MWRA Sustainable Energy in Water sports

Energy Efficiency & Renewables on the Water

ObjectivesObjectives

• Understand drivers for energy use on the water

• Options for Energy efficiency

• Options for Renewable energy

Principles Of Energy EfficiencyPrinciples Of Energy Efficiency

Typical energy use of a standard 100w light bulb in a sitting room

Turn off the light when we’re not in the room

Use a more efficient source say a 20w CFL. Still the same light delivered.

If the sitting room is too bright lets put in a 10w bulb

Then we install renewable energy

1000 hrs a year 100w or 100,000 watt hours or 100 kwh (€17)

700 hrs a year 100w or 70 kwh (€12)

14kwh 700 hrs 20w or 14 kwh (€2.40)

7 700 hrs 10w or 7 kwh (€1.20)

Increasing Effort, S

avings, investment

• Turn it off when not in use.• Maintain systems

– N.B De-ice freezers!– Properly tensioned alternator belt– Good electrical contacts & wiring

• Add cold items to fridge if possible• Buy efficient: get certification/ data not

salesmen.

Simple stuff firstSimple stuff first

Understanding how much energy we use

Hours Running 4 lights on 110AH Battery

0 20 40 60 80 100

Large halogenlight

Small halogenLight

Typical strip(flourescent) light

LED

Lumens/ Watt0 20 40 60

Luminous Efficacy (circuit)

• Typically are 70% efficient & Lose ~1%/week• Can use up to 80% power (50% for starting batteries)• Repeated excess discharges reduces storage and

efficiency.• Limited max charging rate - ~10A charge (110 AH)• Ideally suitable for smoothing out charge & use patterns.• 110 AH leisure battery =>110 x 12.5V = 1375 Watt hours• Deep Cycle 80% recoverable => 1100 Wh or 1.1kWh• Or 1 amp for 120 hours (x0.8) ~ 100 hours• 5 amps for 20 hours….10 amps for 10 hours… etc

Deep Cycle Lead acid Deep Cycle Lead acid batteriesbatteries

Other Energy Uses: Reduce where possible

Typical Energy Use Watts Current

VHF Standby 0.6 0.05

VHF Hi Power Transmit 75 6

High quality 40L fridge 12.5 1

Large Fridge freezer Freezer 37.5 3

Typical Peltier (cheap) coolbox fridge 50 4

Chart Plotter 9 0.7

Bulb based Nav lights 25 2

LED Nav lights 3.5 0.3

Stereo 20 1.5

• Prior to installing renewables – bring down load first• Energy efficiency much cheaper than renewable energy• Estimate load and use of all appliances• Estimate occupancy & pattern of use:

– Blue water cruising Vs Weekend use.– Coastal (diesel available) Vs Ocean

• Size storage (batteries) Vs use & generator capacity

RenewablesRenewables

• Solar Panels: Three types

RenewablesRenewables

  Amorphous Poly-crystaline Monocrystaline

Cost Low Medium High

Efficiency 5% - 10% 10%-14% 15%-22%

Shape Thin flexible multi-shape hard Fixed octagonal

Life Limited 20+ yrs 20+ yrs

Use On deck Bolted to Rail Bolted to Rail

• Not all solar panels are the same: • Cost Vs Efficiency must be noted• Solar charge controller required.• Prices tumbling (20% - 30% per annum)• Great for trickle charging – keeping batteries healthy

• Wind Generators:• Wind proportional to Cube of windspeed – high windspeeds necessary• Necessary to mount as high as possible off deck (wind speed proportional to height off ground).• Clear air if possible (rear mount generally)• Intermittent (Battery sizing important)• Use wind power curve to evaluate• Typical outputs for costal marine would be 25% of rated capacity (15-20% inland)

RenewablesRenewables

• Tow Generator– Needs 4kts to have reasonable output– Good for long cruising passages– Reduces boat speed – useful when excess

wind present– Pointless under power.– Issues with chaffing

• Harness electricity off propeller (engine off)– Reduces boat speed– Need to gear up (pulley(s))– Need to balance forces on prop shaft– Only worthwhile for blue-water cruising

RenewablesRenewables

• Do an Energy Audit – Power rating and usage time• See what can be reduced in time (switch off!)• Any maintenance requirements – healthy battery etc.• See what energy efficiency upgrades can be done

– Interior lights– Navigation lights– Re-fridgeration

• Renewables – battery trickle charger (10 W solar)– Light loads for weekends etc 60W solar + backup engine– Heavy loads: consider wind + solar combination

SummarySummary

• Biofuels

• Solar powered boats

Motive PowerMotive Power

• Tipperary Energy Agency• Craft Granary• Church St• Cahir• Co. Tipperary • Ireland

• Paul Kenny B.E C.Eng MIEI

• Senior Energy Consultant • T: 052 74 43090• F: 052 74 43012• E: info@tea.ie • W: www.tea.ie