Solar Power

Solar Power http://www.globalization101.org/solar-power/

Along with wind power, solar power has experienced a boom since 2002: existing global capacity more than doubled in the past four years. In general, the problems with solar power are less pronounced than those with biofuels, wind power, and hydrogen power.

Energy from the sun’s rays can be manipulated in many ways in order to perform a variety of functions. The most common means of capturing solar energy is the photovoltaic (PV) cell. These cells are made of silicon semiconductors that absorb sunlight and channel it, thus exciting the electrons contained in the chips to rapid motion and generating electricity.

When a collection of photovoltaic cells is encased in glass and installed, it is known as a solar panel. These panels can be connected either to a battery for local usage and storage or to a larger electricity grid for distribution elsewhere ¹. The world’s leaders in terms of grid-connected PV power are Germany, Spain, Japan, the United States, and Italy.²

Arrangements of Photovoltaic Cells

 

 Source: http://www1.eere.energy.gov/solar/pv_systems.html

Efficiency and Storage Technology

The two main issues hampering the development of solar energy are efficiency and storage technology. For all of solar energy’s benefits, current methods of capturing sunlight are only between 14 percent and 20 percent efficient. New materials for making more efficient semiconductors are under development, but it remains unclear when or whether they will become commercially available.³

Detractors point out that, “At present levels of efficiency, it would take about 10,000 square miles of solar panels—an area bigger than Vermont—to satisfy all of the United States’ electricity needs. … [But] all those panels could fit on less than a quarter of the roof and pavement space in cities and suburbs.”⁴ In order to ensure that space and cost considerations are not prohibitive, further technological advancements will be required.

Partially because of this poor efficiency, partially because of the unpredictability of weather conditions (clouds, storms, etc.), and partially because of the absence of sunlight at night, storage is a particularly important element of solar energy production. Battery technology must also continue to improve if solar power is to achieve broader penetration in the global energy mix. There have been recent breakthroughs in which some solar cells reached a 40 percent conversion efficiency rate.⁵ Japanese and European companies have recently announced they are striving to achieve an efficiency rate of 45 percent. The problem now, once these new technologies are commercially viable, is the ability to efficiently store this energy.

Scalable Energy for Development

One of the unique benefits of solar energy that somewhat counterbalances the drawbacks detailed above is its scalability. Solar panels can be installed on a house-by-house basis and do not require the same level of capital investment as some other renewable technologies such as wind power.

This is undoubtedly an expensive proposition for any homeowner, but solar panels hold great potential for communities that are remotely located and widely dispersed, including many in the developing world. According to Solar Energy International:

Providing power for villages in developing countries is a fast-growing market for photovoltaics. The United Nations estimates that more than 2 million villages worldwide are without electric power for water supply, refrigeration, lighting and other basic needs, and the cost of extending the utility grids is prohibitive, $23,000 to $46,000 per kilometer in 1988.⁶ ($43,942 to $87,864 in 2011 dollars).

The advancement of solar energy has potentially revolutionary implications for the developing world as much as the developed one. Technological developments in the past few years have made solar panels more inexpensive and a cost competitive option for many rural areas.  In developing nations, where kerosene is expensive and there is no national electricity grid to speak of, those who are self-installing solar panels in their houses and communities are saving much needed resources and money.

To learn more about recent controversies associated with solar power and Solyndra, click here.

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1 “Solar Basics”

2 “Global Status Report” 19

3 “History of Solar Power”

4 Parfit 18

5 Volynets

6 “Energy Facts”

Further Reading:
Concentrating Solar Power: http://www1.eere.energy.gov/solar/csp.html

CSP Technologies: http://www.energylan.sandia.gov/sunlab/overview.htm

Oliver, Rachel. “Lighting the Way to Affordable Solar Power.” CNN, 1 September 2008.

http://www.cnn.com/2008/WORLD/asiapcf/08/31/eco.affordablesolar/index.html.

Solar Power Boosting Profits. Sara Sidner. CNN, 11 Apr. 2011. Web. <http://www.cnn.com/video/#/video/world/2011/04/12/sidner.bangladesh.solar.power.cnn?iref=allsearch>.

Pictures
Voltaic Cell, Source: http://www1.eere.energy.gov/solar/solar_cell_materials.html

A Flat-plate Solar Panel Collection Capable of Using Direct and Reflected Sunlight, Source:http://www1.eere.energy.gov/solar/pv_cell_light.html