We need better storage on renewable generation. I think that will be coming to some extent from more local solar with vehicle to grid and vehicle to house. Though non vehicle battery storage should be getting much cheaper than it has been
Edited to add - Volkswagen had a battery day this week - announced they will be getting into home battery storage solutions
No mentions of wood pellet boilers? For old properties are they a better fit than an ASHP?
You need to store the pellets well, and a faff to keep the thing fed, and dusty, but that’s what we’re thinking of installing, given issues around heat pumps in hard to insulate homes (old brick built farmhouse). Things being less convenient is something I think we need to consider as the cost of living more sustainably.
Our 20 year old gas boiler is on its last legs, and I’m very reluctant to put another one in.
Well it’s funny you should mention that. My business partner, about a decade ago, purchased from some ‘old eastern block’ country a massive wood boiler; I mean fuel not construction. This thing weighs at least a ton. His plan was to fire it up once a day and to store the heat in a massive underground water tank. Then use the stored heat to provide for his standard hot water tank and the central heating. He’s a bright chap so I’m sure he checked the maths out so it would work. However it’s big install so, 10 years later, this lump of cast iron is still sat in the middle of the garage floor! 
My only experience of wood pellet boilers was getting a quote 14 years ago when we did the house. Didn’t take me long to spot that the quote provider had grossly exaggerated the cost savings compared to oil so didn’t pursue it
The air source cylinder is a bit different to the normal cylinder.
It has a high kw load coil in it, to transfer the heat better.
It also has, if you get the pre jig one to suit, a header, pumps, flow sensors, heat sensor, the wiring controls/ pcb and all the other bits that are needed to run and control the system
Sure it’s the gentle breeze or fresh air from outside that is key … yes I find owl hooting, c o ck crowing, and dawn chorus a wonderful part of the environment of living in the country… shut the window that is all insulated from you… certainly when double glazed… and my neighbour has a couple of co cks, but they still don’t bother us 
… mind you they used to keep turkeys… and they are noisy…
If you house is well insulated I suspect having fresh air is less of an issue…
Agree something wrong with forum software… it seems to have trouble with names of some country animals…perhaps written by townies…
We fitted a wood pellet boiler (Okofen) just a year ago, replacing fuel oil. We have no gas option here.
Delighted with the system and the efficiency. We get the full rate RHI grant. Effectively last year our fuel was paid for plus a ‘profit’ of about £300. The capital cost of installation is not trivial though, and you clearly need space for the largish boiler plus pellet storage. We have a manual fill hopper. The comparative fuel costs (ignoring the grant) are a bit cheaper than oil, and we definitely don’t miss the nasty smelly oil tank.
Happy to give more details to anyone interested. The website organicenergy.co.uk is a good place to start. We had three estimates and it was clear that not all installers, or pellet boilers, are created equal. We picked an experienced company and a well established boiler manufacturer.
Bruce
Sounds like you need a fair amount of space to mount/fit all the ‘bits’ 
That’s another problem with air-source that, last time I looked at it, put me off: Somewhere to put all the gubbins that goes with it. Next door-but-one built a customer brick outhouse to fit all this stuff. I’d guess perhaps 6x6ft… from memory.
I’ll be honest this airing of ideas and thoughts has started to put me off. Okay go for the insulation, radiators, and pressurised cylinder upgrade but as too the air-source? Probably not.
When we did our boiler replacement at the old house, 10 years ago now. This was another option considered… the room for things like hoppers &c. killed the idea. There’s a local farmer that has a wood chip boiler but he has a massive silo in his yard for the chips. Heck there’s another farmer that has a huge silage digester and runs a boiler off poo! 
Our house is a 1970s dormer bungalow. When we moved in 10 years ago it had cavity walls, suspended wood floor, 25mm fibreglass roof insulation.oil fired central heating with the original boiler, and HW cylinder. It had been double glazed throughout some time ago. Approx 150m2 living area
We did this:
At the same time we enlarged the house by 30%, having three extensions done, enlarging the lounge/music room, doubling the size of the sunroom, adding a second bathroom with dormer window, and adding a utility room, with similar insulation levels as other areas.
My wife likes it quite warm, wherever she is sitting having to be at least 21C, 24 preferred! However normally only one room that warm - I’m normally happy with 20C. The sunroom readily achieves that on sunny days even in winter, though of course not all day. We have two adult sone who spend their whole time in their bedrooms, so those are also sitting room temperatures evenings and weekends.
Our heating bill, including hot water, we estimate has dropped by around 60% compared to the cost of heating the smaller original house At the same time the house is so much more comfortable to live in, no draughts but effective ventilation ensuring no smells, no damp anywhere. We have as much hot water as we want whenever we want it.
And the house is quieter - and also has less noise penetration outwards with the triple glazing. (N.B. Although the foam board insulation materials are the most efficient for thermal insulation, (other than going to the mega expensive vacuum panels), their sound insulation is quite poor compared to mineral wool, which is worth bearing in mind if you need both.)
I haven’t attempted to calculate the cost recovery aspect of the work: we did it mainly because at the time we intended thid to be our home for the rest of our days, so were more interested in not having ongoing bills of significance given that energy inevitable will go uo in price, and wanting the comfort aspect - though we hadn’t realised just how big a difference it would make to comfort.
N.B. No grants or rewards for fuel efficiency where We live.
A similar story when we moved into our old house. The first year we were there I got the oil tank refilled three times and this was when oil was typically 60p/litre!
Then we got a new boiler, new stat, new cylinder, double glazing, new doors, surface insulation on the dorma walls, &c. When we moved out we were going through one oil tank refill a year.
I am sure Richard D will share my email if you ask him nicely.
I suspect it is the email’s owner who must do the asking!
We got a new oil boiler 3 years ago… we replaced our previous 20 year old boiler… and it’s hugely more efficient… albeit there is much steam coming from the heat exchanger exhaust vent. We use about 2/3 of our 1200 litre tank a yearly but does vary on how cold the winter is… and what with the very cheap price of oil over the last few years, I think it’s around 40 p a litre right now, is certainly cost effective…
Agree Tim . I own a barn conversion and rent it out . 5 years ago we put annASPH for 10 k but RHi payment is 2.4K a year for 7 years . It won’t be as good now I am sure . You must have a well insulated house for this to work ., lecky is going up in price all the time . We now live in a big 100 year old farm house . Ripped out the back boiler to the oil fired Aga and Put a pressurized system off the old ( and working well) the oil fired boiler . I liked a volume shower . Have a couple of electric showers in on suites but rarely
Used . Ground source and wood pellet boilers ( can’t remember correct the name ) are expensive and incentives aren’t as lucrative Agas are great , simple but are like naim systems … can’t live without them . Have a clear view and open fire in drawing room and loads of wood round the farm
Summary
Wood burner a must
Check out RHI payments
Don’t buy Air source if it is and old cold house
Put a jumper on and listen to Naim system
Ours is same . No meter
Fixed payments . Like most of these things. Get in early and it paid . Like solar panels
New boilers are way more efficient . Fuel about 35p./ litre . We buy in a group . It went to down to 17p last year ! Cheap as chips then
They are aren’t they… yes we use a top up account system… it’s less bother… and oil is so cheap i find it not worth saving a few pennies per litre using Boiler Juice or equivalent community systems.
Maybe it’s a local thing . Local supplier is v competitive.
What did you go for in the end ?