Solar power starts with sun rays coming down through the atmospheric layer, and hitting the earth, is many thousand times over the energy sources which are commonly used by mankind. The capability of this natural resource is massive and makes it a crucial element for renewable energy source. Solar energy is aimed at reducing the disturbance in the ozone layer and trying to maintain the greenhouse effect on the atmosphere.
Only 1% of the total electricity is from this renewable source. Implementation of the photovoltaic solar panels for harnessing this resource is rising for the past 20 years.
How is solar energy processed?
The concept of traditional system of architecture, can be applied to harness sun’s energy for our benefit. Homes and buildings can be designed in such a way that they get maximum light and heat. Before any construction is done on the site, the land should be studied to find out direction of air, water and sun. The design should be such that 60% of the windows are facing south as this reduces heating requirements by approximately 25%. The structures can be built on east-west axis so they can remain cool in summers and warm during winters.
Thermal materials like stone, cement and water can be used in warm temperate regions to keep buildings cool by absorbing solar heat during the day and radiating the stored heat to cool the at night. They are also used in cold temperate areas to maintain warmth as well. This is the passive way of processing solar energy. The other way to process energy is the active method.
In this method, solar panels consisting of photovoltaic cells are used to convert solar energy to heat and electricity. Large solar parks, also known as photovoltaic power stations are built to convert energy directly to electricity. These are also known as solar ranches or solar farms if situated on agricultural areas. Worlds first solar park was built in 1982 in California but have since been decommissioned. Many other countries have started utilizing this power source. Germany is the top most country to utilize this power source.
Solar energy is also processed for cooking food. Mirrors and dark colored utensils are used to absorb solar heat for the food to be cooked. Solar cookers are manufactured using this technology. Mirrors are to be placed at certain angles so that after reflection the sun rays should fall on the utensil. The utensils are painted in dark colors on the surface to absorb maximum of heat.
Types of solar panels
- Monocrystalline solar panels: these are the purest form of panels made from single crystal of silicon substrate. They have uniform dark look. These are most efficient, can convert 20% of the sunlight to energy. Installation requires less space and have life expectancy of 25 years. They can even perform in cloudy weather. But these are expensive because of their purity and also because wastage is huge in residential installation.
- Polycrystalline solar panels: these are less pure as many crystals of silicon substrate are fused together to form one panel. It has a blue speckled look. Efficiency is around 15% and a lower life span than monocrystalline panels. The performance is affected by the weather. Wastage is less as angles are not cut.
- Thin film solar cells: these are the less expensive option as they are made by placing thin films of silicon, cadmium, copper and other photovoltaic material onto a substrate. These types of panels are flexible and less affected by high temperatures. Lots of space is required for the solar power installation therefore unsuitable for residential installation.
- Amorphous silicon solar cell: used in calculators as they are very thin, 1 micrometer thick, because of the triple layered technology. Efficiency rate is 7%. Only advantage is that these are very low in price. Also known as a-si-cells.
- Concentrated photo voltaic cells: generate electricity just like photovoltaic cells and have high work efficiency rate i.e. 41%. Curved mirror surfaces, lenses and cooling systems are used to harness sun rays to increase its efficiency. These can only be efficient if the mirrors face the sun at perfect angle. Solar trackers are installed inside the mirrors so that they ca follow the sun.
- Bio hybrid solar cells: still in research phase. The idea is to use the process of photosynthesis, combining the multiple layers of photosystem which converts chemical energy to electrical and thus becomes much more effective.
- Cadmium telluride solar cells: cadmium telluride enables production of solar cells at a very low cost. Keeps carbon footprint to the lowest and very less amount of water is required during production. Only disadvantage is that cadmium telluride is toxic in nature.
Monocrystalline and polycrystalline are first generation solar panels. Thin film solar cells and amorphous silicon solar cells are known as second generation and the rest are third generation solar panels.
Residential solar installation system
To find out your requirement of the household solar panel system you have estimate your power consumption. Collect your power bills for the past year, add all the kilowatts and divide it by 12. You will get your usage for one month. Now divide the value by 30 to find out the daily usage. Now select which type of solar panels do you want. If you do not know which to choose, consult your solar PV installer from reliable solar electric company. Also, determine the space you have allotted for your solar power installation system.
One can hire solar PV installer to install them on the terrace. According to the size of the terrace and type of solar panels, the technician form solar electric company can calculate number of panels required. For example, a 2000 square foot can have 12 -18 solar panels.
The approximate cost of residential solar installation would be $15000-$29000. This will be an average size system between 4 kW to 8 kW. Household solar panel system consists of solar panels, electrical wires and an inverter.
From dawn to dusk the solar panels will directly convert solar energy to electricity and send it to the inverter. The inverter will further change into alternating current, the type used for household.