Some interesting facts about solar thermal power
27 May 2008
Solar thermal power plants, often also called concentrating solar power (CSP) plants, produce electricity in much the same way as conventional power stations. The difference is that they obtain their energy input through concentrated solar radiation, rather than fossil fuels, and then convert it to high-temperature steam or gas to drive a turbine or motor engine. This difference means that no pollutants are emitted in producing the electricity.
- A solar thermal power plant built on about 1 per cent of the surface of the Sahara Desert would be sufficient to satisfy the entire world's electricity demand.
Solar energy arrives on the earth at a maximum power density of about 1 kilowatt per square meter. However, solar "productivity" is limited by certain geographical factors, including cloud cover and atmospheric humidity. In sunny, arid locations, one square kilometer of land can generate as much as 100 gigawatt hours (GWh) of electricity per year using solar thermal technology, enough power for 50,000 households.
- Solar thermal power plants reduce air pollution: The solar energy falling on an area the size of a basketball court is equivalent to 650 barrels of oil a year
In other words, each square meter of CSP concentrator surface is enough to reduce annual consumption of 200 to 300 kilograms (kg) of carbon dioxide. In addition, the "energy payback" time of CSP systems, taking into account the energy expended in their manufacture, is about five months, which compares well with their useful life of approximately 30 to 40 years. Most of the CSP solar field materials can be recycled.
- Solar thermal power is reliable and available when needed most - during peak demand hours
In most developed countries, the peak demand period - during the hottest part of the day, when air conditioners are running in the office and home - coincides with the period of time when the solar thermal power plant is at peak production. In addition, solar thermal power, as predictable and reliable as the sun shining in the desert, is a renewable alternative to natural gas "peakers", as opposed to other forms of renewable energy, which are either baseload or intermittent.
- Solar thermal power plants can be built (relatively) quickly
Solar power plants can generally be built in their entirety within a few years and can follow demand more closely than most conventional power projects. This is primarily because solar plants are built almost entirely with modular, commodity materials and thus have short development and construction times. In contrast, many types of conventional power projects, especially coal and nuclear plants, require long lead times, and this causes significant disparities between the demand and the supply.
- Solar thermal power plants are big - but relative to other types of power plants - they're space efficient
CSP plants seem to use a lot of land, but when looking at electricity output versus total size, they use less land than hydroelectric dams (including the size of the lake behind the dam) or coal plants (including the amount of land required for mining and excavation of the coal). While all power plants require land and have an environmental impact, the best locations for solar power plants are on land, such as deserts, for which there might be few other uses.
- Solar thermal power can be used with energy storage systems or combined with other energy sources to provide all day power
