionwould be that an item that uses a large amount of electricity, say a heater or an iron will draw more current than alittle electrical appliance like a light globe. Current is measured in amps or more correctly amperes. While voltagecould be called the potential of electricity, current is the amount of power that comes out of the wire.

Electricity will be in two forms: AC or DC. DC Electricity is; "direct current" and is the electricity generated by your solar panels and stored in yourbatteries. AC Electricity is; "alternating current" as connected to most houses and buildings in most areas of the world. This

is the electricity your inverter will produce to run your appliances like the TV stereo and blender in a desirablemanner. Grab a CalculatorHopefully it will be powered by a solar cell! You are going to have to perform a few simple calculations on a piece of paper called a load sheet. Prior to putting pen to paper however let's take a quick look at what a few of theaforementioned electrical pioneers actually discovered.

WattsThe watt is named after Mr. Watt. He was a pretty clued up dude and invented (amongst other things) the steamengine. The watt is the unit of energy you must become familiar with. A watt is a measurement of work just like alitre is a measure of liquid. Solar panels are rated in watts. A simple calculation to remember is "Volts x Amps =Watts. See "Ohms Law" below.

Enter Georg OhmGeorg Ohm was a brainy German physicist who loved fooling about with electricity. While doing so he discovered arelationship between voltage, electrical current and work performed (watts) This is called Ohm's law. Ohms law states (in part) that: Amps (current) x Volts = Watts

Later you will find this calculation very useful. Of course you can reverse this for another common calculation;Watts divided by Volts = Current. Useful stuff indeed! At this stage don't fret about remembering all of this stuff though! Later pages will contain hints as to what to do calculation wise.

Parallel and Series connections

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Later on as you ponder connection solar modules or batteries together you will hear the term "connecting inparallel" or the term "connecting in series". It is important to gain an understanding of what this means: Basicallyspeaking a device like a solar panel or a battery will have what is termed as a nominal voltage. The nominalvoltage of a solar panel is usually 12 volts. The nominal voltage of a lead acid battery is 2 volts.

A parallel connection between two devices will result in the voltage remaining the same. A parallel connection isconnecting the positive and negative terminals of one device to the positive and negative terminals of the otherdevice. The voltage will remain the same.

An example of parallel connection (above), voltage will be unchanged, power output can be taken from anyterminal.

A series connection is somewhat different: Opposite polarities are connected. You will take the positive terminalfrom one device and connect it to the negative terminal of the other. This will double the voltage. See diagramsbelow.

An example of series connection (above), voltage will be doubled; power output can only be taken from remainingterminals on both devices.

Perfect Efficiency?A final part of this subject is a little thing called efficiency. Unfortunately all things won't add up to a perfect powersystem. You will hear about efficiency in later pages. To summarise what this is simple:

Your solar system will loose a bit of power as the electrons flow from place to place. A bit is lost in the wiresbetween the panel and the regulator, a touch more is lost in the regulator and still more is lost as the electricitygets stored in the battery. Converting your battery electricity to another form via an inverter will result in still morelosses. You will calculate in an efficiency factor using your calculator (with the solar cell). Typically the efficiencyfactor can be as low as 70% which might sound a tad sad, but there you have it and in reality is not that grim! The next lesson is all about calculating what sort of equipment you need in the way of panels and an introductionto the "POWER NEEDS FORM".

A solar panel is a device that consists of a few bi ts of silicon, usually glued under glass, that you put in the sun togenerate electricity. There are no moving parts and very little to wear out. A solar panel will go on producingelectricity year after year with only one proviso ... it must be in full sun to produce full power. Forget about shade

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tolerant panels and other marketing hype, sunlight = power from your solar modules, shade, overcast, rain and allthe inclement stuff means nil or very little output.

Some useful information to know: A solar panel is supplied ready to mount. It will have an aluminium frame that you use to attach the panel

to any surface. Typically this will be with tags, strips of metal, wood or anything else that suits theparticular location. Because aluminium reacts with some dissimilar metals you should either use aluminiumfor tags or separate different materials with a non-conductor like plastic.

A solar panel should have a tilt angle wherever possible to face it square on to the sun at midday. A fewdegrees here and there is not critical. If you are mounting your panels flat, such as on the roof of acaravan they will still work fine, you will however get slightly less power per day compared with a correctlytilted array.

No matter what a solar panel salesman tells you there is really no such thing as a "shade tolerant" or"cloud tolerant" panel! A small loss of sunshine equals a large loss of output. A slight overcast typicallywipes out 90% of a panels output. Partial shading from that tempting tree in the desert will mean nobattery charging. Do not believe otherwise!

A solar panel is not magic! If you use a 60 watt light globe for one hour at night you will need full sun on a60 watt solar panel for one hour plus to generate what you have used.

Your solar panel will typically be 12 volt rated although there are now some 24 volt panels on the market.

You will need pairs of panels to generate 24 volts if you use 12 volt panels. You will need your panels ingroups of four for a 48 volt system.

A 12 volt panel will have a typical output of 20 volts! You need an excess of voltage for power to flow fromyour panel to your battery.

A solar panel will either be supplied with a junction box containing a positive and negative terminal or with "flyingleads" which are your positive and negative connections.

Calculating the Size of Your Solar Array Determining the size of a solar system that will power your electrical needs requires some simple calculations and achart/form. The form is called a "POWER NEEDS FORM", this is covered extensively next. Below is a sample "POWER NEEDS FORM" and the steps required to fill one out. Skim through this then move alongand get started on your own "POWER NEEDS FORM" in the next section.

1. Prepare a simple chart to list and calculate total electrical load. 2. Itemise all electrical appliances, the power they use and the length of time they are on per day. (For

appliances used occasionally a weekly power use can be divided by seven). 3. Total these electrical loads to arrive at a watt/hour per day electrical load. Divide this power

requirement by 0.7 to achieve a factored power requirement. Factoring the power requirementcompensates for losses and inefficiencies in the batteries, wiring, inverter etc.

4. Calculate the sun/hours per day average for your area. Information on this may be available from themeteorology office, library etc. If a wind turbine is going to be used as well, wind figures could be obtainedat the same time. It is useful to have the sun hours for each month if possible to determine if anyparticular month or period in the year is lower than average. A back-up generator could be considered formonths with below average sun/hours.

5. Divide your total factored load by the average sun hours per day to arrive at the size of the solar array.

Below is a sample chart prepared for a small cabin.

Electrical appliance Wattage x Hours per day = Av. Watt-hours per day

KITCHEN

Light 40 x 4 = 160

Blender 250 x 0.1 = 25

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Other Appliances 200 x 0.5 = 100

LOUNGE

Light 60 x 4 = 240

Lamp 20 x 2 = 40

Small television 60 x 2 = 120

Video player 30 x 1 = 30

Stereo/radio 20 x 2 = 40

BATHROOM

Light 20 x 1 = 20

Fan 10 x 1 = 10

Washing machine 600 x 0.5 = 300

BEDROOM

Light 60 x 1.5 = 90

Lamp 20 x 0.5 = 10

OTHER

Outside light 100 x 0.5 = 50

Drill 600 x 0.1 = 60

Total daily electrical requirements in Watt/hours = 995

Factored daily power requirement = 995 / 0.7 = 1721

This cabin is in an area that receives an average 4 hours of sun per day over 1 year. Dividing the factored dailypower requirement by the average sun hours will give you the size of the solar array required. 1721/4 = 430. Inthis instance a 430 watt array should be sufficient. Given that solar panels are commonly sold in 60, 80 and 120watt sizes the array would in reality end up being 480 watts. The voltage could be 12, 24 or 48 volts. The mostcommon size would be 24 volts, 12 would be OK, 48 would be the most efficient however it would require 4 x 120watt panels or 8 x 60 watt panels.

You should now be ready to fill out your own load chart. ( Fill a form online here ).

Without some idea of what you actually want to run with your solar system you are unfortunately wastingeveryone's time. Start by ruling out everything that uses continuous heat. This means electric stoves (exceptmicrowaves), electric hot water and electric room heating and cooling. Forget your air conditioner and fan heater

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(except for very brief periods). Forget asking your solar dealer to do your designing. No excuses folk you must getat least some idea of what you personally want to power. Without coming to terms with this basic concept yoursolar system will quite possibly not work they way you hope! Then ask your dealer.

Consider what you really need ...

You need to become an electrical sleuth! This means starting to look at every electrical appliance you can lay yourhands on and discovering its electrical consumption. Just about everything on the market today has an electricalplacard on it stating the power consumption. This may be in watts or it may be in amps. To get the wattageremember Georg Ohm and his rule: Amps x voltage (of appliance) = watts.

In becoming an electrical sleuth you are working out what an appliance costs to run in terms of energy. This will beeither expressed in watts or as a current and a voltage. Virtually all modern electrical appliances will have thisprinted on them in the form of a placard. The wattage figure is what you are after. If the appliance placard states avoltage and a current you can convert this to watts by the sum: Voltage x current = wattage. (Ohms law)

Lets look at a few appliances: Lighting: This is high on the priority list. Seeing in the dark is all important. How many lights, how long for

and what is the wattage of each bulb? Television: Most folk have one. Mine is rated at 90 watts with an average load of 60. Video and Stereo: Not to huge a power consumer , most are under 20 watts.

Microwave: You will need a largish inverter for one of these. Could use 1500 watts or more. Don't go onthe cooking rating, this will be different from the power consumption. Find the placard!

Toaster and Kettle: I have both. While they use a large amount of electricity they are usually only used fora short time .

Refrigerator: Very opinionated subject for solar buffs ... We have a page on refrigeration in thisinformation section.

How to fill in the form ... (when you have read the following tips, click on the link below to fill in an online form)

1. List your appliances down the left hand column. It may be easier if you divide this column into rooms if you are planning a household load sheet.

2. List the appliance wattage in the watts column. Remember the formula current x voltage if all you have iscurrent data.

3. Determine the average daily run time of the appliance in hours. For items that may only be used once aweek or so, work out the weekly wattage and divide by seven

4. Calculate the watts per day then tally up the total foe your electrical load. 5. Divide this by 0.7. This gives a factored amount and will allow for inefficiencies etc. in your power system.

Fill in a Power Needs Form! You need to make a list. The shorter it is the less your solar system will cost you. You need to fill out a chart. We

have designed a simple form for you to fill in and email to us.

Click here to fill in a power needs form! ! !

1. In order for your solar system to be useful you need storage ... Search WebsiteTop of Form

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2. If you want to collect solar energy you are going to need somewhere tostore it. This is where batteries come in! Here we are dealing with leadacid batteries and although you could conceivably use ni-cad batteries(at somewhat of an expense) it is the lead acid battery that we will dealwith in this section. Modern lead-acid batteries come in flooded, gelledand absorbed glass mat types just to name a few. For the purpose of this lesson let's assume that they are all the same.

3. Voltage: A lead acid cell, regardless of size is a two volt device. Regardless of how

large you build a lead acid battery the nominal voltage will always be 2volts. If you put 6 of these batteries in one box and join them in seriesyou will get a 12 volt device as is used to start your car.

4. Battery Capacity: Battery capacity is measured in amp-hours (A/H or amp/hour or AH). This

measurement is the amount of amps (energy) the battery will providefor one hour. Battery capacity is also relative to speed of discharge. Aslow discharge over 50 hours will produce a higher total energy fromthe same battery than a rapid discharge. Temperature also affectscapacity. A battery bank at 30 degrees Celsius will have a significantlylarger capacity than if it were cooled to 0 degrees Celsius.

Battery capacity is stated as discharge over time. The time depends on whatthe battery manufacturer had in mind when designing the battery.Forklift and electric vehicle batteries usually have a stated capacity over5 - 10 hours @ 30 degrees Celsius, batteries specifically for solarinstallations have the capacity stated at 100 or 120 hours @ 25 degrees

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Celsius. 5. Summary so far: Battery capacity is measured in amp/hours and

provided to us by battery suppliers as capacity over time.

6. Battery Life: If you get a brand new battery and store it with some means of maintaining

its full of charge status (like a trickle charger) and put it on a shelf inthe shed its life will be determined by the length of time it takes for theacid to degrade the bits the acid is soaked in (like all the internal bits).Typically this could be 10 - 20 years.

You are not going to buy a battery and store it on a shelf are you?!The next thing that determines battery life is cycling (using thenrecharging) it. A discharge followed by a recharge is a cycle. The depthyou discharge a battery to before recharging it is the depth of cycle. Asmall cycle could be a battery discharged a little, say 10%. A deepercycle could be more like say 30 - 50% and a really heavy cycle could be80%. If you discharge a deep cycle battery by more than 80% on aregular basis you will quickly ruin it.

Battery manufacturers will state the cycle life for batteries designed to storepower. Batteries designed to start things are not storage batteries.They are "cranking" batteries and there capacity is not stated, ratherthere usefulness as a starting battery is stated in "cold cranking amps".We are not interested cranking batteries here but you should know thedifference.

7. Typical spec for a deep cycle battery for solar system use:

4000 cycles to 10%3300 cycles to 30%2500 cycles to 50%1500 cycles to 80%

From the above information we can determine a life expectancy: A solarsystem discharged on average 10% per day could be expected to havea battery life of around 4000 days or 10.9 years.If you were a little harder on your battery and discharged it to 80%down every day before recharging it fully you could expect a battery lifeof around 4.1 years.Given that the worst thing you can do to a battery is to leave it standingaround "flat" and a daily discharge of 80% is enormous and in realitynot likely your battery life is realistically about 8 - 15 years. Quitecommonly I see good quality deep cycle batteries still in service after 20or more years so the above figures are conservative ...

8. The manufacturer of this battery also states capacity as follows: Capacity C120: 375, C100: 340, C20: 213, C5: 171. These listings are not

until the battery reaches zero volts but are typically the capacity youwill get until the voltage reaches 1.8 volts per cell or for a 12 volt bankuntil it reaches 6 x 1.8 = 10.8 volts.

9. Summary so far ... Battery capacity is measured in amp/hours andprovided to us by battery suppliers as capacity over time. Battery life isdetermined by the number of cycles. A battery has a greater totalcapacity if it is discharged slowly.

A final rule: (made to be broken of course). Plan to be able to use about50% of a manufactures stated battery capacity at the C20 rate. Morethan this constitutes a pretty heavy discharge.

10. Working out what you need:

It is a relatively simple matter to determine what size battery bank yourequire. You have already read and retained the prior knowledgeimparted to you by way of our "Power Needs Form" page (haven't you)?Another big word we solar designers use in calculating what to install

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where is "Autonomy"Autonomy is simply the number of days you would like to have powerwhen things are inclement ... like no sunshine! A good figure would beabout 4 days.

Get your total electrical load in watts per day. Multiply this by four days.Double this because you only want to discharge to 50%

Divide the result by the battery voltage you have chosen and you willhave your required amp/hour capacity at the C100 rate.

OF course you may well choose a higher or lower autonomy than 4 days.

11. Choosing a battery bank voltage:

No matter how much I stare at my thumb there seem to be no rules writtenon it! Here is a guide though:

Up to 1000 watts: 12 volt battery bank1000 - 3000 watts: 24 volt battery bankAbove 3000 watts: 48 volt battery bank or larger. It is not uncommonfor battery voltages to be as high as 120 volts or more in largehousehold power systems.

12. Measuring battery level: This is covered in the "system monitoring" page of this information section.

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olar Regulators

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1. A solar regulator will prevent your batteries being over-charged. When a battery is "full" a means of tapering back or turning off the solar array is required. It also serves to protect the battery from overdischarge. This is the function of the solar regulator or controller.

2. What is Available 3. Solar regulators come in four varieties: 4. 1. Switching Regulators.

These regulators switch off the solar array at a predetermined voltage and turn it on again at another(lower) pre-determined voltage. These regulators are often referred to as simple regulators and are themost common small regulator type available. Once all regulators were switching devices however modernelectronics have made PWM regulators affordable and reliable. The most economical regulator for smallsolar arrays is still switching regulator

2. Pulse Width Modulated or PWM. PWM control of solar current is more efficient than switching. Instead of your solar array being switched off at a pre-determined voltage, PWM type regulation will reduce panel current while maintaining a constantvoltage at the battery terminal. A single constant voltage can still over-charge a battery bank so mostmodern PWM regulators actually provide an initial (high voltage) bulk or boost voltage. After a pre-determined time at this setting a further reduction in battery terminal voltage is initiated. The second lowervoltage is called the float setting.

3. Diversion Regulators.Instead of switching off or reducing your array current a diversion regulator will diver t unneeded panel

current to another device, usually a heating element. This type of regulation is very efficient if you have alarge solar array and want to extract all energy it provides. This type of regulation is often offered as anoption on high current PWM solar regulators

4. Maximum Power Point Tracking Regulators or MPPTThese regulators operate on the principle that a solar panel is at its power producing best at a variety of voltages and temperatures and therefore will product the most power into the battery when theseparameters are met on the input side of the regulator.

5. In order to understand what is happening refer back the first three types of regulators. All three have onething in common; when the battery voltage is below the regulation voltage the panels are connected

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directly to the battery. When regulation voltage is reached the panel to battery connection is either brokenor interrupted to reduce or eliminate panel output. Connecting the panel to the battery is fine butautomatically the voltage of the panel becomes the same (for all intents and purposes) as the batteryvoltage.

6. Check the typical spec of a solar panel:

7. It could look like this:8. Peak power watts: 125

Peak power amps: 7.2Voltage @ peak power: 17.4

9. Impressive?Actually it is the spec "Voltage @ peak power" that the makers of MPPT chase and this figure variesaccording to cell temperature. If you run the panel at this voltage and then turn this voltage into what isrequired to charge the battery without linking the panel to battery you will get a substantial increase inpanel output on most days. An even bigger advantage of using these MPPT thingies is that you can use a24 volt panel on a 12 volt system or use a grid feed panel (32 odd volts usually) on a battery system. Evenmore impressive you can wire all your modules up in series and feed the high voltage over a largishdistance through thinner wire to the MPPT and have it convert this higher voltage to battery chargingvolatge with an impressive efficiency level. Typically you may choose a 48 volt nominal array voltage for12, 24 or 48 volt systems.

10. In a coldish climate a MPPT on an array of say about 450 watts or larger is simply too good a device toignore. The benifits are huge and far outweigh the initial higher cost of these type of solar controllers. Seeour products pages for more details on these devices.

Calculating your regulator size: 11. Simply add up your panel wattage and divide by your system voltage at its maximum (full charge) level.

For a 12 volt system this will be 15, for a 24 volt system this will be 30 and for a 48 volt system this will be60 volts.

12. 2 x 125 watt panels in a 12 volt system would need a regulator sized: 2 x 125 / 15 = 16.6 amp regulator. 13. If you are using an old regulator or a cheap and cheesy devise from a dubious manufacturer you are better

off dividing the panel wattage by the nominal voltage ... 12, 24 or 48! To calculate the rating for a MPPT is somewhat easier. You need to look at the spec sheet for the device in question.

The manufacturer of the MPPT will state a maximum array size in watts. Obviously you won't exceed this ...

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An inverter is a box full of electronic goodies that will convert your battery voltage into mains type power.Once upon a time if you wanted to get "mains" type power from your battery bank you used a device called a rotaryinverter. This was simply a battery powered motor spinning generator with an output similar to mains power. Asyou can probably imagine efficiency was somewhat lacking...To the rescue came the elect ronics era and a bunch of silicon bits called transistors and MOSFET's, which are metaloxide switching field affect transistors just in case you needed to know. Without them we would have no computers,compact electronic devices or efficient inverters to power our electrical appliances.The modern inverter is so efficient and reliable that using appliances powered directly from the battery, as was thenorm in the past, is now all but history.The modern concept in solar design for anything other than a small campervan, 4WD or campsite is to power

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everything from "mains" type voltages "inverted" from the battery bank. The advantage this gives us is that we cango shopping in a local electrical store and buy conventional appliances just like the common folk on grid fed power.Take the humble light globe for an example: A 12 volt device that gives good light output for a reasonable powerconsumption is getting hard to find and somewhat expensive. Choosing 24 volts for your lighting makes light bulbhunting even more difficult.If on the other hand you get all your power from an inverter you can trot off to the local supermarket and choosefrom a great selection of super efficient low power consumption light globes that will often cost a fraction the price

of anything dc rated.To sum up ... You need an inverter to utilize the power your solar system will produce! Without further ado let'slook at what's in the box. BUT and its a BIG BUT ... An inverter is only as good as the battery bank it is connectedto and that battery bank is only good if your power system is capable of charging it when needed!

Inverter ratings. The three ratings that should concern you when buying an inverter are:

1. Continuous Rating: This is the amount of power you could expect to use continuously without the inverteroverheating and shutting down. 2. Half Hour Rating: This is very useful as the continuous rating may be to low to run say a large power tool orappliance but if the appliance was only to be used intermittently then the half hour rating may well be high enoughto cover this. 3. Surge Rating: A high surge is required to start some appliances that once up and running may only need

considerably less power to keep functioning. The inverter must be able to hold its surge rating for at least 5seconds. One well known brand we used to sell was incapable of this and led to disappointment and hassle. Wedropped it from our line! Televisions and refrigerators are two such items that require only relatively low poweronce running but require a high surge to start.

What the market can provide for you The inverter market today will basically supply you with two inverter types:

Low Cost: These inverters are available from electrical stores, hardware stores and electronic suppliers arecommonly available. Often you will find them sold by folk who know nothing of inverters or electricity. Theseinverters usually lack devices such as auto-start or any form of adjustability. Performance may or may not be asstated (or even not properly stated at all). However they are not all bad. Consider one if your needs are modest andyour budget is limited. Usually they present no problems for TV and video, computers and smaller appliances. Highoutput models can be good "power tool" inverters. We don't sell them. High Quality: There is no substitute for quality. You will find only a small handful of companies worldwide whomake high quality power inverters. You don't need a price tag here; one look will convince you of a superiorproduct.

With a High Quality Inverter You will Get: An auto-start system. An auto start allows an inverter to switch to a low power consumption standby state

when nothing is connected and turned on. This will save you a lot of manual switching and/or wastedpower

Adjustability. An ability to adjust parameters such as auto-start and battery depth of discharge is alsohelpful.

High quality heavy-duty power transformer. You won't see this unless you go poking around inside yourbox of electronic goodies but looking at the weight spec or picking up your quality inverter will demonstratea heavy transformer inside.

Two Types of Electrical Wave Your inverter will either be a modified sine wave variety or a sine wave variety. If you could see electricity youwould notice a difference between two types. You may have to take my word on it here however if you can lay yourhands on an oscilloscope (and work out how to use it) you can easily view the differences on the monitor.

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Modified Sine Wave Inverters Virtually all low cost inverters are "modified sine wave". A modified sine wave is easier and cheaper to produce thana sine wave inverter. It is also a fact that cheaper modified sine wave inverters have given this type of inverter abad name. Very few "high quality" inverter manufacturers even make an inverter with this type of electrical output.If you buy a high quality modified sine wave inverter however you will get an inverter that will run 99% of everything electrical, have a higher surge rating and cost you less than a sine wave inverter.

Sine Wave Inverters - The Cutting Edge of Inverter Technology. A small bunch of inverter manufacturers worldwide have developed quality sine wave inverters to highly efficientlevels. Efficiency has reached up to around 94% and the electricity from these devices is of a higher quality thangrid power virtually anywhere in the world.

Choose a cheap modified sine wave inverter if your needs are modest and occasional.Choose a high quality modified sine wave inverter if you want value for money.Choose a high quality sine wave inverter if you want the best available.

These devices are inverters when no e lectricity or generator power is available and battery chargers when mains orgenerator power is available.

This makes really good sense in something like a house that suffers from unreliable electrical supply. It also makesreally good sense if you have a high quality generator and are installing a solar system or if you are planning a solarsystem and need a quality battery charger for occasional use. An inverter/charger is heaps cheaper than a qualityinverter and a separate quality battery charger of the same power output/input.

The combination of inverter + separate battery charger

An inverter/charger has several advantages and some disadvantages over the battery charger and separate invertercombination. First let's look at using a battery charger that is separate from an inverter:When the power is low you start your generator and plug in the battery charger, battery charging commences. Youstill continue to use power from your battery bank as required via the inverter. An inverter delivers high qualitypower and your power supply remains quality. This can be an advantage as you will see shortly when you look atthe difference. A problem arises here if you need more power than your inverter can provide and you wish to usethe generator for this power. You need separate circuits or a changeover switch to direct your generator to yourpower points.

Joining inverter and charger together into one box ...

When you use an inverter/charger all the above stuff about separate devices is redundant. You are using inverterpower through your power outlets when the device is an inverter. You are using generator power through your

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power outlets when your device is a battery charger.

The process of going from inverter power to generator power at your power points is automatic and this function isprovided by the inverter automatically with a built in automatic transfer relay. It is so simple that most electriciansscratch and mumble and fail to grasp the basics without explanation! The swap between inverter power andgenerator power is virtually instantaneous.

Check it out so you can explain it if need be! Your inverter/charger has three connection points: Battery, household supply and generator (or mains

etc.)

When it is used as an inverter, power comes from the battery, gets "inverted" to household power thencomes out the household supply line. Nothing different from a conventional inverter here.

When you start your generator or plug in the mains an automatic transfer takes place via an inbuilttransfer relay. Transfer is virtually instantaneous ! Power is also provided from the input back throughthe inverter to the batteries. Battery charging commences.

The whole process is automatic, needs nothing added and is ready to function straight from the box. (This is whatelectricians fail to comprehend). The inverter/charger has everything, even a delay so your generator can warm upand stabilize prior to supplying energy. A quality device will also look at and match the generator output prior totransfer so that even sensitive devices like computers will continue to function right through transfer.

There are a few advantages and a few disadvantages associated with this automation The obvious advantage is that everything is in one box and the purchase price will have been a lot less than aseparate inverter and separate battery charger of the same quality. If you use heavy power tools or welders or suchstuff you need not worry about plugging them into separate power points or switching over your generator via aswitch. All this is done for you. Your inverter/charger could have on board electronics to automate starting thegenerator (if your generator is suited to auto-start) and will be a highly reliable device saving space as well asmoney. A good inverter/charger will have electronic sensing to determine generator load and will reduce batterycharger output if your household demand on the generator is high.

The disadvantage is this: If you use anything but a high quality generator your power quality will suffer. The outputfrom the average generator is way inferior to that of a modern inverter. Whether you want to or not, if you arebattery charging with the charger part of your inverter/charger you are also using generator power from yourgenerator in your house.

Some other uses for inverter/chargers: The use of an inverter/charger is not limited to solar power systems that need a generator. These devices are prettyneat! For example if you only have a generator for your power and nothing else, adding one of these devices plus abattery bank will give you 24 hour power for a vastly reduced generator run time. the savings in fuel alone couldwell pay for the installation cost.

If you have mains power connected and it is unreliable or you need a guaranteed continuous supply for medicalequipment or computer systems an inverter/charger will provide all of this automatically and reliably.

An inverter charger is a device that will be around for a long time!

WindGenerators

A wind generator is a pretty neat device. Wind power is about the cheapest form of renewable energy you can addto your site. BUT! But before you rush out and buy a wind generator consider this: A lot of folk out there have made

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the wind generator purchase only to discover that although they think they live in a windy site the power output isless than anticipated.

The perfect wind site From the above info you can deduce that having wind alone will not make a wind generator work. You need windplus location. A wind generator likes smooth undisturbed air. Anything else and it will "hunt" and "twist" as itconstantly seeks wind direction. Australia is starting to bristle with wind farms. They are so common now that mostfolk who have ventured on a long country drive (and not so long if you live close by) will have seen one. All windfarm sites share one thing in common: They are all located in flat open treeless plains, often near to the coast.

Another good location is a hill top.

More Marginal locations All this no doubt sounds somewhat sad if you are in a windy area but are surrounded by hills and trees. NoChance....... If you have the space to fly a kite, you can get your kite airborne and if you can keep it airborne allwith a minimum of fuss and running around you will probably be in a reasonable location for a wind generator.Another option to asses your location is to buy a weather station complete with wind sensor and data logging.These devices aren't altogether out of the price range of many people and are available from electronics stores like"Dick Smith" or "Jaycar" here in Australia.

The final option to asses whether your site is any good for wind is to actually buy a small wind turbine and install it.

This is what most people do. An "AirX" for example (see our products pages) is a very popular device.

Height The higher you can mount your wind generator above the ground the better it will work. There is a considerabledifference in wind speed in just 6 metres of height. It is not unfeasible to make and install towers up to 15 metres

high.

Distance Small wind turbines for 12 volt systems are limited in the distance that they can carry the electricity. To a certainextent all the battery charging wind turbines are limited by cable size and cost to being within 100 metres or so of

the battery bank with one exception:

High Voltage AC Wind Turbines for Battery Charging Alternating current (AC), unlike direct current (DC) has a distinct advantage; it can be carried over distance withless loss in a thinner cable than the equivalent DC voltage. Should you have a suitable hilltop where you can site awind generator that is some distance form your power system then a high voltage AC wind turbine may be theanswer. We have installed such a device on a hill top on an island in Bass Straight. The wind turbine is a highvoltage (150 volts AC) unit and it feeds 150 volts AC over one kilometer to the battery bank located by theresidence on the property. At the battery bank the 150 volts AC is converted into DC then controlled by a custombuilt AERL maximising controller and fed into a 24 volt battery bank.

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Using Refrigeration in Solar Systems

Your choice here is reasonable however all refrigeration is somewhat of a disappointment when it comes to solarelectricity. Unfortunately refrigeration is not a highly efficient commodity at this time. It is also a relentless load,consuming power whether the sun shines or not and if you want it to work correctly you cannot turn it off whenyou feel like it.

Refrigeration choices are outlined below along with their advantages and disadvantages (as well as my opinion).All prices are in American dollars and are an average sort of figure gained from casual inquiry. We do not sell anyof these appliances yet, and you may find prices vary greatly in your area of the world.

1. Gas or Kerosene refrigeration.

This is obviously not an electrical load! It is perhaps a suitable choice for some people. Gas refrigeratorsare expensive to buy and operate and you will need to consider the cost in your particular situation.Our opinion... we have tried a couple and they all used a lot of gas. The gas heating section requiresregular cleaning and maintenance and mine always seemed to run out of gas at the most inopportunetime. A comparative cost in US$ dollars i s as follows. Purchase price around $750.00 for a 220 litre fridge.Gas use = 4 x $120.00 gas bottles per year = $480.00 per year running cost. Given a maximumrefrigerator life of 20 years; at today's gas prices the cost of this refrigeration would be $9600.00 in gasalone! Over a 20 year period solar/electrical refrigeration is most definitely cheaper.

2. Conventional household refrigerator.

These are the cheapest refrigerator on the market due to the volume sold worldwide. The averageexamples are not highly efficient and need an inverter of suitable size to power them.Purchase price: $550.00 - $1,100.00 + Running cost average = the output from 3 x 120 watt solar panelsper day for a 220 litre version up to 6 x 120 watt panels per day for a largish family size refrigeratoraveraged over 1 year.Beware if you are going to take this route. You must be careful in your choice of refrigerator due to

inverter requirements. An inverter converts battery power into household power and this conversion usesenergy even if no appliance is connected to the inverter. Good inverters have a standby (auto start)system fitted to avoid unnecessary electrical use when no power is being used from them.With no other electrical load plugged in the refrigeration cycle should work as follows: The refrigeratorthermostat switches on the refrigerator to start the refrigeration process. The inverter senses that there isan electrical load and starts up from standby to run the refrigerator. The refrigeration process completesitself and the thermostat turns off the refrigerator. The inverter senses the loss of electrical load andreturns to standby.Most modern fridges have either, some or all of the following: Auto defrost, frost free, electrical spikesuppresser. All these items must be disconnected to allow the inverter to turn off when it is not required.This process is often as easy as a simple wire disconnection. In addition to the above, if you want yourinverter to return to standby when it is not in use the refrigerator will have to have a manual control dial

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for the temperature.

3. The electronic controls fitted to some refrigerators require constant power and keep an inverter on.Manual control dials are temperature controlled switches requiring no electricity for the switching process.An inverter for a refrigerator must be rated at least 3 times the refrigerator power consumption. This isbecause initially the power requirement to start the refrigerator is often 3 times higher than the powerrequired to run the refrigerator once it is running.

4. Buy a conventional refrigerator and have it converted to operate directly off the battery (i.e.: 12 or 24Volts). This process is relatively easy for a refrigeration mechanic and some refrigeration businessesspecialize in the conversion. The ac driven motor and refrigeration compressor are removed and replacedwith a high efficiency dc driven compressor unit. Cost for conversion around $600.00 - $2,200.00. Youmust consult the refrigeration mechanic prior to purchasing your refrigerator. The result is a higherefficiency refrigerator, the losses from the inverter are eliminated and the new compressor (whichprobably cost you as much as the fridge) is a better unit than that previously fitted.

5. Our opinion: This is what we should have done. The refrigerator we brought is not particularly suited toconversion process (we consulted the mechanic after purchase!). Converting your fridge to DC can also

free up the use of a small inverter if that is all you have. It's not much fun to be watching television orusing a computer from your inverter then have it shut down because this load plus the refrigerator startup load exceeded your inverter rating. Generally the gain in efficiency is most in fridges at or under 230litres in capacity. It is of the opinion of the refrigeration mechanic I consulted that anything larger thanthis may even be more efficient on ac power. A possible 20% reduction in refrigeration array size isgained from this process.

6. Buy a purpose built high efficiency refrigerator that is designed for a solar system. If you can afford it thisprobably is the best choice. These high efficiency refrigerators seem to cost heaps! Around $2,500.00 for220 litre plus paneling.

7. Make your own! This is not as hard as you would imagine. A conversion that is becoming popular is aconverted freezer unit. Small freezers use less power than refrigerators. This is because of the top loadingdesign and the fact that they are often insulated better. If you can live with a top loading fridge thenconvert a small chest freezer. All that is required is a different thermostat to keep your goods at thecorrect temperature. Most refrigeration mechanics should be able to perform this operation however itwould be sensible to consult the mechanic prior to purchasing your freezer.

8. Go without refrigeration. This actually suits some people.

Finally I will leave the mathematics up to you as to what will cost you how much when. In a perfect solar systemall appliances would be of the highest efficiency available regardless of cost.

It is also worth considering that a refrigerator has a life of maybe 20 years. Most solar panels will last 40 years ormore. It is up to you whether you buy efficient refrigeration or extra panels or adopt my route and use a directcharging system when the solar input is low.

Solar Power for your 4WD, Camper or Campsite

Solar power is fast becoming a common way of powering campsites around the world. As campsites become morecomfortable and campers become less inclined to "rough it" solar power is increasingly being used to power small

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refrigerators, kitchen appliances, tools and provide for lighting at night. Noisy generators are becoming less andless popular and are now banned from many campsites.

Solar panels are easy to use and transport, and are generally used to charge an auxiliary battery that can also becharged by a vehicle alternator while on the move. Panels can be mounted on a Camper or 4WD roof or connectedto a lead and placed in a convenient position when a camp has been established. If panels are roof-mounted, caremust be taken to park in a site that gets full sunlight. If panels are kept on a lead they can also be tracked formaximum efficiency by orientating them towards the East in the morning and towards the West in the afternoon.Two smaller panels can easily be joined together to make a folding panel for ease of transport.

Calculating a solar array for camping. Consideration needs to be given to how long you wish to remain in one spot and how large the auxiliary battery is.Often a panel that does not quite meet power requirements is sufficient, as the vehicle can charge the batterywhile on the move and the time of stay in one spot is not long enough to fully discharge the battery.

An example of this would be a camp where a small refrigerator is used. With no solar panels the refrigeratordischarges the batteries chosen to run it in 1 day (24 hours) The average stay "in camp" is 2 days. The vehiclealternator is set to direct charge the battery whenever the vehicle is running. The panel output can be as low ashalf the refrigerator power requirement. This can mean cheaper refrigeration than if the average camp stay wassay 4 days. The panel output required for 4 days would then be higher as the full refrigeration load would be fromthe panel.

Will solar power work for me? Maybe... Some folks understand it and make good use of it, some through ignorance or bad experience will bequick to inform you of the shortfalls. The most common shortfalls are:

1. Lack of sun. If you are visiting a warm climate you will tend to want to park in shade wherever possible.Pity about the roof mounted panels! No matter what the panel salesman told you will quickly discover thatthere is no such thing as a shadow tolerant panel! Continual overcast weather or rain in your location willalso severely reduce panel output. This may result in no power when you want it most!

2. Lack of battery capacity. This is related to no sun. When the batteries are not being charged they go flat!An undersized battery bank will quickly disappoint you. More so if you have no additional means of charging.

3. Poor quality batteries. This is unfortunate, especially i f you have paid good money for them. You needheavy duty deep cycle batteries and you must limit the total discharge to avoid your battery becomingtotally discharged. You should never leave your battery in a discharged state for longer than 2 - 3 days.

4. Not enough solar panels for the load used. Unfortunately being human we want as little cost as possiblefor the most power. When we have some power we want more... Beware of increasing you electrical loadwithout realizing it! It's very easy to add small components over and above the planned load. Suddenlywhat should have worked no longer does. If you can only afford a small investment keep your electricalrequirements small. Always use high efficiency appliances when possible.

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But look at the advantages! You no longer need that expensive powered site. You have power where there is none. You are responsible foryour own energy. You learn about a new technology.

BatteryCharging

There comes a time in most battery owner's life when current methods of charging simply are not enough. Youmust know the feeling, otherwise you wouldn't be here on this page: The sun won't shine, the wind won't blow oryou wish to undertake a power intensive activity that is just too much for the setup you have.

What is battery charging? Simply put it is adding electricity into a battery that is less than fully charged. There are a few basic sorts of rulesto assist you in selecting a method of charging and an appropriately sized battery charger.

To get power to flow into a battery the charging source must have a higher voltage than the battery. If you evercheck out the voltage from a 12 volt solar panel you will quickly discover that the voltage present on the terminalswhen the panel is in full sun is around 20 volts or more. The voltage of an alternator as used to charge your carbattery can be even higher, up to 90 volts or more on old alternators, and diode limited on newer alternators toaround 40. When you connect any of these devices to a battery the output voltage is stabilized by the battery andheld down to slightly above battery voltage.

The charging stages: You will hear a lot about battery chargers, solar regulators etc. and the type of output they have, often referred toas charging stages. A quality modern charging device like a solar regulator or a battery charger will typically offerwhat is called three stage charging. Let's look at the three stages as are offered by most quality charging devices.

Stage 1: Bulk charging

This is the initial stage and is when you first connect your charger to the battery. Current is "poured" in until thebattery terminals reach a certain pre-determined voltage. Usually around 15 volts for a 12 volt flooded lead acidbattery. This voltage is called regulation voltage. A good battery charger will determine when bulk charging isfinished because as the regulation voltage is maintained and the battery fills, less and less current will be requiredto maintain this voltage.

Stage 2: Absorption charging Once the regulation voltage has been reached and the current flow stabilized a timed period should commence atwhich this voltage is maintained. Usually around 1 hour.

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Stage 3: Float charging After the period of time at absorption has passed the battery is for all intents and purposes "full of charge". At thisstage if you were say, running a generator you would "switch off" and that would be the end of the process. If your charging source was a solar array via a solar regulator you would want a further stage other thandisconnection. When a battery is full it can be maintained full at a lower voltage then the absorption voltage. Theadvantage of this is that there will be less water loss, the battery will last longer etc. Typically the voltage on a 12volt battery would be further reduced to around 13.5 volts.

Sometimes a forth stage is added, usually on battery chargers designed for permanent (live) connection to abattery bank. This will be a slightly lower voltage than the float stage.

Some useful information A battery will only efficiently take a certain amount of current, regardless of state of charge. This is calledacceptance current. You can work this out easily for flooded lead acid batteries; it is usually around 10% of thebatteries capacity in amp/hours @ C100.

A 100 amp/hour battery will efficiently take a 10 amp charge. Which of course begs the question; what if I have ahuge size battery charger connected instead. Typically if you connected say a 50 amp battery charger to a 100

amp/hour battery you would do no harm, what would happen is the terminal voltage would rise very fast to theregulation voltage and the battery charger regulator would taper off the charge rate to something the batterycould accept like about 10 amps. The other more common way is to have a battery charger that is less than largeenough, again no problems, it will of course just take longer to charge the battery than it would take with anappropriately sized charger.

Charging while consuming It is common practice to charge a battery bank while you are drawing power from it. This is a time when a largecapacity charger on a small battery bank will work highly efficiently. An electrical load on your batteries will alwaysget its supply from the highest voltage source. If you are charging the batteries the highest voltage source will bethe battery charger, no matter what form it takes. Power will flow from the charging source to your load using thebattery as a buffer.

Finally... Charge efficiency is a term you may come across. A modern, good quality lead acid battery in new condition hasan efficiency of around 96%. As it ages this efficiency will drop slowly to around 92%. Simply put if we push in 10amps for one hour into a battery, about 9.2 - 9.6 amps will be stored.

Alternator basedcharging

In a residence were everything is powered by the inverter. Normally the batteries are charged by my solar array, if I want to use a power intensive device like a wood circular saw, or if the weather remains cloudy for several daysyou may start up an engine turning a 24 volt 55 amp alternator and bingo, up goes the voltage.

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The solar trade calls this "direct charging" and it is probably about the most efficient way to charge batteries usingmechanical (engine powered) means.

Direct Charging is also what you will do if you own a caravan or use a battery for energy in a recreational vehicle or4WD. Basically it goes like this in a vehicle: While traveling you use your vehicle alternator or auxiliary alternator tocharge you battery bank. When stationary the solar panels take over. Commercially available direct charging plantsare certainly available however it is comparatively easy to make your own. Full information on doing just that isavailable on request, email us at [email protected] This e-mail address is being protected from spambots, you need JavaScript enabled to view it .

Monitoring your solar system

System monitoring of some kind is essential to ensure reliable performance and long life of your solar systemcomponents. The main component of your power station will be your battery and your battery capacity will be the mostimportant thing to understand so system monitoring really means knowing the state of charge, or lack thereof, inyour battery. You can choose simple like an accurate digital voltmeter or get a little more hi-tech and use apurpose built monitoring system.

Monitoring via a voltmeter only A digital voltmeter can provide very useful system information and was once the only device I used to monitor myentire solar system.

Using only a voltmeter can be a bit confusing and a little time spent understanding battery terminal voltage is timewell spent even if you decide to install something slightly more sophisticated to monitor your power system.

For the purposes of this lesson we will look at a 12 volt battery, technically speaking I should talk about 2 volt cellsand "voltage per cell" but for the benefit of folk like me "plain speak" with a common voltage is a little easier tounderstand.For a 24 volt system you will of course double all the figures here, for 48 it will be four times the 12 volt numbers.

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Lets grab a hypothetical 12 volt battery "off the shelf" supplied (as all batteries should be) full of charge. It has asmallish capacity of let's say ... 120 amp/hours. As you will discover later on down the track, voltage variationsunder load and charge will differ a little depending on the capacity of the battery.

Grab a digital volt meter ...

But a word of warning here ...we are talking hypothetical, not actual and frigging around with battery terminalsand charging devices as I am about to list could well be a tad dangerous without some basic safety rules beingfollowed. In this case you don't need to actually grab a battery even if that is what I am saying! Just read oninstead...

If we measure the voltage of fully charged 12 volt battery with nothing connected it should be around 12.6 volts.

If we connect a reasonable load to the battery, let's say 6 lights, the voltage will drop to around 12.1 but thebattery is still full of charge at this point. Let's turn off the lights so we don't send the battery flat ... The voltageshould slowly return to something in the vicinity of 12.6

If we connect a charging source to the battery, for example an 80 watt solar panel that is in full sunlight or abattery charger that is plugged in, the voltage will rise to about 15 - 16 volts if the charge supply is unregulatedand the battery is still full.

If the battery was flat, let 's say about 60% had been used from it, we might see the following... No load: 12 volts6 lights: 11.0 voltsCharge connected: 13 volts

If the charge source stays connected you would see the voltage rise slowly until the battery was full and thevoltage had risen to around 15 volts.

The whole point of this is not to cause confusion, getting to know your battery capacity by voltage alone is not anexact science but a matter of observation over a period of time and a wide variety of charge and load conditions.The voltage will vary widely from about 10 volts right up to 16 volts depending on battery type and charge and orload conditions. If you install a power system and monitor it via an accurate voltmeter you will learn (and quitequickly) what is happening just by observing differing voltages at different times. It is not exact! No one can comeup with a perfect list of voltages relating to battery capacity and a batteries voltage will change no matter whatstate of charge it is in if you add a load or a charging source. That said, here is a simple chart for the open circuit(nothing connected) voltages of a 12 volt battery.

Full charge: 12.6Half flat: 12.0Fully flat: 10.5

If a lead acid battery ever measures zero volts (after a period of sitting idle) it is usually damaged beyond repair.

You could add a few more meters...To compliment your digital volt meter you could add an ammeter to measure input and perhaps another tomeasure output. For sure something to monitor the solar gain is a useful device, even just to see the differences ininput over varying conditions. If you are going to add all sorts of different meters though, it may well be moreeconomical to fit something a little more sophisticated than just a digital voltmeter and an ammeter to measuresolar input.

Using a dedicated system monitoring device

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There are a few very good devices on the market that will measure all inputs and all loads connected to yourbattery and come up with a set of figures in easy to understand formats to let you know exactly what is happeningwithin the workings of your power station. They all work by measuring what goes in and what comes out of yourbattery. In just about all applications this involves fitting a device called a shunt to one of your battery leads.

All about biodiesel

Once upon a time, long long ago a bloke named Rudolph Diesel thought he could change the world with arevolutionary engine that ran on peanut oil. Pity he tried to sell it to both the French and English naval fleets fortheir submarines, got mixed up in political intrigue and was next seen face down in the English Channel.

Still, despite all this his name is carried on with the diesel engine. The only difference is that the fuel companiescapitalized on his name, engine and a byproduct of the newly founded oil industry. The inevitable result was a fuelcalled "diesel" and an engine modified to run on the new, less viscous stuff "they" decided "you" should use. Good-bye peanut, hello money!

All this is very jolly and all, but you should know that it is still possible to run your modern computer controlleddirect injected turbo super charged intercooled piece of gizmoland on veggie oil, or at least on biodiesel made fromveggie oil. Any old diesel in fact will do, from today's hi-tech piece of trickery to yesteryears rattler. They will allrun on biodiesel!

You could spend a heap, start and stop you vehicle on diesel and run it on preheated straight veggie oil if you werereally keen. It is however a very easy process to convert veggie oil, in fact even used veggie oil into good dieselfuel the trade has named "biodiesel" or "bio-diesel". This stuff is commercially available in Europe, America and toa limited amount in Australia.

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So how do you do this magic? Picture an oil molecule? Now that's probably a bit hard, without a microscope you can't actually see one. Insteadlet's look at a ping pong ball with three tennis balls stuck to the side. The three tennis balls are what we areinterested in; the ping pong ball is glycerin

A simple chemical reaction with a big name will separate these tennis balls from the ping pong ball. In fact thischemical reaction will do a lot more. You will note when you get used veggie oil from the local fast food store thatit looks a bit yuk. Apart from the veggie oil you will have bits of cooking detritus like chip bits, crumbs, bits of burnt stuff and other gunk that make the oil unsuited to healthy cooking. Performing this chemical reaction willseparate this stuff as well as the glycerin. What you will get is clean biodiesel separated from and l ighter than theglycerin and gunky stuff that once made up your used veggie oil.

This simple process with a big name is called transesterification! At right is a sample of transistorized veggie oil orbiodiesel, (keep reading for a recipe)! In this sample you can clearly see the clean biodiesel fuel above anddistinctly separated from the glycerin and cooking contaminants.

OK how do I perform this unpronounceable task?

Transesterification of veggie oil (making biodiesel) can be performed at home using a home made mixing tank andtwo readily available ingredients. The mixing tank(s) I use are pictured below, the simple ingredients are methanoland caustic soda. Methanol is a racing fuel available from fuel agents and specialized fuel providers, caustic sodaor lye is available from the cleaning goods section of your local supermarket.

Basically what you do is mix the caustic soda with the methanol and then mix the resultant brew into the veggie oilthen settle the resultant mix in a tapered bottom mixing tank. The biodiesel, which is lighter than the glycerin anddetritus, will sit on top of a totally separate layer of glycerin and contaminants.

Try at home now! Here is a quick recipe to see if making bio-diesel is for you. You will need:

Some vegetable oil, new or used, suggest cheapest new stuff you can buy. Some caustic soda, by a 500 gram container from your supermarket for about three bucks. Some methanol. Try the local petrol head car racing type or ask at you local service station. This will be

your hardest find. Methanol is easy to get if you want 20 or 200 litres, small quantities are harder to find.For this experiment you need 200 ml. A model shop may also be able to help. Methanol is also used inmodel engines. It must be pure however. (No additives)

A glass jar with a screw top lid that will hold around 750 ml.

A smaller glass jar and wooden stirring dowel.

Accurate scales to measure in half gram increments.

An accurate measure that will measure in ml.

Put 500 ml of veggie oil in your big jar. In your small jar put 100 ml of methanol. Into this mix in 2 grams of caustic soda. Use the wooden dowel to alternately crush caustic against the jar bottom and stir into methanol. Thiswill take around 3 - 5 minutes.

Caution: Caustic and methanol mixed together is poisonous and a skin irritant, use gloves and eye protection.Perform this task near a water supply and immediately flush any skin contact with water.

Add your methanol/caustic mix to your veggie oil, screw on cap and shake for 3 - 5 minutes.

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Bingo! You have just made some biodiesel. Put your jar aside to settle and look at the separation! New oil willresult in clearish glycerin; used cooking oi l will separate black glycerin. Check my picky. This sample was madefrom used cooking oil and has actually been set tling for 24 hours; however, the glycerin should become apparentafter around 20 minutes.

Biogas

Biogas is generated when bacteria degrade biological material in the absence of oxygen, in a process known as anaerobic digestion (in the abscence of oxygen). Since biogas is a mixture of methane (also known as marsh gas or natural gas, CH4) and carbon dioxide it is a renewable fuel

produced from waste treatment. Anaerobic digestion is basically a simple process carried out in anumber of steps that can use almost any organic material as a substrate - it occurs in digestivesystems, marshes, rubbish dumps, septic tanks and the Arctic Tundra. Humans tend to make the

process as complicated as possible by trying to improve on nature in complex machines but asimple approach is still possible, as I hope you see in this website.

Conventional anaerobic digestion has been a "liquid" process, where waste is mixed with water tofacilitate digestion, but a "solid" process is also possible, as occurs in landfil sites.

Methane is difficult to liquefy, since it has a critical point of -82 degrees Celsius. Biogas burnswith a hot blue flame and can be used for cooking, lighting and to run refrigerators. It is also

possible to run engines on the gas, diesel engines being suitable, and realising a substitution of some 80% of the diesel normally consumed. A 100% substitution is possible in the case of petrolengines. The difference is due to the absence of a spark plug in the diesel engine necessitating theinjection of some diesel to effect ignition. The sludge that remains after digestion can still be usedas high quality fertiliser, so there is no waste. See Fig 1.

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Fig 1. Closed Loop of Biogas Production and Use.

Apart from getting biogas and fertiliser, decomposition and fermentation of organic material in biogas digesters improves sanitation because the gas and the slurry/sludge obtained does notusually smell, and moreover breeding site for flies, gnats and mosquitoes, which transmit diseasee.g. malaria, are eliminated. Most of the pathogens are also killed during the fermentation process

What can Biogas do?

1 m 3 of biogas can:

cook three meals for 4 people or

provide 7 hours of lighting or

run 300 litre fridge for 3hrs or

run a 2 horse power engine for 1 hr or generate 1.25 kWh of electricity

Put in other words; the following are guide values for the composition of biogas for:

- Cooking: 0.25 m 3 per person per day

- Lighting: 0.12 m 3 per hour per lamp

- Driving engines 0.30 m 3 per kWh

There are many advantages of biogas over wood as a cooking fuel:- Less labour than tree felling Trees can be retained Biogas is a quick, easily controlled fuel No smoke or smell (unless there is a leak - then you need to know

anyway!) so reduced eye/respiratory irritation Clean pots Sludge is a better fertiliser than manure or synthetic fertilisers (and

is cheaper then manufactured products)

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Reduced pathogen transmission compared to untreated waste

Biogas in Vehicles

Once upgraded to the required level of purity (and compressed or liquefied), biogas can be usedas an alternative vehicle fuel in the same forms as conventionally derived natural gas: compressed

natural gas (CNG) and liquefied natural gas (LNG)

A 2007 report estimated that 12,000 vehicles are being fueled with upgraded biogas worldwide,with 70,000 biogas-fueled vehicles predicted by 2010. Europe has most of these vehicles. Swedenalone reports that more than half of the gas used in its 11,500 natural gas vehicles is biogas.Germany and Austria have established targets of 20% biogas in natural gas vehicle fuel.

In the United States, biogas vehicle activities have been on a smaller scale. Examples include alandfill in Whittier, California , that fuels vehicles with CNG derived from the landfill (also seethe EPA's Clean Fuel Facility page) and an Orange County, California, landfill that produces

LNG for use in transit buses. Several DOE-sponsored projects also have developed biogasvehicle technologiessee the Research and Development section.

Interested in a bio-gas system then reach us at [email protected] This e-mail addressis being protected from spam bots, you need JavaScript enabled to view it or call us at +263912 716 594 ; +263 11 702 454 or +263 4 293 6650

How Lead Acid Batteries Work

Here is a short run-through of how lead-acid batteries work. I'll start with some basics and work my way up - hence the absence of an alphabetical order. Depending on your familiarity with thesubject, you may want to scroll down more or less.Voltage

Voltage is an electrical measure which describes the potential to do work. The higher the voltage the greater its risk to you and your health. Systemsthat use voltages below 50V are considered low-voltage and are notgoverned by an as strict (some might say arcane) set of rules as high-voltagesystems.

Current

Current is a measure of how many electrons are flowing through a conductor.Current is usually measured in amperes (A). Current flow over time is definedas ampere-hours (a.k.a. amp-hours or Ah), a product of the average currentand the amount of time it flowed.

Power

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http://www.lacsd.org/about/solid_waste_facilities/puente_hills/clean_fuels_program.asphttp://www.epa.gov/lmop/res/cleanfuel.htmhttp://www.ngvglobal.com/technology/prometheus-produces-world-s-first-commercial-lng-from-landfil.htmlhttp://www.afdc.energy.gov/afdc/fuels/emerging_biogas_research.htmlmailto:[email protected]://www.lacsd.org/about/solid_waste_facilities/puente_hills/clean_fuels_program.asphttp://www.epa.gov/lmop/res/cleanfuel.htmhttp://www.ngvglobal.com/technology/prometheus-produces-world-s-first-commercial-lng-from-landfil.htmlhttp://www.afdc.energy.gov/afdc/fuels/emerging_biogas_research.htmlmailto:[email protected]


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Power is the product of voltage and current and is measured in Watts. Powerover time is usually defined in Watt-hours (Wh), the product of the averagenumber of watts and time. Your energy utility usually bills you per kiloWatt-hour (kWh), which is 1,000 watt-hours.

What is a Lead-Acid Battery?A lead-acid battery is a electrical storage device that uses a reversiblechemical reaction to store energy. It uses a combination of lead plates orgrids and an electrolyte consisting of a diluted sulphuric acid to convertelectrical energy into potential chemical energy and back again. Theelectrolyte of lead-acid batteries is hazardous to your health and mayproduce burns and other permanent damage if you come into contact with it.Thus, when dealing with electrolyte protect yourself appropriately!

Deep Cycle vs. Starter Batteries

Batteries are typically built for specific purposes and they differ inconstruction accordingly. Broadly speaking, there are two applications thatmanufacturers build their batteries for: Starting and Deep Cycle .

As the name implies, Starter Batteries are meant to get combustionengines going. They have many thin lead plates which allow them todischarge a lot of energy very quickly for a short amount of time.However, they do not tolerate being discharged deeply, as the thinlead plates needed for starter currents degrade quickly under deepdischarge and re-charging cycles. Most starter batteries will onlytolerate being completely discharged a few times before being

irreversibly damaged. Deep Cycle batteries have thicker lead plates that make them tolerate

deep discharges better. They cannot dispense charge as quickly as astarter battery but can also be used to start combustion engines. Youwould simply need a bigger deep-cycle battery than if you had used adedicated starter type battery instead. The thicker the lead plates, thelonger the life span, all things being equal. Battery weight is a simpleindicator for the thickness of the lead plates used in a battery. Theheavier a battery for a given group size, the thicker the plates, and thebetter the battery will tolerate deep discharges.

Some "Marine" batteries are sold as dual-purpose batteries for starterand deep cycle applications. However, the thin plates required forstarting purposes inherently compromise deep-cycle performance.

Thus, such batteries should not be cycled deeply and should beavoided for deep-cycle applications unless space/weight constraintsdictate otherwise.

Regular versus Valve-Regulated Lead Acid (VRLA) BatteriesBattery Containers come in several different configurations. Flooded Batteriescan be either the sealed or open variety.

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Sealed Flooded Cells are frequently found as starter batteries in cars. Their electrolyte cannot be replenished. When enough electrolyte hasevaporated due to charging, age, or just ambient heat, the battery hasto be replaced.

Deep-Cycle Flooded cells usually have removable caps that allow you

to replace any electrolyte that has evaporated over time. Take care notto contaminate the electrolyte - wipe the exterior container whilerinsing the towel frequently.

VRLA batteries remain under constant pressure of 1-4 psi. This pressure helpsthe recombination process under which 99+% of the Hydrogen and Oxygengenerated during charging are turned back into water. The two most commonVRLA batteries used today are the Gel and Absorbed Glass Mat (AGM) variety.

Gel batteries feature an electrolyte that has been immobilized using agelling agent like fumed silica.

AGM batteries feature a thin fiberglass felt that holds the electrolyte inplace like a sponge.

Neither AGM or Gel cells will leak if inverted, pierced, etc. and will continue tooperate even under water.

Battery Cells

Battery Cells are the most basic individual component of a battery. Theyconsist of a container in which the electrolyte and the lead plates caninteract. Each lead-acid cell fluctuates in voltage from about 2.12 Volts whenfull to about 1.75 volts when empty. Note the small voltage differencebetween a full and an empty cell (another advantage of lead-acid batteriesover rival chemistries).

Battery Voltage

The nominal voltage of a lead-acid battery depends on the number of cellsthat have been wired in series. As mentioned above, each battery cellcontributes a nominal voltage of 2 Volts, so a 12 Volt battery usually consistsof 6 cells wired in series.

State of Charge

The State of Charge describes how full a battery is. The exact voltage tobattery charge correlation is dependent on the temperature of the battery.Cold batteries will show a lower voltage when full than hot batteries. This isone of the reasons why quality alternator regulators or high-poweredcharging systems use temperature probes on batteries.

Depth of Discharge (DOD)

The Depth of Discharge (DOD) is a measure of how deeply a battery isdischarged. When a battery is 100% full, then the DOD is 0%. Conversely,

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when a battery is 100% empty, the DOD is 100%. The deeper batteries aredischarged on average, the shorter their so-called cycle life .

For example, starter batteries are not designed to be discharged deeply (nomore than 20% DOD). Indeed, if used as designed, they hardly discharge at

all: Engine starts are

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