- Detail to add is that a solar house is any house that makes good use of the suns energy. It's a solar energy fact that an ordinary house becomes a solar house when it gains more energy than it looses.
Solar Collectors transform short wavelengths into long wavelengths and trap this energy in the form of heat which is transferred and transported into a heat storage vault. Solar panels convert selected wavelengths of light into electricity. It is most common that we utilize solar thermal technologies when wanting to heat substances such as water or air, air meaning the temperature. It is most often that we use this application for pool heating and water heating for homes and businesses. In this time period we have a variety of products on the market with the use of thermal energy. The most common names for these products used in this application are thermal collectors and are often mounted on the roof of a building or in another sunny location to receive thermal energy.
Right below us we can observe how the function of solar water heating collector functions. As we can observe there is a solar absorber plate collector and it is a thin, flat rectangular box with a transparent cover. As I explained from previous this is then mounted on the roof, facing the sun. The sun then starts the action by heating the absorber plate in the collector which in turns then heats the fluid running trough tubes within the collector. To then move the heated fluid between the collector and storage tank we use a system which either uses a pump or gravity, as water has a tendency to naturally circulate as it is heated. Functions that use fluids other than water in the collector’s tubes usually heat the water by passing through a coil of tubing in the tank.
Solar Electricity
Solar energy can also be used to generate electricity. It can provide hot water and heat, cool and light buildings. Photovoltaic (solar cell) systems convert sunlight directly into electricity. A solar or PV( Photovoltaic) cell consists of semi conducting material that absorbs the sunlight. The solar energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity. PV cells are typically combined into modules that hold about 40 cells. About 10 of these modules are mounted in PV arrays. PV arrays can be used to generate electricity for a single building or, in large numbers, for a power plant. A power plant can also use a concentrating solar power system, which uses the sun's heat to generate electricity. The sunlight is collected and focused with mirrors to create a high-intensity heat source. This heat source produces steam or mechanical power to run a generator that creates electricity. Electrical conductors attacked to the positive sides of the material allow the electrons to be captured in the form of what we call a D.C current. This
Electricity can then be used to power a load such as a
water pump
or to be stored in battery.
The PV Market and Future Predictions
According to the Department of Energy, the costs of solar photovoltaics (PV) have dropped 200 percent over the last three decades. Costs today range from 10 to 40 cents per kilowatt-hour.
The PV market is worth $2 billion today, but is expected to grow to $10 billion by 2010. The growth rate of solar PV products has grown by 20 percent annually and is expected to double every three years for the next 20 years.
The strongest market for solar PV is Germany, where laws that went into effect in 2001 require payments of 48 cents/kilowatt-hour over 20 years for solar PV installations of any size, up to five megawatts. Funding and intending to keep going for the program would pave the way for 300 megawatts over the next five years, a solar market representing $3 billion. In Japan, demand for solar PV has jumped from 20 megawatts in 1997 to 60 megawatts in 2000, a 44 percent growth figure. There is a slight problem in the US with solar energy. First of all it is very expensive due to the fact that the competition is minimal and government regulation does not allow people to install there own electric system. A detail to keep in mind is that oil is three or four times more expensive in many non American countries. Solar energy alternatives are less expensive than fossil fuels and grid power. This is why the price of solar energy is so expensive.
Value of solar energy
The energy from the sun varies from place to place and is very dependent on weather conditions. Without an atmosphere 1.4 KW/m2 per hour is available, but with an atmosphere we can only count on 1KW/m2 per hour in the absence of clouds. We’re talking about electricity and we say that electricity is worth $0.10 per KWH than 3KWH’s are worth $0.30. The problem is that PV panels have a radiant energy conversion rate of about 20% or less so three hours of sunlight on one square meter of a solar panel is worth less than $0.06.
Use of Energy in agriculture
For many working in the agriculture business solar energy is a big advantage for them. It is common that farmers use diesel or propane to power generators.
- Drying crops and grains by simply exposing them to the heat of the sun. This is a very old method being used for many years.
- Modern solar crop dryers
- Water heating and require a solar collector, storage tank and plumbing and pumps
- Water pumping
Drawbacks of Using Fuel
- Transportation
- Noise and fumes can annoy community
- Expensive. When a spill occurring it could contaminate your land.
- Not good for environment
- Not economical
Drawbacks of Solar Energy
- Most logical one is not every country has the same sunny climate
- We don’t know for sure how long the sun will survive.
- Some solar energy is more expensive than fuel.
Most Popular Uses of Solar Energy
- Solar pool heating
- Solar water heaters
- Solar electric Systems
Environmental effect
- When using fuels instead of Solar Energy it pollutes a lot in our environment. This is a huge drawback which fuels have today. What has happened over the last years is that our fuels are running out and this is when the solar energy got introduced to the market. When fuels run out, we will have to use cars with solar energy batteries. This is a great advantage for those who live in the right climate. If every car in the world would have a battery loaded with solar energy, when reflecting at this, it is interesting to see how our atmosphere would of changed and how much the pollution would of decreased all over the world.
Conclusion
As a conclusion to my essay I believe that we should be great full that we have solar energy in our world. As well as solar energy, maybe not so much now but in the future will be essential to our lives. This is why already now you should start thinking the use of solar energy. The fuel market is just going to increase in price so it’s a good idea to check and see if you economize when using any sort of solar energy. Already now solar energy is becoming essential especially to the agriculture. Only big drawback is that how long will the sun last? And what if it explodes and solar energy disappears for good and fuels have run out? These questions are trying to be answered but no one seems to know the correct answer.
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Keith Johnson ( Physics For you )
