what are some of the disadvantages shared by all renewable-energy sources such as solar cells and . . .?

Question

wind turbines?

Answer 1

Well, in some cases (like solar cells) the cost can be prohibitive. Retrofitting a house with enough solar energy to participate in a buy-back program can cost $35,000, which would mean (at the current pricing structure) a 20-year ROI. Most folks in the US move every 5-10 years, so you would never realize that "payoff".
In other cases, like biodiesel and ethanol, the distilling process can take almost as much energy to produce, overall, as it will harness. Sure, you get portability with the non-fossil liquid fuels, but the energy to make the stuff still has to come from somewhere else, and right now, that means coal, nuke, or oil power primarily (at least in the USA).
Other disadvantages include unreliability, slow recharge times, limited range, and limited performance when compared to fossil fuels. Even wind power (which is fairly cost-effective) is not terribly reliable, depending on a variable power supply (wind). If generation points were distributed more broadly around the country, there might be more reliable average generation, but a still day still means "no power."
There is no doubt that "renewable sources" are a possibility, but the state of the art right now is about at the "finger painting" level.

Answer 2

They all depend on solar energy and there is a finite amount of solar energy available on the Earth. For example, a 1 m^2 solar panel that was 100% efficient (not likely) would probably only make 4 or 5 horsepower. You'd need a monster panel to give a street car 150 horsepower or so.

Answer 3

Co-efficient is the greatest problem with all forms of energy generation.

For instance, the incandescent light bulb in your kitchen is using around 10% of the energy it's consuming to create light. The rest is wasted as heat.

For solar, the biggest problem that has yet to be overcome is storing the power for later use. At present, our batteries are wholly inefficient to store large amounts of electricity.

Answer 4

They are subtle but they do change things, like how much sunlight hits the face of the planet and how much wind blows across an area. This can affect things like the planet's temperature and the ability for seeds or whatever to move around.

It doesn't seem like much now but if it were to go to full-scale usage we would start to see ecological changes which are not generally good.

Better to cut down on our consumption.

Answer 5

Expense!