The growing need for emergency power in the home. More than 800,000 small generators (less than 15 kW) are sold in the U.S. annually, and that number is growing. The first reason is the country's dependence on a reliable electric supply is growing. As consumers use more and more electronic devices, the need for advanced electronic control systems is soaring. Second, people are increasingly concerned about the reliability of the U.S. electric power infrastructure.

Aren't current emergency power generators able to be redesigned to address market needs, without employing CHP? Yes. Some manufacturers are already doing this. But the products they're developing are just as expensive as full-blown Micro-CHP systems.

What about importing Micro-CHP products from overseas? Micro-CHP systems are currently being launched in Europe and Japan. These systems are generally designed to follow the household thermal load and generate electricity opportunistically. In many cases, the excess electricity can be sold back to the grid (net metering). But these foreign imports are unlikely to meet the demands of the U.S. market. They typically aren't designed for use in homes with forced hot-air heating, which is the nation's dominant heating system. Nor can they generally operate and provide emergency power when grid power is lost - a critical feature to U.S. market success.

What's being done about this potential market? The Gas Appliance Manufacturers Association (GAMA) and several of its members have recognized this opportunity. GAMA has formed a Power Generation Division to specifically address this market. The U.S. Department of Energy has also recognized the potential national benefits of Micro-CHP - both for energy savings and electric power reliability - and recently solicited bids for Micro-CHP system development and commercialization.

What role can appliance makers play? Internal-combustion engines that meet the needs for Micro-CHP are currently available, but more development is needed to bring other prime movers to the market. Stirling engines and Rankine cycle systems are close, and fuel cells will follow. Sophisticated controls, including whole-home load-management systems, are needed to minimize first costs (i.e., minimize generation capacity requirements), while still providing power for critical loads in an emergency. Energy storage systems (batteries, flywheels, etc.) may also be needed.