If you were to install a new boiler but want to future proof...

macman

Since a full 37% of our electricity is still generated from gas plant, then I don't expect electricity to become competitive with gas any time soon...

Bendy_House

It depends on how they load the 'green' levy on to domestic gas. If you want to get rid of summat, just pile on the taxes.

neilmcl

macman said:

Gas boilers are not going anywhere, not in 2030 or 2035. There will be a ban on them in new builds at some point, but there will have to be a replacement market available for decades going forward-no govt is going to start ripping out boilers in 25m homes by compulsion.
The gas grid will only be converted to hydrogen if the considerable technical problems of hydrogen extraction can be solved, which could take decades. We were promised carbon capture years ago, and how far has that moved forward since?
As the OP quite correctly points out, millions of homes with combi's do not have the room for stored hot water, which will be a requirement of solar/heat pump/electric systems. Nor do many flats above ground floor level have anywhere to install heat pumps.

Extracting hydrogen isn't the difficulty, as any schoolboy in science class will testify, it's the storage that's proved the sticking point.

Emmia

One of the difficulties of the "no gas boilers after X" is whether alternatives are viable in terms of size etc., in the millions of flats this country has, especially in cities.

Flats mostly have combis, and don't usually have lots of space for extra water tanks (no lofts) and there may be nowhere suitable for heat pumps to be installed.

If the govt. wants to abolish GCH in 2040 - then it needs to alter planning permission rules today to require all new builds to have heat pumps and water tanks installed as standard.

Of course a shared hot water tank in a block of flats is also likely to put buyers off. Personally I'd want my own tank and boiler/heating system independent of those elsewhere in the building, and not something that the management company/freeholder maintains - as you know it will break in the middle of winter, and you'll be freezing for weeks.

Section62

macman said:

Gas boilers are not going anywhere, not in 2030 or 2035. There will be a ban on them in new builds at some point, but there will have to be a replacement market available for decades going forward-no govt is going to start ripping out boilers in 25m homes by compulsion.

Of course they won't.  In just the same way the government didn't go round seizing cars that only ran on leaded fuel.

The strategy is simple.  Legislate for a ban on new manufacture, tweak taxation to make the economics of leaded (=gas) more expensive, offer incentives to switch (scrappage).

If you believe that replacement gas boilers will be sold in ever decreasing quantities 'for decades' then could you please let me know where I can get my hands on a brand new 1800W vacuum cleaner to replace mine?

macman said:

The gas grid will only be converted to hydrogen if the considerable technical problems of hydrogen extraction can be solved, which could take decades.

Extraction is easy.  But it needs energy (e.g. electricity) which is as easy to transport as gas.  The niche for hydrogen will be as a means of energy storage at times where electricity generation exceeds demand (including battery charging + pumped-storage)

macman said:

We were promised carbon capture years ago, and how far has that moved forward since?

Carbon capture is a developing technology which economically doesn't really make sense to fit to ageing generating plant. Compare/contrast with flue-gas de-sulphurisation which was implemented because the economics stacked up.

Carbon capture isn't comparable with banning gas boilers.  The alternatives to gas - e.g. heat pumps, storage heaters, immersion heaters, instantaneous electric heating - have been around for decades and are mostly mature technologies.  The cost of installation (except heat pumps) is trivial in comparison to the development of production-scale carbon capture.

macman said:

As the OP quite correctly points out, millions of homes with combi's do not have the room for stored hot water, which will be a requirement of solar/heat pump/electric systems. Nor do many flats above ground floor level have anywhere to install heat pumps.

A standard airing cupboard is typically around 0.7m2.  If people don't want to use that floor area for hot water storage then other options are available.  Perhaps a demand for something with a smaller footprint will lead to the ready availability of smaller diameter cylinders which are much taller?

Some out-of-the-box thinking is needed here.

Communal/district heating schemes are also part of the mix.

macman said:

Since a full 37% of our electricity is still generated from gas plant, then I don't expect electricity to become competitive with gas any time soon...

The 'wholesale costs' of electricity makes up only 30% of the retail cost.  'Environmental and social obligations' are 25%, VAT adds another 4.76%.

The 'Environmental and social obligations' costs on a gas bill are 2.46%. (wholesale costs = 41% )

https://www.ofgem.gov.uk/energy-advice-households/costs-your-energy-bill

It isn't difficult to see how the price gap between electricity and gas could be narrowed, or even reversed, simply by government policy.

goodwithsaving

Thank you all for your contributions and thoughts - it's been really interesting on the further reading front, as well as for the considerations I have. I have decided to go down the unvented route. I would like the airing cupboard for other purposes, but ultimately, for now, can keep the washing appliances in the kitchen. I wondered about the loft but can't remember the details, it wasn't easily possible due to pipework, loft hatch, weight and so forth.
I'm not sure how I feel about not having a combi boiler installed but have been assured the unvented cylinder won't lose much heat if I, say, get through minimal hot water one day and want to store it for the next or one after that?

Section62

Emmia said:

Flats mostly have combis, and don't usually have lots of space for extra water tanks (no lofts) and there may be nowhere suitable for heat pumps to be installed.

Gas was/is banned in many flats on safety grounds.  Somehow the occupiers of these flats got/get by without a gas boiler.  In the past, possibly resulting in higher energy bills than in gas-connected properties - but that may not be true in the future.

There's no need to have a loft to have stored hot water.  Unvented systems work just fine.

Emmia said:

If the govt. wants to abolish GCH in 2040 - then it needs to alter planning permission rules today to require all new builds to have heat pumps and water tanks installed as standard.

It would definitely make sense for building regs to be changed so that space has to be provided for energy storage and/or a heat pump.  But exactly how that is done needs careful thought rather than some knee-jerk policy change.

The regulatory approach doesn't always work well - as owners of homes with compulsory low-energy light fittings discovered when the CFL stopgap was replaced by LED technology.

The ideal will be housebuilders smelling the coffee and seeing a marketing opportunity in selling homes which are 'future-energy ready'.  Even if at the point of sale they are fitted with a gas boiler for economy.  There is already a date for a ban on new-builds with gas boilers, I think it would be confusing to change that now.

Bendy_House

goodwithsaving said:

Thank you all for your contributions and thoughts - it's been really interesting on the further reading front, as well as for the considerations I have. I have decided to go down the unvented route. I would like the airing cupboard for other purposes, but ultimately, for now, can keep the washing appliances in the kitchen. I wondered about the loft but can't remember the details, it wasn't easily possible due to pipework, loft hatch, weight and so forth.
I'm not sure how I feel about not having a combi boiler installed but have been assured the unvented cylinder won't lose much heat if I, say, get through minimal hot water one day and want to store it for the next or one after that?

70L seems to be about the smallest, although I've seen 60L in 'direct' type (ie heated by immersion, and not gas boiler). Any 60L or less 'indirects' out there?

Stll pretty compact, tho', and very well insulated. Eg: https://electricaldealsdirect.co.uk/heatrae-sadia-megaflo-eco-70i-indirect-unvented-hot-water-cylinder.html

Section62

goodwithsaving said:

Thank you all for your contributions and thoughts - it's been really interesting on the further reading front, as well as for the considerations I have. I have decided to go down the unvented route. I would like the airing cupboard for other purposes, but ultimately, for now, can keep the washing appliances in the kitchen. I wondered about the loft but can't remember the details, it wasn't easily possible due to pipework, loft hatch, weight and so forth.

I'm not sure how I feel about not having a combi boiler installed but have been assured the unvented cylinder won't lose much heat if I, say, get through minimal hot water one day and want to store it for the next or one after that?

The vented/unvented point doesn't make a difference to heat loss.  I used to have an indirect hot water cylinder (originally installed in the 1990's) in a property which wasn't used every day.  It was heated by an immersion heater (on E7) most of the time.  On days when the immersion was switched off completely the water would remain 'hot' for two days - i.e. if the immersion went off at 7am on day 1 then there was still 'hot' water in the evening of day 2.  On day 3 the heat was still detectable, but it would be a stretch to have called it 'hot'.

On the days when the immersion heater was on, but no hot water was used, the total overnight consumption averaged around 1.5 kWh - but that included running separate fridges and freezers as well.  So I'd guess that the loss per day worked out at around 1kWh.

That HWC was pre-insulated to the standards of the day, and in a relatively small airing cupboard.  I could have added a lagging jacket as well, and done more to insulate the pipes connected to the cylinder.

How much heat loss you'll have depends on your exact circumstances. It is also important to consider the location of the cylinder (or a combi) compared to the point(s) hot water is used.  Both will involve loss of heat in the pipework between the boiler/cylinder and the point of use - the longer the pipework the greater the heat loss.


On the question of vented vs unvented, you do need to check that your mains water supply is adequate for the purpose.  Also, if you aren't planning to use the loft for anything else, there is not much to be gained by removing the cold water storage tank.

Where space is not a factor, the choice to go unvented should be based on it being the most economical way of achieving the pressure you want at the point of use - but only if the mains supply is adequate.  You need to get checks on the flow and pressure to make sure you can achieve your objectives, and at the same time try to explore why the current system isn't delivering the flow/pressure you are expecting.  It could be something as simple as a valve being partially turned off, or a build-up of limescale around/in the hot water draw-off pipe.  Fixing those is a trivial cost compared to converting to unvented.

Emmia

Section62 said:

macman said:

Gas boilers are not going anywhere, not in 2030 or 2035. There will be a ban on them in new builds at some point, but there will have to be a replacement market available for decades going forward-no govt is going to start ripping out boilers in 25m homes by compulsion.

Of course they won't.  In just the same way the government didn't go round seizing cars that only ran on leaded fuel.

The strategy is simple.  Legislate for a ban on new manufacture, tweak taxation to make the economics of leaded (=gas) more expensive, offer incentives to switch (scrappage).

If you believe that replacement gas boilers will be sold in ever decreasing quantities 'for decades' then could you please let me know where I can get my hands on a brand new 1800W vacuum cleaner to replace mine?

macman said:

The gas grid will only be converted to hydrogen if the considerable technical problems of hydrogen extraction can be solved, which could take decades.

Extraction is easy.  But it needs energy (e.g. electricity) which is as easy to transport as gas.  The niche for hydrogen will be as a means of energy storage at times where electricity generation exceeds demand (including battery charging + pumped-storage)

macman said:

We were promised carbon capture years ago, and how far has that moved forward since?

Carbon capture is a developing technology which economically doesn't really make sense to fit to ageing generating plant. Compare/contrast with flue-gas de-sulphurisation which was implemented because the economics stacked up.

Carbon capture isn't comparable with banning gas boilers.  The alternatives to gas - e.g. heat pumps, storage heaters, immersion heaters, instantaneous electric heating - have been around for decades and are mostly mature technologies.  The cost of installation (except heat pumps) is trivial in comparison to the development of production-scale carbon capture.

macman said:

As the OP quite correctly points out, millions of homes with combi's do not have the room for stored hot water, which will be a requirement of solar/heat pump/electric systems. Nor do many flats above ground floor level have anywhere to install heat pumps.

A standard airing cupboard is typically around 0.7m2.  If people don't want to use that floor area for hot water storage then other options are available.  Perhaps a demand for something with a smaller footprint will lead to the ready availability of smaller diameter cylinders which are much taller?

Some out-of-the-box thinking is needed here.

Communal/district heating schemes are also part of the mix.

macman said:

Since a full 37% of our electricity is still generated from gas plant, then I don't expect electricity to become competitive with gas any time soon...

The 'wholesale costs' of electricity makes up only 30% of the retail cost.  'Environmental and social obligations' are 25%, VAT adds another 4.76%.

The 'Environmental and social obligations' costs on a gas bill are 2.46%. (wholesale costs = 41% )

https://www.ofgem.gov.uk/energy-advice-households/costs-your-energy-bill

It isn't difficult to see how the price gap between electricity and gas could be narrowed, or even reversed, simply by government policy.

I live in a flat with gas central heating via a combi, and a gas hob - there isn't really room for a hot water tank without substantial rebuilding (the kitchen for example is 2m x 3m, so no room there, even for a small footprint cylinder) and we don't have an airing cupboard. 

The flat is pretty spacious in comparison to many - especially new build.