Producing solar thermal energy requires two things—sunlight and building materials that trap, store and disperse the sun’s energy. Thermal energy is heat energy, not to be confused with the type of power generated by photovoltaic semiconductors like silicon. When used effectively, solar thermal energy can make electric heating systems obsolete and may just be the future of the global power supply.
Inexpensive Water Heating
Using the sun’s thermal energy to heat water can dramatically reduce your electricity bill. Instead of using an electric hot water heater, many homes have solar hot water heaters that not only heat water but pump it through the house. According to the government’s Energy Savers website, solar hot water heaters work in any climate and the fuel is always free. They note that passive water heating systems—those without pumps—require very little maintenance, as infrequently as every 3 to 5 years.
Inexpensive Home Heating
Passive solar heating uses a structure’s location and building materials to collect and store the sun’s energy. According to the Whole Building Design Guide website, features like south-facing windows, building materials with heat storage capacities, natural convection vents and glazed windows can all reduce the need for electrical heating and cooling. In fact, the website reports that even modest usage of passive solar design can reduce heating needs between five and 25 percent, at little or no cost. Buildings designed entirely on these principles can reduce heating needs between 25 and 75 percent, making them cost-effective over the life of the building.
Unlimited Source of Energy
Unlike fossil fuels, the sun’s thermal energy is in no short supply. According to BP’s 2007 Statistical Review of World Energy, the earth’s known oil reserves will last approximately 40 years; however, Britain’s Oil Depletion Analysis Centre criticizes that estimate, predicting a sharp decline in oil availability as soon as 2011. Alternative energy sources such as coal and natural gas exist, but both are considered “dirty” sources that will pollute the environment and the atmosphere. The sun, in contrast, offers a limitless supply of free energy.
Cost-Effectiveness of Solar Thermal Power Plants
Although many solar applications are small-scale and exist in individual homes or offices, the potential exists to build solar thermal power plants to replace traditional oil- or gas-powered plants. According to Ferrostaal, a German solar contractor, solar power plants are already competitive in terms of cost with their fossil-fuel-powered competitors. They claim that solar thermal plants remain competitive when oil costs $70 per barrel. Should that price rise as high as $130 per barrel, solar thermal plants will be more economical than plants fueled by oil or natural gas.
Environmental Friendliness of Solar Thermal Power Plants
Solar thermal power plants have several other advantages over their fossil-fuel competitors. According to Ferrostaal, solar thermal plants don’t require a great deal of space and can make use of undeveloped, unproductive land. They’re built using recyclable materials such as glass, steel and concrete. Best of all, no fossil fuels need be consumed during the power production process, resulting in zero harmful carbon dioxide emissions.