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Comment by Gordonjcp | Hacker News Reader

Well, it doesn't sound like they know much about the geography or geology of the UK, quite frankly.

How is every house builder going to afford a million quid borehole?

I don't think the original claim is quite right. The UK govt is banning new gas boiler installations after 2025, but I believe there's a range of alternatives such as an air or ground source heat pump, or a hydrogen boiler.

From what I've read through, replacing my boiler with a gshp would cost in the tens of thousands, not a million pounds.

How would a hydrogen boiler work? Hydrogen trucks deliverying? Is the UK piped for hydrogen? Electrolizing water on site?

Somehow all the leaky old cast iron pipes that just about suffice for carrying gas around the country will be able to be used for hydrogen Real Soon Now, and everyone will be able to just go out and buy a new £6000 boiler to replace the natural gas ones they had fitted recently.

Then all we need to do is start turning the natural gas into hydrogen - releasing just as much carbon dioxide as burning it does - and we've got a clean green hydrogen economy!

The plan is to convert the existing pipe network to use hydrogen. British Gas are planning to trial it starting with a village of around 2000 homes next year. Meanwhile modern boilers are often being sold as "hydrogen-ready" in preparation for the switch.

Ground source boreholes are mostly 10-15 metres deep, so not wildly expensive, especially when part of a new construction. You may be thinking of classic geothermal bores? Drilling down to proper hot-rocks would be a much costlier scheme in most of the UK.

Wonder if you could drill centralised borehole and then use retrofit old gas lines to move compressed refrigerant…

> Drilling down to proper hot-rocks would be a much costlier scheme in most of the UK.

Is this something people do?

Big buildings do. They often have to go down that deep for foundation pillars anyway.

You don’t need a borehole at all. Ours uses coils of pipe that are about 1m deep.

So, not really suitable for most of the north-west then.

I skimmed the plan and didn't find any requirement to use a ground to water heat pump. Air to water devices are mentioned several times as viable heat pumps for this plan. These do not require boreholes.

I think the UK is effectively banning gas boilers and its upto the developer/consumer to choose an alternative - a combination of CHP (local heating), GSHP, but most likely air source heat pumps.

Almost all heat pumps in the UK being installed these days are air-source.

Those work in hot dry countries. Lots of the UK - in particular the north-west - is neither hot nor dry.

Up here you end up with the outdoor part freezing into a block of ice.

I live in a similar climate and have never once had this problem in the winter. Something is wrong if this is happening to you.

Every one we've got fitted around sites at work freezes up in the rain. Given that they have to be outside, I'm not sure how to solve that.

Incorrect. Try a quality brand like Mitsubishi or Thermia.

These are all Mitsubishi ones, fitted by the manufacturer's recommended installer.

The problem is that the outdoor part has to be, well, outdoors, and that's where all the water is.

Canadians have air source heat pumps with backups that get used ~5-10 days a year...

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