Solar Energy Facts

Published in Green Energy, Solar Energy on 17th October 2010

Solar energy is one of the sources of renewable energy that can be used to generate electricity for our usage. As the name suggests, it is energy harnessed from sun’s rays. The energy from the sun’s rays is then converted to usable electricity via solar panels.

In this post, I have summarised solar energy facts for its consideration as a potential source of energy to replace fossil fuels.

Why Solar Energy? What are the Advantages?

Renewable Energy Source

As the name “renewable” suggests, solar energy is continually replenished and is present everywhere in virtually unlimited supplies.

Solar Energy is Free

You do not need to pay for solar energy.

Generates Zero Pollutants

There is no burning thus no emission of fumes is involved when solar energy is utilised to generate electricity.  

Plethora of Usages for Solar Energy

Solar energy powered heater for showers and swimming pool/spa, cooking and also landscape lighting; power facilities that are not connected to the grid; pumps for irrigation purposes; road signs and remote gates; navigational systems, buoys; DC (direct current) electrical motors.

Economical Value

From an economical point of view, installation of solar systems in properties will add to its value as developers can advertise it as being green housing. 

Government Incentives

Active government support is also one important advantage. The Californian government gave out tax incentives and credits to citizens supporting the installation of solar photovoltaic (PV) cells and PV cells on their rooftops through the Million Roof Initiative.

Therefore since the advantages of solar energy are many, it is a worthwhile effort for you to install solar energy technology in your homes for you to start saving money and the Earth.

Uses of Solar Energy

Via solar panels, there have been uses of solar energy in a variety of operations as mentioned below.

Solar power plant

Solar Power Plants

Via thousands of solar panels, harnessed solar energy is converted to electricity to power homes. Solar power plants are green alternatives to the conventional coal-fired power plants which release a lot of harmful gases and pollutants in their emissions.

There are two operating systems for these power plants; solar PV and solar thermal power plants. Solar PV generates power using the PV effect; a photon of light hitting and being absorbed by the atoms of the pv cell. This energises the electrons in the atoms and allow them to move from their normal positions in the PV cell creating an electric flow. 

Solar thermal plants collect and concentrate sunlight using reflectors for producing the heat needed to generate electricity. The light is focused onto a receiver, which contains a fluid that will be heated and circulated in the receiver for producing steam. The steam is utilised for powering a turbine that powers a generator to produce electricity.

Solar-Powered Homes

Due to government incentives and enhancing of property value, there have been increasing number of homeowners installing solar panels on their rooftops. Among the US states, California is the leader in the amount of solar-generated electricity.[4]

Besides US, solar panels have also been used in other countries like Singapore to generate electricity for powering the lifts, corridor and staircase lightings for their housing estates. A total of about 3.6 mega-watt-peak (MWp) of solar PV systems have been installed in different precincts under the Greenprint framework.

Transport

Solar panels have been used for powering satellites, space crafts, cars and boats. A good example is the Sun21 team from Spain that sailed across the Atlantic from Sevilla to the Caribbean island of Martinique. This feat allowed them to set a Guinness Book Record in becoming the world’s first transatlantic solar-powered journey. 

Warfare

This idea was mooted in an effort to reduce the load carried by soldiers for the generation of electricity in the field that involves lugging heavy generators and fuel. It was put into practice by the US[1] and Australian Army.[6]

Disadvantages of Solar Energy

There are some disadvantages in utilising solar energy.

Expensive

A lot of money has to be pumped in the initial start-up of a solar power plant. This involves the manufacture and setting up of enough solar panels to generate enough power for the plant. However, technological advances below have greatly increased the efficiency and decreased the production costs of PV cells.

Availability 

Solar power cannot be generated at night and storms and is also reduced during cloudy days. Nevertheless one way to overcome this will be use a larger capacity battery to store the generated power during day time or when there is sunshine.

Efficiency

Solar panels with an area that are suitable for usage for generating electricity have an efficiency of 20.4%[5]. However, it will improve with technology.

Advances in Solar Energy Technology

There have been technological advances made in the development of PV cells to reduce their production costs and improve their capability in harnessing solar energy.

To reduce their production costs, one way will be the replacement of cadmium chloride to magnesium chloride in thin film solar cells.[2] Cadmium chloride is coated on thin-film solar cells to increase the efficiency of converting sunlight to energy. During the manufacturing process, the coating process is carried out by chemists donned in protective gear and in fume hoods. The toxic dissolved cadmium waste has to be disposed carefully. This switch to magnesium chloride will also make it safer for production of PC cells.

Aside from utilising visible light, there is a new PV cell capable of using the ultraviolet and infrared region of the spectrum to generate electricity.[3] This allows the possibility of a more efficient single-junction PV cell able to absorb the entire light spectrum with no requirement for a multi-junction cell. If successfully implemented, it will also reduce the production costs of the individual PV cell.

Highly transparent solar cells that can also function as windows allow the generation of electricity by homes and buildings are available based on the research carried out by teams in University of California – Los Angeles (UCLA) and more recently University Michigan. The team from University Michigan achieved 8.1% efficiency and 43.3% transparency using solar cells made from a carbon-based design rather than conventional silicon. This advance paves the way for these solar cells to function as smart windows for new or replacement for existing buildings.[7][8]

Another way will be to use concentrators (Fresnel lenses) to gather and focus sunlight into a small area with PV cells to generate electricity.[9] This has been implemented in solar thermal plants with the concentrators able to track the sun automatically throughout its traverse through the sky maximising the amount of sunlight being collected for generating electricity. This technology is called concentrated photovoltaic technology (CPV). It will reduce installation costs as lower number of PV cells will be required.

References

  1. ^Bathmann., D. (2010). Army deploys innovative battery-recharging kit. https://www.army.mil/article/43176/army_deploys_innovative_battery_recharging_kit (last accessed 03/03/2021)
  2. ^Connor., S. (2014). Breakthrough in solar panel manufacture promises cheap energy within a decade. https://www.independent.co.uk/news/science/breakthrough-solar-panel-manufacture-promises-cheap-energy-within-decade-9563136.html (last accessed 03/03/2021)
  3. ^Lin., E. (2010). New PV cell generates electricity from IR and UV light. https://newatlas.com/pv-cell-ultraviolet-infrared-light/14708/ (last accessed 03/03/2021)
  4. ^Frangoul., A. (2018). From California to Texas, these are the US states leading the way in solar. https://www.cnbc.com/2018/09/19/the-us-states-leading-the-way-in-solar.html (last accessed 03/03/2021)
  5. ^https://www.pveducation.org/pvcdrom/appendices/solar-cell-efficiency-results2 (last accessed 06/03/2021))
  6. ^Tecca. 20 August 2011. Australian soldiers to tap into solar power on the field. https://news.yahoo.com/blogs/technology-blog/australian-soldiers-tap-solar-power-field-163616743.html (last accessed 06/03/2021)
  7. ^University of California – Los Angeles. “Highly transparent solar cells for windows that generate electricity.” ScienceDaily. ScienceDaily, 20 July 2012. <www.sciencedaily.com/releases/2012/07/120720135715.htm>.
  8. ^University of Michigan. “Transparent solar panels for windows hit record 8 percent efficiency.” ScienceDaily. ScienceDaily, 18 August 2020. <www.sciencedaily.com/releases/2020/08/200817150449.htm>.
  9. ^Fridell., R. Earth-friendly energy 72pp. Lerner Publications Company Minneapolis USA 2009.