How Many Solar Panels To Power The World?

Is covering 500,000 sq KM of desert (which has a relatively high albedo for a non-frozen surface) with dark solar panels really going to help with global warming? Especially considering that as our power needs expand, we will decrease the surface albedo even more. However my biggest concern is the effects on the local regions, it's been shown that when rainforest is cut down, the change in surface albedo and evaporation can increase temperatures by 3C.

Covering 1/18th of the Sahara with solar panels (a number that will drastically increase as African economies grow and as the large majority of Europe is still growing quickly) will not only raise the temperature in one of the hottest places on the planet, but it will cause significant changes to the climate of Eurasia and Africa. The weather in most of Europe is heavily influenced by Saharan winds, and I don't think it's especially wise to screw with the one thing that keeps the region temperate and capable of widespread food production.

Their predictions don't appear to include the fact that solar power isn't 100% guaranteed, you need extra production if you're planning on powering a region. Most wind and solar production has to be turned off after meeting a quota, because they have to supply customers with the same amount, you can't go producing 500MW one day and then produce only 50MW the next because it's cloudy.

Perhaps I'm just a doomsayer, but all the gung-ho environmentalism that gets proposed seriously disturbs me. Farmers get paid to have wind turbines on their land, not only does this cause demineralization of their fields, which increase fertilizer use, which no matter what causes nitrates to get into the water, but it also decreases bird and bat populations that act as natural pesticides. Now you have to increase pesticide usage too, which gets more into the food and more into the water. There's a solution to all this, whilst sticking with wind turbines, but I've yet to see a company deploying helical wind turbines (which significantly reduce demineralization and bird strikes).

I like good old green nuclear, it produces guaranteed amounts of power on a daily basis rain or shine, windy or calm. Modern reactors produce significantly less waste than old reactors, produce medical isotopes. Reactors also often cause a benefit to the environment as the majority of their land is a buffer zone, which goes untended and becomes a natural habitat.

I'm sorry but when nuclear frequently increases biodiversity and 'green' frequently reduces it, you've got some serious shit going wrong with your plans to save the planet.

That shows you how powerfully a good visualization can deceive you.

Here's the same statistic, shown in another light:

http://www.bingocardcreator.com/blog-images/lying-with-numbe...

"solar panels, distributed across deserts and areas with almost 24/7 sun"

Um... I don't think so...

How much energy would it take to produce and ship that many solar panels?

Now, supposing that our solar panel capacity increases by something reasonable every year, like 25%, how many decades would that take to cover square miles upon square miles upon square miles with collectors, and, given that power demands will rise in those decades, how much longer will it take to catch up to that again? How expensive will it be, in light of an effectively infinite demand during those periods where it hasn't been completed yet?

Some people see these charts and see possibility. I see the sheer scale of the operation and boggle; it's absurd.

I have seen far smaller estimates, 300x300 km area for entire world (current consumption) in Sahara, or 125x125 km area for Europe. Dunno about credibility, was in a newspaper article related to some German investors building large solar farm in Sahara.

I actually think that the 125x125km area should be doable. Its not like we don't have space in Sahara. US is more difficult as its probably not practical to transfer electricity as it from Africa. Maybe as hydrogen, dunno.

And thus, we could also expect a boom and bust cycle for the solar tech industry. Boom: Let's see how fast we can make money selling solar panels. Bust: We sold so many solar panels that we have more energy than we need.

This has been on HN already yesterday and it's logic is flawed as I explained last time. You don't need to cover extra space with solar panels as they are situated on roofs etc.

See: http://news.ycombinator.com/item?id=800264