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From my comic a few weeks back.

 

HOME HEATING

 

Many uses for hydrogen are mooted, but some are far from guaranteed to materialise. One is decarbonising home heating, with proponents arguing that countries, including the UK, could repurpose existing gas pipe networks to carry hydrogen and swap natural gas boilers for ones capable of burning hydrogen.

 

Leeds in the UK has been mooted as an early candidate for switching entirely to hydrogen instead of natural gas for heating and cooking, with a 2016 report by the local energy network finding the idea “technically possible and economically viable”. In November, the UK government said it would support a village-scale hydrogen heating trial by 2025.

 

Sceptics say it would be more efficient to use renewable electricity directly with heat pumps to warm homes, rather than losing energy by converting it to hydrogen first. A recent report by Jan Rosenow and a team at the UK Energy Research Centre concluded that there is so much uncertainty about hydrogen’s role in decarbonising heat that other options should be the UK’s priority in the next decade. These include networks that pipe heat to many homes from a large, central source such as an industrial plant, energy efficiency improvements and heat pumps.

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None of the data I have read mentions gas usage per Kw of heat and electricity produced although average efficiency across the year is reported as 192%... the cost of unit is quite high. Just about to start building and with the £7000 grants coming in April 2022 it might be an easier and more consistent solution than PV with ACHP. 

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51 minutes ago, gravelrash said:

although average efficiency across the year is reported as 192%...

 

But what I read, it did not make it clear what they were comparing the efficiency to. It seemed to be to a commercial natural gas reformer process, producing hydrogen, that doesn't capture the heat produced, hence this claimed efficiency that's moving the heat energy to a tank of water.

 

This doesn't appear to be a total heating solution, "just" an electricity generator that gives you some hot/warm water, and releases a lot of CO2 in the process.

Edited by IanR
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I understood that the unit uses a viessmann boiler unit to act as a backup heating/HW if demand exceeds the amount stored. the co2 reduction comes from onsite electricity production, removing supply losses from the equation. They claim mains electricity production and supply as only 44% efficient at point of use...so presumably the fuel cell reduces co2 by  whatever %, it is also a low temp chemical conversion so no Nox pollution. As Joe90 pointed out...the Japanese have 500,000+ units installed so far and its doubtful the Germans entertain producing a product with no meaningful benefit. 

 

As the thread started- Anybody any experience with vitovalor pt2 hydrogen chp units? Cost, reliability, benefits?

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1 hour ago, gravelrash said:

 the co2 reduction comes from onsite electricity production, removing supply losses from the equation.

 

Careful how they're selling this. They're not mentioning the CO2 released in the reforming process from Natural Gas to Hydrogen. Commercially, for every 1Kg of hydrogen produced by this process, 9kg - 12kg of CO2 are released. The process is also around 65% efficient, ie. you get 65% of hydrogen kWh out from the reforming process from the natural gas kWh that went in. This does make sense, if you specifically want the electricity generated, in cost terms when comparing domestic prices for gas and electricity, although PV would be cheaper to install.

 

They appear to only be counting the emissions once the hydrogen is produced and being consumed in the fuel cell.

 

Japan is heavily subsidising hydrogen production, and accepting its large carbon footprint, in the hope of it being a stepping stone to a cost competitive, electrolysis produced, hydrogen from renewables. There's no route to that goal yet though.
 

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I looked at PV with ASHP but cant make the sums add up considering  winter months and the array size required. If we could bank power to the grid like some states in US then it would be a no brainer...Id like to save the world but it still has to at least pay for its self over its life time...and I ain't got that much life left.

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only in a few states but your excess lecy passes to the grid and instead of getting paid they give energy credits at a set value i.e 1:0.95 to cover transmission fees or some states you pay a transmission fee to local utility of about $100 a year and they credit 1:1. When you draw from the grid it uses your credits first. Thats why some areas they have large arrays because they can bank for the winter. I presume the utilities benefit from carbon credits and that makes it cost effective and offsets there oil burning power generators.

 

Usual US business strategy - think of profits long term rather than UK's tear your arms off short term. Example being  costco's US policy of stack it high and sell it cheap, and in UK there policy is f**k em and charge what we can.

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  • 1 month later...
On 05/10/2021 at 09:41, gravelrash said:

None of the data I have read mentions gas usage per Kw of heat and electricity produced although average efficiency across the year is reported as 192%... the cost of unit is quite high. Just about to start building and with the £7000 grants coming in April 2022 it might be an easier and more consistent solution than PV with ACHP. 

New builds won’t qualify, unfortunately.  We’re still biting the bullet and having one fitted in our new build next year.

 

https://www.greenmatch.co.uk/blog/clean-heat-grant

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  • 1 month later...

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