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Can the Sun Realistically Power Datacenters?
1sockchuck writes: A massive solar array in central New Jersey provides the daytime power for a server farm delivering online financial services for McGraw Hill. The 50-acre field of photovoltaic solar panels symbolizes a new phase in the use of renewable energy in data centers. Massive arrays can now provide tens of megawatts of solar power for companies (including Apple) that can afford the land and the expense. But some data center thought leaders argue that these huge fields are more about marketing than genuinely finding the best approach to a greener cloud.
Can a certain number of solar panels power a datacenter with a given load? Sure! Just not 24/7. But that doesn't mean they can not. Your datacenter takes 1 MW/h. You receive roughly 8 hours of usable sunlight, so you need 3MW/h capacity of solar panels to produce the power you need. During the day, the power company will take your excess power, and light up factories, offices, Air Conditioning, etc... During the night, you will use the power company to power your datacenter, when it has to keep its power systems up anyways, and therefore has excess capacity. Look up the terms "base load" and "peak load", understand that not everything that plugs into the power grid needs to be up 24/7 ( not even all servers, look up "DRS"). So can that much power be produced to have a "net neutral" load on the grid? Sure!
But there is always the desire to be completely self-reliant. In this area, I always liked the idea of using the excess power during the day to lift water to a lake high up, and running hydro at night to power the datacenter. This is of course expensive, especially since power companies have excess power at night anyways, since the cycle time to stop / start producing base power won't allow the company to shut down X generators at night.
If you have solar panels on a rooftop that would otherwise be cooked by the sun, aren't you also saving on the amount of power required for air conditioning?
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A: Yes. It's called "evaporation." Next question, please.
There's no -1 for "I don't get it."
Sadly, there just aren't enough places with lakes to store anything like the amount of power we'd need to store.
This is actually a silly concern. Electricity demand is highest in the middle of the day when the sun is shining. That is also when the spot price for power is highest. It makes no sense at all to store that power to sell it in the middle of the night, when prices are far lower.
Storing solar power is an issue in niche applications, and it is an issue in a future fantasy world where 100% of our power is solar. But it is not an important issue in the real world, and is unlikely to be for a long, long time.