PV Gap

Dana Said:

debate solar energy.?

We Answered:

1) Expensive (silicon panels typically $6-7 per watt-peak installed. CdTe panels $3-3.50)

2) Can't contorl the output - you get power during the day but not at night. And more during summer than winter.

are the two real problems with it IMO.


1) is slowly being solved as prices fall and tech improves. By 2020 it's generally expected prices will be cost competitive in a lot of the world (First Solar's CdTe panels and Nanosolar's CIGS panels are pretty close to cost competitive in sunny places already).

2) isn't much of a problem in hot countries where energy demand is higher during the day/summer anyway because of air conditioning. But it's definitely a bigger problem in places like the UK where demand is often higher in the winter. So you either need to build far more solar than you can use during summer, or you have to have backup batteries or power stations. Both of these add to the cost and pollution caused by solar panels (though I've seen no evidence to say this makes them worse than normal power sources).

Everett Said:

how much (percentage) oil is used to make energy compared to wind, solar, etc...?

We Answered:

From the graph in the source it looks like about 40% of world energy comes from oil while all renewable sources combined (wind, solar, hydroelectric, bio fuel) is maybe 5%.

Sarah Said:

How much energy is used to make a solar panel? Do they take more energy to make than they produce?

We Answered:

This Yahoo Answers question and the subsequent response should give you an informed answer (linked below). Be sure to check out the link given, quite informative.

It boils down to the operating life of the solar panel, the efficiency of the solar panel and the energy needed for the manufacturing process, all of which vary for different manufacturers or technologies.