No more gas boilers? You must be joking!

As has been noted elsewhere, reducing the UK gas consumption will be much harder than it was to increase it when north sea gas came ashore in the 1960s and the following decade when most of us saw ‘central heating’ for the first time, and new generations got out of the habit of using hot water bottles in winter and scaping ice off the inside of the windows in the morning.

To some degree that cooler life will need to return, but we also have the option to make our buildings a lot less lossy, and that is a better place to start. A straight swap of wasting electricity instead of wasting gas, even with heat pumps and the like, will help no-one, especially while it is still gas burnt to generate half the electricity. And as you note the distribution will not stand it.

It is not as sexy but I firmly believe that polyurethane foam and rockwool will save moremoney and more lives than fancy boxes with lots of electronics in. Pity really as  I design the latter  for a living…

Mike

Interesting. I see there is an option to have hydrogen gas replace natural gas in homes, has this been evaluated as an option For the uk rather than heat pumps? I believe New Zealand is taking this path. My follow on question is do we have a plan? Or is this evolving (make it up as go along). I have found some interesting papers on current and past energy mix but is there a strategy? Eg convert existing gas networks to hydrogen, quadruple wind power to create the hydrogen during off peak. Get nuclear up to 30 per cent, increase overall capacity from 75.8GW to 100GW . Stop natural gas, coal, wood pellets …alll by 2023….wishful thinking i know. So far I have failed to see a plan for electricity generation or gas…is there such a thing?

In the short term, we could add a little hydrogen to the natural gas.  Like our petrol is now 10% bio-ethanol.

But 100% H2 would require new boilers, or at least the old ones adapting.  We managed that when we went from town gas to natural gas.

But if the H2 is going to be green and affordable, it needs to be generated from spare electricity.  That means over-building wind and solar, then on windy or sunny days, generate H2 and store it somewhere.  If only we hadn't removed all our gas storage in the UK.

In May 2021, the RAEng produced a report on electric vehicles. Chapter 10 details load demand on the grid and so on. Figures 19-24 are particularly interesting. The grid as it was then could not cope with large numbers of electric vehicles doing what people did in 2010 with their cars and trucks.

https://www.raeng.org.uk/publications/reports/electric-vehicles

 If we now add building heating to that, then I think Andy is quite right to worry.

In 2013, the Academy produced a report on GB generating capacity and its margins, in response to a request by The PM's Council for Science and Technology

https://www.raeng.org.uk/publications/reports/gb-electricity-capacity-margin

(Disclosure: I haven't read it)

As for hydrogen, Bill Gates has suggested it could be used as a means of electricity storage. I can't see using it as a building energy supply for any except the most well-protected and supervised buildings well away from anything else. It is exceptionally explosive when it meets oxygen. Remember what it did to the reactor buildings at Fukushima Daiichi after the tsunami?  My building has gas central heating and there is no way you could get me to accept hydrogen coming in in any great quantity. That's even before I talk to my insurance company…….

Mike is surely right that good insulation is part of any solution. However, it is not inexpensive – for my building, I haven't been anywhere near to affording it for 15 years. Roof insulation is relatively cheap and brings you 25% – that is worth it; I've done it and the 25% is real. For the rest, cladding the walls has downsides (condensation build up and mildew. German installations are guaranteed for five years, but five years ain't long) and new windows+frames are not cheap.  

So we are talking revolutions in electricity supply, in energy for heating, and in energy-efficient building mods. Not a small ask.

Certainly the hydrogen blending is being tried, and seems to work well, though it is very much at the experimental learning stage, so not ready for part of the bigger plan. 

At low pressure H2 is not so bad - here  in the days of coal gas we had about 50% hydrogen and a far more laid back approach to thin wall lead pipes, string and pitch seals on threaded joints, and there were not many accidents, more carbon monoxide poisoning than explosions actually, although CO was only 10-20% of the mix. We'd need to add a stinking agent as we do to methane, and perhaps something to make the flames visible. Domestic gas supply in the UK is at  a pressure that struggles to blow bubbles in a milk shake - 20mbar is about 8 inches of water.

Oddly I had cause to remove a dead length of former gas pipe from my house some years back, and as I unscrewed the joints I was greeted by the “town gas smell” I only recognised from childhood. Presumably prior to about 1970 the coal gas had diffused into the thread seals and became trapped, and the next 40 odd years of use with methane did nothing to shift it.

The next 40-50 years will see change again, but we will only see the beginning of course.

Mike

My mother once asked me whether she should get rid of her old gas fire she rarely used, in the lounge. Her house was central-heated and the radiators kept her warm enough.

My advice was, provided the gas fitter certified it as safe, keep it as a standby. In the unfortunate circumstnce of an electric power failure, it would provide a means to keep the lounge warm. Turn on the gas oven and keep the kitchen warm too. That's two rooms kept warm. Heat would migrate to other rooms to take the chill off them.

It seems that the prospect is less reliability of electricity power supply. Already, given the urge to shut down coal-fired stations, we are operating on a narrower load margin than previously. The prospect of rising demand for electricity for electric cars and heat pumps, combined with the demise of non-renewable sources, makes me wonder how well our national grid will grow to meet this demand.

I can well understand the strong interest in heat pumps; their effective efficiency of up to 300% is well worth pursuing. They do have their problems, however, apart from the well-publicised expense. Ideally they need an outside wall - added problems if this is not practicable. They can't heat the water so warm. Not a big problem for a new installation, but if retrofitted, the radiators may need to be replaced with much bigger ones; possibly piping may need to be upgraded.

Air source or ground source? Each has its potential problems.

How will air source systems cope with external conditions of low temperature and high humidity? That sounds like a formula for build-up of frost on the heat exchanger, reducing its effectiveness. Fan assistance may help but fans can be noisy; consider the nuisance effect on the neighbours if these should become widely used. Also, the fans consume power, reducing the efficiency of the whole set-up.

Ground source, I have been told by someone with specialised knowledge, works well and reliably. The temperature a metre below the ground surface is fairly constant and there is a lot of thermal mass there, so this can work well, especially when the air temperature outside is below freezing. But there is a lot of expense and disruption in digging up the ground to bury the element. I wonder what the long term will be on the ecology of the soil if these are installed en masse. I anticipate a gradual cooling; would we be approaching permafrost conditions?

I live in the hope that someone will one day come up with a way to apply carbon capture and storage on a small scale to gas boilers. We could keep them after all.