Pillar to Post: Peter Welander's Blog
News and comment from Control Engineering process industries editor, Peter Welander
Apple to build major fuel cell installation for data center
Green power for your iCloud application will come from natural gas and solar.
Apple is building a new data center that will feature two cutting edge sustainable power schemes, photovoltaics and fuel cells. This in itself is interesting, but the fact that it is being built in North Carolina and not the left coast is particularly curious. (Full disclosure: My family and I own many Apple products and have been users since buying our first 512k Macintosh in 1985. I still have it. Don’t ask me why we thought we needed a computer back then.)
The initial plan for the site calls for a 4.8 MW fuel cell facility, which they are characterizing as the largest private (i.e., non-utility company) installation in the U.S. Bloom Energy is providing the solid oxide fuel cells (SOFCs) for the project that will be fueled with natural gas. This specific fuel cell technology is simple and very efficient (in fuel cell terms) but runs at high temperatures, usually in the 800 to 1,000 °C neighborhood, which normally limits it to larger stationary installations. At that temperature, natural gas can be reformed into hydrogen which the cell uses. The leftover carbon atom combines with atmospheric oxygen and goes out the stack as carbon dioxide. So, even if there is no combustion, there is a greenhouse gas aspect to it, albeit a small one in that the fuel cell produces more electricity per unit of natural gas than normal combustion technologies. Efficiencies of SOFCs are normally >60% even if you don’t capture the waste heat. (Read a Control Engineering article from 2007 on fuel cell technologies.)
I haven’t seen any indication if Apple plans on recovering the waste heat off the fuel cells. Given the high temperature of SOFCs, some installations have used a recovered heat boiler similar to those used in a combined-cycle gas turbine facility. If they aren’t using it to make steam, I’m not sure what you would do with that much heat at a giant server farm.
This project isn’t cheap, but if any company has the cash to undertake something on this scale, it’s Apple. Estimates suggest it will cost around $30 million for that generating capacity. However, once they’re past the initial cost, generating costs are very low and reliability is exceptionally high, hence its desirability for a data center. The next construction phase planned is a 20 MW photovoltaic installation, much larger than any other in the state.
Now, where did I put my iPad?