Bloom Energy today formally unveiled its energy server, an industrial solid oxide fuel cell that can convert natural gas or other hydrocarbons into electricity pretty much on demand. And in the process, the company has ignited a debate over which of the alternatives to coal, nuclear and centralized natural gas plants might be best. Can we answer it today? No — one of the pivotal factors will be how Bloom’s servers (formerly known as Bloom Boxes) perform over time. Board member Colin Powell said at the unveiling that the company doesn’t have twenty years of user data. But we can speculate and compare. And here are some of the key things to keep an eye on. Versatility and Up-Front Cost: A 100-kilowatt Bloom server array costs around $700,000 to $800,000, or $7,500 a kilowatt, after incentives that cover around 50 percent of the costs. The company hopes to have home versions that generate a few kilowatts and cost about $3,000 in ten years, but they don’t exist now. Bloom, however, doesn’t scale down yet. It sells its 25 kilowatt boxes four units at a time. Home and small businesses need not apply just yet. Solar […]