The impact of renewable energy

May 2, 2006 3:47 PM

What effect would a massive growth in renewable energy sources have on the environment?

Besides the obvious impact of rivers dammed for hydroelectric power-stations, what effect would it have if, for example, every new building was fitted with solar panels and wind turbines, enormous wind farms were built or the Sahara covered in solar collectors?

I'm thinking on both a local and global scale - given enough wind turbines, could wind patterns be altered? Could the decrease in reflectivity caused by massed solar panels alter the local ambient temperature? More to the point, how many of these things would it take to see a significant difference?

posted by ganseki to science & nature (7 comments total)

Well, I'm no meteorologist, but I can't see wind patterns being changed by any number of windmills. Buildings cover an unimaginably minuscule percentage of the earth's surface, so no amount of building-mounted solar panels would change anything.

There would be huge indirect effects, obviously, from the reduction of carbon/sulphur etc emissions.
posted by matthewr at 3:55 PM on May 2, 2006

Semiconductor solar panels are energy-neutral over their lifecycle I've been told... the energy required to make then and ultimately reclaim/recycle them is about the same as the energy they put out. We use them because there are no batteries that have the same sort of performance criteria in terms of volumetric or mass-based power density.

Hot water solar panels are probably pretty efficient at making hot water though, if that's what you need. And they're not very complex: black pipes and a water pump.

So huge installations of semiconductor solar panels would require a lot of factories to make them, which would definitely have some local environmental impact. Semiconductor plants use a lot of water in the manufacturing process.
posted by GuyZero at 4:10 PM on May 2, 2006

It would likely decrease global warming/global dimming, at the very least.
posted by fvox13 at 4:16 PM on May 2, 2006

A cheap energy source would simply encourage further unchecked economic growth. I don't know if I fall on the realist or pessimist end of the scale, but I think anything that allowed us ballooning growth would end up being environmentally disastrous anyway.

That is to say that a cheap, renewable energy source would result in the quickened depletion of all else.
posted by sourwookie at 4:41 PM on May 2, 2006

This may be more ecological, but windmills apparently kill local birds. I recently read something (in the blue, maybe?) about how they affect migratory patterns too. Some people, of course, disagree. More here [pdf].
posted by spiderskull at 4:45 PM on May 2, 2006

This paper looks at the possible atmospheric impact of large scale windfarms.
posted by thrako at 6:25 PM on May 2, 2006

It takes 2 acres of land to grow enough biofuel crop to fuel one average sized car for one year in the UK. It would require 5 times the arable acreage of the UK to fuel the UK's car fleet, or 6 taking in to account the acreage we need for growing food, or 8 when you account for the reduced crop yields when we are unable to manufacture hydrocarbon based fertilisers any more.

For some people, that statistic is the first time they come face to face with what a unique, irreplaceable fuel source hydrocarbon has been.
posted by falcon at 12:46 PM on May 3, 2006