Solar Fridge

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Transcript of Solar Fridge


Using the sun to generate electricity


INRODUCTION In Todays world global warming is being increasing year by year. There are many reasons like pollution, deforestation, water contamination, etc...In coming years the major problem before us is depletion of ozone layer which is caused by the release of CFCs. Some of the equipments which cause this effect are refrigerators, ACs. In this project we are mainly focusing on a solution to control this problem we have focused on refrigerators which releases CFCs. Here we are designing a mini solar based refrigerator which is cheaper as well as eco-friendly.




WORKING: Here we are using Micro controller (AT89S52) allows dynamic and faster control. Liquid crystal display (LCD) makes the system user-friendly. The sensed and set temperature values are simultaneously displayed on the LCD panel. In this project we are using solar panels for charging a Lead Acid Battery (12V, 1.2 Amp hrs), a pelteir thermoelectric device which when connected to battery generates cooling effect on one side and heat is dissipated on other side through heat sink, a cooling fan is used for dissipating the heat from the heat sink. A regulator 7803 is used to drive the internal cooling fan and LED. The temperature sensor LM35 senses the temperature and converts it into an electrical signal, which is applied to the micro controller through ADC. The analog signal is converted into digital format by the analog-todigital converter (ADC). The sensed values of the temperature are displayed on the 16x2-line LCD. The temperature range of the sensor is 10C to 2550C.


The main task has been to develop a new cooler, which fulfill the current WHO requirements for vaccine coolers with battery back up, as no standard exist for the battery less type. According to these guidelines the design temperature interval is 0 C to + 8 C. The vaccine must also be kept cool for four days without power, and this is the sizing criteria for the ice storage in the cooler.



The reason for choosing energy storage in ice was to avoid a lead battery for energy storage. Lead batteries tend to deteriorate, especially in hot climates, or they are misused for other purposes. This makes it necessary to install a new battery after a couple of years, and has in practise been an obstacle for the use of solar powered refrigerators.



The solar cell is composed of the semiconductors of the P-N junctions. It can convert light into electric energy. Therefore we can assume that electricity produced using sunlight shining on the solar cell can be used like common electricity.

Specifications 12V 1.3Ah sealed lead acid battery 1. CE and RoHs 2. high quality and relaibility 3. miantenance free 4. long life cycle 12V 1.3Ah sealed lead acid battery General Features: Sealed and maintenance free operation. Non-Spillable construction design. ABS containers and covers(UL94HB, UL94-0)optional. Safety valve installation for

Lead Acid Battery

Fridge Features: Cools a beverage from 5V USB Power Stylized as a mini fridge Holds one can Internal LED light USB powered No batteries required11

Plug and play Temperature of cooling pad decreases to 8.5 degrees after 5 mins Dimension: 19.4x9x9cm Weight: 362g




Calibrated directly in Celsius (Centigrade) Linear + 10.0 mV/C scale factor 0.5C accuracy guaranteeable (at +25C) Rated for full 55 to +150C range Suitable for remote applications Low cost due to wafer-level trimming Operates from 4 to 30 volts Less than 60 A current drain Low self-heating, 0.08C in still air Nonlinearity only 14C typical Low impedance output, 0.1 W for 1 mA load

Absorption coolers are used for both vaccine storage and for household applications and obviously needs regular supply of fuel. Furthermore, they are difficult to adjust, which does often result in destructive freezing of the medicine. So far, two generations of prototypes have been build and tested in climate chamber at the DTI and an advanced control were build with the purpose to control the temperature in the cooler and the speed of the DC-compressor in order to exploit maximum power from the solar panels.14

Highlights Unit runs on a single 70 Watt/Ref 1.5 KW/AC module in most climates Fast cooling due to compressor speed control Low maintenance and easy to clean


Features A++ cooling technology Lockable lid Compressor speed control Automatic selection of 12V / 24V Temperature fully programmable Fridge or Freezer in one cabinet Applicable for all DC applications



Your outdoor lights Your pool and hot tub Use a solar oven Use passive heat storage tubes to increase and store solar energy Use solar chargers to charge your MP3 player Use solar powered appliances Heat your water with solar power Use solar indoor lights Try using solar powered electronics A solar power generator



Portable solar fridges Ease of installationto save time and money Included mounting back plate Included communication ports Included LCD display with back-light for 24 hour display viewing High efficiency and outstanding energy harvest in a small modular design Fast cooling due to compressor speed control Low maintenance and easy to clean18

Applications: Chilling cold drink cans For household applications For medical applications Can be used for instant heating applications


Conclusion The project is useful for the instant chilling/hot applications. Experimental work has been carried out carefully. The result shows that higher efficiency is indeed achieved using the embedded system according to requirement of the user.20