Microgen, running all the time.

[N. Thornton]

I think this is a misunderstanding. First, electrickery will only be produced when heat is wanted, it will not run when heat is not needed. Now the 'inefficiency' of the generating system is guess what - heat! And this heat is harvested in the usual way to run your heating and HW. In other words nothing is wasted, so there is no real inefficiency in leccy generation.

The 1/3 price electricity is just a side benefit. You will only benefit from it when net metering is available: when it isnt it would be prohibitively complex to make use of the benefits. And when it is, you dont get anything like as much as you pay for your leccy, the rate is way lower. The end result is that although microCHP is great in principle, it isnt great in practice today for home use.

Now if you had a few houses running on a private generator, installing CHP would bring you big benefit. But its 99.9% likely that youre not.

Whats the way forward with microCHP? One possible way would be a unit that produced your whole leccy requirement, 10kW rather than 1kW, and with say 33% efficiency. Then you could run with no leccy grid connection. In summer your leccy would cost the same, and in winter it would only cost you gas price.

If you were willing to install a load shedder you could safely cut that back to 4kW.

Regards, NT

[Pete C]

Maybe my choice of words could have been better, what I meant was the generating efficiency is lower than than 25% so it's not a cost effective way of generating electicity alone.

The way I see it is that when your heating is running you have up to

1.1Kw available at gas prices, ie 1.4p/kW.

The best way to take advantage of this might be to use the boiler with a thermal store and have the boiler fire when the mains load rises above a certain level as you switch on a kettle or use a microwave.

Also have dishwashers, washing machines etc on a timer triggered by the boiler so that they can be run while the thermal store is heated at the start of the day.

If the stirling engine generator could work though an inverter, you might even be able to supply less than 1.1kW at greater efficiency, as the generator could run at a slower speed.

Might be worth doing for flats, the waste heat could be used to supply metered hot water for heating.

Not very green if you can't use the waste heat, as the gas turbines for electricity generation are around 60% efficient.

Another way forward might be to have a 'micro grid' whereby you can sell or buy electricity to and from your neighbours at below market prices - p2p electricity generation...

cheers, Pete.

[IMM]

You could have a large interseasonal heat store, to store this excess heat and use low temperature UFH.

Microgen are non-committal on whether the unit can produce electricity alone with little waste heat. The unit has two burners, which indicates that it can. I have the impression the design has not stabilised, or a number of variations may be available on, or soon after launch.

[N. Thornton]

You can, but once you get into this kind of load shedding approach youre paying 2 prices:

1. inconvenience, which most people dont want
2. the cost of the control equipment

In short, load shedding can work upto a point, but most people these days dont want to purchase that kind of inconvenience. Most folk are heading in the opposite direction.

One could limit house feeds to 3kW with load shedding, but I wouldnt want to live in such a place long term. I have lived off a low power supply before, and its a pain. But at least some shedding can be done with little noticeable effect. Lower peak power delivery would translate into a cheaper supply, to some extent. With a bit of electronic control, most of us could go back to a 40A supply without noticing anything much. I used a 3kVA 13A private gen feed for a while, and dont recommend it. But 7kVA (IIRC) was no problem.

you lost me there

you mean private gen? Or CHP? Private gen is never worth doing unlss you really have to. CHP would work much the same with flats, except that with a whole block you've got a much more even load distribution, and a much higher base load. Both of these make CHP a lot more workable, in principle.

Fair point. OTOH grid supply involves a huge use of energy in running the system, installing and maintaining it all, operating the business, etc. How things compare when all thats taken into account I dont know.

If leccy cost was a problem for people, this would be a nice way to go. But it isnt... people just hook up and thats the end of that. Almost no-one wants to get into running their own grid. Life's too short. Now add the many regulatory issues, and such small private domestic grids are going nowhere.

Regards, NT

[IMM]

One great point about the Micrgen is that electricity generation is very efficient and hence much more eco friendly than taking from the grid. From the grid is about 33%, by Microgen 90% plus. If millions of these types of units are installed total UK emission would go down. Well not increase anyhow, as power usage is set to rise, so any saving measures only keep the status quo.

[N. Thornton]

I doubt that very much. Do you have a reference for this optimistic figure?

Regards, NT

[IMM]

I think the figures are deduced from the heat and power generated. Remember power is being extracted from latent heat, that normally would be dumped. Must be far more efficient than taking from the grid.

[Pete C]

People with economy7 tend to run their washing machine, tumble drier etc overnight so it shouldn't be too hard to schedule these loads for when the boiler is heating up the home.

RF remote sockets are widely available and it should be pretty easy to adapt them for switching by a heating controller.

I agree that you want to be able to boil a kettle whenever you want, but if you have microCHP it would be worth scheduling and controlling some non essential loads to best take advantage of it.

There's not much need to limit individual house feeds as the combined load evens out, and at peak times some industrial users are required to dom power shedding to offset domestic demand.

For limited power feeds it's a pain to do manually, but if you can automatically shed certain loads according to demand then it becomes much easier.

Where I live my supply is through a 13A cable, and with that sort of load the voltage drops to ~200v :)

Well it looks like the generator in the microCHP runs at a constant speed to give a 240v 50Hz output. But an inverter would give a 240v

50Hz output regardless of generator speed. So you could run the boiler at a low output to supply low power loads like lighting and audio/video/PC stuff.

It's a pity that the generators will only pay a pittance for power fed back into the grid when it goes to next door charged at a full price. If there was net metering whereby they paid the market rate then it would make it much more attractive to people with a microCHP boiler to feed their surplus power back instead of having to use as much of it as possible.

cheers, Pete.

[Pete C]

Agreed, with surplus microCHP power there no waste heat involved other than the flue gases from the boiler, so it's far more efficient and green than power conventional generation.

If there was net metering whereby the surplus power was sold back to the grid at market prices then it would make it *much* more simple and viable. There would be no advantage in trying to use it all in the home, and the income gained would pay back the cost of the system and reduce energy bills.

Eg while your boiler was running you would make about 5p/kWh for the energy fed back into the grid, taking into account the cost of the gas. So if your microCHP was running the equivalent of three months a year you would make £115 generating 2400kWh of almost emissions free electricity.

Unfortunately our Govt opposed net metering but invented NETA, whereby wholesale prices dropped so low that British Energy and other generators went bust or almost did so, while the prices to the consumer didn't fall at all.

cheers, Pete

Now that electricity companies are more orientated to making a profit than the public good I doubt

cheers Pete.

[N. Thornton]

As well as paying more per unit for your primary source, youre also eliminating the business side of things, which costs the power cos a fortune, the distribution network, and all the regulatory issues with it. Thus we cant conclude its a hiding to nothing on the basis you suggested.

Regards, NT

[N. Thornton]

Many of us dont run the washer at night because its too noisy. A lot of people live in old terraces with no sound insulation at all. Many folk run it more than once per day. etc etc etc. Ie its an inconvenience most wont buy. And it costs for the equipment.

Could you show us the numbers? I'm not convinced, either way.

It doesnt even out at peak times, it peaks. Iron flat those peaks and your national generating network can produce less peak power and run at greater %age of capacity the rest of the time.

Yeah, I've had that experience... youre lucky if youre getting 200v. We were using a portable 3kVA gen at one point, until the wiring was completed, and it dogged down something bad. Soon got rid of that. I dont remember the numbers, but I reckon it must have gone down to more like 110 when loaded up.

sounds good.

It is a pity, but its the business reality of it. One would have to change the rules and the setup to get round that: for example theres nothing wrong in principle with supplying your neighbours at close to full price, but things arent set up that way now.

Regards, NT

[IMM]

In Switzerland, after 8.00 p.m. it is illegal to run a washing machine in flats.

[IMM]

Yun jest of course. This law sound like good common sense to me.

[Andy Hall]

They have all sorts of peculiar legislation in Switzerland. It's essentially a police state.

Would you trust anywhere that looks like a train set?

.andy

To email, substitute .nospam with .gl

[Owain]

"IMM" wrote | > Many of us dont run the washer at night because its too noisy. | In Switzerland, after 8.00 p.m. it is illegal to run a washing | machine in flats.

Was that law introduced before or after women got the vote?

Are the Swiss populace sufficiently law-abiding they can be trusted to switch off their washing machines at 19:59 (being Switzerland, presumably

19:59 *precisely*), or do all Swiss washing machines come with a teleswitch so that Swiss High Command can make sure their citizens comply?

Owain

[Lurch]

On Fri, 5 Mar 2004 15:55:32 -0000, in uk.d-i-y "IMM" strung together this:

[115 lines snipped]

IMM, could you occasionally use the delete key please? Not everyone has ADSL and wants to download pages of irrelevant nonsense for a 1 line response.

[IMM]

I am the world's greatest snipper.

[Lurch]

On Fri, 5 Mar 2004 20:19:46 -0000, in uk.d-i-y "IMM" strung together this:

I think you misheard when that one was shouted.

[Andy Hall]

No I don't - I have numerous friends and colleagues living there.

I'll give you some examples:

- In an apartment building it is very typical to have a communal washing machine in the basement since in many apartments you can almost stand in one spot in the living room and touch all four walls. The washing machine will have a rota and you have to do your washing on a specific day or miss out; and the detergent chute had better be spotless afterwards.

- Some friends lived in an apartment in Bern and decided to have a party. They were on good terms with their neighbours and went to see each of them beforehand to let them know and to invite them. Some came and none had a problem. However at 11pm there was a knock on the door. The police. There had been a noise complaint and could they turn off (not down) the music. They complied (being auslanders) and asked the cops who had complained. It had been the neighbour across the landing. They saw the neighbour the following day and asked him why he had complained rather than just coming over and asking himself. They wouldn't have minded. The neighbour explained that he was on good terms with them and that because of that he didn't want to say anything to them that might spoil the friendship. Therefore he asked the police to deliver the bad news.

- A friend lives close to Geneva and often travels on business to other countries. Normally he goes to Geneva airport and flies from there but occasionally he needs to visit somebody in Zurich first, so takes the train and then leaves from Zurich airport. As he was going through passport control, the officer stopped him and said that they had had a message from the police in the village where he lived to say that he had left his ground floor bathroom window open. The message went on to say that he shouldn't worry because the policeman had been able to climb in, lock the window and leave through the front door. When he went to the police on his return, it turned out that had checked with the railway and determined that he had bought a ticket to Zurich airport....

This is all very nice of them, but as he felt, a trifle intrusive on his privacy.

.andy

To email, substitute .nospam with .gl

[IMM]

My God! They like washing machines going off at 1.00 a.m.?

Westminster a 14/7 noise team who do the same.

Where is the intrusion. They simply traced him, which wasn't difficult as he was in a village, and gave him a message that all was well and they actually secured his place for him.

All sounds like a lot of common sense there.