Bloom Energy has developed a natural gas/air fuel cell. This is an important development if it can be made low cost and reliable. However, most reports covering this technology distort the benefits to the point of making it sound like some type of free energy machine, which it is certainly not.
Fuel cells are great technology because they can convert fuel directly into electricity at very high efficiency (60-80%). This is much better than an automobile engine (20-25%) or a power plant (40-50%). The down side is that the power is direct current (DC) and one needs an inverter to generate the AC power commonly used. This inverter costs about 40-50 cents a watt, so its cost cannot be ignored in a cost benefit analysis, nor the inverter or fuel cell reliability.
Assuming we get past all this and the fuel cell is low cost and reliable, the device becomes an attractive technology for homes or cars. A home can now use natural gas for heating AND electricity generation and may have a lower total bill. The bill should be lower as compared to a central utility burning natural gas for 2 important reasons. First, the fuel cell is converting natural gas to electricity at a higher efficiency. Second, the cost of the transmission lines from the utility to the home are avoided. This is distributed generation at its best. If cost and reliability targets are met, this fuel cell technology should have a very good market and will save a considerable amount of natural gas and utility infrastructure. But here is the down side:
This country only has 10 years of "known" reserves of natural gas and 234 years of coal. A significant investment in fuel cells to power homes and businesses will cause the price of natural gas to rise much faster than it would otherwise. Before long, the total cost to power a home could be higher with this fuel cell than by buying electricity from coal fired plants, since coal is very inexpensive. A homeowner might buy this product today and then regret the decision if the price of natural gas increases dramatically.
The other natural markets for this technology is in transportation or off-grid applications. A natural gas or hybrid vehicle using this fuel cell might achieve a remarkable "MPG." And the fact that the fuel cell produces DC power is no penalty in an electric or hybrid since its main bus is also DC. This technology would play very well with T. Boone Pickens' plan to use wind machines to save natural gas for vehicles, rather than burn it in power plants.
This is a great new technology and should help extend our natural gas resources and make biogas a more viable alternative. Best of luck to Bloom Energy in achieving a low cost and reliable product.