Future of UK generated power

[Raditechman]

Using the link in post#1 to look at Gridwatch I noticed that the site now has the option to see the French Grid. France seems to be Nuclear and Hydro, whereas the UK seems mainly gas, although the UK does have more alternative supplies.

John

[ppppenguin]

Nukes dominate the French electricity supply system as can be seen from a graph on this page: https://en.wikipedia.org/wiki/Nuclear_power_in_France Hydro comes a fairly distant second, along with fossil fuels.

[Terry]

Unless you have huge amounts of storage or massive interconnects (like the Desertec project, nice idea but I don't see it happening anytime soon) you need backup generation on the system. Since it's only going to be used occasionally it needs to be low capital cost and easy to start. Fuel efficiency is secondary. Open cycle gas turbines are a likely solution.

You are ignoring the elephant in the room. If the use of gas is banned we will lose 50% of our generating capacity and the OCGT stations that we already rely on for temporary periods of excess demand will also be banned. That means that we will need double the amount of all other energy generating plant just to stand still - and it is not going to be used occasionally.

But the problem doesn't stop there. Gas central heating systems will be banned and need to be replaced by electric central heating - at considerable cost to the home owners who will also be facing an increase in running costs of around 400%. I don't know how many households this affects and, of course, the ban will also extend to industrial use as well. Then there are all those electric cars ...

It is very difficult to quantify but I don't think it beyond the bounds of reason to say that a quadrupling of all existing non-gas capacity will be needed. By 2050? I don't think so. Perhaps 2150 would be a more easily attainable target - provided, of course, that we don't wait until 2120 to start planning it!

Whatever happened to the plans for tidal energy? Unlike the wind and sun it never stops apart from the inevitable null every six hours when the direction of flow reverses. That is accurately predictable and, as the times of the tides vary in different parts of the country, pairs of systems with the appropriate timing differences could ensure a virtually constant supply of energy 24 hours a day.

Every little helps, as they say, and I'm surprised that the Thames Barrier hasn't been converted for electricity generation. The barrier already exists so only the cost of conversion would be needed. Convert two central gates into locks so that shipping can still pass up and down the river, install a permanent barrier with the generators across the entrance of one of the other gates and close all the other barriers. Simple!

[ppppenguin]

I don't think gas will be banned as some are suggesting. Certainly not as a sudden thing. Just the gradual phasing out of gas, starting with new instals.

The best way to deal with domestic heating is better buildings. Retrospective upgrading of buildings is possible but expensive. All this needs decent public policy which seems a bit unliklely at the moment. But in a couple of years who knows. I would love to live in a Passivhaus and have near zero energy bills: http://www.passivhaustrust.org.uk/ If the building regs mandated all new build to be to Passivhaus standards the housebuilders would protest but they all need a good kick up the rear end for several other reasons. If a decent system of grants was available for upgrading to Passivhaus standards there would be a lot of interest. Of course it's expensive but not doing anything is even worse. The half baked insulation schemes promoted by various governments were close to useless.

There is some activity in this sector but not enough: https://passivehouseplus.ie/magazine/upgrade

Tidal and wave energy are a very good idea. Shame that Salter (and his ducks) weren't properly supported back in the 1970s. Britain would be a world leader now. I worry about tidal barrages because of their side effects but they need to be properly evaluated. I think the Severn Barrage (about 7GW of reliable generation) was cancelled due to cost rather than environmental issues.

The change to LED lighting has already had a significant impact on the total UK power demand. In industry any company that hasn't invested in better pumps etc is throwing money away.

[Nick]

I'm not sure why you think electric heating costs 4x that of gas...

We have a heat pump - it's electric AND solar and is far far cheaper to run than gas.

Caveat: You need really good insulation for a heat pump to be effective.

[peter scott]

There are rather a lot of old houses many of which are listed or in conservation areas and trying to give them all good insulation would be prohibitively expensive.

I think we need to concentrate on zero emission electricity generation and the storage and distribution of hydrogen.

Peter

[ppppenguin]

It is possible to upgrade the insulation in many older houses, even those in conservation areas. It's not cheap though. But even if half are done that's halfway to solving the problem in that sector. It's not an "all or nothing" sort of problem. if you can upgrade 5% of the housing stock, followed by another 5% etc you're working towards an overall solution. There will always be difficult cases and they will be among the last to be upgraded if at all. When you have plenty of pople boasting that they only pay £50 per year for heating everyone will want a slice of that. Nobody wants to buy gas or electricity. They want a warm, light home with modern conveniences.

Heatpumps can work very well. If your gas is about 4p/kWh and leccy about 14p/kWh you need a COP of 3.5 on your heat pump to get equivalent cost. That's a fairly tough target. If you don't have mains gas and can't get local wood to burn then heatpumps are a no -brianer. But energy efficient buildings matter even more. You carry on saving fuel for a very long time.

Space heating using solar power to power a heatpump just ain't going to work But solar power can be a good match for aircon. Which is a heatpump working the other way round.

In sunny parts of the world (Nick knows some of them very well) there's a huge surplus of solar power free for the asking. Solar PV, solar powered steam plant are both entirely feasible; there's lots of desert in Arizona, Africa, Australia and the Middle East to accomodate them. So where is the public policy in those countries that will make it happen? In the US it needs better policy at both state and federal level. Plus direct public investment or appropriate incentives for the massive HVDC interconnectors that will be needed. Desertec have high ambitions and vision: https://www.desertec.org/ They will need not just national but international policy to make their dreams come true. And in some politically very unstable parts of the world too.

[Terry]

I'm not sure why you think electric heating costs 4x that of gas...

Taking a tariff at random, electricity is 18.13p per kWh and gas is 4.023p per kWh, a difference of 451%.

I've no idea how the efficiency of gas CH compares with electric Ch (which should be 100%) but modern gas boilers are very efficient and should be very much cheaper to run.

[pwdrive]

The gas we use can be efficient as it wants but one day we won't have any in the same quantity that the UK is used to...…

Meanwhile the you know whos make meat of it all, it would be a brave one that seriously put a radical plan in their terms of engagement.....

Lawrence.

[ppppenguin]

Terry, a decent ground source heatpump will give you 3kWh of heat for each kWh of leccy. That's a COP of 3. The reason is that you're moving heat from the ground to your house rather than heating up a coil of wire.

I thought I'd crunch some numbers for my own house. It's a fairly big end of terrace house. Fairly insulated but not superbly. Gas heating and hob. Leccy everything else. 2kWp solar PV. I use about 20000kWh/year of gas and 2000kWh of leccy. With about another 1000 coming from the PV.

Gas standing charge is 20.48p/day, unit cost is2.775p
Elec standing charge is 22.05p/day, unit is 14.36p
That tots up to £972 per year

At a rough guess 1000kWh of gas is for the hob and 2000kWh for hot water. The rest is for space heating. I have a modern condensing boiler so should be getting about 90% efficiency.

If I had a heat pump with COP=3 and no gas at all I reckon that it would cost about £737 to run. A saving of £235/year. Not worth it for a retrofit but worthwhile for new build or major refurbishment. If the insulation is improved to Passivhaus standards then the space heating bill would drop to near zero. A heatpump would only be marginally worthwhile over direct heating. Guessing at a saving of about £600/year.

A full upgrade to Passivhaus is likely to be north of £100K so the rate of return on investment is very poor, less than 1% per annum. Hence only worthwhile for new build, major refurbish or with subsidy. Another benefit is no radiators taking up space and for a new build no capital cost of heating system.