I am assuming you are talking about solar power. Well its expensive and It can only generate power during daylight hours. Another con is that pollution can reduce the efficiency of the solar cells.
Check out this site for all the pros and cons of solar energy.
http://www.clean-energy-ideas.com/articles/pros_and_cons_of_solar_energy.html
It's extremely expensive!!
They will be useless without light
The two most abundant elements in the solar system are hydrogen and helium.
the bad thing about solar energy is that is thatfirstly the amount of energy we get from the sun is dilute even in the hot desert of world and secondly the technology we use for this energy is very expensive.
one day is 2010 it might hit us
very expensive and only available while the sun shine
Two things the Sun provides is heat and light.
If your house catches on fire the fire brigade will not put out the fire because they cant turn the solar panel off and its gay
it is flammable
anything under the solar panel doesn't grow. also its extremly expensive but never in your life would you have to pay an electric bill.
solar cycles and ocean currents are two of the main things
Assuming the question is asking what are the bad things about solar energy, the main problem is that one cannot drawn power from the sun if the sun isn't shining. Solar power plants for instance cannot generate electricity at night or if the sun is blocked by cloud cover.