OK, here's a fun one...

The National Grid with several partners provide an API for people to retrieve carbon intensity data. that is perfectly possible to get hold of in a home automation system and incorporate into one's choice about turning on or off various electrical devices. However, I doubt it'd figure too much with regard to home heating since if you're cold you're cold.

Nonetheless....

I am hardly unusual in having a wood burning stove. I'm also well aware that because of the releasing of particulates it isn't entirely eco-friendly but since it only burns what has been fairly recently grown it is to all intents and purposes carbon-neutral (assuming where I source my wood from is operating sustainably). It's also true that since my house is thermostatically controlled if I have a fire then the ASHP will reduce its output to compensate.

All that means that I could (although I haven't done so and am not sure if it'd be worth doing) get my home automation system to look at the weather forecast (to predict whether we'll need to heat the house and to predict whether we'll be generating solar PV energy), the state of the battery (to see if we have energy stored to power the ASHP) and the carbon intensity (to see how clean or dirty is the energy we'd have to import would be at the time the house needs to be heated) and then send me a notification telling me if lighting a fire would be more environmentally friendly than letting the ASHP do its thing.

I suspect that's an exercise to undertake just because one can but I do think it's amusing to see how creative one can be with the information available.

@majordennisbloodnok Could burning wood in that stove ever be as green as running the heat pump? Even if the electricity is somewhat less than a good shade of green, would it still not be better (at a reasonable COP of course!) than burning the wood with all the inefficiencies that entails. (Yes, I know there are various other ‘comfort’ factors of a roaring wood fire on a cold winter’s day!) Regards, Devil’s advocate.

I thought about that, @toodles, but I think the key is the fact the wood stays above ground. Anything coal or gas has already been locked away and, left to its own devices, would stay that way so releasing it again will add to the carbon in the atmosphere. Wood, however, is just atmospheric carbon dioxide in solid form and if we did nothing with it the wood would die, rot and release the carbon dioxide again. Burning it releases it quicker but if trees are being planted and harvested for burning at the same rate the net atmospheric carbon dioxide increase is zero.

I hasten to add, having had the chance to reread my post this morning, that I'm not suggesting anyone should use their woodburning stove in preference to a heat pump just because there is some gas being used to generate the electricity supplied from the grid. What I am doing is just highlighting and what I'm highlighting is two things:

• Firstly, the amount of fossil fuel used to produce the leccy we are consuming is an extra bit of information some will want to factor into their choices and that information is available in a format that's readily consumable by automation systems.
• We often have more options at our disposal than we realise and how those options can be made to fit together is an interesting exercise in creative thinking. In the case I laid out, using wood as a heat source could be a valid occasional alternative when there is very little renewable energy available and it only recently occured to me how it might be done.

In theory, burning wood from a sustainable source should be better than using any electricity generated from fossil fuels. In practice, I'm absolutely sure there will be a balance required and that the use of wood should only be seen as a preferred alternative on a relatively small number of occasions.

@majordennisbloodnok Yup, that makes a lot of sense. OE supply my energy via the grid and I produce some with my PV; OE proudly claim to be supplying green electricity. Now, shouldn’t the measure of how green our energy is be carried out at least nationwide (if not globally!) after all, if some less than bright green fuel source is being employed, does that not affect us all? Striving for ALL energy to be sourced from renewable energy (non fossil I mean) is the ultimate goal, but I don’t think I wish to fool myself into a warm fuzzy glow because my energy supplier sources ALL their energy from renewable sources whilst there are still lumps of fossils being consumed elsewhere at power generating plants. Quizzicaly, Toodles.