More than 80 % of power generation is derived from fossil fuels today. With increasing energy demand & dwindling supply of these fuels, renewable sources of energy are the obvious answer to energize our future. Solar Photovoltaics provide only 0.1 % of the world’s total electricity generated today, although the demand for solar PV is growing at an annual rate of 40 %!
A solar farm is an arrangement of a large number of solar panels which convert light energy from the sun into electrical energy without the use of any fuels. They are similar to centralized power plants, capable of generating electricity based on any amount of energy demand.
The main components of a solar farm are:
- Solar photovoltaic generator- Solar panels connected together to generate power.
- Batteries which store the power generated from the pv generator
- Inverters which convert the DC (Direct Current) Power of Solar Panels to (AC) Alternating Current to run the AC loads at the household levels.
A standalone Solar Farm
Solar Farms are of 2 types- Stand alone Solar PV Systems and Grid Connected PV Systems. The diagram above is a stand-alone system. These systems are also called off-grid systems & find applications mostly in rural central power plants. The most common stand-alone solar farms are in the range of 5KW – 100 KW in capacity.
Grid Connected solar farms feed the electricity generated from the solar panels directly to a power grid through an inverter, without the use of a battery backup. Thus the power generated should be consumed within a few milliseconds after generation to prevent energy losses because there is no option of energy storage with these systems. Grid connected solar farms are the fastest growing power generation technology today.
Benefits of Solar Farms
The modularity of the solar PV gives this technology an upper hand compared to conventional energy technologies. A solar farm could kick off with as small as a 1 KW power generation unit and progress towards a megawatt based farm by plugging in more solar panels. For conventional energy technologies, enlarging the power plant would lead to setting up new infrastructure for procuring, transporting & storing more fuel.
The long life of a solar farm owing to the long operational life of solar panels (at least 25 years) and no recurring costs has enormous economic benefits. In the current scenario when solar power costs more than grid power , solar farms may still be the smart choice because the lifetime cost of solar is less than the rising cost of grid electricity. An estimate of the savings from solar compared to grid power over 25 years is stated – for every percentage point annual increase in electricity prices, solar can be 10% more expensive than grid power today and still be at “parity.” With an electricity price inflation of 2% per year, solar grid parity shifts up two years using this method .
Solar Farms are even more beneficial in off-grid locations. The cost, effort & time required to stretch the grid lines from power plants to distant off-grid areas to provide grid electricity is not viable. Solar farms can be established close to demand centres, provided there is sunlight which saves costing on building the infrastructure to transport power to such far-off location. The current off-grid solution for electricity is diesel generators, which have recurring costs, are inefficient in operation and have a limited life of 10-12 years. Solar farms have an even quicker payback compared to diesel generators & a longer operation life.
Using conventional fuels for power generation like coal & diesel has large environmental impacts. The combustion of these fuels contributes to rising carbon emissions into the atmosphere which is thought to be the direct reason causing global warming. Erratic climate change & unpredictable natural calamities are surfacing due to global warming which calls for a curb in usage of such fuels. Using solar farms for power generation, can offset 50 gigatonnes of carbon emissions from the period of 2008 to 2050.
Limitations of Solar farms
Although solar farms seem to be economically a smarter investment today, the technology suffers from a few limitations. The current urban grid infrastructure in many countries does not have the capacity to accommodate power generated from solar farms. Hence the technology for such systems is yet to develop & standards for grid integration need to be established.
Solar farms have been implemented in many off-grid areas in the past. Their success rate has been rather low because of equipment failure or a gap between the energy demand and the supply by solar PV after a short period of time. The reason for such faults are because, when electricity is available in a given area, people tend to buy more electrical appliances leading to larger power consumption. As power produced from solar farms are limited, if the energy demand cannot be met, it leads to blackouts resulting in unsatisfied customers. Thus future electricity consumption needs to be evaluated before setting up a solar farm.
Mapping the Future of Solar Farms
It is estimated that 2 billion people around the globe today live do not have access to the grid. With improvement in technology & price declination, the future for solar farm is bright & promising. Solar farms in off-grid areas are already reaping success in developing countries.