The UK government knows that having a policy of substituting windmills and solar power for proper power generation leaves a big black hole when the wind drops and the sky is cloudy.

Is there any evidence or experience of that actually happening?

Right now on a calm but sunny Autumn day wind and solar between them are meeting a third of demand.

Or for that matter any evidence your assertion about smart meters and using car batteries actually stacking up?

Can`t really say i believe that we generate that amount of electric on a dull day with hardly any wind, unless the solar panels panels are a lot larger and wind turbines are more efficient than before.

In fact I will be very surprised if millions of cars will be able to charge all together at all even in 10 years, the maths may add up but reality is a lot different

The UK government knows that having a policy of substituting windmills and solar power for proper power generation leaves a big black hole when the wind drops and the sky is cloudy.

Is there any evidence or experience of that actually happening?

Right now on a calm but sunny Autumn day wind and solar between them are meeting a third of demand.

Or for that matter any evidence your assertion about smart meters and using car batteries actually stacking up?

Keep your eye on www.gridwatch.templar.co.uk/

You'll soon see what I am talking about when a combination of weather conditions leads to less solar and wind generation.

And the weather is mild at the moment, with very little heating load on the grid,

it will be a different story in a cold winter, and then there is all thee EV cars to charge up..............!

Do you have any evidence that smart meters linked to EV car batteries will not be used as battery back-up to the grid?

I vaguely remember it being touted as a benefit of widespread EV car use.

""A strategy of reducing reliance on carbon based fuels and exposure to fluctuations in price on world markets seems entirely sensible.""

At least 10 years too late. The only thing we seem to get from GOV is reactionary, there has been no forward planning for years let alone what was going to happen after Brexit. Why everything seems to be coming to a head just now is any ones guess. Why after 9 months is there a shortage of HGV drivers.. If this country was so great why have so many returned back to Europe when the gate was left open for them to stay?

Boris is a flawed individual but he seems to have a vision and the resolve to see things through - eg: Brexit. Whether he delivers, only time will tell.

IMHO he may have a vision, but that vision doesn't seem to include the consequences arising from his spur-of-the-moment ideas. His chief ability is blurting out the noises many people like to hear. That's how he has got where he is today (CJ) .....

Capacity issues can be easily overcome with more turbines, nuclear power stations, field of PVs.

At least with turbines, the ground below can be used productively. We are already unable to supply ourselves adequately with home-grown food, so covering acres with PV panels seems a poor trade-off, apart from being most unsightly. I suppose someone might grow mushrooms underneath, or goats probably wouldn't mind much ?

I have seen some huge coverages in places like Sicily, and there are an increasing number here - presumably because the owner of the field can be easily 'bribed' to give up growing crops or livestock. In the end we may have to live on money ....

Not all unused land is arable farmland or bio-diverse woodland. There are large bits of the country which are unproductive, relatively unpopulated and unattractive. We have a choice - - use them for energy generation or carry on consuming carbon fuels.

Putting enough photo-voltaic panels to deliver 100% of total UK energy requirements would take something under 2% of land area. As most would come from tidal, nuclear, wind the actual requirement would be far less than that.

In fact if the roof of every house was correctly aligned, covered with PV cells, and domestic battery storage - there would be no need for a domestic supply.

The sun does not shine at night.

It does not shine much in winter.

And the complex battery concept is based on the proposition that you charge it when the sun shines, and discharge when it gets dark.

Not all unused land is arable farmland or bio-diverse woodland. There are large bits of the country which are unproductive, relatively unpopulated and unattractive.

Those are just the places which need additional generating capacity least !

Not all unused land is arable farmland or bio-diverse woodland. There are large bits of the country which are unproductive, relatively unpopulated and unattractive. We have a choice - - use them for energy generation or carry on consuming carbon fuels.

Putting enough photo-voltaic panels to deliver 100% of total UK energy requirements would take something under 2% of land area. As most would come from tidal, nuclear, wind the actual requirement would be far less than that.

In fact if the roof of every house was correctly aligned, covered with PV cells, and domestic battery storage - there would be no need for a domestic supply.

Do you have a worked example of your 2% of uk land area to deliver 100% of uk power needs.

It seems excessively optimistic.bearing on mind that the average output of a solar PV panel is only around 5 watts per square metre in the UK.

Great! Not much help if you live in a ground floor flat! But seriously if the efficiency of solar panels could be increased it could solve a lot of our energy problems. Having them fitted at my age would be a loss maker and I also worry about the roof leaking as a result of poor fitting and the wind lifting them off.

The weight of a typical solar panel is ~20kg. It covers an area of 1.6 - 2.0 sq m.

The weight of roof tiles varies by type between 50 and 120 kg sq m. Timber adds to this. The total weight of roof structure below a solar panel is in the region of 100-250kg.

A solar panel represents a load increase on the roof structure of between 7-20% - well within normal roof design parameters which also need to deal with snow and winds.

There may be other good reasons to decide not to install them cost, appearance, listed building, wrong orientation etc. A proper roof condition survey should pick up any deficiencies before installation - installation on to a deficient structure would be foolish!

I'm glad I didn't have them fitted years ago when I was considering them. I had to have my tiles off recently, as the battens had rotted

All but the most cowboy-type fitters would assess the load-bearing ability of your roof before setting foot on it themselves to fit the panels ?

2% would be a gross overstatement and would allow room for 100% PV energy generation, replacing wind turbines, nuclear, gas etc + growth with EVs.

But from dusk to sunrise, 2% of not very much is very close to nothing, as everyone keeps pointing out. And those are the hours when a lot of lecky is called for, especially in winter.

We can approach the answer either by looking at total insolation and PV efficiency, or by individual households. The latter is probably easier to deal with.

The average UK household uses 3100 KWh of electricity per year - approx 9 KWh per day.

A 4KW array on a roof will produce around 3400 KWh each year taking account of night, cloud etc. South facing and south of UK will be more productive than Scotland east facing. Differences in daily output obviously in winter and summer.

The area covered by a 4KW array is around 30 sq m. Bit more or a bit less depending on efficiency of cells.

There are 20m households in the UK - total area required to service all their current electrical needs is 600m sq m of panels.

The area of the UK is 242495 sq km. Each sq km is 1,000,000 sq m. So 600 sq km of surface area is required for all the photovoltaic panels.

600/242495 = 0.24% (that's right - less than 1%). 2% would be a gross overstateent and would allow room for 100% PV energy generation, replacing wind turbines, nuclear, gas etc + growth with EVs.

There are 20m households in the UK - total area required to service all their current electrical needs is 600m sq m of panels.

The area of the UK is 242495 sq km. Each sq km is 1,000,000 sq m. So 600 sq km of surface area is required for all the photovoltaic panels.

You seem to have mixed up panel area with land area.

600 sq km = 231.661 square miles

square root of 231.661 = 15.22 - so a piece of land 15.2 miles by 15.2 miles would supply all the UK's electricity needs?

Or do you mean PV panels totalling 15.2 miles x 15.2 miles would do it?

I'm not doubting what you say as such, just saying are you sure?

I suggest you read "Sustainable energy without the hot air"

By professor David J C MacKay - it's a free e-book.

And watch any of his youtube videos

<< 600 sq km = 231.661 square miles. square root of 231.661 = 15.22 - so a piece of land 15.2 miles by 15.2 miles would supply all the UK's electricity needs? >>

I think he means that if you cover an area 30km x 20km (18 x 12 miles) with PV panels, that could supply the whole country. Probably many people would object to that idea, just as they did to wind farms.

A small wind farm was built just below here a few years ago on a strip of land which already had the Ship Canal, the M56 and a power line along it and chemical plants at each end. It seemed a good choice to me, but the local nimbys objected, ostensibly because of the noise it would make (can't hear them for the motorway!) but actually because they would rather not see them.

An 18 x 12 mile area of PV panels just seems too small, to supply the UK, ignoring the intermittency, the fact that the UK is cloudy about 34% of the time, the huge amount of storage required, the electrical losses from dc to ac etc etc.

And the myth that PV panels carry on producing useable power when it's cloudy,

Why not just get on and build a dozen or so nukes?

The issue of the sun not shining is covered by storage - current main solution is batteries,

During our winter there will have to be all kinds of sources to cover for the absence of PV, especially in Scotland and further north. Scotland, of course, has hydro.

And the myth that PV panels carry on producing useable power when it's cloudy,

It's not a myth - they do produce power.

As Paul Daniels often said - 'not a lot'. I know, because I have monitored the output from mine for the last 10 years. The best days are those with passing bright cumulus clouds, which can often provide reflected light from other directions than the direct sun.

I believe the problem is this planet is over populated. I said at Christmas 2019, covid may be the solution and recognised that at my age I'd be part of the cull.

Feck civil mate. You go on calling out stupidity where you see it. And we will all be behind you.

If tehy were sere serious they would tackle the cause of the issue : population growth.

No -one mentions it.

They can't sort out easier things so no chance of that even becoming a talking point.

The climate change proposition is that unless humanity changes behaviours radically it can look forward to a future dominated by higher sea levels, more or less rain, wind, storms etc. The catastrophic concern is runaway climate change.

Yet we do nothing about population. We justify that lack of concern based upon the theory that increasing living standards will stabilise populations and possibly even fall as they have done in a few countries.

I can buy into the climate change concerns but doubt that the fundamental global adjustments will be made until things are evidently at the critical stage - eg: major cities under water through sea level rise, total crop failure as weather patterns change..

Attitudes towards population growth are at the utterly complacent end of the spectrum, yet is a matter of certainty that with (say) half the population, consumption of resources will also be roughly halved, and impacts on the global environment similarly reduced.

Solving the population problem may not wholly affect the old folk - that is just a temporary solution. Reducing the rate at which those below the age of ~40 reproduce is the key to sustainable population reduction. Oldies wll die in the fullness of time anyway!

As a fundamental imperative for all species (including us humans) is reproduction, population controls are about as plausible as China giving up coal by 2030!

If tehy were sere serious they would tackle the cause of the issue : population growth.

Absolutely correct.

If air heat pumps, they don't work under 5C so you need oil or gas or electric heating in addition. So £10k becomes £20k and they don't save CO2.

And this 'fact' is based on what, exactly, the temperature of your fridge?

Presumably these air and ground source pumps depend on an electric supply. So if the electric goes off no pump?? Also if you come home to a cold house how quick does the place heat up? Must take ages. Do you have to run the pumps 24hrs in winter. How hot would your hot water supply be? Will we still be able to run electric fires , fan heaters etc. all expensive. The gas fire will be a no like the boiler.

I do not think any of the measures to stop CO2 rising will make much difference to climate change. Governments would be far better devoting their time to mitigating what is happening. ie looking at sea defences, not building on flood plains, and taking a lot more care of the planet. Air pollution is a major problem so anything that reduces this is a plus. What comes out of the COP26 will be very interesting.

If air heat pumps, they don't work under 5C

They do, although they are less efficient. Your freezer is still moving heat into your kitchen when it is -18C inside it.

Allowing that you probably mean they won't produce enough heat, I'm betting on you being wrong, and I'm in real jeopardy because herself 'feels the cold'. We're putting an air-source heat pump on the new house we're building and we will have no supplementary heating save a 5kW multi-fuel stove in the sitting room (which we'll need for power cuts anyway!)

At temperatures above freezing, on average we expect to get 4Wh of heat out for every 1Wh we consume. At -5C we might have to put 2Wh in to get 4Wh out. And the house will be losing heat faster at the same time, so the heating cost will rise proportionately more than that of ordinary heating in very cold weather.

A number of people who haven't had a heat pump themselves have told me we won't be warm enough. I think that probably happens in some cases, when heat pumps are fitted to older properties. Our walls are designed to 0.13W/sq.m./degree K. Current building standards imply about 0.2 minimum, the difference actually being fairly trivial because houses built in the 1980's and earlier, and unimproved, can have more than 10 times the rate of heat loss. Annoying as the protesters are, they have a point about home insulation.

We have also installed a mechanical ventilation system with heat recovery (MVHR) which should retain 80% of the heat from the exhausted air.

We have very large radiators - already under the floors.

I'll let you know how it goes, even if you're right.

"""Also if you come home to a cold house how quick does the place heat up? Must take ages. Do you have to run the pumps 24hrs in winter."""

Anyone any idea about for an average house using a heat pump?

Probably better off using electric panels, apparently a company are making panels that take up less room,are more efficient and cheaper to run as they only come on when someone enters the room and take seconds to heat up

I haven`t put the company name in as it is adverting but if you check out youtube channel about electric cars they have interviewed the maker...they look good tbh better than rads imo

The 'new' infra red panels are an obsolete idea dressed up in marketing. All that's new is a techy appearance, and controls. They are radiant heathers that, instead of heating the space, heat what they radiate on. So unless you want to wait a while, by which time you'll think you are being roasted alive, you'll feel warm on the side receiving the heat and cold on the other. To heat the space with them would be expensive. And the floor will of course be clap cold in winter if nobody has been in the room since the previous day. They are no different to the old electric 'fires' with the coiled element glowing orange. Overhead radiant heaters (the glowing orange coils) are great for village halls where the space is too expensive to heat properly and people are there for an hour or three. Turn on the heaters, they get warm bonces and an hour later they beg for them to be turned off even though their feet are still cold.

As for efficiency, at the point of use they are 100% efficient like all resistive heating. But for 1kWh of heat you need 1kWh of electricity. With a heat pump, 1 kWh of power should get you up to 4kWh of heat.

You don't necessarily need to leave a heat pump running constantly but it is what people with under floor heating tend to do. Our pipes downstairs are under about 75-80mm of cement screed and an engineered timber or tiled floor (there's a layer of thermalite blocks and 90mm of Kingspan under the pipes). It will take a long time to warm up and cool down so the heating will run fairly constantly. There are lots of different loops (I think we have about 14) and zoned thermostats.

To Terry's point about retrofit, I know a builder with a 19th century house who has a heat pump and UFH that he says costs a fortune to run. I think the issue is probably that he has to run it fairly constantly but despite some insulation being added it just has higher heat loss than a modern home. It will definitely have solid walls, and as it is visibly brick outside any added wall insulation must be inside.

We haven't moved in yet - a couple of months to go on the build so could be early next year.

New houses can be built to a standard that almost eliminates the need for space heating with better insulation (walls, floors, windows, roof), correct orientation, thermal mass, heat recovery systems etc.

"Almost" as on a few days (in the UK) is it so cold that supplemental heating may be required. Options include woolly jumpers (or a "companion"!).

Heating is not the only requirement. Lighting is a low power requirement easily covered by PV with battery back up. Cooking and hot water may need more complex solutions but are feasible in new builds.

The problem is retrofitting technology. Some things are proven, simple, low(ish) cost and complexity. As properties are routinely updated. - PV panels, thermostatic heating control, sealing draughts, cavity and loft insulation, etc can be installed.

Ground and air source heat pumps are more cost and complexity. Cavity walls cannot be retrofitted into solid wall without knocking the house down (although internal or external isulation could be added).

Even at historically high cost levels, energy is still cheap. Were average energy costs £6000 pa annum, not £1500 currently, energy profligacy would change radically.

What would YOU do if:

• income tax was halved, energy prices hiked x3 through tax increases, or
• base energy of (say) £500 per houehold free of tax with any excess taxed x4. (to protect those on lower incomes)

None of this precludes action on population growth. The older you are the less impacted you will by any of this - so why bother. These actions may not produce the outcome you want - but you are giving your children and grandchildren some hope in the future.

Otherwise you may be remembered by your descendants not as "good ol' grandad" but "the b********* who caused all the grief".

Mind you with rising sea levels London will need £billions to prevent large scale flooding.

Thats coming already as some parts of the City get flooded regularly next to the Thames, they have built up too much considering they know its flooding now, but still they build Mad imo

no different to flood plains, they carry on building and don`t seem to care about the estates flooding.