Thermal energy is a type of solar energy that is becoming more popular as consumers discover the options of solar-generated power. The most common types are solar thermal energy and ocean thermal energy.
There are three basic forms of solar thermal energy collectors: low, medium, and high. Each can be used residentially or commercially.
1. Low temperature thermal energy collectors, are flat plates that are most often used for heating, cooling, ventilation, and to process heat. In the United States, 25% to 50% of energy is used on heating, ventilation, and air conditioning. This percentage can be offset by the use of solar thermal energy. The collectors gather energy throughout the day, then release it as temperatures lessen, usually in the evening. Most often, thermal collectors use stone or concrete in water. Solar chimneys have been used for hundreds of years, collecting energy throughout the day, then releasing it later on. Updrafts from the chimney release the heat. This technology is still used in the Middle East today.
2. Medium thermal energy collectors are also in flat plate form but are instead used for creating hot water, residentially and commercially. They are primarily used for cooking, drying, and pasteurization. This technique is valued because it lowers pollution, as well as the use of fuel and firewood.
3. High temperature thermal energy collectors are not in plate form, but use fluid-filled pipes and mirrors and lenses to collect and focus the sun. In the past, water was used in the pipes, but newer technology is using molten salt, which is converted to liquid form, then heated by the sun. The energy generated with high temperature thermal energy collectors is generally used for electric power production.
Ocean thermal energy is generated using the temperature difference between deep and shallow waters.