New uses
Photovoltaics- Generating Electricity from the Sun
08/06/2010Solar radiation can be converted directly into electricity using special collectors, known as photovoltaic collectors. This electricity can be used to supply public or private buildings both in urban or isolated environments.
© Total / Daniels William
The Advantages of Photovoltaic Electricity
Since 2000, global production capacity of photovoltaic electricity has grown 35% per year.
There are three reasons for this success:
• Photovoltaic systems can supply rural areas that have no electricity grid. They are easy to install, require little maintenance, and will provide energy for 20-30 years. It is easy to upscale the systems when local energy demand rises. This is why photovoltaic technology is ideally suited to developing countries such as Morocco, Senegal, India, Bangladesh, and Thailand.
Photovoltaic technology is ideally suited to developing countries
• This form of energy has limited environmental impact. Photovoltaic panels have a relatively short energy payback time (i.e. the time it takes for the panels to generate as much energy as was required for their production and transportation)- between one and five years. Furthermore, photovoltaic electricity generation does not emit any pollutants or greenhouse gases and a large proportion of the panel components are recyclable, particularly for the most widespread technology on the market - silicon-based panels.
• Like other renewable energy sources, photovoltaics offer an alternative to the rapidly dwindling stock of fossil fuels as they require no fuel.
Photovoltaic electricity generation is only for sunny countries.
False. It is quite feasible to generate photovoltaic electricity in countries with less sunshine, such as Denmark and Germany. However, to obtain as much energy as in a sunny region, the surface area of the photovoltaic panels used in the solar power system needs to be bigger. The cost of solar electricity generated in this way should be compared to the cost of solar electricity generated in a sunnier country plus the cost of transporting this electricity to the place where it is consumed. There are advantages to generating electricity locally, even in a country that is less sunny. This has also contributed to the popularity of photovoltaic electricity in Northern Europe.
A Wide Variety of Applications
Photovoltaic technology can be used in a wide variety of situations. These include:
• Stand-alone plants that are not connected to the electricity grid, representing 10% of all photovoltaic systems worldwide . These plants supply satellites, radio relay stations, time clocks, public lighting, roadway, maritime or airway signage; or are used to supplement oil and gas power plants. These plants also provide energy to mountain refuges and to isolated dispensaries and schools in developing countries. Photovoltaic cells can also be used to recharge mobile telephones, watches, and calculators.
• Plants connected to the electricity grid, including:
o Building-integrated systems or systems placed on private or public buildings’ roofs (houses, residential or office buildings, farms, factories, hotels, hospitals, schools, sports facilities, stadiums, airports, and car parks). These plants are common in Germany, France, and Japan. The electricity generated is fed back to the grid and purchased by electricity companies.
o Ground-based solar power plants and solar farms. There are a growing number of them in the United States, Germany, and Spain. Rows of photovoltaic panels are aligned over thousands of square metres. The panels can be attached to a mobile base so thy can follow the sun’s trajectory, thus increasing performance. The electricity generated is usually fed back into the electricity grid (to benefit from repurchase rates).
Energy Access in Emerging and Developing Countries
1.6 billion people in emerging and developing countries have no access to an electricity grid. Stand-alone photovoltaic systems and solar systems providing decentralized rural electricity are one way of providing them with access to electricity.These systems supply energy to isolated villages in Africa (Morocco, Senegal, and South Africa) and Asia (India and Bangladesh), thus providing them with new systems and facilities.
• Telecommunications systems (radio, television, and telephone booths)
• Cooling systems (refrigerators)
• Solar pumping of underground water (for drinking water and irrigation)
• Lighting
• Electrical appliances (mobile telephones and sewing machines)
Similarly, in India, the number of households with photovoltaic panels doubled between 2000 and 2006, from 500,000 to one million. Over 3,000 villages use only this form of energy for their electricity supply and Indian businesses are making substantial investments in photovoltaic research.
Thus, all around the world, solar photovoltaic energy provides people who are too isolated to be connected to conventional electricity grids the means for development.
[1]Source: Rapport Poignant 2009
[2]Source: Syndicat des Énergies Renouvelables
[3]Source: Énergies et matières renouvelables, questions-réponses ADEME
[4]Source: Observ’ER
