Solar PV Terms Explained
Frequently Asked Questions
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QUESTION:
Who thinks America and Britain should invest in giant solar power stations with the money it wastes on war..?I think that it is a great idea, Although a wave generator maybe more appropriate for Great Britain as we don't get so much sunshine over here.
also thinking of a bumper sticker saying.< The car you are driving is running on fuel gained at the cost of soldiers lives in hot stinking countries..Try walking to the store>
Many thanks Ron....sorry-
ANSWER:
Good question. You say 'investing' so looks like you are in the right place!
Probably because govts/companies cannot see good profit in the short/med term. Don't forget no-one cares a fig unless they can see a profit. You get some twat saying use energy-saving bulbs when the street lights glare out everynight. Or don't use plastic carrier bags when all the supermarket produce is highly packaged; I could go on.
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QUESTION:
How is Solar Energy Obtained? And How is it released at power stations?
1. How is Solar Energy Obtained?
2. And How is it released at power stations?
3. Is Solar Energy Efficient?
4. Is it widely used?-
ANSWER:
it is obtained by putting active or passive solar collection devices in the sun, they have to be angled to get the best advantage of the light. I dont know how its released, it is efficient where there is a lot of sun, Its not really as widely used as it should be but i think the technology is getting better and the oil prices are getting out of hand, soon there will be wider usage .
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QUESTION:
Are the start up and running costs of solar energy power stations high or low?-
ANSWER:
they are very high
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QUESTION:
Why is solar power at least 50 times as costly as power from coal powered stations.?
Solar power is too expensive to be anything except a curiosity.-
ANSWER:
NO. the initial cost, investment is high but then, this cost is recovered soon in few months as the power generated will be from renewable energy source, i,e sun which doesnt costs anythng also, its pollution free n clean.
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QUESTION:
What is efficiency of coal power stations and solar energy?-
ANSWER:
Coal-fired power stations are not very efficient. Most of them don't reach more than 40% efficient. A few can reach 45%.There is a theoretical limit to the percentage of energy that can be converted from heat to mechanical energy in any heat engine, which is the first part of what a coal-fired power station does. This limit depends on the difference in temperature between the heat source (burning coal) and the heat sink (the steam coming out the end of the turbine). The higher the difference in temperature, the more efficient. Most coal fired plants are well below the theoretical limit for their temperature delta, and typical efficiencies are in the 30-40% range. Coal quality also has an impact on efficiency. For example, coal with a high moisture content will be less efficient, because some of the heat energy in the coal will be used up converting the water in the coal into steam, rather than into heat. (State change from liquid to gas uses energy without producing heat, which is why when you boil water, the thermometer rises steadily to the boiling point, stays there for a while, and then once boiling starts, it keeps rising.)
There are two main types of solar electricity generation. Small-scale and most large-scale installations are photovoltaic systems, which capture the energy from the photons that make up light, in order to create an electron and its opposite, a 'hole', which then power a circuit. Again there is a theoretical limit to the efficiency of a photovoltaic cell, but most commercial solar photovoltaic panels fall well below this limit. Current efficiencies are in the low to high teens for the more affordable units. Much higher efficiencies are possible - as high as 40% or more - but these often cost as much as 100 times as much.
The second common type of solar electricity is produced by concentrating sunlight, using mirrors, onto a small target containing a liquid; that liquid becomes very hot due to the concentration of light and its conversion to heat, and that heat is then used to boil the liquid in order to drive a turbine. What you might notice here is that that turbine is basically, once again, a heat engine, and so subject to the same theoretical efficiency limits as a coal fired power plant.
The main difference, however, is that with coal we are looking at a non-renewable resource which costs money and causes environmental damage to extract, whereas with solar we are looking at a renewable resource that is basically free once the solar station is set up.
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