Natural gas–fueled combined heat and power systems produce thermal energy and electrical power together to reduce a home’s operating costs.
An emerging natural gas-fueled technology called micro-CHP, or combined heat and power, has the potential to significantly reduce operating costs for homes and businesses where it’s installed.
CHP, also known as cogeneration, has been in use in industrial settings for decades, but only in recent years have manufacturers developed micro-CHP units suitable for home applications.
Here’s how the technology works: An internal combustion engine powered by natural gas generates thermal energy for a home’s space heating or water heating, or to heat a backyard pool or spa. While the unit generates that thermal energy, it’s also generating electricity, which can be used to supplement or offset electricity coming from the grid.
The electricity generated by micro-CHP units can save homeowners hundreds or even thousands of dollars on their electric bills, according to Chris Dockery, project technician in the Energy Systems department for Yanmar America. “This is the alternative to traditional heating systems in the home,” he explains. “It’s a product that actually saves money and reduces the carbon footprint.”
Yanmar’s 10-kilowatt (left and middle) and new 5-kilowatt (right) micro-CHP units will be on display at the American Natural Gas & Propane Industries Exhibit, Booth C2614, at the 2013 International Builders’ Show.
Yanmar offers a 10-kilowatt model, the CP10WN, and recently debuted a 5-kilowatt model, the CP5WN, suitable for homes ranging from about 2,500 square feet to 8,000 square feet. “Instead of producing 60,000 Btus like the 10-kilowatt model, the 5-kilowatt unit produces 34,000 Btus, which makes it more suitable for the average home,” Dockery says.
John Burrell, president and owner of Hall Heating and Cooling in Pelham, N.Y., says that having the 5-kilowatt unit available should increase uptake in small residential and light commercial applications. “We work in anything from a 300-square-foot beach house to a 300-family apartment building, but we see a lot of homes in the 3,500-square-foot to 5,000-square-foot range,” he says. “We’re excited to work with the smaller units.”
Micro-CHP systems are generally installed with a buffer storage tank and a complementary gas-fueled boiler, according to Michael Monohan, sales and marketing director for Marathon Engine Systems, which offers an Ecopower micro-CHP unit that produces 2 to 4.7 kilowatts of electricity. Whenever there’s demand for thermal energy in the building, the buffer tank sends heat to where it’s needed — for instance, the fan coil, baseboard radiator, potable water supply, or swimming pool. The boiler provides supplemental heat for any thermal needs not provided by the CHP unit.
The Ecopower micro-CHP unit from Marathon Engine Systems.
Because CHP systems need to be running in order to generate electricity, they have the highest rate of return in applications where there is a steady, year-round demand for the heat produced by the system. Homes with swimming pools and spas are some of the most cost-effective applications, Burrell says, because they use the hot water heat in the summer.
Builders should also be aware of the net metering rules in their state, Dockery recommends. If the CHP units produce more electricity than the building consumes, net metering allows customers to “bank” those kilowatts with the utility and use them when their electric demand is higher.
Building pros will also have an opportunity to see these units in person at the International Builders’ Show, held Jan. 22–24 in Las Vegas. Both Yanmar and Marathon will have their units on display at the American Natural Gas & Propane Industries Exhibit at Booth C2614. For innovative and energy-saving solutions that showcase the capabilities of abundant and clean-burning natural gas, the exhibit is a must-see stop on your IBS itinerary.