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Solar Thermal

Solar thermal energy is designed to harness solar energy for heat, which is then used to generate electricity. Solar thermal, also referred to as Concentrated Solar Power (CSP) differs significantly from photovoltaics. Photovoltaic technology generates electricity directly from sunlight whereas solar thermal energy uses lenses and reflectors to concentrate solar heat to generate power. This heat is then used to generate electricity which can be stored or released directly on to the grid.

The modern solar industry began with the oil embargo of 1973-1974 and was strengthened by the second embargo in 1979. In recent years the solar thermal market has experienced renewed growth and a number of technologies have emerged which include solar dishes, solar troughs, solar towers and linear fresnel reflectors.

Increasing demand for renewable energy and solar power

Renewable energy sources are becoming a very important component of the global energy mix. Under the International Energy Agency's 'Alternative Energy Scenario', the share of renewables in electricity generation could rise to 25% by 2030.

McKinsey estimates that the global solar capacity will rise from 6 GW in 2005 to over 200 GW in 2020, of which concentrated solar power (CSP) capacity would amount to about 46 GW.

In the US the Energy Information Administration (EIA) expects renewable sources to rise from about 9.9% of electricity generation in 2006 to nearly 12.2% in 2020, amounting to an increase in installed capacity of about 31 GW. If the approximately 20 states with Renewable Portfolio Standard (RPS) legislation meet their stated targets, the US market could be even larger at 32 - 40 GW of incremental capacity. Given that wind power may only have the ability to meet approximately 55% of RPS demand, solar energy will be an important component of US renewable electricity generation.

As can be seen from the map below the areas with the greatest potential for solar thermal power include North America, Africa, Middle East and Australia.

Global locations suitable for harnessing solar thermal power

Map of World showing locations suitable for harnessing solar thermal power

Source: Pharabod and Philibert, 1992