PV power plants have grown up in last decades as a viable resource of large – scale renewable energy power production. A main aspect of that initiative is the application of PV technology to convert light into electricity. A key question, facing these PV systems at the utility scale, is their cost-effectiveness in comparison with other sources.
From a technical point of view, solar cells are just one of the components in an electricity-generating system that consists of PV modules, inverters, and BOS components. From economic, financial, and policy perspectives, solar cells are just one element in a power – generating equipment; its efficiency depends on the quantity of energy the system produces, the system lifetime, installation costs, operating and maintenance costs, a range of financial options, and governmental incentives.
PV power generation is largely dependent on the solar energy resources of the ground. Therefore, it is necessary to know the distribution of the solar energy resources in the country. The distribution of solar energy resources has some limitations like restrictions by weather and geographic conditions. Currently, the fundamental restrictive factor for growth in PV power development is the high cost. Solar cells account for over 60% of the value of a PV power plant. Consequently, developing efficient, cheap, stable, reliable, and long-lasting solar cells constitutes the priority of the PV technology globally.
For the time being, the R & D of the solar industry mainly stresses on the commercialized Si crystalline solar cells, CIGS, CdTe, and concentration solar cells. Consideration is also given for next – generation solar cells like crystalline Si thin – film cells, dye- sensitized cells, organic thin- film cells, nanometer cells, and spectral absorption cells, through large investment and research efforts. In the coming of solar industry, the remote power applications required smaller expensive solar modules that were generally assembled in a fixed position. The initial cost of the solar modulus in U.S. dollar per watt was the basic economic metric, and the early solar subsidies and incentives were based on this metric. Tracking the sun for these smaller systems just increased expenses, and there was no financial incentive to do so. Recently, solar cell systems have gotten larger in scale, and the economic metric has decreased to cents per kilowatt hour.
By following the sun all day, the module’s productivity usually increases by 25 – 40%. At present, the tracking becomes the preferred option for many high-scale applications. For ground-mounted solar systems producing electricity for peak power, solar tracked systems now go beyond 50% of the new installations. Solar tracking systems on commercial buildings at rooftops become economically attractive options. Fortunately, commencing with the solar FIT in Germany, the government incentives now endorse systems that maximize the kilowatt hour produced and minimize the cost of solar electricity in cents per kilowatt hour. Trackers are a supplementary hardware modulus used to elevate the energy output from solar cells.
The PV manufacturing industry has grown dramatically in recent years due to a strong demand from markets. Global production of solar cells and modules has grown at an average annual rate of 49.5% since 2002. The production of solar cells worldwide reached over 37.2 GW in 2011, up from 27.4 GW manufactured in 2010. The European market accounted for 68% of the worldwide solar production. Germany, Italy, China, the United States and France are the top five PV markets, making up 74% of global demand in 2011, according to Marketbuzz. Nowadays China and Taiwan are the largest producers of solar cells in the world, accounting for 74% of world solar cell production, up from 63% in 2010.
While turning sunlight into electricity, photovoltaic systems use resource, which has an unlimited potential in practice. Therefore, the energy from the sun has a direct, positive effect on the energy independence and security of supply. Energy independence and source diversification become factors with increasing importance for economic stability and political security. As energy from PV systems may be produced anywhere and in small scale, it provides energy supply diversification at national, regional, local and individual level. PV power plants has already become a winning investment for many homeowners, farmers and enterprises globally. By delivering secure, renewable energy for the society in decentralized manner, photovoltaic power production represents a technology, that guarantee security, prosperity and sustainability for the global economy. Driven by the rising oil prices, global warming, and a deteriorating environment, clean renewable energy is getting increased attention globally. All these factors boost the support for the advancement of this sustainable energy technology that optimizes energy efficiency.
Author: Rumen Dimitrov, MSE, CEO of Oto Group JSC