Clean energy home ends 12-month trial with surplus

Jul 13, 2014

By Becky Crew

Built by researchers from the National Institute of Standards and Technology (NIST), the two-storey, 252-square-metre home is located in Washington, DC. On the outside it looks like a regular house, but on the inside it’s a laboratory for clean and sustainable energy research, with geothermal systems and double insulation to create a ‘thermal envelope’ to minimise the need for internal heating and cooling.

The experiment started midway through last year, when the research team moved a virtual family of four in.

“A computer simulator syndicated the energy consumption with that of a typical American family of four, the inhabitants going about everyday activities such as taking showers, watching TV and charging laptops,” says Nick Lavars at Gizmag. “There was more at play than a life-sized game of The Sims, however, with the researchers able to gain realistic insights into the energy efficiency and how viable planting such a home into a real-life American neighbourhood could be.”

An unexpected stint of bad weather really put the house to the test – for 38 of the 365 days in the year, its solar panels were largely covered in snow and ice, which meant they couldn’t harvest nearly as much energy as they could without obstruction. But despite that, the house still managed to generate some 13,577 kWh of energy. This amount exceeded the virtual family’s energy usage by 491 kWh, which could either power their electric car, or be fed back into the grid.

14 comments on “Clean energy home ends 12-month trial with surplus

  • There are great improvements to be made with “negawatts”. Energy which is recovered from waste heat and stored for later use, or energy which is not needed in the first place, by designing systems which do not leak heat or waste energy.



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  • This is brilliant.

    But I wonder what the thinking about this will be in fifty years time; what took them so long? Or, how did they get into such a mess in the first place?

    Most probably it’ll be more along the lines of: Oh, how quaint!



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  • 3
    TwoReplies says:

    Harvesting waste energy isn’t a simple feat though. It’s got to be done right.
    In areas that generate lots of waste heat that normally would be vented away, harvesting said heat needs to be secondary to that normal venting, because you don’t want to accidently insulate the primary item needing cooling, while you’re trying to use it’s excess heat to do work.

    For example, there are quite a few companies that create products that make direct use of the thermoelectric effect to charge small devices (one spotlighting one recently was/is the BioLite stove which uses campfire heat to charge USB devices).
    Many people have suggested using the same thermoelectric technology to directly harvest chip heat instead of using heatsinks, but doing so would impede the chip cooling and actually cause damage.
    A better solution would be to direct the already vented heated air, over a “coolsink” to reharvest the heat (but then of course you run the risk of impeding airflow).
    Needless to say, it’s a tricky proposition.

    So in the end, the most efficient solution is to avoid all the energy conversion at all, and just not produce waste heat to begin with.



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  • That is an excellent point Alan. There is much to be gained by simply making the grid more efficient. I can’t recall any solid numbers off the top of my head, but I do know that a significant % of power is wasted in the transmission process.



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  • TwoReplies Jul 14, 2014 at 2:07 pm

    Harvesting waste energy isn’t a simple feat though. It’s got to be done right.
    In areas that generate lots of waste heat that normally would be vented away, harvesting said heat needs to be secondary to that normal venting, because you don’t want to accidently insulate the primary item needing cooling, while you’re trying to use it’s excess heat to do work.

    Seasonal heat storage sounds like a good option.

    http://en.wikipedia.org/wiki/Energy_recycling

    Waste heat recovery from air conditioning is also used as an alternative to wasting heat to the atmosphere from chiller plants. Heat recovered in summer from chiller plants is stored in Thermalbanks[3] in the ground and recycled back to the same building in winter via a heat pump to provide heating without burning fossil fuels. This elegant approach saves energy – and carbon – in both seasons by recycling summer heat for winter use.



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  • 6
    robin48gx says:

    I imagine the house may have, over a year generated 13,577 kW,
    but I doubt its output was 13,577 kWh (i.e. 14 Mega watts per hour).
    Unless it had a massive slab of plutionium under it or something.



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  • 7
    pattison says:

    Your units aren’t quite sensible… The article says the house generated 13,577 kWh of energy. That’s total energy for the hole year. That’s compared to their estimate of a family consuming 491 kWh throughout a year.

    Remember, kW is a rate of energy delivered (joules per second) while kWh is a measure of actual energy (joules)



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  • Robin Jul 14, 2014 at 3:54 pm

    If we look at approximate figures;

    365days X an average of 12 hours daylight = 4,380 hours of daylight, X a 4KW electrical panel output, =17,520KWh.

    If you take off a bit for cloudy days and snow cover, 13,557 KWh looks feasible!



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  • This is completely incorrect. Real power loss on the transmission system is negligible. Like on the order of 2.5% on the highest demand days.



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  • There are green energy solutions at national, district, buildings, and personal levels.

    http://ngm.nationalgeographic.com/2014/07/next/tiny-turbines

    Last year electrical engineers J-C Chiao and Smitha Rao, and their University of Texas at Arlington team, developed a prototype of a wind turbine—half the size of a grain of rice—that could be integrated into future electronics. Made from durable metal alloy and connected by tiny wires, it would deliver a tiny burst of energy to compact devices—think smartphones, not refrigerators—that need quick juice.

    It’s the latest mobile-technology idea aimed at making power outlets obsolete. Solar backpacks that charge handheld devices already exist. Next up? A new generation of wearable energy sources could include solar-powered fabrics and wind-powered hats that restoke a phone battery. —Daniel Stone

    Even tiny ones can use solar or wind power.



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  • Did the simulation put the same amount of moisture into the air a family would generate? Well insulated houses sometimes have trouble with getting rid of excess moisture.



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  • Stafford Gordon Jul 14, 2014 at 8:48 am

    This is brilliant.
    But…how quaint!

    This house is a prototype:

    “…the researchers (were) able to gain realistic insights into the energy efficiency and how viable planting such a home into a real-life American neighbourhood could be.”

    I wonder what the market price of such a dwelling would be and whether anything approaching it could be made economically viable for people who don’t live in a developed society’s privileged class.



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