Future home use of Gas Central Heating boiler systems

[Xenophon PCDGS]

Has a proposed future date been set where the use of such a heating system will be banned?

 

[JamesT]

Has a proposed future date been set where the use of such a heating system will be banned?

2025 has been suggested for when no new builds would have it. https://www.ft.com/content/3f50601c-45a5-11e9-b168-96a37d002cd3
But there doesn’t seem to be any suggestion that existing installations would be removed any time.

Although it gets rid of local pollution, I’m not sure whether we’re yet at the point where switching from gas to electric heating is an overall win. A large proportion of our electricity is from gas and I’d wonder about the efficiency of generating electricity from gas and associated transmission losses compared to just burning it for heat.

 

[yorksrob]

There are experiments underway currently to assess the viability and safety of using the current gas network to supply hydrogen gas. This would at first, involve sequestering the carbon from methane (natural gas) before it gets into the network. Later phases could include producing hydrogen from renewable powered electrolysis.

 

[Peter Mugridge]

The proposals would also seem to make it difficult to use direct hot water systems, meaning a return to the hugely inefficient practice of using immersion heaters and storage tanks...

 

[JamesT]

The proposals would also seem to make it difficult to use direct hot water systems, meaning a return to the hugely inefficient practice of using immersion heaters and storage tanks...

Surely there's no reason in principle why you can't have hot water on demand from an electrical system? That's essentially what an electric shower is. You just need one with a big enough heating capacity to handle the demand from a typical house.

 

[Peter Mugridge]

Surely there's no reason in principle why you can't have hot water on demand from an electrical system? That's essentially what an electric shower is. You just need one with a big enough heating capacity to handle the demand from a typical house.

The point is that's likely to use more energy overall than a gas fired system is, so unless the percentage of renewables in the electricity generation system is increased somewhat from the present already improving level, it's not going to reduce emissions much is it?

 

[yorksrob]

Carbon emissions from electricity have been on a downward trajectory for sometime, due to the switch from coal fired power stations, to natural gas and renewables.

The problem for policy makers is that, for the end consumer, a kWh of electricity is still considerably more expensive than a kWh of natural gas.

 

[big all]

Carbon emissions from electricity have been on a downward trajectory for sometime, due to the switch from coal fired power stations, to natural gas and renewables.

The problem for policy makers is that, for the end consumer, a kWh of electricity is still considerably more expensive than a kWh of natural gas.

Carbon emissions from electricity have been on a downward trajectory for sometime, due to the switch from coal fired power stations, to natural gas and renewables.

The problem for policy makers is that, for the end consumer, a kWh of electricity is still considerably more expensive than a kWh of natural gas.

yes indeed 3 or 4 times the cost although electric is fairly near to 100% turned to useable energy where as gas is perhaps 75-85% useable energy typically

having said that air or ground sourced heat pumps can give up to around 4x input energy but probably closer to 2-2.5 times in the real world

 

[yorksrob]

yes indeed 3 or 4 times the cost although electric is fairly near to 100% turned to useable energy where as gas is perhaps 75-85% useable energy typically

having said that air or ground sourced heat pumps can give up to around 4x input energy but probably closer to 2-2.5 times in the real world

Indeed. Ground source pumps are the most efficient of the heat pumps, but you either need a lot of land to dig a trench, or a lot of money to dig a bore hole.

 

[HSTEd]

Part of my PhD is about future heating systems in the UK - its important to understand the load we face in the future to be able to quantify possible roles for nuclear within it.

Using hydrogen in the natural gas system for heating is an insane idea - it is peddled primarily by companies like Gas companies who are desperate to avoid their gas grid becoming a stranded asset.
It is worse than simply using storage heaters, since the hydrogen has to be made from electricity in the first place!

The probable future is air source heat pumps and large hot water thermal stores to provide a modicum of load flattening.
Although the peak heating load is potentailly enormous, even 24 hours of thermal storage allows the load to be reduced in magnitude to only something like 70GWe of additional power in midwinter.
That is a lot, but it is not infeasible.

Surely there's no reason in principle why you can't have hot water on demand from an electrical system? That's essentially what an electric shower is. You just need one with a big enough heating capacity to handle the demand from a typical house.

Typical combi boiler thermal output can reach 30kW or more.
That implies a heater current of well over 120A - larger than a single phase house supply.

It looks challenging even with a three phase supply, adn the grid supply issues are enormous.

The realistic answer is a very large thermal store - 2000L of water or equivalent.
It will be hard to fit into current housing stock without loss of usable space, however phase change materials may assist in that regard.

Indeed. Ground source pumps are the most efficient of the heat pumps, but you either need a lot of land to dig a trench, or a lot of money to dig a bore hole.

And not usable in urban environments because the housing density and thus heat load density will be high enough to cyclically freeze the ground solid to a depth of several feet.

This is very bad for foundations not designed for it.

 

[GusB]

We have an air-source system for the heating and hot water, combined with solar panels on the roof. I believe the boiler is capable of heating water instantaneously, just as a gas boiler would, but we do have a storage tank as well. At this time of year with the long hours of daylight, the sun mostly takes care of the hot water. It doesn't even have to be particularly warm outside. I'm not familiar with the science of how it all works together, but the solar panels alone resulted in a drop in energy bills (these were installed when we still had Economy 7 with storage heaters).

The only downside is that the fan in the exterior unit does generate a bit of noise, but I'm used to it now.

 

[big all]

Indeed. Ground source pumps are the most efficient of the heat pumps, but you either need a lot of land to dig a trench, or a lot of money to dig a bore hole.

yes indeed plus when you need the most heat the efficiency is the worst as your heat source is the air or the stored energy in the ground mass that will be far less in the winter

 

[mmh]

We have an air-source system for the heating and hot water, combined with solar panels on the roof. I believe the boiler is capable of heating water instantaneously, just as a gas boiler would, but we do have a storage tank as well.

How can you "believe" it does? If you turn a tap on does hot water come out of it or not?

 

[GusB]

How can you "believe" it does? If you turn a tap on does hot water come out of it or not?

Yes, of course hot water comes out of the tap when I turn it on! I don't know exactly how the boiler functions, but I was led to believe that the system is capable of heating water instantaneously, although it usually doesn't have to due to the solar installation.

 

[yorksrob]

Part of my PhD is about future heating systems in the UK - its important to understand the load we face in the future to be able to quantify possible roles for nuclear within it.

Using hydrogen in the natural gas system for heating is an insane idea - it is peddled primarily by companies like Gas companies who are desperate to avoid their gas grid becoming a stranded asset.
It is worse than simply using storage heaters, since the hydrogen has to be made from electricity in the first place!

The probable future is air source heat pumps and large hot water thermal stores to provide a modicum of load flattening.
Although the peak heating load is potentailly enormous, even 24 hours of thermal storage allows the load to be reduced in magnitude to only something like 70GWe of additional power in midwinter.
That is a lot, but it is not infeasible.



Typical combi boiler thermal output can reach 30kW or more.
That implies a heater current of well over 120A - larger than a single phase house supply.

It looks challenging even with a three phase supply, adn the grid supply issues are enormous.

The realistic answer is a very large thermal store - 2000L of water or equivalent.
It will be hard to fit into current housing stock without loss of usable space, however phase change materials may assist in that regard.



And not usable in urban environments because the housing density and thus heat load density will be high enough to cyclically freeze the ground solid to a depth of several feet.

This is very bad for foundations not designed for it.

The problem with storage heaters is their controllability. People want something that they can turn on or up when they feel chilly.

Air source heat pumps are better in this respect, but I've still heard feedback that a lot of residents don't find them controllable enough.

Whatever happens, we won't be burning methane in our homes in twenty years time.

 

[Bletchleyite]

Has a proposed future date been set where the use of such a heating system will be banned?

I would venture that no such date will ever be set. However, once demand is too low to keep it viable the gas piping system will no doubt be decommissioned, thus rendering any such remaining system useless. It may also be that sales are banned at some point, which given that they don't last forever[1] will give a 10-20 year lifespan for remaining installations.

[1] Blown-air systems on the other hand...the one in our Scout hut is about 55 years old and still going strong. Dead simple, I guess, and no water to cause things to corrode.

 

[Bletchleyite]

The point is that's likely to use more energy overall than a gas fired system is, so unless the percentage of renewables in the electricity generation system is increased somewhat from the present already improving level, it's not going to reduce emissions much is it?

Electric heating - all of it - is 100% efficient - it converts all of the energy that goes in into heat (except maybe a tiny proportion for an indicator light and maybe a slight red glow). It costs more but it is not fundamentally less efficient than gas.

I suppose you get transmission losses, but I reckon large scale generation is probably better than burning it in your boiler.

The UK is already on a surprisingly high level of renewables and nuclear anyway. This is fascinating:

https://www.gridwatch.templar.co.uk/

Presently, as at 1110 on 28th July, NO coal generation is in use at all. The key ones are nuclear 17.5%, gas 37.5%, solar 10% and wind 15%, the rest being imported, biomass and other obscure ones. That's pretty good but I have seen it better on a windier day!

 

[Xenophon PCDGS]

I would venture that no such date will ever be set. However, once demand is too low to keep it viable the gas piping system will no doubt be decommissioned, thus rendering any such remaining system useless. It may also be that sales are banned at some point, which given that they don't last forever will give a 10-20 year lifespan for remaining installations.

I wonder how and when British Gas, who are still using extensive television marketing for domestic gas central heating boilers that uses their produced gas product, will adapt their company to meet the changes that will come in the future.

 

[Bletchleyite]

I wonder how and when British Gas, who are still using extensive television marketing for domestic gas central heating boilers that uses their produced gas product, will adapt their company to meet the changes that will come in the future.

As British Gas is not just a supplier of gas (they supply my electricity as well) I don't suppose they will really care. That said, gas is fairly unique in its "dangerousness" (so not DIYable by most people) so a lot of their business is charging a fortune for engineers.

 

[yorksrob]

I wonder how and when British Gas, who are still using extensive television marketing for domestic gas central heating boilers that uses their produced gas product, will adapt their company to meet the changes that will come in the future.

BG are also big electricity suppliers as well nowadays, so probably no different from the rest of the big six.

 

[AndrewE]

Electric heating - all of it - is 100% efficient - it converts all of the energy that goes in into heat (except maybe a tiny proportion for an indicator light and maybe a slight red glow). It costs more but it is not fundamentally less efficient than gas.
I suppose you get transmission losses, but I reckon large scale generation is probably better than burning it in your boiler.

It is not - unless you only consider the heat delivered in the house against the electrons that come in through the wires.
Making electricity from fuels (I don't consider electricity or hydrogen as fuels as you can't mine or collect them directly) is inefficient by definition. That's why electricity costs so much more than gas per kilowatt-hour.
If it wasn't for the carbon dioxide emission problem, gas would be the best fuel to use as it is the most efficient fuel (in terms of losses between extraction and delivery/use) for heating and cooking in a house. Even with losses in the exhaust it is better than the losses during electricity generation.

 

[Bletchleyite]

Making electricity from fuels (I don't consider electricity or hydrogen as fuels as you can't mine or collect them directly) is inefficient by definition. That's why electricity costs so much more than gas per kilowatt-hour.

It's financially less efficient, hence the cost. However, in carbon terms, you don't burn dead dinosaurs to run a nuclear power station or a wind turbine. So as you said in the bit I forgot to quote, this headline figure is not the key factor.

I was indeed referring to the "electrical energy in, heat energy out" equation.

 

[AndrewE]

It's financially less efficient, hence the cost. However, in carbon terms, you don't burn dead dinosaurs to run a nuclear power station or a wind turbine. So as you said in the bit I forgot to quote, this headline figure is not the key factor.
I was indeed referring to the "electrical energy in, heat energy out" equation.

That's debatable too. The amount of energy consumed (and carbon dioxide emitted) in making the enormous amounts of concrete and steel needed for a nuclear power station (not to mention the same factors in making safe then the indefinite storage of the nuclear waste) make me wonder whether nuclear power is actually a net contributor to CO2 emissions.
Has the environmental footprint of Windscale/Sellafield ever been quantified? And that is before you consider the costs of safe storage ("disposal") of high-level waste: digging and maintaining for ever a deep mine that will produce nothing except waste rock!
(p.s not to mention the fuel enrichment plant at Capenhurst that had power lines to it like those from a power station: it must have consumed the output of one by itself.)

 

[HSTEd]

That's debatable too. The amount of energy consumed (and carbon dioxide emitted) in making the enormous amounts of concrete and steel needed for a nuclear power station (not to mention the same factors in making safe then the indefinite storage of the nuclear waste) make me wonder whether nuclear power is actually a net contributor to CO2 emissions.

Nuclear actually consumes far less concrete and steel per unit of energy produced than wind turbines do.
It's just our concrete and steel is concentrated in one place rather than scattered across the landscape/ocean, so it's a lot more noticeable.

Has the environmental footprint of Windscale/Sellafield ever been quantified?

Most things that were done at Sellafield were only done because of the demands of the weapons programme - if we had not had that we would have made an entirely different set of choices.

And that is before you consider the costs of safe storage ("disposal") of high-level waste: digging and maintaining for ever a deep mine that will produce nothing except waste rock!

The mine will actually be rather small compared to mines for almost anything else.
The material is really nasty, but the amoutn to be disposed of is extremely small.

Even one 20kg CANDU fuel bundle, a relatively low burnup and thus voluminous nuclear fuel, which is a cylinder 500mm long and 100mm in diameter, contains about 1.2GWh of electricity. That is equivalent to about 300 tonnes of coal in a modern ultra-supercritical unit.

(p.s not to mention the fuel enrichment plant at Capenhurst that had power lines to it like those from a power station: it must have consumed the output of one by itself.)

The original UKAEA enrichment plant at Capenhurst was a gaseous diffusion system that did indeed consume ridiculous amount of electricity, as all gaseous diffusion plants do.
But modern centrifuge plants consume a tiny fraction as much energy for the asme result.

When the Gaseous diffusion plant at Tricastin in France was replaced by a modern centrifuge plant a few years ago, electricity consumption dropped from ~2700MWe to about 50MWe.

 

[dgl]

To add to the previous statements our original fleet of nuclear reactors were initially based on the original gas cooled reactors at Calder Hall (Sellafield) and Chapelcross. These were originally designed that electricity was a by product and their main use was to create plutonium for the weapons program, due to this the ones that used a development of the design but designed primarily for electricity generation weren't all that efficient (I.e. Hinkley Point A, Oldbury, Wylfa, Trawsfyndd, Dungeness A, Sizewell A, Bradwell, Berkeley Etc.), the later AGR (I.e. Hinkley Point B, Huntstaton, Heysham, Torness Etc.) were never used for plutonium production so are much more efficient.

 

[MidlandsChap]

Has a proposed future date been set where the use of such a heating system will be banned?

There are currently two frontrunning replacements being considered. Firstly air source heat pumps which will be significantly more expensive to run, thats assuming we are currently able to produce enough electricity to power them. Which currently we dont. The other alternative is hydrogen boilers which are a darn site more dangerous than the natural gas boilers they may replace.

Unfortunately this whole chirade has come from noisy activists who want to reduce carbon output to zero but dont actually have a clue how difficult it will be.

 

[Bletchleyite]

There are currently two frontrunning replacements being considered by the department of energy. Firslty air source heat pumps which will be significantly more expensive to run, thats assuming we are currently able to produce enough electricity to power them.

Heat pumps use electricity only for circulating the refrigerant - they are basically a fridge working in reverse. They therefore aren't "significantly more expensive to run".

Which currently we dont. The other alternative is hydrogen boilers which are a darn site more dangerous than the natural gas boilers they may replace.

In what way are they more dangerous? Both natural gas and hydrogen will explode if you chuck a match in.

 

[HSTEd]

To add to the previous statements our original fleet of nuclear reactors were initially based on the original gas cooled reactors at Calder Hall (Sellafield) and Chapelcross. These were originally designed that electricity was a by product and their main use was to create plutonium for the weapons program, due to this the ones that used a development of the design but designed primarily for electricity generation weren't all that efficient (I.e. Hinkley Point A, Oldbury, Wylfa, Trawsfyndd, Dungeness A, Sizewell A, Bradwell, Berkeley Etc.), the later AGR (I.e. Hinkley Point B, Huntstaton, Heysham, Torness Etc.) were never used for plutonium production so are much more efficient.

They are more efficient in terms of thermal efficiency, however the later Magnox reactors probably have the AGR fleet beat operationally, given that they actually worked properly from the get go.

 

[dgl]

They are more efficient in terms of thermal efficiency, however the later Magnox reactors probably have the AGR fleet beat operationally, given that they actually worked properly from the get go.

From what I've heard, sort off, the high gas temperatures supposedly reacted badly with the steel used in the system and so the operating temperature (and therefore electrical output) was reduced.

And for the Nuclear naysayers, A Fukushima/Chernobyl style accident is physically impossible with an AGR/MAGNOX design as there is no steam to build up and explode, and is also not possible, or so I understand, on our single PWR Sizewell B .

 

[HSTEd]

From what I've heard, sort off, the high gas temperatures supposedly reacted badly with the steel used in the system and so the operating temperature (and therefore electrical output) was reduced.

They were indeed derated due to breakaway corrosion appearing in the reactor coolant loop which had not been anticipated.
But that single problem is considerably less horrendous than the problems the AGR fleet has experienced - many are still not capable of on load refueling for example.

If we had simply built ever larger Wylfa derivatives we would probably be in a better place today (the dry storage of fuel used at Wylfa could have avoided the need for reprocessing)

And for the Nuclear naysayers, A Fukushima/Chernobyl style accident is physically impossible with an AGR/MAGNOX design as there is no steam to build up and explode, and is also not possible, or so I understand, on our single PWR Sizewell B .

A Fukushima style station blackout accident could occur at Sizewell, but Sizewell is probably the most overengineered PWR in history, to match the safety performance of the AGRs and Magnox, which were lightyears ahead of the light water reactor people in terms of engineered safety.