KWh question

Okay. Bear with me.

If I look at power tariffs on the netty we get

3p per KWh for gas

12p per KWh for electric

So If I set up a gas powered generator in my shed can I make 1KWh of electric with 3KWh of gas and save money?

Discuss!

Yes. But the efficiency of your generator will need to be pretty good! Most IC engines would be very proud of 40% efficiency and then you have the generator and inverter cost and efficiency to think about....

And currently, if you were to generate a surplus and fancied selling it back to the grid, you would be limited to a mere 1kW and the payment (feed in tariff) would be pitiful, IIRC. Something to do with their irrational hatred of windmills and tree huggers I guess.

Murray

The best the grid can do by the time it has reached your house is ~33%, with high efficiency combustion, condensing turbines, huge transformers and all the rest of it. So you would be lucky to generate power at 12p/kWH at home (though you would miss out the transmission loss). I suspect those tariffs reflect odd historical differences in fuel pricing to the generator.

That's why people can make money with gas fired power stations, but you don't see electrically powered gas stations....

Neil

Today i get a letter from EDF saying they will fit a Smart Meter on the 22/8/17. Do I have to? What are the pros' and cons. I pay by DD so doubt I will know anything about it!

Clive

I'm supposed to be hoovering so this is more fun...

If absolutely everything in your generating shed was spot on, the maximum conversion efficiency would be about 34%, so 1kWh of electricity would cost you 8.57p.

More realistically, you might get a conversion efficiency of 25%, with 1kWh of electricity costing 12p.

This means that the conversion efficiency of your generator is critical. High efficiency means big and expensive to buy and maintain. To make the scheme pay, you have to repay the cost of owning the generator within its operational life. That's difficult to do on a small scale. Any downtime will cost you money. To make electricity from gas at an economic rate, you need produce a lot of it continuously and sell any excess production. The economics very much favour the big boys.

Quite a lot of electricity is made from natural gas. After considering conversion efficiency and the cost of generating and distributing power, it's probably not a coincidence that electricity turns out to be about 4 times as expensive as gas per kWh.

I used to heat my house with electricity and was delighted when gas arrived in the village!

Dave

Edit PS: assumes I got the maths right.  I am now wearing a tin hat.

Edited By SillyOldDuffer on 04/08/2017 16:58:32

No you don't have to accept one, they are just desperate to hit their targets.

The best advice is don't. They are a good idea but the current ones don't have all the functionality they are panned to have and they don't work with all suppliers so you could change supplier and be faced with having to pay for a new one at some point in the future.

Wait until they bring out a universal smart meter and have cracked all the functions.

Neil

No it's totally voluntary according to all the radio ads about it. Don't think there are any pros or cons for the end user just the supplier, You soon get fed up of looking at the display showing how much energy you're using/used.

I am paranoid, but I think one feature of a smart meter will be remote control.

In the event of likely future power shortages and load shedding it will be possible for the provider to prioritise who gets power on a per household basis. So not having a smart meter might mean you're the only one in the street with power apart from hospitals and police stations etc. This may not be a good thing; your neighbours will all be asking you for hot meals and telly access!

Dave

I am paranoid, but I think one feature of a smart meter will be remote control.

I reckon that they will introduce variable day rates via smart meters

So from 7am to 9am and 5pm to 7pm you pay 20p KWh, the rest of the day 11p and 10p from midnight to 7am kinda stuff

All in the interest of saving the planet of course (sigh)

Today i get a letter from EDF saying they will fit a Smart Meter

I had my meter replaced a couple of months ago. A "standard" electronic meter was fitted in place of the old mechanical one & I mentioned Smart meters to the installation chap. He wouldn't be drawn on the matter, beyond saying that he wasn't fitting a Smart meter at that moment & suggested that I would be well advised to research them thoroughly before going down that route if I had a mind to.

Nigel B

I resent the government using our taxes to exhort us to fit smart meters. Obviously we will pay for them one way of the other. It must be great to own a smart meter manufacturing company right now - talk about coining it in on a near monopoly.

I'm not going to get a smart(??) meter until they are actually smart enough to work after you change suppliers. Again, it's quite bizarre that the government exhorts us to change suppliers frequently, yet doesn't seem bothered that said smart meters won't survive the change. I suppose it further helps the smart meter industry....

Then of course, the same government uses our taxes to exhort us to "get superfast broadband". Why do we need to be told?? Particularly ironic that their predecessor free market evangelist (Thatcher) actively prevented BT from installing the proposed high speed "digital highway", for fear of upsetting the BBC. How things have changed (not least for their stance on the BBC) - but imagine if we'd had fast internet back in the 80s!

Murray

I have a smart meter. I installed it myself. It tells me via a web page what my consumption profile is and it's sometimes quite useful. That's the only function of a smart meter that is any use to the householder. The ability to switch you off if you don't pay your bill is nice for the utility but no use to their customer. My supplier only gets my monthly readings which I supply.

My brother's one was replaced after 3 years - apparently because the batteries which were supposed to last 10 years were failing!

But just for the record, there would have been no use for superfast broadband in the 80s as the basis of the WWW, html, was first published in 1991 and domestic use of the internet was only really widespread by the end of the 80s.

What are you going to use the electricity for? You can power your machines off the line shaft your gas engine drives so it is only needed for light. You can charge up batteries for light during the periods when you are setting up the lathe or using your hand shaper.
Don't forget the value of the heat the other 60% or the energy is going to. Even if you don't need all the heat in the shed you can pipe it into the house.
Alternatively if you run a wood powered gasifier genset you can grow the fuel.

We've already got a split meter that does that for the storage heaters, they wouldn't need smart meters to put people on 'economy 7' or 'economy 10'

Or get a staffie...

N.

I think the point with a smart meter is that they can have economy 1,2,3,4,5,6,7 flipping whenever they want to modify consumption. Like encourage use on a bank holiday when industry isn't buying, special offers on sunny days when there is lots of solar, or windy days with a kike when the evenings draw in at 4pm but industry is still using.

It's all relative but I don't think I was really suggesting they were planning 50Mb speeds back then, somehow. However, it would have saved many years of silly dial-up modems trying to achieve a whopping 52kb (actually 45kb). Remember that? Before the proper internet arrived, people (like me) were using bulletin boards etc. Painful but exciting.

Even today, the UK is way down the table of speeds. Stifled by a monopoly supplier (BT Openbreach) pretending to be operating in a competitive market.

Murray

2,7 p/ gas kWh and 12p/ el kWh somewhere in UK.

Young people from Denmark technical University won a Shell fuel contest with a modified 50 ccm Yamaha moped engine claiming a fuel conversion of 42%.

Power to electricity to grid can be done with 95% . 40% gas to grid and 60% free heat in winter where electricity is most valuable to society.

To make one kWh electricity and get 1,5 kWh free heat we buy 2,5 kWh gas and pay 6,8 pence.

It would be fun to run a contest like IMLEC seing who can make say 2 kW electricity from gas with best efficiency..

My candidate

**LINK**

Edited By Niels Abildgaard on 04/08/2017 21:05:15

Edited By Niels Abildgaard on 04/08/2017 21:41:08

The best way to do what the OP has in mind is to wait till the cold weather, and then run the gas-to-electric converter inside his shed (garage, house, etc). If the engine is water cooled, keep all that system inside as well. This will allow him to benefit from the 'waste' heat produced in the conversion, so he will need less electricity or gas (or fewer logs) to keep warm.

If the grid generators sent their waste heat to houses, and their CO2 to greenhouses, they would be more efficient, too.

Cheers, Tim