Jan 21, 2016

Solar Air Conditioning

Solar Air Conditioning

The primary source of energy for a Solar Air Conditioner or Solar AC is solar power. India being a hot and humid country, can benefit a lot from use of solar Air Conditioners and there can be tremendous amount of energy savings. The main advantage being that enough insolation exists, to power solar AC energy needs. The overlap lies that the Indoor Air-Conditioning is required, and peaks when solar power and irradiation is available in plenty, outside homes and offices. 
There are mainly two methods and principles used for Solar Air Conditioning - 
a) Solar Thermal & 
b) PV Solar Air Conditioning
While solar water heating is a proven concept, and feasibility exists, solar air conditioning uses the same principle in reverse. It is expected that for smaller installations ( such as residential) more and more Solar PV AirConditioning is likely to be used. This is in the backdrop of, decreasing Solar PV prices. However, for larger customers, ( a.k.a industrial customers ) Solar Air Conditioners are gaining traction in China where there are a number of suppliers and the costs are much cheaper. In fact, most of the China based solar AC manufacturers have started to push to India, with their products, and see a large market in India.

While Solar Thermal Technology is mainly used in industrial air conditioning, with decreasing prices of solar panels PV Solar Air Conditioners should become the more common technology. 

Solar Air Conditioner Types

1) Passive Solar Air Conditioning
In this type of cooling the design of buildings is done in such a way that it  slows the rate of heat into a building in the summer, and improving the removal of unwanted heat. It involves a good understanding of the mechanisms of heat transfer. Passive solar cooling is much easier to achieve in new construction than by adapting existing buildings.
2) Solar closed-loop absorption and adsorption Air Conditioning
Active solar cooling uses Solar Thermal Collectors to provide thermal energy to drive thermally driven chillers. Solar thermal Energy heats the heat transfer fluid within the system. The generated heat is then used in conjunction with absorption chillers to provide a renewable source of industrial cooling.
3) Photovoltaic (PV) Air Conditioning
This is mainly used in residential air conditioning.The power generated from the solar panels is used to drive conventional compressor-based or adsorption/absorption-based systems. PV cooling cost effectiveness depends largely on the cooling equipment and  the efficiencies in electrical cooling methods is quite poor.
What is Direct Current Solar Air Conditioners
Household Appliances mostly run on Alternating Current (AC) while Solar Power generated is Direct Current(DC). The conversion from DC to AC is done through a Solar Inverter which leads to increased cost and loss in efficiency of about 15%. In Direct Current Solar Air Conditioners that AC is directly powered by solar energy without conversion to AC leading to power savings.

Solar Air Conditioner Manufacturers/Suppliers/Installers in India

In India, manufacturers do not supply air conditioners based on solar energy. Due to the high cost and almost complete rewiring (in some cases) needed for the home, solar air conditioners are absent. Some industrial units are going for this solar energy based solution to reduce the electricity cost which is ballooning. Also some LEED buildings and green friendly organizations are implementing solar air conditioners. There is a growing trend of industrial units, who have started to adopt solar rooftop solutions, as a way of reducing energy costs. The energy costs are spiralling upwards for common fossil fuel based electricity. Air Conditioning consumes a lot of this energy and hence, it is natural for a shift to happen to solar based energy, in a bid to reduce energy costs. For customers, who are looking to buy such ACs in India, there are only a couple of air conditioners suppliers that one could find in India currently. 
1) Onyx – is India’s largest solar air-conditioning company making hybrid solar air conditioners for industrial clients. The company’s product are not pure solar air conditioners but use the existing solar air conditioning technology to make it more efficient using solar collectors. The same principle of using compression techniques, evaporation and cooling using air conditioning gases are use.
2) Urja Unlimited – This organisation is also supplying and importing solar air conditioner for residential and industrial units besides a host of other solar products like solar modules. It is coming up a player in the IoT space, and combining solar with IoT technology.
4) Arka Technologies – The company is also like the others providing a host of solar solutions which includes a Solar Air Conditioning System (SACS).

And now the bottom line...Costs of Solar Air Conditioner

The cost of a Solar Air Conditioner is still quite high. For Example to install a 1000 Watt Solar Air Conditioner you would need at least 2 kw solar panels system which would imply about Rs. 1.1 lakhs of investment without considering the cost of a battery. This system can replicate the functioning of a 1.5 ton AC for a room. If you included the price of storage, charge controller and accompanying electronics, then the costs would be higher by about Rs. 50-60,000. While the running costs of a system would be minimal, note the high initial investment on a solar air conditioner implies that it would cost you almost 7 times the price of a normal AC unit. For larger industrial units, this cost may be even higher.