CHP (combined heat and power) units for local power generation have been around for years. Its success has been hampered by the fact that most households have their own heating system. Another issue: most CHP units are large enough for several homes and therefore require some kind of cooperative venture to implement. A CHP unit small enough for a single household might prove successful.
One leading CHP maker, the United Kingdom’s Microgen, designed a Stirling engine small enough to be built into a residential boiler, which has not been done before. This is being utilized by Dutch natural gas provider Gasunie, which is cooperating with boiler manufacturer Remeha (part of De Dietrich Remeha Group) and Microgen to design an integrated solution suitable for Dutch users.
“We want to design a unit that is compatible with existing installations,” explains Marco Bijkerk, product manager, Sustainable Systems for Remeha. “Most components are available, but no one integrated them all into a good residential appliance. It needs to be a combi boiler. Of course the control unit has to be redesigned to make the Stirling module and the traditional components work together.”
One major hurdle in terms of implementing the system is the tariff for delivery of electricity back to the power grid. “It would be perfect if the price for power to and from the consumer would be the same,” Bijkerk tells APPLIANCE. “But then the power companies would need to be compensated as they cannot bear all the costs alone. So all parties in this project (including the government) are working on a viable business model.”
The venture expects to conduct large-scale field-testing of the units in late-2007, just before the winter cold sets in. “Actual introduction is then foreseen for 2008,” Bijkerk says. “We need this time, because everyone needs to be educated: the installers and the service organizations. Reliability of the product has to be proven.”
UK boiler manufacturer Baxi is joining forces with Microgen, targeting the UK market, and other manufacturers are said to be working on this technology.