Another reason for switching to HPs nationally

[Beelbeebub]

Tenuously connected to HPs but

 

https://www.theguardian.com/environment/2023/aug/06/ulez-just-the-start-and-similar-scheme-needed-for-buildings-experts-warn

 

The gist is nitrogen oxide pollution from building heating is going to be an increasing issue in urban areas as the pollution from vehicles falls away.

 

Nitrogen oxide pollution is a (near) unavoidable side effect of combustion. In fact the more efficient your device, the higher the combustion temps and more nitrogen oxides you put out.

 

The only way to avoid these pollutants is to use electric, which means heat pumps*.

 

*I suppose the calculation has to be the additional cost of a heatpump system over a direct electric system Vs the additional cost of the extra power generation required.for a direct electric system.  

[dpmiller]

there are technologies in vehicles and in industry to deal with NOx

[SteamyTea]

Really comes down to combustion technology is a bad thing.

How different the world would be if electricity was the primary energy source and not carbon//hydrocarbon energy.

 

There was this in my comic this week about timber, not all is rosy there, but we knew that.  Comes down to two thing, resource management and what is measured.

 

Building things with wood may not be as climate-friendly as thought

Wood is a versatile construction material that could be used to replace carbon-intensive steel and concrete in construction, however the emissions involved may have been underestimated

By James Dinneen

25 July 2023

 

 

 

Wood can be turned into sturdy replacements for steel and concrete

Shutterstock/Kletr

 

Using more wood for construction has been touted as a lower-emissions alternative to carbon-intensive steel and concrete but it may not be as carbon friendly as thought.

“It would be very convenient if wood were a better solution,” says Tim Searchinger at Princeton University. Wood is, in theory, a renewable resource and any wood used in buildings acts as long-term carbon storage. The advent of sturdy engineered-wood products like cross-laminated timber has also made it more versatile. Past research has found using wood for construction instead of concrete and steel can reduce emissions.

But Searchinger says many of these studies are based on the false premise that harvesting wood is carbon neutral. “Only a small percentage of the wood gets into a timber product, and a fraction of that gets into a timber product that can replace concrete and steel in a building,” he says. Efficiencies vary in different countries, but significant amounts of a harvested tree are left to decompose, used in short-lived products like paper or burned for energy, all of which generate emissions.

Many of those emissions may eventually be returned if forests are replanted or they grow elsewhere. But Searchinger says that won’t fly when we need CO2 out of the atmosphere now. “Over a long enough period of time you get a greenhouse gas reduction,” he says. “But in the interim you’ve increased warming.”

Searchinger and his colleagues modelled how using more wood for construction would affect emissions between 2010 and 2050, accounting for the emissions from harvesting the wood. They considered different types of forests and how different fractions of wood going towards construction would change the calculus. They also factored in the emissions savings from replacing concrete and steel.

In some scenarios – such as in fast-growing plantations in Brazil – the researchers found significant emissions reductions. But each of those cases required what they considered an unrealistic portion of the wood going towards construction, as well as rapid growth only seen in warmer places. Growing more trees might help, but they found land for such plantations isn’t available, and clearing existing forests would make the problem worse.

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In general, they found a large increase in global demand for wood would probably lead to rising emissions for decades. Accounting for emissions in this way, the researchers report in a related paper that increasing forest harvests between 2010 and 2050 would add emissions equivalent to roughly 10 per cent of total annual emissions.

[ProDave]

I keep saying this so apologies for repeating it.

 

There is no point switching to heat pumps for every house until there is enough green energy to power them.  If the whole of London switched to heat pumps tomorrow I bet a few mothballed coal power stations would be brought back on line to power them.

 

When are the environmental lot going to start talking about a properly planned progressive move to renewable heating at a rate that matches our ability to to build and bring on line more renewable electricity generation and update the grid to transport that extra power?  If there was such a well thought out plan, I would give them a lot more credability than I do now.

 

The other problem of course is one I have thought for a long time (and voted with my feet)  that if you all choose to live together crammed into such cities with such high population densities, then ANYTHING you do is going to reduce your air quality.  But I do accept we can't all live in low density rural housing.

[Beelbeebub]

1 hour ago, dpmiller said:

there are technologies in vehicles and in industry to deal with NOx

There are, catalysts and recirculation technologies for example. 

 

But that does add to the cost (and physical size and maintenance) of boilers and needs to be factored in.

 

A HP moves the combustion out of the point of use (to a power station) where it isless problematic (in terms of air quality) and can be delt with more economically.

 

 

[HughF]

43 minutes ago, ProDave said:

I keep saying this so apologies for repeating it.

 

There is no point switching to heat pumps for every house until there is enough green energy to power them.  If the whole of London switched to heat pumps tomorrow I bet a few mothballed coal power stations would be brought back on line to power them.

 

When are the environmental lot going to start talking about a properly planned progressive move to renewable heating at a rate that matches our ability to to build and bring on line more renewable electricity generation and update the grid to transport that extra power?  If there was such a well thought out plan, I would give them a lot more credability than I do now.

 

The other problem of course is one I have thought for a long time (and voted with my feet)  that if you all choose to live together crammed into such cities with such high population densities, then ANYTHING you do is going to reduce your air quality.  But I do accept we can't all live in low density rural housing.

You’ll use less gas if you burn it in a ccgt and stuff the resultant electricity into a heat pump instead of burning it on site in a condensing boiler.

 

No gas transmission issues, no gas risk in domestic properties.

 

More renewables is obviously a good thing, but I disagree that we should be holding back on the rollout even though we rely heavily on ccgt.

[JamesPa]

5 minutes ago, HughF said:

You’ll use less gas if you burn it in a ccgt and stuff the resultant electricity into a heat pump instead of burning it on site in a condensing boiler.

 

No gas transmission issues, no gas risk in domestic properties.

 

More renewables is obviously a good thing, but I disagree that we should be holding back on the rollout even though we rely heavily on ccgt.

Exactly, furthermore electricity capacity will only grow when there is demand, that's how markets work.  Demand and supply build together.  That's ok and the argument by @HughFmakes it doubly ok.

Edited August 6, 2023 by JamesPa

[ProDave]

8 minutes ago, JamesPa said:

Exactly, furthermore electricity capacity will only grow when there is demand, that's how markets work.  Demand and supply build together.  That's ok and the argument by @HughFmakes it doubly ok.

The market for renewable generation is there already.  Even with no more heat pumps. There is a market for more renewable generation until we are not burning any fossil fuels for electricity generation.

 

It should not be left to market forces, there should be a plan stating how much renewable generation is needed and by when and then everyone know how it will happen and when rather than guessing and I suspect hoping.

[SteamyTea]

50 minutes ago, ProDave said:

There is no point switching to heat pumps for every house until there is enough green energy to power them

Yes you do keep saying this.  The same argument is used by the anti-EV lobby as well.

How fast do you want this change, and how much are you will to contribute to it.  Are you willing to help stop some of the perpetual myths about renewable energy.  What societal changes are you willing to put up to reach these goals.

 

The 'renewables' industry is not a single pressure group, it is many dispersed groups ranging from individuals spouting their hobby horses i.e. me and Chris Packham, farmers, local councils, to government departments i.e. Department of Energy and Climate Change.

They all have different motivations and aims.

Why I keep to the same story that combustion technology is a bad thing and using less primary energy is a good thing.

 

As for renewables being built, it is happening quite fast, could be faster with a clean up of planning laws and stopping this pandering to local opposition groups. 

 

Environmental stewardship is not about standing still or changing nothing, it is about, using the best evidence available to improving the environment into the future.

Just yesterday, on the Radio, here and here, highlights the problems nicely, it highlights that a lot of people genuinely believe that the problems of renewable energy delivery is either insurmountable, or too expensive, or relies on some magic storage, or a tidal barrage between Devon and Wales.

 

What gets my goat about the whole climate change/ energy debate is the polarisation.

Wind Turbines get heavily criticised because the old blades get sent to landfill (which is only partly true), PV gets criticised because of the 'toxic chemicals' used in manufacturing.  It is as if the no other manufacturing industry has these problems, farming is the worlds largest polluter, should we all stop eating?

What really needs to happen is that we have to accept that to improve the environment i.e. less pollution of all sorts has to happen.  Then let the engineers, technicians and scientists find good ways to sole the problems, then the politicians, pressure groups and individuals have to sell it to the public.

Sell is the important part as it implies a price.

Just what price people will accept.

[Beelbeebub]

57 minutes ago, ProDave said:

I keep saying this so apologies for repeating it.

 

There is no point switching to heat pumps for every house until there is enough green energy to power them.  If the whole of London switched to heat pumps tomorrow I bet a few mothballed coal power stations would be brought back on line to power them.

 

When are the environmental lot going to start talking about a properly planned progressive move to renewable heating at a rate that matches our ability to to build and bring on line more renewable electricity generation and update the grid to transport that extra power?  If there was such a well thought out plan, I would give them a lot more credability than I do now.

 

The other problem of course is one I have thought for a long time (and voted with my feet)  that if you all choose to live together crammed into such cities with such high population densities, then ANYTHING you do is going to reduce your air quality.  But I do accept we can't all live in low density rural housing.

You are right, if we snapped out fingers and transformed every boiler into a HP, there would be an issue with electrical generation capacity.

 

This is a common objection.

 

I'm not sure it is valid.

 

Rough estimates put the heat value of gas burned for space heating as about twice the current electrical power generation of the UK.

 

If all of that were to be swapped for fleet of HPs with an average SCOP of 2.5 we would need to add about 80% of current capacity. If we hit an ambitious average of 3 it's only 65%

 

So how do we do it?

 

Gas power stations. Specifically Combined Cycle stations.  These take around 3 years to build (and that could be shortened if we get into the swing of things) and are more efficent than steam plants. 200MW costs about £100m

 

Let's say we need to double output, leave a bit left over for the electric cars.

 

We need another 75,000MW which is about 375 plants which would be £38bn. Time taken would be the bigger issue, every plant would provide enough elec to heat about 50k homes with HPs. The gov needs to go for 600k a year, so 12 new plants a year (£1.2bn)

 

Yes we are building fossil fuel plants, but the overall gas demand of the country falls.

 

Any renewables we build (which we should still be doing! At pace!) Would just mean we fewer new build CCGT plants.

 

In the future as we build out more renewables, the new CCGT plants would remain as the "cold, dark, still" backup option, maybe running a few weeks.of the year.

 

 

 

 

 

 

[HughF]

8 minutes ago, ProDave said:

The market for renewable generation is there already.  Even with no more heat pumps. There is a market for more renewable generation until we are not burning any fossil fuels for electricity generation.

 

It should not be left to market forces, there should be a plan stating how much renewable generation is needed and by when and then everyone know how it will happen and when rather than guessing and I suspect hoping.

Isn’t this already a thing? So many GWh of offshore wind by 2035…. I work indirectly in the offshore wind sector and we’re busier than ever.

[Beelbeebub]

7 minutes ago, SteamyTea said:

Yes you do keep saying this.  The same argument is used by the anti-EV lobby as well.

How fast do you want this change, and how much are you will to contribute to it.  Are you willing to help stop some of the perpetual myths about renewable energy.  What societal changes are you willing to put up to reach these goals.

 

The 'renewables' industry is not a single pressure group, it is many dispersed groups ranging from individuals spouting their hobby horses i.e. me and Chris Packham, farmers, local councils, to government departments i.e. Department of Energy and Climate Change.

They all have different motivations and aims.

Why I keep to the same story that combustion technology is a bad thing and using less primary energy is a good thing.

 

As for renewables being built, it is happening quite fast, could be faster with a clean up of planning laws and stopping this pandering to local opposition groups. 

 

Environmental stewardship is not about standing still or changing nothing, it is about, using the best evidence available to improving the environment into the future.

Just yesterday, on the Radio, here and here, highlights the problems nicely, it highlights that a lot of people genuinely believe that the problems of renewable energy delivery is either insurmountable, or too expensive, or relies on some magic storage, or a tidal barrage between Devon and Wales.

 

What gets my goat about the whole climate change/ energy debate is the polarisation.

Wind Turbines get heavily criticised because the old blades get sent to landfill (which is only partly true), PV gets criticised because of the 'toxic chemicals' used in manufacturing.  It is as if the no other manufacturing industry has these problems, farming is the worlds largest polluter, should we all stop eating?

What really needs to happen is that we have to accept that to improve the environment i.e. less pollution of all sorts has to happen.  Then let the engineers, technicians and scientists find good ways to sole the problems, then the politicians, pressure groups and individuals have to sell it to the public.

Sell is the important part as it implies a price.

Just what price people will accept.

People say "we can't switch over quickly" - yet ignore the fact we we phased out coal in a decade.

[HughF]

Technology connections (YouTube) has done a great series on the humble air-air mini split, and why the efficiencies stack up, irrespective of how carbon heavy the grid is.

[JamesPa]

21 minutes ago, Beelbeebub said:

How fast do you want this change, and how much are you will to contribute to it.  Are you willing to help stop some of the perpetual myths about renewable energy.  What societal changes are you willing to put up to reach these goals.

We have only two options.  Do it quickly and fairly painfully, or do it slowly/when we are forced to, but even more painfully, quite possibly fatally so and with societal consequences that make today's 'problems' look like nothing.  The option to do it slowly with little pain was passed up by us decades ago.

 

Politicians need to be honest with the public that this is the situation.  Then the choice becomes obvious.

 

Probability of that?

[Beelbeebub]

15 minutes ago, HughF said:

Technology connections (YouTube) has done a great series on the humble air-air mini split, and why the efficiencies stack up, irrespective of how carbon heavy the grid is.

Yeah. Minisplits, possibly r290, would be a great solution, especially if we could sort the ecosystem installers, planning, interoperability, end of life, user familiarity etc.

 

However we do seem to like our wet systems in the UK (and I can see the attraction)

[JamesPa]

10 minutes ago, Beelbeebub said:

Yeah. Minisplits, possibly r290, would be a great solution, especially if we could sort the ecosystem installers, planning, interoperability, end of life, user familiarity etc.

 

However we do seem to like our wet systems in the UK (and I can see the attraction)

With open plan becoming more popular A2A becomes more attractive to my mind.  Even where living areas aren't open plan (as in my house for example) doors are often left open.

 

However most don't have open plan bedrooms and also value quiet in these areas.  The combi of A2A for living areas, where most of the heat demand is, and A2W for bedrooms, where the demand is lower and other considerations come into play, might be attractive if it could be well packaged. Probably too complex to be practical though.

 

[Beelbeebub]

10 minutes ago, JamesPa said:

With open plan becoming more popular A2A becomes more attractive to my mind.  Even where living areas aren't open plan (as in my house for example) doors are often left open.

 

However most don't have open plan bedrooms and also value quiet in these areas.  The combi of A2A for living areas, where most of the heat demand is, and A2W for bedrooms, where the demand is lower and other considerations come into play, might be attractive if it could be well packaged. Probably too complex to be practical though.

 

This is what I mean by ecosystem.

 

If they sold a "manifold", basically a large shoe box with a water pump small expansion vessel and a PHX plus ports for refrigerant and a hydraulic flow/return, then you could connect whatever system you wanted to your outdoor unit. UFH, few rads, whatever.

 

The UFH bit is important as I think, with it's very low flow temps, it's about the most efficient emitter system you can get, but there is no way to use it with refrigerant directly.

[Beelbeebub]

The other ones to consider are the "through the wall" individual units.  Only 1 or 2 kw, but retrofit could be easier in some circumstances (external walls available and especially high properties like flats) with little external visual impact.

 

A really clever design would double as MHRV

 

Currently I think they are a bit too expensive - no cheaper than a single split system with less efficency and power.

 

If they could be got down to the £500 for a 2kw unit range, they would be very viable.

[SteamyTea]

23 minutes ago, Beelbeebub said:

The other ones to consider are the "through the wall" individual units

As a thought experiment, why don't we collectively design one.

I wonder what the power of the AC unit in my car is. There are millions of them about.

 

[JamesPa]

Sounds like a good idea and fun too. We could offer the result to cool energy.  Ditto for the solution to some of the other problems we have identified!

 

Perhaps we should start with a list?

[saveasteading]

1 hour ago, Beelbeebub said:

If they could be got down to the £500 for a 2kw unit range,

These are very common for  diy on the med.

Can be very cheap for unknown or own brands, and double for known names. They are designed for cooling though, and the heating coefficient is usually about 2.5.

I dont know if that is readily swappable so the heating is the more efficient.

 

[Beelbeebub]

16 minutes ago, saveasteading said:

These are very common for  diy on the med.

Can be very cheap for unknown or own brands, and double for known names. They are designed for cooling though, and the heating coefficient is usually about 2.5.

I dont know if that is readily swappable so the heating is the more efficient.

 

I think there is no reason the units can't be optimised for heating efficiency. It's just a question of world wide demand, with cooling being the bigger market.

 

 

[SteamyTea]

48 minutes ago, saveasteading said:

They are designed for cooling though, and the heating coefficient is usually about 2.5.

Possibly because of the temperature differences.

Take the South of France, not unusual to se 35°C.

Take the inside temperature way, say 22°C, that is 13K difference.

In the UK, during the heating season, that would be an outside temperature of 9°C.

There could possibly be defrost cycles when heating.

 

[DanDee]

15 minutes ago, SteamyTea said:

Possibly because of the temperature differences.

Take the South of France, not unusual to se 35°C.

Take the inside temperature way, say 22°C, that is 13K difference.

In the UK, during the heating season, that would be an outside temperature of 9°C.

There could possibly be defrost cycles when heating.

 

From mitsubishi, both same compressor size.

 

the AC loses efficiency due to the length of line set, both by losing temp and higher workload to achieve the same condensing pressure

 

the A/W has a compact refrigeration system, bigger evaporator, refrigerant receiver to optimize the unit

 

The AC is sold world wide, the A/W not so much. £1.5K vs £2.5-3k

 

[MikeSharp01]

3 hours ago, JamesPa said:

will only grow when there is demand, that's how markets work

Not sure this is exactly a perfect market as highlighted above

 

3 hours ago, Beelbeebub said:

overall gas demand of the country falls

some of that fall might be down to Gas costs!