The Trouble with Heat Pumps Part 4

This is the last in a series of four posts where I have tried to challenge some of the over-selling and hype surrounding heat pumps. The start of this four post series is HERE.

In this post I want to look at the concept some people promote of a mass national replacement of gas boilers with heat pumps.

The purpose of this mass adoption would be to replace the current usage of natural gas for domestic heating. This would be done solely to cut Carbon Dioxide emissions. It would serve no other purpose. 

Currently 85% of UK homes are heated by natural gas. So this replacement concept is not for the faint hearted.

Last year domestic gas use was 310 TWh.  (Cooking accounts for under 3%) (DUKES spreadsheet HERE)

Meanwhile the entire national usage of electricity was 324 TWh (DUKES pdf Here)

In other words, gas usage for domestic heating (mostly over a short 4 month period) more-or-less matched the entire electrical generation of the UK for all types of use over the full year.

So if we assume that domestic heat pumps can deliver 3:1 energy output when compared to gas, then nationally we will need an extra 100TWh/year of electrical generation to drive their compressors. (The 3:1 is a big assumption – See last post Here)

An extra 100TWh is roughly equivalent to an increase on current generation of 30%. This though does not account for the fact that most of that 100TWh will be required over a four month period and the generation capacity will be surplus to requirements in the summer. But never mind.

So how can this be powered? Of course the "green" solution would be to use solar and wind. In my opinion neither solar or wind could remotely address the demands placed on them for this. But never-the-less, lets look at them and skim over their lack of capability where possible.

Solar. Sadly the incapability of solar in winter is so marked it is impossible to skim over it's failings. In winter there is little sun. So there's little electricity generated. It's probably best for me to let the Centre Alternative Energy explain it to those who disbelieve me. (HERE - see Q&A at end)

Wind. Currently the existing Wind turbine fleet intermittently generates about 20% of current UK demand. There are, in total around 11,000 wind turbines both onshore and offshore in the UK. If we forget about intermittency, grid connectivity, site availability, storage, sea bed damage and impact on those living nearby we would need another 16,500 turbines, just to cover domestic heat pump use in homes.

 The current wind fleet has cost well in excess of £50 Billion to build and only functions due to massive on-going government subsidies. An additional 16,500 turbines would add another £75 billion.  But it doesn’t stop there. Increasing the carrying capacity of the Grid  as well as connectivity, backup supply and cabling would add at least another 25 – 50 billion.  Say a £100 billion all-in – and that, I would suggest, would be wildly optimistic.

But really that is small beer compared to the cost of installing the heat pumps themselves.  Half of the cost is installation and groundwork and so is fixed. Even if we assume the price of the hardware halves we are still looking at £12,000 per installation averaged across GSHPs and ASHPs.

Lets assume the target installation is in 19 million homes.  (As suggested on record by  Committee on Climate Change and also stated HERE ) So the cost of installing heat pumps in these 19 million homes comes out at a whopping £228 Billion.

So all in, to convert 19 million homes to heat pumps would cost well in excess of £325 billion.

In essence we would be spending over £325 Billion to  replace a perfectly serviceable (and more capable) gas supplied heating system. We would be doing this in order to cut Carbon Dioxide emissions from the cleanest fossil fuel available while plenty of dirtier targets remain.

Even if you substitute in more realistic and capable methods of generation (like nuclear - or even gas!) the figures are still ruinously huge. 

Reduce the adoption rate the figures remain ruinous, just less so. It is only when you get to very low rates of adoption (like today) that the pain reduces and heat pumps can run off existing electrical supply without the need for more infrastructure. 

Mass adoption of Heat pumps to replace gas boilers is a non-option. They are less capable and cost far more to install and run than the condensing gas boilers they are supposed to replace. Even so, there are lunatic plans in place to ban new gas boiler installations in new build properties by 2025. (See Here) 

On the plus side heat pumps do make great talking points down the golf club or in a Green Peace meeting and are marvellously fashionable and very, very politically correct. Sadly though when it comes to heating the average home they are not in the same league as condensing gas boilers.

Without the governments bribe Renewable Heat Incentive, uptake would peter-out to nothing. The zealots and the rich would baulk at the cost. Even with the current bribe the take up rate is so pitiful that it would take 700 years to replace all 19 million gas boilers

So how can we reduce Carbon Dioxide? More to the point how can we reduce Carbon Dioxide at significantly less than £500-£600 a tonne? These are difficult questions. 

But clearly, heat pumps do not provide the answers. 

To pretend they do is criminally irresponsible.