Introduction to Thermal Technology

With the pending threat of continually rising natural gas prices, alternative energy technologies are taking on greater significance. This article on thermal technologies explains how  the natural tendency of heat to travel from hot to cold is leveraged to turn heat into useful energy.

Thermal Technology – Beyond Photovoltaic Panels

Photovoltaic (PV) panels are used to convert sunlight into electricity, but, to date, they are relatively expensive and less efficient than other power technologies. Thermal technology appears to be a viable solution:

• Solar thermal energy is clean, and
• Has the potential to be competitively priced.

Counter to PV panels, the concept behind solar thermal energy is to indirectly convert solar energy into electricity, using the heat to turn water to steam, which, in turn, will turn a turbine that powers the electric generator.

There are a number of systems available to collect this heat:

• Solar Towers use special mirrors to track the sun, known as heliostats, and store the heat in special liquid salts that can be transported to a steam generator.
• Parabolic Troughs that intensifies the heat, collects it, and then uses the heat to warm up special fluids (typically oils with the capacity to reach 750 degrees F) passing through the system in tubes. By carrying the heat to the water, steam is created.
• Fresnal Reflectors heat the water directly by increasing the atmospheric pressure, which results in steam.
• Solar Dishes move with the sun and collect heat all day. Mirrors reflect the sunlight onto a focal point, convert heat to mechanical power, and expand the hot compressed fluid to operate a piston and produce useful energy.

As with the majority of renewable energy technologies, the challenge is to make solar thermal energy cheap enough to compete with fossil fuels, independent of any taxes that may or may not be levied on carbon emissions or special incentives. To do so would mean technological and process advancements that would drive costs in the range of 10 cents per kilowatt-hour, viewed by many as feasible.