Air Source Heat Pump Questions...

[dirtychinchilla]

So you are proposing to continue burning old dinosaurs? Or maybe, with increased (and guaranteed demand) investment in green energy is a whole lot less risky and 'faddy'?

That's not the point he was making. The government seems to treat electricity like it's made of fairy dust and has no carbon footprint. For electric cars to work with our current system, we continue to have to burn fossil fuels. Instead of burning them in our car's engines, we burn them in a centralised place i.e. power station, which then distributes the electricity through the grid to our cars. So all we've done is move the fossil fuel burning from a multitude of small locations to a few much larger locations. Then there are losses and inefficiencies in the grid etc. So whilst electric cars aren't a fad and aren't a bad idea, electricity generation by power stations is not solving any problems, it's just moving them to somewhere else. I believe this fits the definition of NIMBY.

More than that, the guidance that they produce via CIBSE has been proposed to use carbon factors that make it look like electricity generation has exactly the same carbon footprint as natural gas i.e. electric heating is more efficient than gas heating. It's not though - you need not only to generate that electricity somewhere but also get it to where you need it and then you have to consider whether transmission of heat via electricity is more efficient than water to metal etc.

I may not be explaining myself terribly well, but it's political BS.

 

[Deleted User 298457]

That's not the point he was making. The government seems to treat electricity like it's made of fairy dust and has no carbon footprint. For electric cars to work with our current system, we continue to have to burn fossil fuels. Instead of burning them in our car's engines, we burn them in a centralised place i.e. power station, which then distributes the electricity through the grid to our cars. So all we've done is move the fossil fuel burning from a multitude of small locations to a few much larger locations. Then there are losses and inefficiencies in the grid etc. So whilst electric cars aren't a fad and aren't a bad idea, electricity generation by power stations is not solving any problems, it's just moving them to somewhere else. I believe this fits the definition of NIMBY.

More than that, the guidance that they produce via CIBSE has been proposed to use carbon factors that make it look like electricity generation has exactly the same carbon footprint as natural gas i.e. electric heating is more efficient than gas heating. It's not though - you need not only to generate that electricity somewhere but also get it to where you need it and then you have to consider whether transmission of heat via electricity is more efficient than water to metal etc.

I may not be explaining myself terribly well, but it's political BS.

I don't disagree with anything you've said - but continuing to burn fossil fuel in a multitude of many small locations that are hard to control and govern isn't the answer, is it? Rather a handful of centralised locations that can be pinpointed for investment; seems like a progressive step to me. The demand that electric cars are placing on the grid also helps secure investment on SMRs and other modern ways of generating juice.

 

[sovietspybob]

That's not the point he was making. The government seems to treat electricity like it's made of fairy dust and has no carbon footprint. For electric cars to work with our current system, we continue to have to burn fossil fuels. Instead of burning them in our car's engines, we burn them in a centralised place i.e. power station, which then distributes the electricity through the grid to our cars. So all we've done is move the fossil fuel burning from a multitude of small locations to a few much larger locations. Then there are losses and inefficiencies in the grid etc. So whilst electric cars aren't a fad and aren't a bad idea, electricity generation by power stations is not solving any problems, it's just moving them to somewhere else. I believe this fits the definition of NIMBY.

More than that, the guidance that they produce via CIBSE has been proposed to use carbon factors that make it look like electricity generation has exactly the same carbon footprint as natural gas i.e. electric heating is more efficient than gas heating. It's not though - you need not only to generate that electricity somewhere but also get it to where you need it and then you have to consider whether transmission of heat via electricity is more efficient than water to metal etc.

I may not be explaining myself terribly well, but it's political BS.

While it is true that for some of our electric needs we are just moving the pollution elsewhere you also get the efficiencies of scale with a power plant, the power plant will be a whole lot more efficient than burning fuel in each car on the road so even if we did power all our electric vehicles or home heating from fossil sources it'd still be a net benefit. Not that i advocate that as it's clearly stupid but the point still stands

 

[b0rn2sk8]

Not only that it moves the emissions away from the road I am walking down to huge chimney stacks out of town and will massively improve the quality of air you actually breathe.

 

[dirtychinchilla]

I don't disagree with anything you've said - but continuing to burn fossil fuel in a multitude of many small locations that are hard to control and govern isn't the answer, is it? Rather a handful of centralised locations that can be pinpointed for investment; seems like a progressive step to me. The demand that electric cars are placing on the grid also helps secure investment on SMRs and other modern ways of generating juice.

While it is true that for some of our electric needs we are just moving the pollution elsewhere you also get the efficiencies of scale with a power plant, the power plant will be a whole lot more efficient than burning fuel in each car on the road so even if we did power all our electric vehicles or home heating from fossil sources it'd still be a net benefit. Not that i advocate that as it's clearly stupid but the point still stands

Not necessarily. You lose a substantial quantity of energy taking it from point A to B, so it can be less efficiency to generate electricity in a centralised location.

It's said that our grid needs to be 3 times the size if we are to all have electric cars.

 

[b0rn2sk8]

Not necessarily. You lose a substantial quantity of energy taking it from point A to B, so it can be less efficiency to generate electricity in a centralised location.

It's said that our grid needs to be 3 times the size if we are to all have electric cars.

Citation needed.

 

[dirtychinchilla]

Citation needed.

Losses: https://publications.parliament.uk/pa/cm201415/cmselect/cmenergy/386/38607.html

Grid - interestingly I haven't been able to find something that supports my statement - I was wrong. One source suggested an extra 10% required, and much of this will be accounted for by reductions in energy consumption of existing technologies. That sounds good to me.

 

[b0rn2sk8]

Losses: https://publications.parliament.uk/pa/cm201415/cmselect/cmenergy/386/38607.html

That doesn’t support your statatemt.

You said (my emphasis on the part in bold which is the point you were trying to make):

Not necessarily. You lose a substantial quantity of energy taking it from point A to B, so it can be less efficiency to generate electricity in a centralised location.

Grid losses aren’t anything anyone is trying to argue against but that doesn’t make localised generation more efficient than centralised generation. Grid losses are a factor in both central and local generation, particularly when it comes to heat from the burning of fossil fuels or the electrification of vehicles. For example producing and distributing petrol and diesel has a huge energy cost, far greater than distributing electricity to a cars battery and gas boilers are connected to the grid and suffer all the leakage losses you point out.

 

[dirtychinchilla]

That doesn’t support your statatemt.

You said (my emphasis on the part in bold which is the point you were trying to make):

Grid losses aren’t anything anyone is trying to argue against but that doesn’t make localised generation more efficient than centralised generation. Grid losses are a factor in both central and local generation, particularly when it comes to heat from the burning of fossil fuels or the electrification of vehicles. For example producing and distributing petrol and diesel has a huge energy cost, far greater than distributing electricity to a cars battery and gas boilers are connected to the grid and suffer all the leakage losses you point out.

Decent gas boilers are generally over 90% efficient. Power plants can't achieve that sort of efficiency to the home. If anything, district heating is far better in that case.

 

[b0rn2sk8]

Decent gas boilers are generally over 90% efficient. Power plants can't achieve that sort of efficiency to the home. If anything, district heating is far better in that case.

The problem is that gas boilers aren’t ‘generally’ 90% efficient in the real world. They can reach 90% efficiency if they are set up correctly and operate in condensing mode with low (ideally as low as 30c) return flow temperatures.

Most installations take little or zero account of flow return temps. That 90% also doesn’t take into account leakage from the grid which you are doing with electricity.

Compare that with an electric heat pump which can be be ‘500%’ efficient in similar ideal conditions. So yes, a gas fired power plant with electric heating can be significantly more efficient than a direct gas boiler.

Anyway, it’s also not about efficiency, it’s all about total emissions output. When you also account for that grid electricity has low carbon generation from nuclear, wind and solar, electric based heating (and cars) completely blow away a gas (and petrol/diesel) in terms of total emissions (but it comes at a financial cost). Grid emissions are also galling significantly year on year.

Those any emissions you do make from fossil fuel generation are also concentrated to large smoke stacks instead of spewing out the flue by your house and polluting the air you actually breathe.

 

[dirtychinchilla]

The problem is that gas boilers aren’t ‘generally’ 90% efficient in the real world. They can reach 90% efficiency if they are set up correctly and operate in condensing mode with low (ideally as low as 30c) return flow temperatures.

Most installations take little or zero account of flow return temps. That 90% also doesn’t take into account leakage from the grid which you are doing with electricity.

Compare that with an electric heat pump which can be be ‘500%’ efficient in similar ideal conditions. So yes, a gas fired power plant with electric heating can be significantly more efficient than a direct gas boiler.

Anyway, it’s also not about efficiency, it’s all about total emissions output. When you also account for that grid electricity has low carbon generation from nuclear, wind and solar, electric based heating (and cars) completely blow away a gas (and petrol/diesel) in terms of total emissions (but it comes at a financial cost). Grid emissions are also galling significantly year on year.

Those any emissions you do make from fossil fuel generation are also concentrated to large smoke stacks instead of spewing out the flue by your house and polluting the air you actually breathe.

Fair enough man, I think you know a bit more about this than I do! I pick up titbits at work as we're heavily involved in district heating, but I'm on the ventilation side.

I, for one, am glad that I don't have a power plant near my house.

 

[b0rn2sk8]

No worries, always good to have a healthy debate and there is a lot of mis information out there.

District heating can be very effective, even better if it’s powered by a ground or water source heat pump from a local river.

That said, I wouldn’t be running out to retrofit a heat pump right now as I posted in this thread. They are good but only in well insulated buildings. The price is just too high at the moment and there is little incentive to buy or little disincentive to buying gas.

 

[Flake87]

So you are proposing to continue burning old dinosaurs? Or maybe, with increased (and guaranteed demand) investment in green energy is a whole lot less risky and 'faddy'?

During the past week omitting the obnoxious 'biomass' generation, renewables night time contribution to the load has been a mere 3% and no amount of economising on energy consumption is going to make that sufficient. Michael Moore - not someone who I would normally quote, film planet of the humans illustrated the ridiculous myth of renewable energy and the fact that we are going to have to continue using fossil fuels because the renewables simply don't work as well as we are being lied to that they do.

The only sane way forward is reduction in use. Why are we allowing the sale and installations of heaters to heat the night sky? I can't think of anything more wasteful or insane. Why do we allow private jets or commercial aircraft at all? Why do you need to take a weeks holiday in Bali or Thailand and if you do need to go to Spain why not by boat or rail? Why are people allowed to live 150 miles from their place of work and to commute both ways every day?

 

[Deleted User 298457]

During the past week omitting the obnoxious 'biomass' generation, renewables night time contribution to the load has been a mere 3% and no amount of economising on energy consumption is going to make that sufficient. Michael Moore - not someone who I would normally quote, film planet of the humans illustrated the ridiculous myth of renewable energy and the fact that we are going to have to continue using fossil fuels because the renewables simply don't work as well as we are being lied to that they do.

The only sane way forward is reduction in use. Why are we allowing the sale and installations of heaters to heat the night sky? I can't think of anything more wasteful or insane. Why do we allow private jets or commercial aircraft at all? Why do you need to take a weeks holiday in Bali or Thailand and if you do need to go to Spain why not by boat or rail? Why are people allowed to live 150 miles from their place of work and to commute both ways every day?

I stopped at Michael Moore.

 

[bJN]

During the past week omitting the obnoxious 'biomass' generation, renewables night time contribution to the load has been a mere 3% and no amount of economising on energy consumption is going to make that sufficient. Michael Moore - not someone who I would normally quote, film planet of the humans illustrated the ridiculous myth of renewable energy and the fact that we are going to have to continue using fossil fuels because the renewables simply don't work as well as we are being lied to that they do.

The only sane way forward is reduction in use. Why are we allowing the sale and installations of heaters to heat the night sky? I can't think of anything more wasteful or insane. Why do we allow private jets or commercial aircraft at all? Why do you need to take a weeks holiday in Bali or Thailand and if you do need to go to Spain why not by boat or rail? Why are people allowed to live 150 miles from their place of work and to commute both ways every day?

I feel like this is probably going well beyond the scope of the thread and OP, but it's an interesting discussion point nonetheless. I work at a gas terminal so from a career-longevity perspective it's in my interest that gas keeps on being used for the decades to come - as it will - North Sea gas reserves are aplenty in the southern North Sea let alone the gas byproduct from oil production in the central and northern North Sea. As a means for electricity generation, CCGTs are terrible. Efficiency wise they're reasonable, but the "bigger picture" of blasting through the gas from our own land is frankly obsurd - we have gas lines linked to Belgium and The Netherlands that we should be utilizing to the max and keeping our own reserves. (Side note, but we do finally have the capability to export to The Netherlands as well as Belgium).

Renewables as a concept are fantastic. However the reality of privatized energy generation is that they are a money sink due to the huge capital requirements and subsequent subsidies to keep them afloat; but it would be foolish to downplay how important they are to the grid today (discounting nuclear here) due to the loss of coal plants and decommissioning campaigns of gas and nuclear plants. You want true sustainable energy? Nuclear is the clear winner. However public opinion and environmental pressure groups put a stop to that years ago and causes the huge diverting of public policy away from that energy source.

The next few decades will be interesting from an energy perspective - there's no denying that further demand will become apparent due to the drift towards electrification (of many things, not just cars) that are the results of environmental policies. The energy shift we're going to see very shortly is towards hydrogen production and a real push for carbon capture. And due to our long exposure to offshore conditions it places us in good stead to achieve both. I'd recommend looking at the OGA (Oil & Gas Authority) and the feasibility study they released last month that goes over it in a little detail and how it will prove significant in the journey to move away from fossil fuels.

 

[Flake87]

I feel like this is probably going well beyond the scope of the thread and OP, but it's an interesting discussion point nonetheless. I work at a gas terminal so from a career-longevity perspective it's in my interest that gas keeps on being used for the decades to come - as it will - North Sea gas reserves are aplenty in the southern North Sea let alone the gas byproduct from oil production in the central and northern North Sea. As a means for electricity generation, CCGTs are terrible. Efficiency wise they're reasonable, but the "bigger picture" of blasting through the gas from our own land is frankly obsurd - we have gas lines linked to Belgium and The Netherlands that we should be utilizing to the max and keeping our own reserves. (Side note, but we do finally have the capability to export to The Netherlands as well as Belgium).

Renewables as a concept are fantastic. However the reality of privatized energy generation is that they are a money sink due to the huge capital requirements and subsequent subsidies to keep them afloat; but it would be foolish to downplay how important they are to the grid today (discounting nuclear here) due to the loss of coal plants and decommissioning campaigns of gas and nuclear plants. You want true sustainable energy? Nuclear is the clear winner. However public opinion and environmental pressure groups put a stop to that years ago and causes the huge diverting of public policy away from that energy source.

The next few decades will be interesting from an energy perspective - there's no denying that further demand will become apparent due to the drift towards electrification (of many things, not just cars) that are the results of environmental policies. The energy shift we're going to see very shortly is towards hydrogen production and a real push for carbon capture. And due to our long exposure to offshore conditions it places us in good stead to achieve both. I'd recommend looking at the OGA (Oil & Gas Authority) and the feasibility study they released last month that goes over it in a little detail and how it will prove significant in the journey to move away from fossil fuels.

An interesting post, but it does only cover the UK and some of Western Europe. We live in a finite world, and what we are doing is burning all the best stuff and leaving the worst for our grand kids (or later) instead of burning a mix and suffering some small consequences.

According to Reuters China has put 38.4 GW of new coal generation into production in 2020 alone. A further 250GW are planned for the future. We have our own coal reserves and there is no good reason we should be deforesting parts of the planet, grinding it up and shipping it halfway around the world to feed the fires at Drax. If coal is available then we should be using it as a mix of fuels.

 

[rangor gubbins]

Interesting discussion.
Thought I'd throw my experience of an ASHP into it.
We completely renovated a 100 year old solid walled house, and wanted to get rid of the LPG tank and boiler and make a more economical and environmental house. We managed it, but it took a lot of effort.
Our LPG gas bill used to be around £1500 per year, plus another £1000 for electricity (heaters, lights, cooking etc). Since the refurb we now pay around £1200 per year total. That's for our electricity which covers all our heating, hot water, cooking, and lighting.
Pretty big saving. We also get a payment of around £350 per year from our solar panels. So net electricity cost is £900 /yr, down from £2500/yr.
We added loads of insulation into the ground, walls (insulated plasterboard onto the solid walls), insulated the roof (two layers), plus insulated the loft floor. Installed UFH on ground and first floor. Double glazing throughout. Solar panels on the roof (32° and south facing). And an ASHP (nibe F2040). The ASHP installation was not cheap but the RHI grant will pay the entire cost over 7years.
The only thing I wish we'd had done is to put some batteries in, as I think that will half our electricity bills again.

Some tips for anyone thinking of installing an ASHP into an old solid walled house.
Use a reputable installer. We used Reina group and they were great. They have developed their own heating requirement calculator to make sure the house is suited to ASHP. This is really vital. It even factors in things like chimneys and drafts. You must know what your wall, floor, window, and roof U values are.
Adding solar panels can help lower the electricity running costs of an ASHP but ideally you also need batteries to help overcome the disconnect between heat demand and solar production. Once wind turbines get cheaper, adding a 1 or 2kw turbine will probably also help during the winter, depending on location of house.
You need to re-think your heating schedule with an ASHP. It works best when providing slow steady heat. Ramping up and then letting the house cool does not work well.
Use a good thermostat system and UFH if possible.

The ASHP does make some noise, but it loads quieter than our old boiler and quieter than our neighbours oil boiler.

A backup heating source can be a good idea for when the weather is wet and very cold. Our ASHP does struggle a bit when it's really cold and misty. Ice builds up on the heating fins, reducing heat recovery from the air. And the defrost cycle is energy expensive. This problem has only occurred for a few days each winter.

 

[ash_scotland88]

@rangor gubbins admittedly jealous/envious that you've achieved what you have. Feels like too many go out to achieve what you have done and fail and that's what put us off going ASHP to our property. Electing to get a gas installed, luckily just in their fixed price distance they still need to come back and finish as it's been a tricky site.

Ours is a 1930s house filled with original features so any planned work is a fine balance between modernisation and museum. Doesn't help the other half is quite tight fisted and often just wants cheapest and not the best, even falling out over it hence budget comes into play.

Again congratulations on achieving what many would like to do.

 

[rangor gubbins]

@ash_scotland88 . many thanks.
Whilst we have managed to dramatically cut our bills with the ASHP, I suspect the insulating work we did to the house means that if we had kept the LPG tank and boiler our energy bills would also have been loads cheaper than it had been before the renovation.
When i look at the U values the house had before and after the renovation, i think that was where the huge energy savings are made. In our case we really wanted to get rid of the gas tank as it was sitting in a terrible place and very difficult to site somewhere else. Putting in the ASHP allowed us to do that.
ASHP certainly aren't problem free, but then neither is gas/LPG or any other system. When we had LPG we ran out of gas one year, because snow meant we couldn't get a delivery. We had to rely on electric heaters for a day or two.

Renovations are not for the faint hearted! Always loads of stress. Working out when to save a few quid or spending a bit more to get it just right is super difficult.
Good luck, and just think it will all be worth it once its done.

 

[Mysterae_]

@rangor gubbins thanks for your thoughts.

I have an assessment booked later in the month with Home Energy Scotland to decide the best approach. I have the land for the horizontal slinky array for a ground source heat pump but the biggest factor is underfloor heating or bigger rads. We don't like the thought of bigger rads and being a concrete floor UFH will be difficult although not impossible to install. It'll be interesting to find out if the UFH install is covered by the RHI scheme, otherwise it'll be another £10k on top of the GSHP install. The maximum RHI payback I've estimated is £28k over 7 years.

If it doesn't cost in I'll probably just replace the oil fired boiler with a new model and continue burning wood in the biomass boiler when oil gets expensive again.