Solar power
Solar power is the technology of obtaining usable energy from the light of the Sun. Solar energy has been used in many traditional technologies for centuries and has come into widespread use where other power supplies are absent, such as in remote locations and in space.
Solar energy is currently used in a number of applications:
- Heat (hot water, building heat, cooking)
- Electricity generation (photovoltaics, heat engines)
- Desalination of seawater.
Its application is spreading as the environmental costs and limited supply of other power sources such as fossil fuels are realized.
Solar power is a form of energy that makes use of the world’s largest energy source: the sun. More than 99% of the world’s available renewable energy is in one way or the other related to solar energy. The sun provides us with 174 petawatts (174,000 terawatts) of energy, of which half (89 petawatts) reaches the Earth surface. Since humanity consumes ‘only’ an estimated 15 Terawatts of power, we only need to convert a tiny fraction of this free solar energy (~0.00016%) in order to fulfill the energy needs of the global population. Due to increasing environmental and climate awareness, the use of solar power has been growing explosively the past few years. Solar power is now the fastest growing form of energy, far outpacing other renewable energy sources like wind and water. The advantages of solar power are many; it is renewable, silent, emission-free and consistently available. Solar power’s main disavantage is its price; harnessing the power of the sun is still relatively expensive. It is however expected that technological and economical developments will within 10 years put the price of solar power on par with traditional energy sources.
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[edit] Types of solar power
Throughout the years, humanity has learned to make good use of both the suns light and heat. The following techniques each take a unique approach towards harvesting solar energy. The specific purpose, advantages and disadvantages of each respective technique allow solar power to be broadly applicable:
- Solar photovoltaic power: solar photovoltaic power is the most commonly found residential application of solar energy. Solar photovoltaic power makes use of solar panels to convert sunlight into electricity.
- Concentrating solar power: CSP is a type of solar power where parabolic mirrors are used to focus sunlight on a central point or plane. In parabolic through systems, the heat is captured and later converted to current through a steam generator. In a parabolic dish system, the sunlight is focused on a special solar cell, which converts the concentrated sunlight into power.
- Solar thermal energy: solar thermal energy uses a solar collector to capture the heat of the sun. The captured heat then used to heat a building’s water supply, providing warm water and/or central heating.
- Passive solar energy: passive solar energy makes use of architectural ‘tricks’ to enhance a building’s interior climate by allowing the sun to heat the building in appropriate times and places.
[edit] Photovoltaics
Is the direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity.
Solar modules used to harness energy from the sun are made up of photovoltaic cells much the way human tissue consists of cells. Photovoltaic cells are constructed of semiconducting materials, usually silicon.
Photovoltaics are used is a wide variety of applications, ranging from personal electronics such as watches to large scale electrical power productions systems.
The largest photovoltaic solar plant is located in Sarnia, Ontario in Canada with a capacity of 80 Megawatts.
[edit] Advantage of Solar Power
Solar cells are long lasting sources of energy which can be used almost anywhere. They are particularly useful where there is no national grid and also where there are no people such as remote site water pumping or in space.
Solar cells provide cost effective solutions to energy problems in places where there is no mains electricity. Solar cells are also totally silent and non-polluting. As they have no moving parts they require little maintenance and have a long lifetime. Compared to other renewable sources they also possess many advantages; wind and water power rely on turbines which are noisy, expensive and liable to breaking down.
Rooftop power is a good way of supplying energy to a growing community. More cells can be added to homes and businesses as the community grows so that energy generation is in line with demand. Many large scale systems currently end up over generating to ensure that everyone has enough. Solar cells can also be installed in a distributed fashion, i.e. they don't need large scale installations. Solar cells can easily be installed on roofs which means no new space is needed and each user can quietly generate their own energy.
[edit] Disadvantages of Solar Power
The main disadvantage of solar energy is the initial cost. Most types of solar cell require large areas of land to achieve average efficiency. Air pollution and weather can also have a large effect on the efficiency of the cells. The silicon used is also very expensive and the problem of nocturnal down times means solar cells can only ever generate during the daytime. Solar energy is currently thought to cost about twice as much as traditional sources (coal, oil etc). Obviously, as fossil fuel reserves become depleted, their cost will rise until a point is reached where solar cells become an economically viable source of energy. When this occurs, massive investment will be able to further increase their efficiency and lower their cost.
[edit] FAQ Solar Power
- How does solar power system work? The solar power system uses the PV or photovoltaic modules to convert sunlight into electric current. The electric current generated by PV modules is DC in nature. So the DC current is converted to 220V volts AC before feeding into home. The picture below shows the conceptual diagram.
- What about the night? There is no sun during night? Where will electricity come from during night? The Solar power system will store the energy in batteries, just like inverters, during day and use that energy to run the home during night.
- Does it mean I will get full electricity all day without paying electricity bill? Yes. Once you install our system, you will have electricity all day, provided the system you bought is big enough for your needs. If your system is of good size you can run AC and other heavy appliances too.
- What about cloudy days? Or the days when there is no sun? The systems are sized to provide 1-2 days of extra electricity even though there is no sun.
- Does this system have any sound or smoke? No. This system works silently without any noise and has no fumes or smoke or any other byproduct. It is the most clean energy available on earth. Also there is no running cost. Once you buy the system you will get free electricity for at least 25 to 30 years.
- How do we trust this technology? How can we be sure that this will really work? Solar energy is being used extensively in westerns countries like US, Germany and is found to be very reliable. In India also there are lots of places where solar energy is being used. You can search web about this subject. We will be using very matured and time tested components in our system to provide high quality systems. We have a plan to run field tests before delivering the technology to market.
[edit] Solar power in the United States
Solar power is the most abundantly available form of renewable energy in the United States. However, compared to European countries like Germany and Spain, the market remains vastly underdeveloped. Considering the US is the very birthplace of solar photovoltaics, this is a wasted opportunity in the least. Things are however changing, due to increasing environmental and geopolitical awareness. Last year, total US solar power capacity grew to 8,775 megawatts, a growth of 17%. Note that these figures include solar thermal appliances like pool and space heating. Looking at solar photovoltaics only we see an estimated increase of 342 MW. Compared to Spain (2,460 MW) and Germany (1,860 MW) this figure leaves much to desire. Things are however bound to improve, in large part due to the eight-year extension of the 30% tax credit on solar photovoltaic installations. Finally, the Obama administrations positive stance towards solar power is likely to further propel solar to the center stage of American energy policy.
Since utilities now view solar as an opportunity instead of a threat, it is expected that solar energy will reach full grid parity in all states by the year 2015 / 2016. By this time, the whole solar industry is predicted to employ no less than 400,000 “green collar” people. Despite the economic setback of 2008/2009, the future of solar is looking sunny indeed.
[edit] Solar power tips
- Install Solar PV (photovoltaic)[1]
- Solar Water-Heating Power
- How to Make a Solar Power Generator for Less Than $300
- Top up your energy from solar panels on cloudy days with the Windwandler - designed specifically to be used in conjunction with your solar panels when they aren’t able to work at optimum output.
- Planning permission for solar panels
- Solar powered bus shelters
- Solar powered parking meters
- Solar powered traffic lights and road signs
- Find out if a solar system is cost-effective for you with the My Solar Estimator tool: enter specifics like your location (US only), expected uses and current electricity expenses and it will calculate an overview of the costs, savings, and benefits of a solar system in your home.
- Solar powered airport to open in Uganda
- Combined photovoltaic thermal systems
[edit] Solar powered gadgets
- The Solar Frog Fountain will cascade continuously when the sun is shining.
- Watch birds take a splash with this romantic Solar powered birdbath fountain
- Go running, cycling or just chill with the Soltronix Solar Charged Headphone Radio. An internal antenna and bass boost button ensure excellent sound quality.
- Get a Stylish Pocket-size Solar Powered Charger
- Recharge your iPod virtually anywhere under the sun with the Solio Solar Charger
- Light your patio with Glow-in-the-dark pebbles.
- The Geodisic Greenhouse Kit with its unique solar design is the most energy-efficient hobby greenhouse for year-round gardening
- The Solar Security Light provides effective motion-sensitive security lighting and lets you welcome guests and deter burglars without electricity or complicated wiring!
- The stylish and aerodynamic SolarVent solar powered fan fits into the roof or wall to provide 24 hour silent and reliable ventilation for hot or humid areas. Reduces condensation and heat build-up in conservatories, greenhouses, sheds, boats and caravans...
- Get Solar-powered Blue String Lights for your christmas tree
- Get rid of burrowing rodents with a Sonic Mole Chaser. Buried in your yard, the Sonic Mole Chaser® blasts a penetrating pulse that humans and pets won’t hear, but which forces moles to pack up and leave. The solar model protects approx. 7,500 square feet and runs on two rechargeable AA batteries, included.
- Chill with a solar powered fan-fitted hat! The sunnier it is, the more the fan will cool you down!
