Solar Energy- an Ever More Accessible Renewable Energy Source

08/06/2010

Since the 2000's, solar energy has become more popular. Solar plants are sprouting up everywhere, increasingly meeting everyday electricity, hot water, and heating needs.

Where Now for Solar Energy?

Solar energy can be converted into heat using thermal collectors (which in turn can be converted into electricity using a thermodynamic system) or directly into electricity using photovoltaic collectors.

Businesses in France, Germany, and Japan have been researching photovoltaic electricity applications since the 1970s, occasionally with public funding. Solar energy was initially used to supply electricity to satellites, residential buildings connected to the grid or isolated infrastructures.

In the decades since, environmental challenges, increasingly complicated access to hydrocarbon resources, and issues relating to the development of emerging countries have changed the energy landscape. Against this backdrop, solar energy took off in another direction. It is used to generate fuel-free heat and electricity with no greenhouse gas emissions and is a resource that is evenly distributed throughout the world.

Solar energy really started to take off in the 1990s. Between 1998 and 2008, worldwide solar electricity generation increased by a factor of 13¹ and the number of thermal collectors worldwide grew 20% per year_². Most solar energy plants are located in Europe, Eastern Asia, and North America.

An Ever Wider Variety of Applications

Nowadays, solar energy is used in many different ways every day. In emerging or developing countries, thanks to photovoltaic plants and systems, local populations now have access to energy where they didn't before.  For example:

  • Since 2002, Temasol has outfitted 25,000 households in Morocco with individual photovoltaic kits. Between 150,000 and 200,000 people living in isolated rural areas now have access to electricity.

   • In Bangladesh, the Grameen Shakti association has installed over 200,000 domestic solar systems, comprising a small photovoltaic panel connected to a battery. Thousands of villages have benefited from this scheme.

In industrialised regions, solar plants provide additional locally-available, renewable, and clean energy. This type of plant has allowed some European countries that were previously sourced exclusively from foreign suppliers to become more energy independent.

Portugal has adopted this approach, opening the largest photovoltaic plant in the world in 2008. Located in the village of Amareleja, this solar power plant covers 250 ha and supplies electricity to some 30,000 households³.

In France, homeowners are availing of grants available to install solar systems. The most common are:

   • Photovoltaic panels, either integrated in the building's structure or placed on the roofs of houses. In most cases, these are made up of electrically connected silicon cells. They capture sunlight and convert it into electricity. The energy generated is used for domestic needs (particularly in isolated areas, such as shepherd huts and mountain refuges) or fed back into the grid (this is the most common use in OECD countries). In 2009, there were 30,000 facilities of this type- with over 80% in individual houses⁴.

   • The individual solar water heater (SWH) operates through thermal collectors installed on the roof of a house. The collectors convert solar radiation into thermal energy to heat a boiler or even, in some cases, a swimming pool. This system can provide 40-80% of the daily hot water needs for a family of four. There are also a number of collective solar water heaters for use in apartment buildings or communities.

   •    The combined solar system (CSS) comprises a solar water heater and heating component, supplied by thermal collectors.

These technologies are slowly gaining ground in France and elsewhere in Europe and the rest of the world. In 2009, 40 million households worldwide already had a SWH or CSS system⁵.

Higher Performance and Reduced Cost

Scientific research has increased conversion yields obtained from thermal collectors and photovoltaic cells.  In other words, the amount of solar radiation they convert into heat or electricity has risen. This means that the productivity of solar equipment available on the market has improved.

In 2009, the output of a thermal collector was 50%⁶ while that of a photovoltaic panel was 10-16%⁷.

Moreover, the cost price of this equipment has regularly fallen: it cost 5 times less to manufacture a photovoltaic panel in 2008 than in 1982⁸. They also require little maintenance and have an estimated life span of over 30 years⁹.

These advances mean that the cost of purchasing and installing solar water heaters is paid off within 10 years¹⁰ while the cost of generating photovoltaic electricity in Southern Europe was divided by seven between 1980 and 2007¹¹.

[1]Source EDF / Observ'Er / ADEME, Laproduction d'électricité d'origine renouvelable dans le monde, 11^einventaire, édition 2009
[2]Source Syndicat des énergies renouvelables, Lesolaire thermique en Europe et dans le monde
[3]Source Le Figaro
[4]Source Photovoltaique.info(ADEME)
[5]Source rapport Poignant, 2009
[6]Source EncyclopédieLarousse
[7]Source Institut nationalde l'énergie solaire
[8]Source Green Univers, Repère :production et coût du solaire
[9]Source rapport Poignant, 2009
[10]Source EncyclopédieLarousse
[11] Source Photovoltaique.info(ADEME)