Any thoughts on the future of heating?

I had my gas combi 'serviced' yesterday and was quizzing the engineer about what the future might hold after the gas boiler ban comes into effect.

Apart from finding out that he was clueless! (Suggesting I could run an electric combi from the existing ring and advocating the use of ASHP's), I wondered what people's thoughts were?

I live in a South Wales town, where a good proportion of the housing stock are small 2-3 bed Victorian terraces, with solid stone walls.
Adding internal insulation or a large electric heating setup would take up a good proportion of the available space.
Electric combi's (as many have mentioned on this forum) are prohibitively expensive to run (although with gas prices rising, the balance may change).
Air source heat pumps would be a no-go due to the lack of existing insulation and the noise would probably be unbearable if everyone on the terrace had one!

The best compromise would seem to be hydrogen.
But is this just (forgive the pun!) a pipe dream

Or are there other alternatives, could community heating schemes be developed in time?

Thanks for your thoughts

Gas isn't going away any time soon. It will be removed for new builds first, and eventually for other properties.
The main driver for people changing over will be the cost of use - currently gas is cheap and other choices are not so there is no incentive to change.
Recent higher gas prices won't change that, as a substantial amount of electricity is still generated using gas, so higher gas price = higher electricity price as well. That will change as the electricity generation moves away from gas.
Currently the absolute best ASHP will have running costs similar to gas, but the installation costs are many times greater.

Direct electric heating is a bust on efficiency and cost, so electric combi boilers will not be a thing. They can be obtained now, but are next to useless and will cost a fortune to run. They are limited by the available electricity supply so any thoughts of instant hot water in the style of a gas or oil combi are total fiction. Absolute max for a normal domestic electricity supply is about 12kW. Even the smallest gas combi is more than twice that, others 3-4x. It's the equivalent of filling the bath using an electric shower, and although 12kW may be enough for space heating in smaller homes, it certainly won't be for larger ones.

All heating requires decent levels of insulation to be efficient, gas and oil included. ASHP in a poorly insulated property won't perform well, just as a gas or oil boiler won't. The main difference is that grossly oversized gas/oil boilers can be fitted and the extra cost of running them isn't seen by some people as a problem, so a poorly insulated home can still be warm by virtue of the boiler being far too large and using a lot more of the very cheap fuel.

The main difficulty with ASHPs is that they work best and are designed for low flow temperatures, far lower than a conventional boiler. Buying one and shoving it onto a normal radiator system won't end well.
Underfloor heating is the ideal choice for ASHPs, but will be expensive to retrofit.
High flow temperature ASHPs are available, but at the disadvantage of significantly lower performance and higher running costs.
They do make a noise, but so do gas and oil boilers.

Burning hydrogen in a boiler is also a total bust, as doing so will create very high levels of NOx pollution. It's theoretically possible to design boilers which can limit that, but that makes them prohibitively expensive.
There is also the question of where the hydrogen comes from and how it is distributed. Ideally it would be from wind or solar electricity, but using electricity to create hydrogen which is then compressed and distributed to homes where it is burned to create heat is a wasteful process. Far more efficient to just send the electricity to homes and use that.

There are other technologies such as heat storage batteries
which may be useful for some situations.

There is no perfect choice, and different buildings will require different solutions.

Thank you for your reply and insight Flameport.

flameport said:

Recent higher gas prices won't change that, as a substantial amount of electricity is still generated using gas, so higher gas price = higher electricity price as well. That will change as the electricity generation moves away from gas.

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Yes, good point. I don't think a lot will change until policies arrive to de-incentivise the use of gas. With the current high prices, there would be too big a backlash if this happened anytime soon.

flameport said:

All heating requires decent levels of insulation to be efficient, gas and oil included. ASHP in a poorly insulated property won't perform well, just as a gas or oil boiler won't. The main difference is that grossly oversized gas/oil boilers can be fitted and the extra cost of running them isn't seen by some people as a problem, so a poorly insulated home can still be warm by virtue of the boiler being far too large and using a lot more of the very cheap fuel.

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Again, well said. ASHP has it's limitations in use, but it is not a bad technology. The problem is the current housing stock may not have the insulation requirements to make it a practical solution for many. It's only the ease of over-specification of conventional systems and the cheap overhead, that allows us to have comfortable, but thermally poorly performing housing stock.

flameport said:

Burning hydrogen in a boiler is also a total bust, as doing so will create very high levels of NOx pollution. It's theoretically possible to design boilers which can limit that, but that makes them prohibitively expensive.
There is also the question of where the hydrogen comes from and how it is distributed. Ideally it would be from wind or solar electricity, but using electricity to create hydrogen which is then compressed and distributed to homes where it is burned to create heat is a wasteful process. Far more efficient to just send the electricity to homes and use that.

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I knew about the inefficiency in the production of hydrogen, and heard of the 'blue hydrogen'/'green hydrogen' debate. However, I hadnt heard about the NOx issue. That's really interesting and something that doesnt appear in any of the hydrogen boiler press releases!

The heat storage batteries look good.

So, for the moment it seems that there isn't one technology that would be a straight swap for a combi-boiler. Hopefully in a few years, when gas is being fully de-incentivised, the alternative technologies would have matured enough to make the swap over a little more straightforward.
I may be wrong, but it seems to me (along with the drive to go electric with cars), that although a very good cause, policies are being pushed forward before the practicalities can be addressed, or the infrastructure can be put in place.
Maybe it's misunderstood reporting, but if I look in the press, the future for heating seems to be ASHP's, or hydrogen.
But it takes discussions like this to show the limitations of those technologies (I for one dont fancy having hydrogen running through the tangle of crimped lead pipework in my place! ).

Thanks again.

Whatever the future holds will be dictated by politicians who often have no idea about how things work and are easily influenced by various industry people who may have different agendas. An example of this is the introduction of condensing boilers where much of the performance data was compared with cast iron boilers when low water content 'standard efficiency' was almost as high and had less complications. Certainly condensing technology in oil appliances produced nowhere near the claimed improvements.
Regulation of heating controls has overcomplicated their use for many people and taken away the facility for individual control options.

Swaffham Prior, a village of around 300 homes in East Cambridgeshire, is to become one of the first villages in the UK to install a heating network into an existing community. Swaffham Prior isn't connected to the gas grid and 70% of homes rely on burning oil for heating.

Swaffham Prior Heat Network - Cambridgeshire County Council
https://www.cambridgeshire.gov.uk › community-heating

It works if the community want it and there is a suitable source of heat.

flameport said:

Burning hydrogen in a boiler is also a total bust, as doing so will create very high levels of NOx pollution. It's theoretically possible to design boilers which can limit that, but that makes them prohibitively expensive..

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That's interesting because hydrogen is often touted as the dream fuel, if it could be generated cleanly, on the basis that the only product of combustion is water.

What's the mechanism for the NOx forming?

Lower said:

What's the mechanism for the NOx forming?

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The air used to burn the Hydrogen is mixture of 20% Oxygen, 78% Nitrogen and 2% of other gases. The heat of combustion causes some of the Nitrogen to combine with some of the Oxygen to create various oxides of Nitrogen.

bernardgreen said:

The air used to burn the Hydrogen is mixture of 20% Oxygen, 78% Nitrogen and 2% of other gases. The heat of combustion causes some of the Nitrogen to combine with some of the Oxygen to create various oxides of Nitrogen.

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That's the chemistry, but is it a bigger problem with hydrogen than with nat gas? Not something I've heard of before either.

oilhead said:

Whatever the future holds will be dictated by politicians who often have no idea about how things work and are easily influenced by various industry people who may have different agendas. An example of this is the introduction of condensing boilers where much of the performance data was compared with cast iron boilers when low water content 'standard efficiency' was almost as high and had less complications. Certainly condensing technology in oil appliances produced nowhere near the claimed improvements.
Regulation of heating controls has overcomplicated their use for many people and taken away the facility for individual control options.

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politicians who also have no worries and will likely claim there new heating system on expenses on the 1st, 2nd, 3rd and 4th homes...

flameport said:

There is also the question of where the hydrogen comes from and how it is distributed. Ideally it would be from wind or solar electricity, but using electricity to create hydrogen which is then compressed and distributed to homes where it is burned to create heat is a wasteful process. Far more efficient to just send the electricity to homes and use that.

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That's true, but it would need beefed-up power supply systems, and it's possible it would be more economic to replace or convert boilers to hydrogen and use the existing gas supply network.
In either case it would need a big increase in generating capacity.

fixitflav said:

but is it a bigger problem with hydrogen than with nat gas?

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Unless the nitrogen is removed from the air that is taken into the combustion chamber NOx will always be produced irrespective of the fuel being burnt.

If the temperature of the combustion process is kept below a certain temperature then NOx is not created. ( I cannot recall what that temperature is )

bernardgreen said:

Unless the nitrogen is removed from the air that is taken into the combustion chamber

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That's never going to be practical.

bernardgreen said:

NOx will always be produced irrespective of the fuel being burnt.

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That's right, but I'm interested in the statement in #2 implying H2 is worse than nat gas.

bernardgreen said:

f the temperature of the combustion process is kept below a certain temperature then NOx is not created.

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I suppose that could be achieved using loads of excess air, but then boiler efficiency would be reduced.

I find @flameport's post elegant, accurate and spot on.

fixitflav said:

I suppose that could be achieved using loads of excess air,

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the more air there is the more un-used Oxygen there will be available to be reacted with Nitrogen

The only way to prevent the production of NOx is to ensure the amount of Oxygen supplied is exactly the amount required to burn the fuel. But that would make it necessary to have a complex air control system and very good mixing of the Hydrogen and Oxygen to ensure all the Hydrogen was burnt.

That is not practical as it has the risk of some Hydrogen not being burnt and escaping via the flue

fixitflav said:

That's right, but I'm interested in the statement in #2 implying H2 is worse than nat gas

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I believe Hydrogen burns at a higher temperature than natural gas and this higher temperature could produce more NOx

We need solar heating (not electric, but from the sun) with well insulated homes with quality glazing that helps absorb maximum heat from sunlight, then insulated shutters for nighttime etc.

I am always amazed at how warm my south facing lounge is on a sunny winter's day, with the heating off.

Obviously, there is a major problem with housing to overcome, but maybe the future will require major rethink on how and where we live.

Community ground source heating does make sense if it can work. All a bit commie though, so a lot of people will be against it no doubt.

"DISTRICT HEATING ACCOUNTS for more than 70 percent of all heat distributed in Russia and ranks as the nation’s single largest product market, worth an estimated 33 billion US dollars in annual sales. A majority of Russia’s citizens live in houses and work in workplaces that depend on district heating."
https://www.alfalaval.com/media/stories/district-heating/russian-district-heating-in-transition/

Economies of scale, efficiencies etc.