Apple builds massive 20 Megawatt solar farm in North Carolina

And how many fuel deliveries a week does it need?

Here is a 47MW plant in Cuba using those generators, looks pretty big:

http://engine.hhi.aramcnc.com/pplant/images/img02_02.jpg

So you will need around 12-30 of those depending on engine choice(1). You will also need fuel tanks, pipes, fire suppression equipment, electrical equipment access roads etc. Also you will need to space everything apart for fire safety, to prevent overheating and to prevent those diesels from breathing in each other's exhaust.

So by the time you are done I would not be surprised if you require about as much space as the solar plant. And of course you will have a bunch diesel exhaust and a lot of noise, so even if you do get a smaller footprint, the land you save will be of very limited use.

Solar plants have much better footprint than it seems, because they do not really impact the land around them. Most other types of power plants will have very significant impact on the land around them and therefore they effectively take up much more space than it seems.

(0)- http://pdf.directindustry.com/pdf/hyundai-heavy-industries-d...

(1) I know the video shows around five of them only, it seems the video has been cut off in the middle.

As for "why there", maybe that was one of the sunniest parts of the US. Maybe Apple has a datacenter nearby or will soon build one -- either for expansion of current cloud services or for new services.

"By the end of 2012, we’ll meet the energy needs of our Maiden, North Carolina, data center using entirely renewable sources. To achieve this, we’re building our own facilities that will provide over 60 percent of the clean power we need."

http://us.sunpowercorp.com/about/the-worlds-standard-for-sol...

Slightly more surface area, back mirror, etc.

The other commentators are missing what the OP is talking about. The grammar is incorrect.

Apple is doing this site because its greener than coal and I doubt they want to run diesel or a turbine. Greenpeace and other environmental companies have been giving Apple grief and the solar farm is part of their response to that. Apparently they also have 5 MW of fuel cells in the farm (where FC is more efficient than coal power plants and by extension fewer co2 emissions for same power). Turbines can easily provide that power and can get up to 60% efficiency in converting natural gas to electricity in ideal circumstances but are also pretty big and loud and may require an actual operations team to run and might be hard to get one that small. Diesel can be more compact but tend to be very inefficient in converting fuel to electricity and you still have to ensure its getting fuel.

http://www.eia.gov/emeu/consumptionbriefs/cbecs/pbawebsite/o... gives 18.9kWh per square foot for office buildings. I assume that is per year (that makes it 50Wh per square foor per day, or 2W continuous per square foot. That seems a bit low, but it includes nights and weekends, and the 25W per square foot I get when that 18.9 is per month seems awfully high)

Let's guess 20MW translates to 100MWh per day (probably generous). That way, it would translate to about 5000 square-foot-years per day, or 1.8 million square-foot-years per year. So, it would power a 1.8M square foot office building. At (guessing) 200 square feet per office worker, that would be about 9000 office workers.

I guess this will mainly power a server park, though. As such, it would power a 4MW server park. At (guessing) 500W/server, that would be 8k machines.

(with lots of handwaiving, possibly some miscalculations, so corrections are welcome)