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Clean Energy Home Ends 12-Month Trial With Surplus

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A prototype home in the US has generated enough energy to sustain a family of four for a year, with enough spare to power an electric car for 2,317 km.

Read more here...

Good stuff. I'm currently helping friends conceptualize an off grid project at their recently purchased farm in Tasmania. Its a new build project so an opportunity to build in high efficiency.

The plan is for 8KW of PV and a Honda micro CHP (LPG) unit which will deliver 1KW (e) and 2.5KW of heat (which will be used to heat water and provide some space heating in winter). Summer time a large solar hot water system and the PV should suffice. Other features include wood burning stove, ultra high insulation spec and 1000 a/h battery bank.

There should be a fair surplus for charging a Prius PHEV

The above costs less than just getting a leccy connection to the farm. Main fuel import will be 700-1000 litres of LPG per year

Falling solar PV costs are making these projects more cost effective all the time.

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It is also a decent size - 2.5x as big as the average UK family home. Perhaps a UK one could be heated by body heat alone...

Can you actually have this sort of a setup in the UK? I thought there were daft planning restrictions like no air sourced heat pumps if you already had a ground sourced one...

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A 2-bedroom converted barn in Cornwall is producing surplus electricity over what the middle-aged couple living there use.

More surprisingly, it was breaking even even in its first month after installation - which was dark and dreary December!

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A 2-bedroom converted barn in Cornwall is producing surplus electricity over what the middle-aged couple living there use.

More surprisingly, it was breaking even even in its first month after installation - which was dark and dreary December!

I measure a 5-fold difference between average January and average June.. they will be doing a fair bit of export by now, I expect.

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Good stuff. I'm currently helping friends conceptualize an off grid project at their recently purchased farm in Tasmania. Its a new build project so an opportunity to build in high efficiency.

The plan is for 8KW of PV and a Honda micro CHP (LPG) unit which will deliver 1KW (e) and 2.5KW of heat (which will be used to heat water and provide some space heating in winter). Summer time a large solar hot water system and the PV should suffice. Other features include wood burning stove, ultra high insulation spec and 1000 a/h battery bank.

There should be a fair surplus for charging a Prius PHEV

The above costs less than just getting a leccy connection to the farm. Main fuel import will be 700-1000 litres of LPG per year

Falling solar PV costs are making these projects more cost effective all the time.

Kurt, what are the materials used in the "ultra high insulation spec" ?

Edited by Saving For a Space Ship

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Good stuff. I'm currently helping friends conceptualize an off grid project at their recently purchased farm in Tasmania. Its a new build project so an opportunity to build in high efficiency.

The plan is for 8KW of PV and a Honda micro CHP (LPG) unit which will deliver 1KW (e) and 2.5KW of heat (which will be used to heat water and provide some space heating in winter). Summer time a large solar hot water system and the PV should suffice. Other features include wood burning stove, ultra high insulation spec and 1000 a/h battery bank.

There should be a fair surplus for charging a Prius PHEV

The above costs less than just getting a leccy connection to the farm. Main fuel import will be 700-1000 litres of LPG per year

Falling solar PV costs are making these projects more cost effective all the time.

Kurt - any chance you could PM me the end woodburner he decides on and why? I am going to fit one in the place I have in Oz, whenever we eventually get back there...

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A personal anecdote if I may.

I calculated our energy bill for last month. Under a tenner - and most of that was standing charge. Our 4kW array basically covered our energy needs (and likely more too). I expect at least the next couple of months to be the same. We live in a bog standard old cottage, but now heavily insulated and with an EPC of C (up from G a year ago).

Now we were already frugal, and there are some circumstances which probably help us a lot:

There's only two of us,

I work from home so able to take full advantage of peak output (we mostly cook, do our washing etc during the day).

We have an immersun so get our hot water from the panels too.

All of our household appliances are now at least A+ energy rated

Electricity only, no mains gas

I made the missus responsible for our energy bill while bumping her allowance. Any additional savings she keeps.

Our electricity company recently reduced our standing charge in favour of increasing cost per unit

But it's also probably not an optimal installation either, the roof is east-west rather than south facing and I live near the mountains so it rains/is cloudy a lot.

On balance, if I were an energy company I think I'd be rather worried about what next couple of decades might bring. Demand could absolutely crash during future summers, and near energy independence is almost within reach for the average guy in the street.

Edited by StainlessSteelCat

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I measure a 5-fold difference between average January and average June.. they will be doing a fair bit of export by now, I expect.

This is the thing - once the whole country is set up with PV enough to cover winter completely, there'll be a huge surplus for foreign export in summer - but given that all of Western Europe will be on the same plan, just where is that energy going to go? Won't it be useful to do something like what Haldane suggested in 1923? -

Personally, I think that four hundred years hence the power question in England may be solved somewhat as follows: The country will be covered with rows of metallic windmills working electric motors which in their turn supply current at a very high voltage to great electric mains. At suitable distances, there will be great power stations where during windy weather the surplus power will be used for the electrolytic decomposition of water into oxygen and hydrogen. These gasses will be liquefied, and stored in vast vacuum jacketed reservoirs, probably sunk in the ground. If these reservoirs are sufficiently large, the loss of liquid due to leakage inwards of heat will not be great; thus the proportion evaporating daily from a reservoir 100 yards square by 60 feet deep would not be 1/1000 of that lost from a tank measuring two feet each way. In times of calm, the gasses will be recombined in explosion motors working dynamos which produce electrical energy once more, or more probably in oxidation cells. Liquid hydrogen is weight for weight the most efficient known method of storing energy, as it gives about three times as much heat per pound as petrol. On the other hand it is very light, and bulk for bulk has only one third of the efficiency of petrol. This will not, however, detract from its use in aeroplanes, where weight is more important than bulk. These huge reservoirs of liquified gasses will enable wind energy to be stored, so that it can be expended for industry, transportation, heating and lighting, as desired. The initial costs will be very considerable, but the running expenses less than those of our present system. Among its more obvious advantages will be the fact that energy will be as cheap in one part of the country as another, so that industry will be greatly decentralized; and that no smoke or ash will be produced.

Obviously he didn't know about the PV potential so had to think of it entirely in terms of wind power, but the principle is the same. But it's funny to think he thought it would take 400 years to implement, or that just after this quote he expressed scepticism about the potential of nuclear power.

Another thought I had re. the OT thread about how to store energy domestically, was to have all new builds, particularly on flood plains, set up on hydraulic stilts or something, which would be slowly raised by any surplus power during the day and slowly descend during the night to provide whatever was needed then.

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Kurt, what are the materials used in the "ultra high insulation spec" ?

400mm of rock wool in the roof plus foil back insulation on the pitch of the roof

150mm of Polyurethane block in the wall

50mm of polyurethane block in the floor slab

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Kurt - any chance you could PM me the end woodburner he decides on and why? I am going to fit one in the place I have in Oz, whenever we eventually get back there...

This is a strong contender

http://www.pivotstove.com.au/catalogue/wood/low-carbon-wood-heaters/the-curve-wood-heater

I have suggested a flat top is better because you can utilise them as a hot plate to slow boil water / simmer food.

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For anyone wanting to go off grid with a PV system but wants some back up these Honda micro CHP units are ideal

http://world.honda.com/news/2011/p110523Gas-Engine-Cogeneration/index.html

Output is 1KW electricity and 2.5KW heat and overall 92% efficiency

Anyone other than a purist is going to have an LPG / CNG tank for cooking so no extra tank installation costs. Also the cost of on of these can be offset against a reduced requirement for storage batteries

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