Ghosh family home in Cupertino stays energy-neutral year-round
Feb 21, 2013 (The Cupertino Courier - McClatchy-Tribune Information Services via COMTEX) --
The Ghosh family home in Cupertino does not appear unusual in the least from the outside or inside. The tidy one-story home is roughly 2,200 square feet and is home to Indradeep Ghosh, his wife, Aninta, and their two small children.
"We are very typical of the average American household," he says.
To understand the home's uniqueness, one needs to look in the family mailbox to see what isn't there: The family has no electrical bills.
Over the past two years, Ghosh has successfully converted his Cupertino home into an energy-neutral household, meaning the family generates all of the energy it needs for day-to-day living for an entire year.
Throughout 2010 and 2011, the Ghoshs retrofitted their home with various devices and technology to greatly reduce their energy consumption, while also generating their own energy.
The first year was a smashing success as Pacific Gas and Electric sent the family money for generating more energy than it used. Based on wholesale prices, the Ghosh family pocketed $122.73.
"Don't try and do what I did if you're trying to make money out of this," Ghosh says. "Just try to balance out what you need."
Over the course of a year, he performed an energy audit using a wattmeter and a digital smart-meter installed by the utility company.
Ghosh found that the annual energy requirement for the family is roughly 14,400 kWh. A surprising amount of that energy is consumed
even when all devices are turned off. Over the course of a year, roughly 2,000 kWh are lost.
Items such as the digital video recorder, a Wi-Fi router and modem, and garage door opener are always on. The family now uses stand-by load cutoff devices to turn off power-leeching products from the power outlet when not in use.
Other energy-saving measures were taken. All 50 lights in the home were replaced with LED bulbs, which reduced lighting load from 900 watts to 150 watts. All appliances, including the washing machine, dishwasher and refrigerator, were replaced with more efficient Energy Star appliances.
Ghosh then went on a quest to fully electrify the house and phase out natural gas. The gas cooktop was replaced with an induction cooktop, which Ghosh says is twice as efficient in terms of energy use. Ghosh admits he had to do some serious convincing to get his wife to agree to give up the gas cooktop.
The gas-burning hot water heater was replaced with an energy-efficient heat pump water heater, and the gas furnace and air conditioning was replaced by an electric air source heat pump that also works as an air conditioning unit in the summer. The device grabs heat from the outside air and pumps it into the house for water and heating.
Ghosh installed a programmable thermostat to shut off the central AC and heating equipment when nobody is present in the house. These modifications, along with the home's already strong insulation, help lower the annual electricity energy consumption by about 30 percent.
After the whole house was electrified, energy consumption was monitored for a year. Not surprisingly, energy use varied with the season, with heating and hot water energy peaking in the winter and cooling in the summer. The total consumption for the house turned out to be 9,900 kWh for the year, which is about half the rate of similar all-electric homes in the U.S.
To generate power, the family has a 11.8 kW solar array on the house. The system was designed by Ghosh himself and installed by a contractor, a move that saved him 20 percent of the solar system costs. The solar array produces about 16,400 kWh for the year.
The home's grid-tied system went online in October 2011. After a full year of operation, the family learned this past October that they generated 16,300 kWh of energy, while the annual consumption of the household was only 12,200 kWh, producing an energy surplus of 4,100 kWh.
The family extends its energy use habits outside the home. The family used to drive two cars, which burned about 600 gallons of gasoline per year.
Both Ghosh and his wife have short work commutes, so the family swapped out their two gas-powered cars for an electric Chevy Volt plug-in hybrid and Ford Focus electric car, which has an 80-mile electric range and uses no gasoline. The Volt has a gasoline back-up engine that engages after 40 miles.
For the occasional long trip well outside the range of its electric vehicles, the family drives a rarely used Toyota Highlander hybrid.
The Ghosh family's home conversion was indeed a luxury, but the total cost of the experiment is not as outrageous as expected. All told, it cost the family $50,000 after government rebates and incentives. Ghosh is confident he will break even on the plan in about 11 years. The family plans to live in the home for at least another 20 years.
Ghosh holds a doctorate in electrical engineering and works for Fujitsu's research division in Sunnyvale. He said he was inspired by former vice president Al Gore's documentary An Inconvenient Truth to do something about climate change.
If you would like to talk to Indradeep Ghosh about energy-neutral homes, send him an email firstname.lastname@example.org.
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