By Paul Homewood

https://www.theccc.org.uk/publication/net-zero-the-uks-contribution-to-stopping-global-warming/ 

I have now obtained some more detail from the Committee on Climate Change regarding their plans to decarbonise household heating, which are contained in their Net Zero document.

You may recall that they put a cost of £15bn a year on this:

It now turns out that this figure is based on some extremely dodgy accounting, and that the true cost is in the order of at least £28bn a year, equivalent to over £1000 per household. But more on this later.

In simple terms, there are effectively two primary ways to decarbonise heating in homes:

1) Heat pumps, powered by renewable electricity

2) Hydrogen.

There is also a third way, called hybrid heat pumps, which combine the two together.

Conventional electric resistance heating is ruled out as it is far too expensive and would create insuperable problems for peak loading on the grid.

District heating may also be able to make a small contribution, but of course this is not zero carbon in reality.

It is worth pointing out that the CCC’s proposals for Net Zero would all be needed to hit the current target of an 80% cut in emissions by 2050, as far as decarbonising heating is concerned. The only exception would be heritage homes, which could not be readily converted.

According to the CCC, the total costs of the three scenarios are believed to be fairly similar. But let’s look at them individually:

Heat Pumps

The CCC’s Core Scenario (that is for the current 80% target) assumes that 17 million homes will be required to fit heat pumps. Under the Further Ambition scenario, (to achieve 100% decarbonisation), this figure rises to 19 million. Most of these would be air heat pumps.

The CCC’s costings for heat pumps are based on a study for BEIS in Dec 2017 by Element Energy here.

According to that study, an air source heat pump (ASHP) would cost £8975 to install, compared to £1570 for a conventional gas boiler. Note that the former includes the cost of replacement radiators, as existing ones are unlikely to be compatible. Also a hot water tank would need to be added.

Significantly however, no allowance is made for the cost of extra insulation. It is generally accepted that heat pumps are ineffective without good insulation, which would likely cost thousands more.

 

Running costs for ASHPs are about £100 pa higher than the conventional boiler:

 

Element Energy assume a life of 15 years, so given an APR of 5%, lifetime costs would look like this, excluding insulation:

	Boiler	ASHP
Capital Cost	1570	8975
Interest	589	3366
Fuel Costs	7770	9150
TOTAL	9929	21491

 

In other words, home owners would be £770 a year worse off.

The CCC acknowledge that full electrification of heating would cause problems for peak loading of the grid in winter.

As Element Energy pointed out in their report:

The concept of hybrid heat pumps is that, while the heat pump provides low level heating, a gas boiler takes over for peak heating needs. This of course begs the question of what to do with the emissions from the gas!

The CCC’s solution is to use hydrogen instead.

Hydrogen

In their Hydrogen in a low-carbon economy report, the CCC have ruled out electrolysis playing any significant role in heating, due its high cost and lack of scale. [Most of the quotes and tables below come from this report, unless otherwise stated].

 

Which leaves steam reforming. However this process also produces CO2:

For it to be low carbon, CCS technology would need to be added. However, even CCS does not eliminate CO2 completely:

Furthermore, steam reforming with CCS is a wasteful process as far as energy is concerned, so more gas would be needed to produce the same amount of energy than if it was burned directly in homes. Therefore the extra carbon dioxide emissions upstream also need to be taken into account.

But what about the costs?

A national switchover to hydrogen would require conversion of household appliances and modification of mains networks. This is estimated to cost between £50 and 100bn.

In addition, the cost of producing hydrogen from gas, and stripping out the carbon dioxide will naturally cost a lot more than burning the gas itself in homes.

The CCC put the wholesale cost of producing hydrogen at £44/MWh, ie excluding the cost of distribution.

The current price of natural gas used in these costings is assumed at 67p/therm, which equates to £23/MWh. In other words, the wasteful hydrogen production process adds £21/MWh to the cost.

Given average household consumption of 16000 KWh, gas bills would rise by £336 pa under this scenario. This would not include the £100bn needed for conversion.

Hybrid Heating

In reality, the CCC’s plan will require national rollouts of both heat pumps and hydrogen heating.

A “full hydrogen pathway” would need investment in massive amounts of steam reforming capacity, probably create  impossible demands on storage capacity,  and would also lock in large amounts of residual emissions.

On the other hand, full electrification would place impossible demands on the grid in cold weather.

Even the hybrid solution will pose mammoth problems for grid capacity and hydrogen infrastructure.

Costs

Which brings us back to overall costs.

Let’s see what the CCC have estimated:

So, £28bn a year. If we assume 25m homes on the gas grid, that equates to £1120 per household every year.

Just look as well at the last sentence:

These cost numbers assume a reduction in average household heating consumption from around 14 MWh per annum today to around 10 MWh per annum in 2050.

 

The CCC seems to have counted the savings from energy efficiency, but not included the cost of fitting insulation! So the real cost to householders will be greater still.

A reduction of 4 MWh would save about £200 per household. In other words, the true cost of decarbonising is not £1120, but £1320 per home.

All of this, according to the CCC, must start during the next decade, if 2050 targets are to met.

But if the extra cost is going to be £28bn a year, where did that headline figure of £15bn come from?

It turns out that the CCC have dishonestly offset the extra costs of heating against supposed non-heating energy efficiency savings we might be making by 2050:

 

[The first box with 27 TWh relates to homes, and the 35 Twh is for non-residential.]

 

There is no guarantee that these energy savings will ever materialise. Nor is the extra cost included that we may have to pay to purchase such appliances.

But what we do know for sure is that the CCC’s plans to eliminate the use of natural gas for heating and cooking will cost all of us dear.

via NOT A LOT OF PEOPLE KNOW THAT

http://bit.ly/2WQqA4g

June 7, 2019 at 05:46AM