Energy and the Environment

How Do Photovoltaic Solar Panels Work?

Wed, 06 Mar 2013 06:25:00 -0600

Solar power is a renewable energy source that can not only reduce a household’s carbon footprint, but also reduce the monthly utility bill. Despite its growing popularity, many Americans are still unsure on how to take advantage of this potential source of energy.

What is solar power?

Solar energy is the primary energy source for Earth. It is received in the form of sunlight. Solar power is the conversion this sunlight into electricity. Photovoltaic solar panels make it possible to convert solar energy to solar power.

How do solar panels work?

Photovoltaic solar panels can harness solar energy from direct sunlight as well as indirect sunlight (i.e. on days when it is cloudy). Photovoltaic solar panels are made using two pieces of silicon – one negatively charged and one positively charged – that are put together in glass casing with a metal frame. Silicon, as a semi-conductor, can transfer the solar energy into electricity. This happens when sunlight hits the cell, and electrons are knocked off the positively charged silicon and move toward the negative charge. While they are moving, a thin wire on the negative silicon piece acquires the free electrons, creating both an internal circuit and electrical current. When connected to an external electrical circuit, the current can then be harnessed and utilized in different areas in ones home and business.

In layman’s terms, the silicon transfers and converts the solar energy into electricity that can be used to power homes and businesses.

What can solar power be used for?

Solar power can be used for residential, industrial, and commercial purposes. Once harnessed through the solar panels, it can be used to provide hot water for washing and heating buildings and pools, as well as air conditioning. Other innovative products that can use solar power include electric vehicles, sports stadiums, and trashcans – and new products are being created every day.

Is solar power right for you?

Solar power is a clean and renewable source of power. Not only will utilizing solar power reduce electricity bills, but also typically the local national grid will purchase excess power generated. However, there are several things to keep in mind when considering solar panels.

The location of your home and the local climate can affect where you install solar panels. Some areas are better suited for solar power systems than others. For example, photovoltaic solar panels in San Diego surpass the numbers in any other city not only in California, but also in the country – because its year-round sunny location is ideal for harnassing solar power.

Roof orientation can also make a big difference, with south facing homes being able to generate more power due to increased sun exposure. Wind speeds, shade, salt water, and heavy snow can also affect a solar panels potential. It is important to consult with a local solar panel contractor before installation to make sure that your home is right for solar power.

Can Carbon Enhance The Future of Solar Power?

Wed, 14 Nov 2012 09:42:00 -0600

San Diego solar project stemming from a mixture of professors and students at San Diego State University (SDSU) is making headlines this week, as the SDSU research team has been able to successfully produce solar-powered electricity by only using sunlight and air. It may seem obvious that sun and air are required to generate solar power, but what many people do not know is that the current concentrated solar power (CSP) systems use water that is heated to produce superheated air. Using water - a nonrenewable natural resource - to generate solar power may not be the most efficient process. Solar power is a great alternative to using fossil fuels and can help reduce greenhouse gas emissions that can cause global warming.

Solar power is the conversion of sunlight into electricity. There are two ways that the light can be converted: 1) using photovoltaic (PV) solar panels that directly convert light into electric currents, or 2) indirectly using CSP systems that use lenses/mirrors and tracking systems to focus sunlight into a small beam that can then heat water or air to generate electricity.

The currently used CSP technology generates solar-powered electricity when the concentrated sunlight is converted to heat. This heat is then used to power a heat engine that is connected to an electrical power generator. A steam turbine is the engine that is most commonly used, which uses the sunlight-heated water to produce steam which then powers the generator.

The research team at SDSU, however, created a new solar technology to use in place of these water-based CSP systems. The alternative CSP technology is not only innovative, but a huge advancement in solar science as the ideal location for such systems are in the desert (where water is lacking and must be imported for use). The new CSP technology releases carbon nano particles into the air to make the thermal absorption process of sunlight more efficient.

The carbon nano particles absorb the beams of sunlight from a field of mirrors surrounding the system and transfer the energy to the surrounding gas. These particles then burn up in the hot gas, which is used to drive a combustion turbine. In laboratory tests, the new CSP technology has been successful in effectively generating solar-powered electricity. Many people would never believe that carbon particles would be able to be applied in the generation of solar power, and in fact enhance its production.

The lead researcher involved in the project, engineering professor Fletcher Miller, was awarded a grant of $3.9 million from the United States Department of Energy's SunShot Initiative for this project. Thanks to the SunShot Initiative, the national initiative to make solar energy costs more competitive with other forms of energy by 2020, Miller's team will now be able to test the non-water CSP system in real life. The CSP system will be scaled-up from it's current lab-sized version and put into use in the field at the National Solar Thermal Testing Facility, Sandia National Laboratory, in New Mexico. If trials are successful, the combustion turbine CSP may replace the current technology and make solar-power an even more efficient renewable energy source to replace fossil fuel consumption.

San Diego is California?s largest solar city

Fri, 05 Oct 2012 07:10:00 -0600

According to a 2012 report published by Environment California Research and Policy Center, San Diego is California’s top city in solar use. The city came first both in terms of commercial, government, and residential solar panels installations and in terms of total amount of solar power generated. The report stated that if San Diego were a nation, it would be one of the top 25 nations in the world in terms of solar capacity, generating more solar power than the entire country of Mexico.

In total, San Diego has completed over 4,500 solar power projects and generates approximately 37 megawatts of solar power. Los Angeles came in a close second, generating 36 megawatts. To put megawatts into usage; one megawatt is equal to the amount of electricty used by approxiamtely 750 average residential homes.

Califronia's solar projects are not only good for the environment, but also for their economy. Solar = jobs, and the state’s solar installation market is projected to keep growing. Experts predict that 1 million residential solar projects will be completed by 2020, from installation companies such as Solaire Energy Systems, which will add $30 billion to the economy and create 20,000 jobs each year.

The solar installation market in California is one of the strongest in the nation, and it will be interesting to see if San Diego keeps it's top position in the coming years. In addition to highlighting the top solar cities, the report also highlights three specific things that could be done to ensure the state’s title:

Increase the use of solar energy systems in new construction by requiring all new homes to include on-site renewable electricity generation by no later than 2020, and all new non-residential buildings by no later than 2030.
Introduce a net-zero energy building code requirement and maintain or enhance the incentive value of net metering and lift the cap on its use to allow all California ratepayers to benefit from going solar.
Make certain that the state reaches it's goal in the "Million Solar Roofs Initiative" by the end of 2016.

Europe leads the race on solar power

Mon, 01 Oct 2012 12:49:00 -0600

According to the latest European Union Joint Research Center report on solar power, two thirds of the solar panels installed in the world were placed in Europe, generating over 18.5 gigawatts of solar energy. The European Commission's goal is to increase renewable energy to over 20 percent by 2020. The report also mentioned that the most rapid annual growth within the past five years has occured in Asia. China is the largest producer of photovoltaic solar panels and its growth is projected to increase.

Where the US stands

The US Department of Energy under the Obama administration launched a $35 billion program to support renewable energy. In 2011, the US solar projects only totaled 1,855 megawatts of solar energy, however, solar panel installation in the US is projected to double by the end of 2012. According to the Solar Energy Industries Association, installation of solar project should reach approximately 2.8 gigawatts next year. However, that is all dependent on the outcome of this November's election.

A recent article published in the New York Times highlights the shift in Mitt Romney's opinions on energy and the environment to the right since becoming the Republican nominee for president. In previous years he showed excitement for initiatives that would reduce the United State's green house gas emissions such as cap-and-trade systems and energy-efficient cars, but in more recent conversations on his thoughts regarding energy and the environment he has backed away from reducing emissions and focused more on assisting industry and increasing oil drilling. In particular, Romney has stated that if elected, he will not only discontinue wind and solar power subsidies and toss out regulations that discourage burning coal for electricity but also immediately approve the Keystone pipeline.

Although the fate of solar energy in the United States is unsure, the rest of the world seems to be picking up their pace. The US is falling behind in the solar energy race, and the consequences remain unseen. If the US wants to compete with other nations' energy goals, it seems that initiatives should to be consistent for more than four years in a row. Total dependence on oil as our primary energy source is not efficient as it is a non-renewable resource. The divide between the current administration and the GOP could be enough to destroy any solar progress the US has made in the past couple years.

Post by Jeana Brookes, a law and energy enthusiast and avid blogger. Read more of her material at Modern-Parents.com.