ASHP v Gas boiler

[K78]

Stumbled across this https://www.greenmatch.co.uk/blog/2016/02/pros-and-cons-of-air-source-heat-pumps

 

It says that ASHP is not the best option if mains gas is available. 
 

Would others agree?

[nod]

We decided against ASHP

for a couple of reasons 

I think if your home is well insulated bills will be low regardless of which system you choose 

[Dreadnaught]

Yes, if its available gas-over-ASHP was the consensus view that I picked-up from a couple of years of solidly reading this site.

 

There is a gas main is in the access road immediately in front of my plot. And so gas it is for my new planned modern bungalow, which is sufficiently small that I can use just a combi-boiler.

 

From a purely intellectual perspective, I would love to skip gas altogether and go electricity-only. But the economic perspective does not support this (yet). The initial capital cost for an ASHP is much higher than a combi-boiler and the payoff of an ASHP is not sufficient.

 

Furthermore, at least for now, any buyer of my dwelling is more likely to have more confidence in a gas boiler than an ASHP.

[Conor]

Same view as above. Gas is about 5p per unit, putting it in the same range as a typical ASHP, but you can get a gas boiler for a few hundred quid.

 

Personally, I'm now going for a ASHP. This is because of my low heating demand that means I can use a 5kw monobloc ashp that can be bought for lass than £2k, and I can install it myself. That makes is near enough that same cost of a gas install (current house gas boiler install cost £2300). And, if I operate the ASHP on night tariff, it becomes significantly cheaper to run than a gas boiler.

 

Another big reason is I want to minimise the life time CO2 emissions from the house, gas is 100% fossil fuel based energy and an ASHP has the potential to be 100% renewable

[Ferdinand]

Personally I think I see the gas grid being capped off to new connections before long.

[nod]

Which ever system you choose 

A well insulated house does need much heating 

We never heat the first floor and have the UFH stats set at 18 The temperature rarely drops and when it does the boiler kicks in for a few minutes 
It costs peanuts to to run

But I do agree at some stage soon new builds will not have the option of gas 

[epsilonGreedy]

2 hours ago, Conor said:

And, if I operate the ASHP on night tariff, it becomes significantly cheaper to run than a gas boiler.

 

 

Worth noting that even the leading eco self builders on this forum concede they do not achieve 100% heating off night time tariffs. Best assume 70/30 split (night/day) in your ££ calcs or worse if your build fall well short of passiv house standards.

[joth]

And here's an article from 2011 stating diesel is the best option for a new car, not petrol

https://www.telegraph.co.uk/motoring/green-motoring/8461146/Petrol-versus-diesel-economy-challenge.html

 

Parallels with this ASHP debate:

1/ the equation is dynamic and will change over time, so an article from 4 years ago may not be valid today, and certainly won't be at some point in the future.

2/ the way we define "best" tends to be purely in terms of direct economic payback, but as we found with diesel there can be other factors that people may make their spending choices on that go beyond the purely economic.

 

All that said, yes I think the economic evaluation it is still in favour of gas. Yet we're currently in the process of cutting of the gas to our house and going the other way to ASHP, for the several of reasons mentioned above and also it's a leap of faith that by the time we sell (at least 10 years) we think/hope/trust this will be common enough it won't be seen as a drawback. Time will tell!

 

[SteamyTea]

8 minutes ago, epsilonGreedy said:

Worth noting that even the leading eco self builders on this forum concede they do not achieve 100% heating off night time tariffs. Best assume 70/30 split (night/day)

I achieve ~85% on the night rate, and 100% heating and hot water.

And I am wasteful with hot water.

Edited January 23, 2020 by SteamyTea

[epsilonGreedy]

2 minutes ago, SteamyTea said:

I achieve ~85% on the night rate, and 100% heating and hot water.

And I am wasteful with hot water.

 

 

I recall your heating is 100% electric storage radiators? I wonder how your daily heat release profile compares to ASPH heating a concrete UFH floor as the slab lacks the thermostatic heat release controls of your radiators.

 

It is unfortunate that people want peak sitting room temperature between 7pm and 10pm which is 13 hours after the nighttime tariff ceases. 

[epsilonGreedy]

16 minutes ago, joth said:

1/ the equation is dynamic and will change over time, so an article from 4 years ago may not be valid today, and certainly won't be at some point in the future.

 

 

This can work both ways, something the eco protagonists overlook. Consider vehicle tax bands, when the car industry did such an effective job of introducing low CO2 sub £30 p/a engines, the Government had to rewrite the tax rules to reestablish overall revenue levels.

 

If 1/2 of the nation's gas boilers converted to nightime powered ASHP, overnight supply & demand would shift out of balance and the night time tariff will increase. Then add in the forecast collapse in nuclear generation capacity over the next 10 years and rising demand from electric vehicle charging and we will likely see further erosion of the nightime price advantage.

 

Conversely softening demand for gas should result in soften prices.

[K78]

16 minutes ago, epsilonGreedy said:

 

This can work both ways, something the eco protagonists overlook. Consider vehicle tax bands, when the car industry did such an effective job of introducing low CO2 sub £30 p/a engines, the Government had to rewrite the tax rules to reestablish overall revenue levels.

 

If 1/2 of the nation's gas boilers converted to nightime powered ASHP, overnight supply & demand would shift out of balance and the night time tariff will increase. Then add in the forecast collapse in nuclear generation capacity over the next 10 years and rising demand from electric vehicle charging and we will likely see further erosion of the nightime price advantage.

 

Conversely softening demand for gas should result in soften prices.

Will be interesting to see what happens as we are pushed toward electric cars and homes. We don’t have the capacity to cope.

 

I wonder how much co2 all those lithium mines will create?

 

I was watching someone argue that forests are growing and deserts are shrinking due to current co2 levels in the atmosphere. He wasn’t wearing a tin foil hat either.

 

It is difficult to gage anything these days. Every argument is toxic and it seems everyone HAS to pick a side. Reasonable debate is not part of today’s culture unfortunately.

 

Edited January 23, 2020 by K78

[SteamyTea]

14 minutes ago, epsilonGreedy said:

Conversely softening demand for gas should result in soften prices

Only temporarily. 

 

15 minutes ago, epsilonGreedy said:

Consider vehicle tax bands, when the car industry did such an effective job of introducing low CO2 sub £30 p/a engines, the Government had to rewrite the tax rules to reestablish overall revenue levels

Isn't that what governments are for.

They have a difficult balancing act to do, so they have to change policies and tax rates as things change.

[SteamyTea]

1 minute ago, K78 said:

 

I wonder how much co2 all those lithium mines will create?

At the moment most is produced by evaporation, so 100% renewable.

Lithium isn't the major issue anyway.

[SteamyTea]

32 minutes ago, epsilonGreedy said:

 

I recall your heating is 100% electric storage radiators? I wonder how your daily heat release profile compares to ASPH heating a concrete UFH floor as the slab lacks the thermostatic heat release controls of your radiators

Probably similar. And if I got some more modern storage heaters then I would have more control than I do now.

[ProDave]

6 minutes ago, K78 said:

I was watching someone argue that forests are growing and deserts are shrinking due to current co2 levels in the atmosphere. He wasn’t wearing a tin foil hat either.

 

It is difficult to gage anything these days. Every argument is toxic and it seems everyone HAS to pick a side. Reasonable debate is not part of today’s culture unfortunately.

 

I thought the problem was deforestation.  If someone thinks forests are expanding I would like to see his evidence.

[K78]

3 minutes ago, SteamyTea said:

At the moment most is produced by evaporation, so 100% renewable.

Lithium isn't the major issue anyway.

There are major issues with battery production though? Surely not all of that is petrol head nonsense?

 

It is so difficult to gage anything you read these days. 

[epsilonGreedy]

2 minutes ago, SteamyTea said:

Only temporarily. 

 

 

Yes if "temporary" is defined as 10 years ahead.

 

When the random factor of public policy is stirred into the forecasting mix who knows what will happen. I believe my economic predictions are sound though I cannot account for punitive CO2 taxation mandated by the UN or frightened local politicians. Punitive taxes are the biggest potential upset for a self builder installing a gas boiler today.

[SteamyTea]

Some forests are expanding. Just like some glaciers are.

But I am pretty sure that on average, both are shrinking.

 

[K78]

Just now, ProDave said:

I thought the problem was deforestation.  If someone thinks forests are expanding I would like to see his evidence.

Randall Carlson. He says global satellite mapping discovered a lot more forest growth than was predicted.

 

kind of makes sense that high co2 would benefit plants. 
 

 

[Ferdinand]

15 minutes ago, ProDave said:

I thought the problem was deforestation.  If someone thinks forests are expanding I would like to see his evidence.

 

UK or worldwide?

 

afaik Uk forest cover has been gradually expanding since WW1 ... by several % of land area. FC have the numbers.

 

One example is that National Forest south of Derby which has added 200sq miles since 1995.

Edited January 23, 2020 by Ferdinand

[epsilonGreedy]

3 minutes ago, ProDave said:

I thought the problem was deforestation.  If someone thinks forests are expanding I would like to see his evidence.

 

 

Rising CO2 is a benefit for plant life because over a geological timescale vegetation today struggles with the relatively low CO2 levels of the present, this is because photo synthesis evolved in a period of much higher CO2. Rising CO2 allows plant life to consume less water and hence flourish in marginal desert conditions. Even NASA concedes the earth has been greening up for a few decades as CO2 increases, the problem however is that geologists have fairly convincing evidence that the earth will eventually warm up and drown coastal cities under 30m of sea water.

[andyscotland]

27 minutes ago, K78 said:

Randall Carlson. He says global satellite mapping discovered a lot more forest growth than was predicted.

 

kind of makes sense that high co2 would benefit plants. 

 

At a total guess:

* Forests that are left to their own devices are growing faster than expected due to higher availability of CO2

* Simultaneously humans are cutting and clearing forests much more rapidly than in the past

 

Entirely possible for both of these to be true. 

 

Also possible for the percentage increase in growth rate to be significant looking only at growth, but to be a tiny figure relative to the rate of human deforestation.

[K78]

21 minutes ago, epsilonGreedy said:

 

Rising CO2 is a benefit for plant life because over a geological timescale vegetation today struggles with the relatively low CO2 levels of the present, this is because photo synthesis evolved in a period of much higher CO2. Rising CO2 allows plant life to consume less water and hence flourish in marginal desert conditions. Even NASA concedes the earth has been greening up for a few decades as CO2 increases, the problem however is that geologists have fairly convincing evidence that the earth will eventually warm up and drown coastal cities under 30m of sea water.

Yet you never see any of this on the news. Just the rising sea levels and melting glaciers. 

 

It is such a important issue, but I get the feeling all the “green” government interventions are just stealth taxes. It’s so hard to believe anything they say. 
 

When they pushed us all towards “greener than petrol” diesel cars it seemed confusing to my simple mind. The only cars/trucks with black smoke blowing out of the back I see have been diesels since I was a kid. Now they say the opposite. 
 

Imo the biggest ecological disaster on the planet currently (other than the human population) is the amount of plastic (and other crap) in our oceans. That is one thing we know for sure we are 100% responsible for.

Edited January 23, 2020 by K78

[SteamyTea]

7 minutes ago, K78 said:

all the “green” government interventions are just stealth taxes

I think it would be better to just be open about taxes.  We don't really have an issue with 'sin' taxes anyway, and they are good at changing behaviour.

It also seems odd that we don't tax at a higher level the things that are easy to tax, but we tax at a low level the things that are hard to tax i.e. income tax v corporation tax.

I would like to see a large sign on council owned carparks justifying the charges and fines.  Something along the lines of:

'Little of the cash raised here go to keeping the crap shops in the High Street'

Or

'Taxing the local workers because the government has reduced income taxes too much'

Or, how about.

'We privatised this as we don't give a (expletive deleted) for you'

That last one would look good on an NHS carpark.

https://www.fleetnews.co.uk/news/manufacturer-news/2020/01/21/jaguar-i-pace-offered-via-nhs-salary-sacrifice-scheme