A flurry of new housing and office projects around the world are billing themselves off-grid, but in fact they are mainly “off-grid ready” – meaning they could operate off-grid in the event of a power or water outage, although they are in fact grid-connected.
From Australia to San Francisco to Cambridgeshire in the UK, ranging from small community projects to major iconic buildings, something is stirring. Green Energy News reports that in Florida ,Centex Homes is taking the next logical step in solar self-generation options: include a battery back-up system as part of the solar package for 89 homes in The Quarry, a new development north of Naples.
At 525 Golden Gate, San Francisco, KMD Architects are planning a self-powered and almost entirely self-watering building. Faucet sensors, waterless urinals, and on-demand water heaters will cut use to 5 gallons per occupant per day, compared to average office-building use of 25 gallons a day. A grey-water wastewater recycling system enables reuse of water from faucets and sinks in the building’s toilets and the cooling system.
In Easthampton, MA, a group of “off-grid” condos are being planned on a community web site.
In Florida, Centex will offer 2.1 kilowatt solar systems supplied by Sharp Solar. Included with the solar system will be a bank of eight, 100-amp/hour batteries housed in the garage to provide emergency power for critical appliances and a few outlets. The solar system will augment power from the grid and keep the batteries charged.
The solar with back-up systems seem a good match for the Sunshine State that has had its share of power outages due to hurricanes and other powerful storms. Predictions of a rise in the number of tropical storms, at least for the next decade or two, will likely be a selling point for the backed-up solar systems.
For areas with insufficient sunlight home combined heat and power generation equipment could be the norm in hundred years, or sooner.
Disenco Energy of the UK has announced it has reached important milestones leading to full commercialization, such as the completion of field trials for its home, micro combined heat and power plant (m-CHP). The company expects to begin a product roll out in the second quarter of 2008.
Operating at over 90 percent efficiency, the m-CHP will be able to provide 15 kilowatts of thermal energy (about 50,000 Btu