Hydrogen Trial - Big Brother

Qyburn

MattMattMattUK said:

Hydrogen is a dead end for domestic supplies. To make it at cleanly and at scale requires a lot of electricity, it makes no sense to use that to convert water to hydrogen, pipe the hydrogen then burn it. The additional losses in the system make it a bad idea overall.

I agree especially on the efficiency side.  The local hydrogen plant was "hoping to reach 60-70% efficiency" when fully scaled up, and that relied on running for at least 10 straight hours at a time. So no chance of using only off peak electricity, or only renewable. The reality is that a lot of their hydrogen is produced by using electricity from gas fired generation.

As well as electricity used in the initial electrolysis the bit losses are in compressing the hydrogen to 900 Bars. In turn this creates so much heat that they need to run cooling plant consuming yet more electricity.

To my mind it only makes sense in some specific niches, where the electricity would otherwise be wasted.

chris_n

I used to work in a plant with a very large hydrogen store, we also used to leak test product with a mass spectrometer under high vacuum so I have some experience of the stuff. The fire brigade had special protocols when our fire alarm went off. I wouldn't have it anywhere near my house.

I would much rather they produced hydrogen with excess renewable and then used it to power gas turbines to produce electricity. You could then build everything new and not be putting hydrogen into old gas pipes. Hydrogen has very small molecules and will expose many leaks that are otherwise undetected. The problem of actually detecting these leaks is something else as hydrogen has no smell, maybe they need to add something. The next problem comes when one of these leaks is ignited (assuming no explosion here) as you cannot see the flame, it burns clear.

chris_n

FreeBear said:

Astria said: Heat pumps are a good idea, if implemented correctly, but really need to be combined with solar panels and battery storage systems, which means they are very expensive to install, but essentially you can get free/cheap energy (Octopus are even doing heatpump friendly tariffs so you can heat your hot water during off-peak times).

You also need a decent level of insulation so that you are not wasting heat. Unfortunately, a large number of UK homes are poorly insulated, so just whacking in a heat pump is going to be an expensive proposition to run.

The same is true of using gas to heat poorly insulated houses, just we have become used to the wastage.

Qyburn

chris_n said:.

I would much rather they produced hydrogen with excess renewable and then used it to power gas turbines to produce electricity. You could then build everything new and not be putting hydrogen into old gas pipes. Hydrogen has very small molecules and will expose many leaks that are otherwise undetected. The problem of actually detecting these leaks is something else as hydrogen has no smell, maybe they need to add something. The next problem comes when one of these leaks is ignited (assuming no explosion here) as you cannot see the flame, it burns clear.

That's the point, the plant can't stop and start to suit, it can't use excess, it has to use whatever mix is being generated during each day. So right now 30% of the power used is from gas generation, and around 30% renewable.

chris_n

Qyburn said:

chris_n said:.

I would much rather they produced hydrogen with excess renewable and then used it to power gas turbines to produce electricity. You could then build everything new and not be putting hydrogen into old gas pipes. Hydrogen has very small molecules and will expose many leaks that are otherwise undetected. The problem of actually detecting these leaks is something else as hydrogen has no smell, maybe they need to add something. The next problem comes when one of these leaks is ignited (assuming no explosion here) as you cannot see the flame, it burns clear.

That's the point, the plant can't stop and start to suit, it can't use excess, it has to use whatever mix is being generated during each day. So right now 30% of the power used is from gas generation, and around 30% renewable.

hadn't read the whole of your post when I wrote that, my main point being the thought of hydrogen in a domestic environment using currently installed transmission medium terrifies me. 💣