Boosting energy efficiency status of buildings to combat climate change - what does it take?

GreatApe

I take back what I said above, thermal heating the mass of the house isn't a good idea and just adds complexity when we can just limit these electric heaters to 1 KW during non windy winter evenings.

Sure this might add 20GW to backup capacity needs costing maybe £20 billion but at the same time you rid the housing stock of having to buy new boilers at £1k a pop every 10 years (cost of £30 billion every 10 years)

And this is the worse case assuming no significant battery storage is in the grid and no EVs.
Both of those might allow less CCGT backup needs

This needs very simple tech. Smart resistance heaters which anyone can make
And for regulators and the grid and power companies to bring out heating tariffs and normal electricity usage tariffs. With the normal usage paying for all the grid and advertising and whatever costs and the heating tariff being charged just the marginal cost of generation.

Deploy first in Norway and/or Sweden and observe results. Since they are more or less fully resistance electric heated it should show up as lower electricity consumption and would be quick to deploy and test. Could be proven and tested in as little as one year. (In other countries there would be potential problems as you have to build out the additional capacity for switching heating to electricity but those countries are already electrically heated so no additional infrastructure needed this smart heating should show up in less energy demand and less grid congestion)

GreatApe

frozen_wastes wrote: »

This is why decarbonisation of our heating systems is going to take a while.

Yes and no

To decarb the grid is going to take some time
To decarb heating could be very rapid
You just ban fossil fueled power heating and let buildings convert to electrified heating as their boilers break down

Since most boilers will not last more than 15 years you would have a rapid switch

The question is can offshore wind power be built over this same 15 years to power the now electrified heating rather than CCGT powered. I think the answer is probably yes.

frozen_wastes

GreatApe wrote: »

The solution is this

£50 smart heater per room (should be possible)

Your energy company charging you only 8p a unit and just limiting your usage to not be during 5-8 pm on winter evenings.

If the smart heaters by virtue of only heating rooms in use save you another 25% that means you would only need 6,000 units of electricity

Smart heaters probably aren't the answer here. The problem is thermal mass. If I just heat the room that I'm occupying and walk into another room, and have the heaters instantly switch over to the other room, then you're going to have to suffer from being cold. There's no such thing as instant heat, when it comes to domestic electrical heaters (especially in bathrooms, you only occupy that room for just a few minutes).

Therefore it is necessary to have some degree of whole building heating in order to not only maintain comfort, but also to keep the building fabric above the local dewpoint (damage from penetrating damp and interstitial condensation certainly is expensive to remedy!).

However there are such things called solid state heat pumps: https://phononic.com/. They are very niche applications right now, but you could look here for insights into thermoelectric developments. They can certainly address to matters of maintenance free operation, but they aren't terribly efficient right now compared to traditional heat pumps.

Now back to the 8p/KWH idea. It is true that the wholesale price of electricity is much cheaper on average, but it's also an extremely volatile price minute by minute. I believe it's also a price paid to the generators only.

The rest of the electricity system is not built into those wholesale prices - transmission, distribution, and of course billing administration. These costs still need to be paid for. Billing admin alone is a fair chunk of the price of your electricity (I think 20% of the top of my head).

With that in mind, bear in mind also that the electricity market makes up only 20% of final energy demand. 100% renewable energy (not just electricity) essentially entails that everything is electrified. The heating sector is supplied by natural gas and that makes up about 40% of final energy and combustion of petroleum products (mainly for transportation) makes up the remaining 40%.

With those sectors to be electrified (keeping in mind the 2nd law of thermodynamics), we won't need to expand electricity generation 5 times over, but certainly it has to probably expanded to twice it's existing size in terms of generating capacity, with targeted investments in transmission capacity. That's not going to happen in the next few years, nor does it need to, but certainly over a 15 year horizon that is certainly "Watt it takes". All that needs to be financed, and 8p/KwH is still something that I think will be confined to dead of night as far as retail prices is concerned.

GreatApe

frozen_wastes wrote: »

Smart heaters probably aren't the answer here. The problem is thermal mass. If I just heat the room that I'm occupying and walk into another room, and have the heaters instantly switch over to the other room, then you're going to have to suffer from being cold. There's no such thing as instant heat, when it comes to domestic electrical heaters (especially in bathrooms, you only occupy that room for just a few minutes).

Therefore it is necessary to have some degree of whole building heating in order to not only maintain comfort, but also to keep the building fabric above the local dewpoint (damage from penetrating damp and interstitial condensation certainly is expensive to remedy!).

However there are such things called solid state heat pumps: https://phononic.com/. They are very niche applications right now, but you could look here for insights into thermoelectric developments. They can certainly address to matters of maintenance free operation, but they aren't terribly efficient right now compared to traditional heat pumps.

Now back to the 8p/KWH idea. It is true that the wholesale price of electricity is much cheaper on average, but it's also an extremely volatile price minute by minute. I believe it's also a price paid to the generators only.

The rest of the electricity system is not built into those wholesale prices - transmission, distribution, and of course billing administration. These costs still need to be paid for. Billing admin alone is a fair chunk of the price of your electricity (I think 20% of the top of my head).

With that in mind, bear in mind also that the electricity market makes up only 20% of final energy demand. 100% renewable energy (not just electricity) essentially entails that everything is electrified. The heating sector is supplied by natural gas and that makes up about 40% of final energy and combustion of petroleum products (mainly for transportation) makes up the remaining 40%.

With those sectors to be electrified (keeping in mind the 2nd law of thermodynamics), we won't need to expand electricity generation 5 times over, but certainly it has to probably expanded to twice it's existing size in terms of generating capacity, with targeted investments in transmission capacity. That's not going to happen in the next few years, nor does it need to, but certainly over a 15 year horizon that is certainly "Watt it takes". All that needs to be financed, and 8p/KwH is still something that I think will be confined to dead of night as far as retail prices is concerned.

Firstly it would be useful to state that resistance electrical heating works and is affordable we can look at Sweden which is more or less 100% heated that way

While the price for electricity will always be more than the price for natural gas, electricity is more efficient 100% vs typically 70% and has much lower maintenance inspection capital and replacement costs. Those alone probably run at £200 per year for a gas fired system

For a 10MWh gas heat demand @ 4p = £400 + £200 costs = £600 annual
7MWH electricity costing £600 would be 8.6p a unit

So with no change in habits for a 10MWh gas demand home you could replace it with 7MWh electricity demand at the same cost if electricity was 8.6p a unit


Re transmission capacity for electrified heating and electrified transport

Transport will be no issue on the transmission system. Self drive EVs will just charge up at the local super charger which will be located close to the HVDC system so will add to the national grid but not the distribution network or can be built in spots of excess distribution capacity.
I think we could go to 100% electrified transport with very little additional transmission or distribution costs.

Heating will probably need distribution upgrades but not as much as imagined and the per unit cost will be lower than now

GreatApe

frozen_wastes wrote: »

With those sectors to be electrified (keeping in mind the 2nd law of thermodynamics), we won't need to expand electricity generation 5 times over

The UK would need

335 TWH for electricity (2018 figures)
~150 TWh to electrify all land transport
~200 TWh to electrify heating with heat pumps ~400 TWh to electrify without heat pumps. Lets use the mid point of the two and call it 300TWh

Total 335 + 150 + 300 = 785 TWh

UK in the very recent past was using 400 TWh of electricity
So we need to roughly double the amount of power through the grid not 5 x

GreatApe

France is an interesting case study

They have electrified about 30% of all their heating needs (not just homes but all heating needs offices shops industrial processes) and the majority of new builds are electrically heated

They have a semi smart system which will just improve in time

Tempo is the third option, which is also very economic if used properly. We chose this option in our previous house. The year is broken up into blue, white and red days. Power supply is between 9-36 kVA.

Blue days are the cheapest; there are 300 blue days in a year.
White days are the next highest tariff; there are 43 white days in a year.
Red days are the highest tariff, there are 22 red days in a year, and occur between 1st November and 31st March, but not on Saturdays, Sundays or fete days.

Each day is then broken up into 2 tariffs, so there are 6 different prices for a kWh.

To use tempo, you need a small box supplied by the energy company which is plugged into a power socket. At 8pm each day, a colour will light up on the box, advising the colour code for the following day starting at midnight. The choice of day colour is made by the meteo and the electricity supply company.

If the colour code is red, then you know the following day is going to be a very cold day – the idea being that people will run their electric heaters (especially) to keep themselves warm! It has been known for there to be 4 or 5 consecutive red days in extremely cold weather.

GreatApe

This is very interesting EDF TEMPO tariff 2010



2019 prices not as attractive but sill bests uk prices 90% of the time
€ 0,1105 € 0.1331 € 0.1256 € 0.1560 € 0.1325 € 0.5414

michaels

GreatApe wrote: »

The UK would need

335 TWH for electricity (2018 figures)
~150 TWh to electrify all land transport
~200 TWh to electrify heating with heat pumps ~400 TWh to electrify without heat pumps. Lets use the mid point of the two and call it 300TWh

Total 335 + 150 + 300 = 785 TWh

UK in the very recent past was using 400 TWh of electricity
So we need to roughly double the amount of power through the grid not 5 x

Hopefully we will also be able to time shift demand so rather than running say between 50gwh and 20gwh over a daily cycle we could use the dip times when there is excess generation and distribution capacity rather than needing to increase overall capacity by so much.

zeupater

frozen_wastes wrote: »

... So what do others think on this forum? What does it take, economically speaking, to make building upgrades to EPC A ratings worthwhile and economic?...

Hi

Make a spreadsheet of what you can do, investigate the potential energy savings for each item (which will include relative heat-loss calculation & comparison), find out what each will cost and perform a simple ROI exercise on each sub-project ...

From this rank the improvements by payback period then address what turn out to be the cheapest & easiest small projects that have the fastest returns first ... forget the big investments until later as savings from all of the small projects may have a knock-on effect which makes them even less attractive ... the sooner you start the better, but be prepared to make it a long-term incremental process ...

Yes, you will find that following 'best practice' isn't good enough & when you think that you've finished insulating, revisit the basis of that assumption & go for more incremental savings ...

Regarding EPCs ... well, they're based on a set of completely dumbed down assumptions so that poorly trained & inexperienced assessors can quickly tick some boxes .... for example, our house is at the top end of the 'B' band before allowing for areas that the assessor effectively refused to confirm or isn't included as an option within the RdSAP process, so that excludes the floor-slab insulation (assessor wouldn't lift the corner of a carpet & check!) as well as a number of hi-tech insulation materials we have that the RdSAP/EPC process doen't specifically recognise - add to this the system's inability to recognise shared/mixed heat-sources and you can start to appreciate the effect on the occupancy assessment & the rubbish that that comes up with! ....

In our case, the U/F insulation alone would push the property into band A, but that's not really the issue, it's really one of a process that's been dumbed down to a level where anything 'out of the ordinary' or not easily checkable is immediately discounted as if it doesn't exist .... but then again, would we all be happy to receive a four-figure detailed assessment bill?!

By the way, we don't have triple glazing etc as all the other improvements mean that the incremental energy saving can't be justified ...

HTH
Z

GreatApe

michaels wrote: »

Hopefully we will also be able to time shift demand so rather than running say between 50gwh and 20gwh over a daily cycle we could use the dip times when there is excess generation and distribution capacity rather than needing to increase overall capacity by so much.

Electrifying Transport will not be difficult on the grid or the distribution networks especially with self drive EVs

A town of population 250,000 will have perhaps 30,000 self drive EVs which can be charged at 15 different super charger sites in town.

Each super charger station would only need a 3 MW connection to the local network
These super charger stations can be built close to a higher voltage AC point and the losses would be closer to 3% rather than 7-10% to your home so more energy efficient too

These supercharger stations can also purchase electricity at cheaper industrial rates of maybe 10p a unit rather than 15p a unit with the difference paying for the upkeep of the super charger network.

You can even own your own self drive car and it can go supercharge itself so this gets around the need/worry about home charging especially for people who live in apartments. It also totally eliminates range problems because everywhere will have a super charger within a mile or two

This mass deployment of super chargers could also allow lower range EVs to be viable and lighter too with 150 mile range EVs perhaps greatly outselling 300 mile range EVs (of the same model) assuming the packs (not just the cells) cost $200/KWh this might save $6,000

$6,000 doesn't sound a lot for a $40,000+ model 3 but the lower segments where a new car costs £15,000 (£12,500 before VAT therefore ~$16,000) the $6,000 difference is significant