Solar Thermal Energy and You
By: Mohamed Mohamed
There are many ways to get renewable resources to work for you and create electricity. The most well-known source of solar energy is solar panels that use photovoltaic cells, but the most efficient energy is solar thermal energy. It can use 70% of energy from the sun’s rays using a solar collector compared to the 12% that PV cells convert. The entire system for solar thermal energy is much less complicated than solar cells and has better energy storage in the form of heated water. I want to inform everyone about the marvels surrounding solar thermal energy so you too can spread the word.
There are many types of solar thermal energy collectors depending on what type of environment you live in and what use you have for extra energy. The low-temperature thermal collector is limited in use, as it is mostly used in certain seasons like summer and has limited storage for the day. It is used in HVAC systems to heat and cool buildings that want to use less energy and are environmentally conscious while still being financially responsible. One example is a solar wall that collects the internal air like a ventilator to redistribute energy throughout the entire building. Another type of collector is the medium-temperature version, where it can be used to heat water for more than 50% of residential and commercial use in the United States. It can also be used to distill water in areas where clean water is uncommon. Another way to use medium-temperature collectors is in cooking or solar drying. Finally, the high-temperature collector is mostly seen in industrial settings using techniques like concentrated solar power. A lot of it is just solar mirrors in a circle aimed at the collector, which then goes to a steam cycle with turbines to create electricity.
Solar thermal energy is versatile in its use and everyone can get a slice in the renewable pie. To understand why solar thermal energy is a great technology, you first have to understand the five principles of heat going through that system. Heat gain is the energy transfer from the sun to the system, where heat is trapped in the collector by using the greenhouse effect. Heat transfer is done through conduction/convection from the collector plates to the collector fluid and travels to the heat storage vault. Heat storage is effective in leaving energy for future use when there is no sunlight to produce extra. Heat transport is the process of transferring heat from the collector and storage. Heat insulation prevents heat loss in all processes and guards against a decrease in efficiency. These five properties dictate how well and efficient the solar thermal power system can be with the right ideas and designs. An equation that helps show how much energy you can get from sunlight is E=hv where h is the Planck constant and v is the frequency at which sunlight can occur. A rule of thumb for solar collections is to have good weather and a clear sky. That is why most of these systems are near deserts and the equator for maximum sunlight collectability.
My hope is for everyone to understand how viable solar thermal energy is compared to solar panels both in efficiency and cost. A benefit of solar thermal energy is that it can store energy better than photovoltaic cells and has a similar cents/kWh rate in the United States. One drawback is that photovoltaics can generate twice as much power as solar thermal energy. Future work can considerably reduce that drawback as long as the public has an understanding of this technology. Heating homes, solving clean water issues, and powering the electric grid can all be done by the wonderful technology that is solar thermal energy.