Electricity generation. The pros and the cons.

[culzean]

Constraint payments are the bedrock of solar and wind,  and required because they are so unreliable with huge variations in their output hour by hour.     

https://news.stv.tv/scotland/electricity-customers-paid-windfarms-1bn-to-switch-off-turbines?top

Why are these payments necessary? Surely it's just the payment system that is wrong.
If somebody runs a taxi firm they can't claim compensation if their taxi is surplus to requirements.
If there was a way of storing the extra energy --in batteries, in the form of hydrogen or in potential energy, there would be no need to shut down excess production in times of plentiful wind and there would be no need to rely on fossil fuels as a backup.

Nobody is going to spend money to build a wind or solar farm unless they are guaranteed a payback because everyone knows how fickle the wind and sun are. So as a bribe the government worked out a payment scheme that would not leave the farm owners out of pocket, whether or not they fed power to the grid.  I have read articles that said 'there was a perverse incentive for farm developers to build the farms in out of the way places that did not have a good connection to national grid, because they got their money whether the farm fed electricity to the grid or not,  and if they produce too much power for the link to grid then the farm owners shrug and say 'not our fault' and put their hand out for constraint payments.  The same thing happened with Hinckley Point nuclear ( LOL ) when government had to promise developers ( Chinese and French ) an exorbitant cost per KWh when site was producing ( another LOL here I think ).   As I write wind contribution to grid continues to drop and of course at this time of year solar is in chocolate teapot category.... Good old renewables,  give you the least when you need it the most...

[DERMOT]

@ culzean  within Europe we are close to zero subsidy wind.
https://www.en-former.com/en/the-era-of-subsidy-free-offshore-wind-begins/

Wind is cheaper than coal, and in middle East solar is coming in At less than oil.

For wind in GB. Last year was 24% average.
Surely being self sufficient has to be a goal for uk.
Solar in uk must be marginal, but it complements wind.

[culzean]

Our electrical supply has never been more fragile, due to intermittency of the wind and Sun, and no real reliable base load supply... China and India must be laughing at our gullibility.  The reason gas prices are rising is that we are using it to generate electricity when renewables do not perform, and stupid UK closed down our large gas storage facilities,  we have about four days reserve......shocking

List of coal fired power stations in various countries, Germany is high up on the list with 74, despite having a green halo and turning up at Flop26 and promising the world.

https://www.statista.com/statistics/859266/number-of-coal-power-plants-by-country/

[culzean]

Sort of applicable to this thread, as with heatpumps and their low temperature output the government is saying that the insulation on homes will need improving ( not easy to do on a house that is already built ).  Years ago I boarded over the lofts in our house, but in the process had to take some glass fibre insulation out, the stuff that was lying across the joists at right angles to them, and made the loft unusable because you could not see the joists to walk on them.  I left the 100mm of insulation between the joists and boarded over with chipboard and left the removed insulation rolled up in the corner - some in black binbags ( well binbags are not what they used to be,  left on their own for a few years modern binbags crumble away and let the contents spill out everywhere ). Armed with overalls, goggles a mask and gloves I set about getting the wayward fibreglass into bags again ( 20 bags of tightly rolled fibreglass to go to tip ).   I got to wondering what the ideal amount of loft insulation was,  and where the 'point of diminishing returns' was.  See attached PDF.. it seems that after 150mm the gains are miniscule, even after 100mm the gains are dropping off rapidly and I reckon 100mm trapped between ceiling plasterboard and chipboard would be about 150mm worth.    The 'retrofit cavity wall insulation' boys have been around our area 2 to 3 times in last 3 to 4 years, the houses are about 20 years old and already have cavity insulation  in the form of battens of expanded polystyrene 50mm thick ( filling half the cavity ) and are pretty energy efficient,  out of 10 houses in our cul-de-sac 3 had the wall insulation (not us,  I had my doubts where the blown in beads would go, with half the cavity already occupied and open airbricks ) - years ago a guy I worked with had the cavities filed in, and within 12 months had mould on his walls inside the house - he had to buy a dehumidifier and run it 24/7 to control the damp.  Strangely our neigbours who did have the insulation fitted have seen no reduction in heating bills,  but their houses are damper than before.   Food for thought    The last guy who came round promoting cavity insulation actually said that unless your windows have trickle vents fitted they cannot insulate the cavities,  so maybe they have had problems with dampness  seems to me that having trickle vents in windows open would cause more heat loss from building than having cavity insulation would save.

[madasafish]

Building regs say you MUST ventilate with insulation...

[culzean]

Building regs say you MUST ventilate with insulation...

Exactly - to prevent dampness within the structure, it is also required to have a 10mm gap under internal doors... so you stop the heat going out through walls and then blow more heat out with wind blowing in and around the house.   We run a humidity controlled de-humidifier set to 50 % - reckon the dryer your walls are the better they insulate.

[springswood]

A single anecdote is obviously useless to prove anything about the worth of insulation. If it weren't I could disprove these opinions with my experience.

Rather than insulation being 'not easy to do' it took one person one morning to insulate the wall cavities in my 110 year old brick and stone faced Yorkshire terrace. The result was around a 20% reduction in heating costs with no damp problems at all and the bonus that the tendency for the front rooms to get too warm on summer evenings as the heat soaked through is also better.

So far this autumn I've only needed my central heating on once.

[culzean]

A single anecdote is obviously useless to prove anything about the worth of insulation. If it weren't I could disprove these opinions with my experience.

Rather than insulation being 'not easy to do' it took one person one morning to insulate the wall cavities in my 110 year old brick and stone faced Yorkshire terrace. The result was around a 20% reduction in heating costs with no damp problems at all and the bonus that the tendency for the front rooms to get too warm on summer evenings as the heat soaked through is also better.

So far this autumn I've only needed my central heating on once.

Bear in mind our fairly new houses already had insulation block inner walls with 50mm of expanded polystyrene bats filling half the cavity and still enough cavity to act as a break to stop any water from outside wall crossing the cavity.  Completely filling the cavity means water can get across.  Retro-cavity insulation is well know to be patchy and liable to settle towards lower part of cavity,  which can block airbricks.  There is an organisation set up to deal with the claims from people who have had problems after retro-cavity insulation installation.  Installers are supposed to survey the cavity with a borescope before installing insulation that was never done for the ones in our street.

https://www.moneyadviceonline.co.uk/claims/cavity-wall-claims.html

[Jocko]

The house I have just moved into has cavity wall insulation. The windows do not have trickle vents but there are airbrick type vents in both bedrooms. There are no dampness or condensation issues in any rooms The internal doors have a 2000+ mm gap beneath them all (we have cats so the doors are all left open to allow them free run off the house).

[richardfrost]

The internal doors have a 2000+ mm gap beneath them all

Ha ha. You had me there for a moment.

My youngest has bought a mid terraced brick faced house with retro fitted cavity wall insulation. The air bricks are blocked up and he has no trickle vents in the windows. They have terrible damp/mould issues in the back bedroom and the bathroom where 'the sun don't shine'. They have treated it and have to leave the windows open more often than not. It really does defeat the purpose of the insulation having to do that, or run a dehumidifier. I will buy him some new windows in a year or two which should hopefully sort that out.

[Jocko]

When I was decorating I took the internal vent covers off to hang the paper. The air bricks were not totally blocked but there was some insulation in the cavity which I just removed. Poked clear the odd blocked hole.

[richardfrost]

Might have to do something similar if the mould comes back. Didn't help that they had their tumble drier in the back bedroom for a while and are not generally in the habit of opening windows.

[culzean]

The internal doors have a 2000+ mm gap beneath them all

Ha ha. You had me there for a moment.

My youngest has bought a mid terraced brick faced house with retro fitted cavity wall insulation. The air bricks are blocked up and he has no trickle vents in the windows. They have terrible damp/mould issues in the back bedroom and the bathroom where 'the sun don't shine'. They have treated it and have to leave the windows open more often than not. It really does defeat the purpose of the insulation having to do that, or run a dehumidifier. I will buy him some new windows in a year or two which should hopefully sort that out.

Running a dehumidifier actually adds heat to the house by recovering latent heat of condensation ( recovering the energy used to turn the water into vapour in the first place ), as well as drying out the walls to make them much better insulators.  So just like a heatpump you get up to 1.5 x the energy back that it takes to run the compressor.  I have noticed in our house that the room with the dehumidifier in it feels warmer than the other rooms.  A dehumidifier is also the cheapest way to dry clothes that have been spin dried, just put clothes on a rack, turn the humidifier down to 40% close the door to the room and they dry  pretty quick, most dehumidifiers actually have a timed 'laundry' setting where the unit will run non-stop for a period of 1 or 2 hours and then shut off.   As a bonus, even without heated towel rails the towels dry quickly, and the bedclothes have a nice dry feel to them.  I you have an allergy to dust mites the dehumidifier also controls them, as at 50% humidity or below they cannot breed ( that was the reason I got our first dehumidifier many years ago ).

https://www.meaco.com/products/meacodry-dehumidifier-abc-range-20l

http://www.iwilltry.org/b/heat-your-home-with-a-dehumidifier/

[Kremmen]

I run a desiccant dehumidifier in the garage.

A normal one wouldn't work as the temperatures do drop out there. It can drop the humidity out there from sometimes over 90% to 70% in about an hour, sometimes less.

Don't need one for the house as I've got a whole house warm air system.

[springswood]

In a lot of ways I think the problem with retrofitting insulation is ultimately an economic one. The technology has been there for decades and it has always been a cost effective. So I've puzzled, for more than 30 years now, over why isn't it done? The answer I think is, it's not profitable enough. The people with serious money in this world expect a certain rate of return and so the money only goes to where you can get that return.

Some of it is to do with the way people talk about it. Often the value of insulation is expressed as a pay back period. Roughly 3 years for draught proofing, perhaps 10 for cavity wall insulation, 25 for double glazing, say. I think it looks very different if you express it as a return on investment. 33%, 10% and 4% respectively.

It also comes down to marketability. Daniel Kahneman, who got the Nobel prize for economics in 2002, put it in his book Thinking Fast and Slow I believe (and I keep meaning to get round to reading it). Slow thinking is the explicit rational argument that shows insulating your home is a no-brainer. Unfortunately purchasing decisions are generally made by Fast thinking. So double glazing has an immediate appeal, and it's the one aspect of insulation that is marketable and has a fairly solid industry and widespread respect. The rest doesn't give you anything immediate so is very hard to sell and the materials are essentially so cheap it has to be sold on price. The result is often poor quality work and bit of a field day for cowboys. In general a bad reputation for the insulation.

So I quite agree badly installed insulation often causes damp problems. In fact in the four years since I had my walls done I've had two people come to the door offering to fix any damp problems. Which means there's another level. An off-shoot industry making money out of fixing the bad work. And incidentally exacerbating the bad reputation.

Which doesn't alter the fact that getting insulation well installed is great value. And going to get greater value as energy costs inevitably rise.

PS
I completely agree about dehumidifiers. I've been using one to dry my washing for around 10 years.