Solar Power Post 3

In my last post I talked about looking at the potential use of energy in the local Madison area. Initially, I was going to take a national approach to the issue of using solar power as an energy source. I have since decided to focus more on local energy sources although the national scope is very important. Through my research on both local and national energy my eyes have been opened significantly to the different types of alternative energies available. I was also amazed at the amount of solar energy types available. The issues have not become whether or not solar energy is something worth investing in but which type of solar energy to invest in and where.

As I have stated before while looking through my research I have wondered whether or not the massive initial start-up costs of solar energy are worth the investment because as I have found solar power is incredibly inefficient and increasingly more so in places with less natural sunlight. I have also looked at what types of energies solar power can reduce if any.

Throughout my initial stages of research I have spent a considerable amount of time on the website http://www.withouthotair.com. This author discussed three major ways to use solar power. The three are listed as solar thermal, solar photovoltaic, and solar biomass. This list is what sparked my interest to possibly switch my focus from large-scale solar power use to more local and small-scale uses. The first use I want to discuss is solar thermal. This form of solar energy is used to heat water (Withouthotair). This form of power is typically used in homes. This option is significantly less costly than the other main option I would like to discuss which is solar photovoltaic. Solar thermal energy is a low-grade energy, which is directly related to the ease in which energy can be converted into other forms of usable energy. The uses of this are great for heating the water in a home or building. The biggest issue with this form is that the energy produced is incapable of being stored in something such as a power grid. This becomes problematic because it causes the unused energy to be basically wasted.

The second type of solar energy I want to discuss is solar photovoltaic. This type of solar power turns sunshine into electricity. This can be used on large-scale as well as smaller scales. However, using this type of solar power can be very expensive and is not often taken up by individual households because of that fact. According to David MacKay the low-end panels in this category are only 10% efficient and the top end very expensive panels only produce energy at 20% efficiency (MacKay). On his website http://www.withouthotair.com MacKay also said that due to the laws of physics the maximum efficiency that is possible to produce using solar photovoltaic is 60%. That is using the most advanced panels and mirrors that are available which would come at an astronomically high price to individuals or large-scale companies alike. Using less developed panels and mirrors would still only result in 45% efficiency.

There are certain characteristics of a solar photovoltaic system that distinguishes it and sets it apart in both the energy in creates as well as the massive price tag it commands. The energy created by these solar panels is created on an atomic level. That means that it uses semiconductors, which contain many free roaming electrons. These semiconductors are in between what are known as a conductors and insulators. The make up as mentioned of these semiconductors is an insulator and conductor. The purpose of an insulator is to make bonds by using the electrons that are between the atoms within the insulator. These electrons that form the bonds are in a much lower state of energy and require other processes before it is capable of producing energy. These low energy bands are known as valence bands. The conduction band is where the high-energy electrons are located. Because of this, electricity begins to first occur in the conduction band. In these conduction bands and valence bands is where the energy in the form of electricity is created. And this creation of electricity is what distinguishes solar photovoltaic energy. This was just a simple overview of a much more sophisticated system that is the solar photovoltaic energy source. This just gives us the basic understanding through all of these high tech sophisticated pieces needed to create electricity through this form of solar panel is so costly (Physics 115 Nov, 4).

If you wanted to look at the best option for people to install on their homes between solar thermal systems and solar photovoltaic systems you would want to look at the price compared to the output of energy from each system. The costs of installing a solar photovoltaic system are four times more than that of a solar thermal energy system. This high price is due to the previous demonstration of the highly advanced systems that make up this type of solar panel. Apart from that, the systems are different in that the solar thermal system heats water and cannot be stored and the solar photovoltaic system that transforms sun into electricity but when you look at the price of four times more it makes one consider it when you look at the fact that the solar photovoltaic system only produces half as much energy at four times the price of solar thermal systems.

Another topic I want to discuss is the option of solar biomass. There are three main routes of getting solar power from biological systems. I will outline these briefly. The first one is to grow specific plants and burn them in a “power station” that can create electricity or heat. The second option is petroleum substitution. This involves growing crops that can produce such things that can be turned into biofuel or ethanol. Another option of harnessing solar power would be to burn agricultural byproducts. An example of this would be to burn chicken feces or straw.

Now, after all of this background information, looking at the solar energy option for Madison is the focus. The big question is should the University invest in large-scale solar panels? The first thing I did was to look at the different amounts of solar energy potential Madison has which turned out to be 4343.1 watt/meter squared/ day. I then compared that to Phoenix, Arizona who is known for having incredible amounts of sunshine a year. What I found was that Phoenix receives 6469.5 watt/ meter squared/ day (Energy.gov). This is a significant increase in energy watts received a day. However, this did not seem to eliminate Wisconsin or Madison particularly from considering having solar panels. However, doing research on a site called desertec.org a fact stood out that made me question whether or not a large system of solar panels in Madison would be effective enough to compensate the large expense of the system. That specific fact that I am referring to says, “within 6 hours, deserts receive more energy from the sun than humankind consumes within a year” (desertec.org). This quote made me wonder if the solar focus should in fact stay strictly within the confines of the desert regions that traditionally get the most sunlight. This of course is not to say that having solar panels in less ideal locations as far as natural sunlight goes is not beneficial at all. Another interesting fact that I learned from desertec.org was that “in a desert, a reflector area of 20 square meters in a solar power plan is enough to supply all the electricity a person would need, day and night with not carbon emission left behind” (desertec.org).  Again, this leads to the question of whether or not the areas with the most sunlight need to be the primary areas of focus of solar power and other area with less sunlight like Madison would be better off focusing their time and energy on some other form of energy.

 

These large-scale systems that would be able to create electricity for the campus are in fact the solar photovoltaic systems, but as my research points out, the price of these systems is very high and the output of energy they create is relatively low. They are very costly to maintain and the energy potential in Madison is less that other high sunlight areas. For the University of Wisconsin to strive to become energy efficient it would be wise in focusing attention on other forms of alternative energy other than solar power on an electricity producing basis.

 

Works cited

MacKay, David. Sustainable Energy- Withouthotair. UIT, 2009. eBook. <http://www.withouthotair.com/&gt;.

 

Adelman, Kenneth. “The Solar Warrior Photovoltaic System.” The Solar Warrior Photovoltaic System. N.p., n.d. Web. 22 Nov 2011.

 

http://www.desertec.org/en/

 

http://www.epa.gov/

 

http://energy.gov/

 

http://www.nrel.gov/

 

http://www.renewableenergyworld.com/rea/home

 

http://solarcellsinfo.com/

 

http://www.usa.gov/

 

Moran, Peter. “Physics 115.” Madison. 4 November 2011. Lecture.