Arizona11 wrote:Thanks for all the replies so far. It would appear that the promise shown on the websites about cutting the nation’s CO2 emissions is just gobbledegook as nobody can explain how it cuts emissions. If anyone does find out, please let us know.
It's fairly straightforward - you can regard it as the next step beyond Economy 7, which needs a different, "slightly smart" meter that effectively has two meters - one to record electricity use between say midnight and 7am and another to record use during the day, so that different tariffs can be applied because there is a surplus of capacity at night so it can be sold more cheaply.
Just to make it simpler I'll take the example of charging an electric car but the same could apply to any application where you just need electricity to be consumed at some point during the night but you're not too fussy when - storage heaters, washing machine, whatever. Say your car needs to be fed 21kWh to get it to a "full tank".
Under Economy 7 you set the car to charge for 7 hours from say midnight to 7am at 3kW. But let's say there is a weather front coming that means you know the local wind turbines will spin furiously from 2am to 5am, but then produce nothing for the rest of the night. Under Economy 7, you'd get 3 hours @3kW of wind electricity in your car, but 4 hours @3kW of backup power, probably provided by gas. Now that's not ideal for lots of reasons - the marginal cost to the power company of wind is virtually zero, whereas the marginal cost of gas power is very much not zero at the moment, that marginal gas has to be imported so there's energy security risks (as Germany is finding out), and (going back to the original question), gas-fired power has CO2 emissions whereas wind power has virtually no marginal CO2 emissions.
Obviously the better solution would be for the car to "know" that this weather front is on its way and that the optimal charging strategy is 7kW for the three hours during the weather front. The way that knowledge is imparted is by the power company setting a tariff of say 10p/kWh during the windy period and £1/kWh when there's no wind. Under that regime the steady charging at 3kW costs £12.90 for the night whereas "smart" charging costs £2.10. So the consumer pays a lot less, and a load of CO2 emissions are avoided.
Modern electric cars have enough technology in them that they could ring home to VW, Tesla etc by themselves to find out what the current price of electricity is, but that's less true of all the other devices in the home, and it makes sense to have a single standard point of reference in the household to receive information on variable tariffs. That single point of reference is a smart meter.
There's other things that smart meters can do, like coping with export from domestic solar panels or even the car battery at peak periods, but it's their ability to match demand to intermittent renewable power sources that's the reason the industry wants them. Obviously something like tidal power can be predicted years into the future, but modern weather forecasting means that they've got a pretty good idea of how much wind power will be produced over the next several hours, it's good enough for these purposes.
Mike4 wrote:Hallucigenia wrote:Well quite. A lot of
HMG's much-vaunted hydrogen strategy is a bit of a con, to avoid frightening the investors who HMG need to keep investing in pipelines with 35+year lifetimes. There will be lots of posturing and trials, but in the real world I doubt we'll go beyond 10-ish% hydrogen mixed in with methane, and economics will push normal people towards electrified heating in some form except for marginal cases.
Here is a chart of the hierarchy of uses for hydrogen. Domestic heating and cars are quite low down.
Quite - guess who was
posting that chart a year ago....?