Geothermal energy is not necessarily the first thing to come to mind when the topic of sustainable energy resources comes up. Although solar is one of the most well known and will also be covered today, the main three aspects I’ll be covering are the political aspect, economics of both, and the technology that's available currently.
Political
An energy-efficient property was formed nine years ago in an effort to lead a helping hand to residential home owners or commercial business, and was shut down on December 31, 2016. To elaborate a little further, for those who have not looked into the political aspect that involves solar, geothermal, wind energy, and biomass power, an extension was made to the IRS in form of 48a and 25d and were asked to be continued till 2020. These additions gave a tax credit of 30% to homeowners and 10% to companies after installation. This tax credit influenced a growth in the market for these different types of renewable energy in 2008. This was to help the market during the recession because congress had recognized the importance of introducing renewable products to consumers.
There is currently a new bill that will be the 115th bill of congress. It was introduced February 2, 2017 and will drop from the 33% to 26% to percent for residential. It would be extended to January 1, 2020 and would be immediately implemented. Right now due to the heavy installation costs most customers are unwilling to invest. A few other reasons as to why the market has not risen is due to low consumer awareness, and the varying methods of installation. To conclude, politics has a huge role to play in renewable forms of energy and can become a huge ally if there is a drive in congress.
Economic
With the tax credit inplay the buyer is reimbursed for the cost of installation. There is also the factor of geothermal reducing certain areas heating and cooling bills by an estimated 4 to 70%. A way to further improve on this is installing a secondary renewable energy source such as solar. Thus decreasing the utilities cost instead of just the heat and cooling aspect. The solar energy source would also assist the geothermal system with increasing the heating or cooling of the liquid used to perfect temperature control within the home or business area. In the United States a conventional method of heating and cooling costs the buyer around $15,000 while geothermal installation costs approximately $25,000. The economical benefit from that is the fuel source is only bought once while for conventional you are required to replenish it over time. Energy efficiency wise fossil fuels put out 70% to 90% of the potential energy they can give. In comparison, geothermal systems have the potential to pull out five times the amount of energy put into the system. Meaning you put in two units of energy you receive back ten times what you gave. With the secondary power source implemented the consumer loses next to none of the energy out into the system.
One example of success with geothermal on a large scale is in Italy. They’ve been relying on geothermal for 60% of their energy since 1990.
Technology
The basics for the technology behind solar is that there is two different types of solar energy in use today. One is direct and the other in indirect and the difference between is how they harness the sun’s energy. Indirect, also known as passive, can be explained as using the sun’s energy via architecture. To elaborate, passive solar energy in the home has to do with the architecture of a home or a building. A few examples of passive solar are direct grain windows, trombe walls, and insulation. Direct grain windows affect the amount of sun collected during the winter and summer months. Due to them facing the south they can collect the most sun during the winter and less during the summer thus heating the home passively.
Moving onward, direct solar also know as active solar requires the use of photovoltaic cell or solar cells. These photovoltaic cells are typically made out of silicon.These operate off the movement of electrons between two different type of silicon named p-type and n-type. The movement of electrons between the two types is because an electron slot is created on the p-type. N-type silicon bonding occurs between available phosphorus molecules and the silicon already present. This bonding leaves out one electron that is now free moving. The typical layering of a solar cell is as follows; n-type on top with silicon underneath then p-type and one more layer of silicon at the bottom. So the n-type has a myriad of available electrons and the p-type has vacancies so the electrons move down towards the p-type layer through what is known as a depletion zone. When the vacancies are filled, the p-type layer each side of the unit is either positively or negatively charged. Electrical charge is created when the electrons continuously cross back and forth between the two layers via a metallic wire.
Geothermal energy is based off of the process of taking liquid and funneling it down into the earth to harvest underground heat. Geothermal systems can be a closed or open circuit that can be installed through three different methods. Closed circuits use refrigerant or are water-based. Closed circuits use refrigerant or are water-based and can be pumped down via plastic or copper piping. Copper piping is known to rot in acidic areas such as New Jersey, and can eventually crack, leaking the liquid and becoming inefficient. Closed geothermal systems, during the summer months, cool a home by carrying liquid throughout the home by placing that heat underground or the homeowner can use that water that's been collected. During the winter months it does this in reverse by heating the home by pumping the warm water from underground through the home. An open loop geothermal system feeds off an open water supply typically groundwater and then redeposit it back into the earth.
To conclude, geothermal and solar have much offer to the world. They are still currently being researched and hopefully the political climate will support investments made toward producing a market for both products.
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