Question: Jim asks: What is a fuel cell and what types of fuel cells are there? Are they cost effective for a home? Thank you for your help.
Hi Jim, thanks for your question. I see lots of questions about renewable energy these days. Not just because there are many significant financial incentives available through programs like the American Reinvestment and Recovery Act (ARRA) and other initiatives to promote the use of renewable energy.
What is a Fuel Cell?
Now, to answer your first question, I’ll need to go into a little background. Fuel cells are essentially a device that generates electricity through an electrochemical reaction.
A common electrochemical reaction that everyone is familiar with is a standard battery. The battery contains a certain amount of chemicals that are mixed to create a reaction and when that chemical reaction has run its course the battery goes dead and cannot generate any more electricity. A fuel cell is different in that as long as you provide a constant supply of chemical, the electrical flow produced is continuous.
The ‘fuel’ is what dictates the type of cell, and there are many types: phosphoric acid, proton exchange membrane, molten carbonate, solid oxide, alkaline, direct methanol, regenerative, zinc air, protonic ceramic, and microbial. Phosphoric acid are by far the most popular and prevalent type and generate electricity at more than 40% efficiency. Industrial sized phosphoric acid cells also have an associated 85% cogeneration capability from their steam byproducts with the added advantage that they can use impure hydrogen for a fuel.
Fuel Cell for Homes
As far as fuel cells for the home, it looks like those are still a ways off until we see widespread implementation here in the US. Last year Japanese electronics company Matsushita was the first to put commercial home fuel cells on the market, but a slew of other companies are in tow. It looks like a minimum investment, counting government subsidies, would be about $10,000. You can read more about that project here.
And if you’re interested in reading more about fuel cells, a good site to check out is this one. Good luck with your project!
Sarah Gudeman is a mechanical design engineer and licensed EIT in the state of Nebraska. Ms. Gudeman also is a LEED Accredited Professional (BD+C) and an active member of the USGBC Nebraska Flatwater Chapter’s board of directors. She specializes in building energy modeling and audits, sustainable design and environmentally-friendly practices.