Free Energy

It looks like a micro-CHP unit. It might prove attractive to replace a life-expired gas boiler with it, perhaps?

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

Sounds more like it runs a small turbine generator.

I'd love to, but in our village..... What gas???? Being within a mile or three of a primary part of Britain's gas grid doesn't appear to qualify us.

Hi Wrenched. I live in the West Midlands, in a place called Sedgley. Where do you live? Spencer.

What BS is this .. Reduce your carbon by burning Gas?

So the power company does not want to, (or is not allowed to) build another gas powered generator plant. Instead it sells mini-plants to the customers. The carbon is reduced at the power plant, however, It is increased in your homes, and you have to pay for the unit, gas, maintenance, and repairs.

The power company is downloading the power generation to the consumer. (not necessarily a bad thing), However to claim it will reduce the carbon is a selling gimmick

The power company is also downloading the maintenance of a power plant to the consumer which will only increase its profit margin.

Burning gas will only reduce carbon if you were originally producing electricity by burning coal.

To burn any fuel to produce electricity is not efficient and will produce carbon. It is also using a non renewable resource.

Better to use Hydro power, or wind power , or solar.

I agree with many of your points, but I thought because you are burning gas anyway to heat your house, the waste heat from generation is not wasted. It is combined heat and power as has been said, you are buying gas, increasing the quality of energy which you sell at a higher price (~3X) into the grid. There is no indication of power output; I just thought it was cute. Other peoples' opinions put it into perspective. Yes, it's gimmicky and because the internal process is unknown maintenance is a worry. It reminds me of the future home experiment in Milton Keynes, in that case they were running an i.c engine on natural gas recovering the heat for home and water heating and exporting excess electricity into the grid. (Just servicing the chp plant, dear). But this is a smaller scale operation.

I think that you replace your current furnace/boiler with one that also has a generator. It is not capturing the excess heat from the flue/chimney/exhaust, it simply has an extra generator to create electricity by burning more gas.

It is simply as the initial add says:

"Power and heat combined in a single boiler"

It may also require that your furnace be on alot more.

I have read about that unit before, they use a Stirling engine to generate power. The cooling side of the engine is fed to the home heating system.

I am not sure if I remember this correctly but I think it might be a free piston stirling, where the magnet and power generator are integrated right into the engine with no rotating parts.

Funny, I was just writing up a patent that mentioned this very system. They are really pretty cool, as are the Honda co-generation units sold in Japan. A 4 cylinder (type A, I believe) Stirling engine is used to generate power (and the alternator is rotary). The "waste" heat is used to heat water. Typically, the ratio of heat to electricity is about 8:1, and I talked to a Whispergen guy about changing this -- but they cannot do so, at least right now. Stirling engines have the potential for being close to 40% efficient, I think, so the ratio could be more like 40% elec, 60% heat (ignoring losses). Losses are quite low, with the whole system about 90% efficient.

In the US, power is generated with overall average efficiency of 38%. So if you use electric heat for your water, you are operating at about 36% efficiency (electric water heaters being about 96% efficient). Assuming you can use the hot water generated by such a unit, your efficiency is much better. The Whispergens will run on natural gas, diesel, biodiesel -- in theory you could modify one to run on wood pellets, because the Stirling engine is external combustion. Unlike a diesel or gasoline generator, they are very quite, because the combustion is external -- thus no loud pop every time an exhaust valve opens.

Been away for a while, thanks for that answer, so it's a Stirling engine: I hadn't realized they were so efficient, but I had always thought their power outputs are quite low so they ended up as working models rather than performing a function. It's great to see an application. Regarding efficiency, if you want heat, which is why you burn gas, I would imagine that the inefficiencies listed would be heat, which would go into your house so it's not wasted?

I would imagine that the inefficiencies listed would be heat, which would go into your house so it's not wasted?

Exactly. So even if the Stirling engine (or any other engine you use in the cogenerator) is inefficient, those inefficiencies show up as what would otherwise be called waste heat. If you capture that heat and use it productively, then the system efficiency is very high: the waste heat is no longer "waste". Typically, excess heat would be a little harder to deal with than excess electricity (which can be sold back to the utility company in many places for full retail price -- spinning the meter backwards) but even excess heat could be used for home heating in addition to bathing and washing. With some planning, you could generate a large percentage of your electricity, all your hot water, and some of your heating needs all at 90% efficiency. Here, natural gas is about half the price of electricity per million btu, so it's a pretty attractive proposition economically, as well as environmentally.