Heat pumps won’t work in old homes, warns Bosch

[SteamyTea]

If, though some magic of science, you can deliver 1 kWh of hydrogen power to a boiler in a house, and it only takes 1.5 kWh to get it there, then you still only get, at best 0.95 kWh of thermal energy out of it.

Even a poor heat pump installation will deliver 2 kWh of thermal energy for every 1 kWh put in.

 

When it comes to price, the hydrogen brigade, are comparing the peak electricity price, which is based on market demand, with the lowest stored, steam reformed, undelivered, hydrogen price.

 

Here is a government report on hydrogen prices

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/1011506/Hydrogen_Production_Costs_2021.pdf

[Iceverge]

3 hours ago, ProDave said:

I believe the new EPC system being talked about will be based on kWh per square metre per year of energy use.

 

 

Tying it to m² has little benefit I would argue, just more unnecessary complication. 

 

The vehicular analogy would be an "A" rated lorry @ 10MPG  or 0.0025Gallon/Mile/Tonne

 

 Vs

 

 a "B" rated hatchback at 50MPG or 0.013Gallon/Mile/Tonne. Twenty times worse on the face of it. 

 

The EPC rating for houses gives the impression that if we all drive efficient 18-wheelers our problems will go away. 

 

In fact it promotes the building of larger houses as on a per m² basis as they're easier to achieve a low kWh/m2/annum than smaller houses. This will increase overall energy use. 

 

3 hours ago, JamesPa said:

Depends what the objective of the EPC is.  If its the public objective of incentivising reduced carbon emissions, then the offset due to the solar production is, at least to an extent, valid

 

Adding solar production to balance high winter losses caused by poor building fabric exacerbates emissions until we have some viable interseasonal energy store. 

 

Take house 1, a glass masterpiece with poor form factor and average glazing etc. Uses 10000kWh per annum for space heating but thanks to a generous solar array generates 8000kWh in the summer. 

 

House 2 has no PV but is super insulated. 2000kWh/ year space heating.  They have the same EPC rating but there is an 8000kWh difference in bought in winter electricity say at 50% fossil fuels means the solar PV house would use 4000kWh more of FF energy. Bonkers. 

 

Houses should be rated at kWh/annum in my opinion. 

 

Keep renewables out of it and offer proper feed in tariffs for that part of the game. 

 

Similarly specific heat demands out if the picture. It's counter productive. 

 

 

[SteamyTea]

5 minutes ago, Iceverge said:

In fact it promotes the building of larger houses as on a per m² basis as they're easier to achieve a low kWh/m2/annum than smaller houses. This will increase overall energy use. 

That may be a useful thing though.  We do make the smallest homes in Europe.

 

Edited March 15, 2023 by SteamyTea

[George]

When I found out hydrogen flames are invisible I figured piping it into homes might not be a good idea.

[JamesPa]

40 minutes ago, Iceverge said:

Adding solar production to balance high winter losses caused by poor building fabric exacerbates emissions until we have some viable interseasonal energy store

Yes and no.  Whilst penetration of solar remains low, any excess pv generation in one dwelling offsets, with high efficiency, consumption in neighbouring dwellings.

The equation changes once pv becomes more commonplace.

 

Having said that I agree that realistic export tarrifs would be a better mechanism to incentivise the necessary behaviours (and would also reduce the artificial incentive to fit batteries).  We are heading there, octopus are currently offering 15p/kW, 40% of the import tarrif.  If this percentage were to double (say) then the market would truly incentivise community level energy self sufficiency.

[sharpener]

47 minutes ago, George said:

When I found out hydrogen flames are invisible I figured piping it into homes might not be a good idea.

 

It's a wonder that piping flammable gas into homes is as safe as it is. Now that open gas fires are less common the flame visibility is not important except that hysdrogen requires new flame failure detection methods in boilers. More important is that CO poisoning is not possible.

 

The recent and seemingly more frequent incidents of property demolition by gas explosion probably don't have much to do with the exact constiution of the gas. Perhaps more likely due to tampering with the supply e.g. bypassing the meter.

 

45 minutes ago, JamesPa said:

Yes and no.  Whilst penetration of solar remains low, any excess pv generation in one dwelling offsets, with high efficiency, consumption in neighbouring dwellings.

The equation changes once pv becomes more commonplace.

 

True. As you say, the equation changes once the renewables displace more than just the load-following CCGT generation. Large-scale nuclear not much help here, SMRs might be a bit better as they were developed for nuclear submarine propulsion. But then again they have in the past been plagued by thermai stress/cycling issues so am not holding my breath. And the RR SMR concept is not really "small" anyway.

 

Edited March 15, 2023 by sharpener

[Temp]

43 minutes ago, George said:

When I found out hydrogen flames are invisible I figured piping it into homes might not be a good idea.

 

Could they fix that by adding something? like they do to make gas smell bad.

[TW9]

37 minutes ago, Temp said:

 

Could they fix that by adding something? like they do to make gas smell bad.

Different chemicals depending on the time of year? Red flames for Christmas. Green for St Patrick's day. A cheery yellow in summer.

[SteamyTea]

27 minutes ago, TW9 said:

Different chemicals depending on the time of year?

What colour for Easter, dripping blood and nails?

[ReedRichards]

5 hours ago, Post and beam said:

Except that it can. The physics of the Molecule mean that it is almost impossible to store it without this rate of loss. Metal pipe is not the 'high tech' required  to contain it.

The consumer wont pay for this loss and if a cheap and easy method of plentiful production were possible then who would care anyway.

So the 0.7% per day figure represents a lower bound on real world leakage rates.  The physics of the molecule means that a pipe that leaks methane at a trivially small rate will leak hydrogen a lot more readily.  Nobody would care unless the leaked hydrogen builds up and then causes explosions.

[ProDave]

18 minutes ago, ReedRichards said:

So the 0.7% per day figure represents a lower bound on real world leakage rates.  The physics of the molecule means that a pipe that leaks methane at a trivially small rate will leak hydrogen a lot more readily.  Nobody would care unless the leaked hydrogen builds up and then causes explosions.

Well the "environmentalists" that are proposing hydrogen as a green energy source, damned well need to start getting interested in the leakage rate and the harm the unburned hydrogen will do as a greenhouse gas.

[Post and beam]

20 minutes ago, ReedRichards said:

So the 0.7% per day figure represents a lower bound on real world leakage rates.  The physics of the molecule means that a pipe that leaks methane at a trivially small rate will leak hydrogen a lot more readily.  Nobody would care unless the leaked hydrogen builds up and then causes explosions.

I might not have explained myself very well. A pipe network containing methane that does not have any damage, and therefore no leaks will not lose any of it. Hydrogen will leach out of the pipework at the .75/day through the metal.

Of course if it builds up in a particular way and explodes it would be bad.

What i meant was, this loss through the fabric, being upstream of your meter would not be your problem from that point of view as you would not be directly paying for it.

If you had a Hydrogen powered car full of fuel and you dont do many miles then you are paying to let it go.

[Post and beam]

2 hours ago, George said:

When I found out hydrogen flames are invisible I figured piping it into homes might not be a good idea.

It would only be a small % Hydrogen. So not much change to the flame from what you would see today.

[Post and beam]

1 hour ago, sharpener said:

SMRs might be a bit better as they were developed for nuclear submarine propulsion.

What is an SMR?  As an ex submariner that used to live next door to a Reactor i dont know this term.

[TW9]

11 minutes ago, ProDave said:

Well the "environmentalists" that are proposing hydrogen as a green energy source, damned well need to start getting interested in the leakage rate and the harm the unburned hydrogen will do as a greenhouse gas.

It seems to be mostly oil companies promoting hydrogen, not environmentalists.

[sharpener]

Small Modular Reactor (as defined here and proposed here - mentioned in the budget so will be in tomorrow's papers)

[IanR]

1 minute ago, Post and beam said:

It would only be a small % Hydrogen. So not much change to the flame from what you would see today.

 

The "up to 20% hydrogen" mixed into the natural gas supply is proposed as a stepping stone by the lobbying gas industry, and will increase CO2 released, not reduce it. 20% Hydrogen = only 6% less gas burnt due to lower hydrogen energy density at current natural gas pressures + green hydrogen won't be used initially, at best it will be blue, which leaks more methane than the CO2 saved from using the hydrogen.

 

The lobbyists say, it will develop the market for the green hydrogen to encourage the needed investment for green hydrogen generation and upgrade of the gas network infrastructure, ready for the 100% green hydrogen heating future they are hoping for.

[Levo]

11 hours ago, nod said:

So true 

 

We had a refurb job in Liverpool Every house fitted with a Mitsubishi HP

Everything supplied and fitted for free

Every day there was people Heras sing the plumbers complaining that there bills had gone up and there rads weren’t heating up 

The heating company that had retrained half there staff (3 day course) Had already stated that there would be issues Yet the government still pours our money into these schemes 

 

Im not saying that all of us should get a HP for free While it would be nice The cost should be similar to fitting a gas boiler 

PV is just as bad with outrageous claims of slashing bills Then saddling home owners with long term debt 

The ambulance chasers will move from PV to HPs next 

The problem with AirSource HP is that as it gets cold, the efficiency suffers, so you are not able to supply the quoted heat while at the same time your need is increasing. So the system needs to be sized to be able to deliver the required energy at -15C. Otherwise you are toast, well I mean frozen!. I am not sure how realistic the cold temp figures the manufacturers are quoting. I know one needs to take any claim with a pinch of salt but besides that, what if their figures are for somewhere with drier air (lower humidity). That would delay any ice forming on the fans/radiators, therefore improving efficiency. That wouldn't apply to your usual UK weather with near 100% humidity almost every night throughout the winter...

As an example, I have friends with a new (less than 10 year) house. I live in a ~50 year old house (maybe 30% smaller than theirs). Assuming their house is much better insulated, I figure they should need less energy to heat their house and at worst, the same amount of heat as we do. In our house we only turn on some of the downstairs radiators, around 5KW max output, and we never have any issues with not being warm. If anything the rest of the lot complain I keep the TV room too warm. I changed all the radiators recently, so know their heat output.

My friends on the other hand keep complaining they are never warm on a cold night. So, their system appears not to be able to supply 5 KW. Their outside unit is rated at 15KW!!!

So to me, Air source HP is good for mildly cold days but you need some backup for the real cold days. Best solution as the others suggested, install couple of A2A units which will do a lot of the heating and at peak times, use the boiler to back them up. Problem solved for 2-3 grand and fully prepared for that cold day.

Edited March 15, 2023 by Levo

[SteamyTea]

23 minutes ago, ProDave said:

Well the "environmentalists" that are proposing hydrogen as a green energy source

I don't think many, genuine, environmentalist, take hydrogen seriously.

 

As well as the storage problems, on top of the high energy costs to produce it, there is also hydrogen embrittlement of metals to take into account.

Gas boilers may have to be replaced a lot more often.

[IanR]

9 minutes ago, Levo said:

 So the system needs to be sized to be able to deliver the required energy at -15C.

 

Not in Berkshire you don't. I can't imagine there're many days a year where the average temp is less than -3°C.

 

What's more important is that you accurately calculate the property's energy losses, at the correct temperature delta.

Edited March 15, 2023 by IanR

[SteamyTea]

4 minutes ago, Levo said:

The problem with AirSource HP is that as it gets cold, the efficiency suffers, so you are not able to supply the quoted heat while at the same time your need is increasing.

As you say, they need to be properly specified.

Most heating systems, in most houses, cannot cope with extreme cold anyway, why the sales of electric heaters goes up when we have a cold snap.  As does the amount of electricity produced.

So in reality, there will be little difference.

 

Burning a methane/hydrogen mix in an undersized boiler will not help any because it is hydrogen.  Same problem, just different gas mix.

[Roger440]

Id suggest that Bosch's statement is driven as much by the wish to avoid reputational damage as wanting to sell something else.

 

Installing in inappropiate and poorly designed systems, with the inevitable outcomes, has big potential to damage the brand.

[JamesPa]

5 hours ago, JamesPa said:

'According to hellohydrogen.com, which is the first hit I got when I googled 'how to make hydrogen', there are two ways to produce hydrogen.  The first is through electrolysis, which uses renewable power to split hydrogen from water. The second is splitting hydrogen from natural gas and storing the remaining carbon dioxide away

I haven't followed the hydrogen debate until now, but I'm getting interested.  As I understand it the advocates are suggesting we use electricity to generate hydrogen from water, yet it takes more electricity than the energy you get from burning the hydrogen.  How can that ever be a sensible way to distribute energy?  

 

If I understand it right they are taking us for fools.

 

What did I miss?

[Post and beam]

1 hour ago, sharpener said:

Small Modular Reactor (as defined here and proposed here - mentioned in the budget so will be in tomorrow's papers)

Ta. They used to call them PWR on the boats then. Pressurised water reactors. Perhaps a different design now, it was a long time ago

[Roger440]

8 hours ago, JamesPa said:

Thats a fair comment I concede.  However I do know people who genuinely couldn't afford it and you also have to consider the almost inevitable effect on the poorest members of society if landlords were forced to upgrade at their own expense.

 

True.

 

The UK GDP is about £M600,000.  We have 23M houses.  So if every house cost 25K to upgrade the total cost would be very roughly equal to GDP.  However this is clearly a gross over estimate, we really do need a realistic estimate of total cost to make headway in this argument!

I completely agree with the first and last part of this sentence.  The middle part is more challenging however, because impediments to property sale, become impediments to workforce flexibility, which is a drag on the economy that we do not need. 

 

This is a macro-economic and social challenge as well as a micro-economic one.  Some of the the best economists, together with some of the best scientists/engineers, should be figuring out the realistic options (for which they will need some realistic figures).  I would love to believe that, somewhere in Government, there is a working party doing just that.  

 

 

Whilst all this talk of insulating existing housing stock is all very well, there are some real world problems to overcome.

 

Given that few people understand old houses, any such program i gurantee will result in a bunch of new, expensive problems.

 

There will be air quailty and mould/condensation problems.

 

There will be all sorts of damp related issues with the structure/walls.

 

As someone who has just bought his 4th old house, its patently obvious that the "trade" by and large dont have a clue. (join some traditional proprty groups and weep at the cobstant "undoing" of inappropiate works)

 

If you could properly insulate an old solid wall house, properly, without creating a load of new issues, for £25k, let me know who they are? Let me tell you, that isnt going to happen. Even if you could get a design, which, by necessity will be very much a "per house" excercise, a program of work, the cost of doing, which again will involve moving out, will far exceed £25k.

 

To be honest, i will struggle to do mine for £25k with me doing ALL the actual work and no design costs. And that doesnt include the actual heating system.

 

Meanwhile, out in the real world, the insulation solutions wont be designed correctly, if at all, the standard of retrofit will be woeful, so wont achieve anything like its stated aim, there will be damp issues galore. And there are not enough people to actually undertake a project of this scale.

 

Theres no possibility of large scale ASHP fitment, never mind tacking on insulating the majority of the UK housing stock

 

It wont happen, cant happen.

 

If some system comes in mandating an EPC of x prior to sale, all that will happen, just like building control, you will be able to buy the certificate you need.

 

Keep on daydreaming chaps(esses)

 

In my case, they will need a court order before i let a bunch of government funded cowboys anywhere near my house, and even then id likely refuse.