@chris, welcome to the forums – what area (in sqm) are you heating? It sounds like a large property.

@transparent Daikin assessed the house and ran heat loss calculations using their s/ware. Their experts revisited all that when they agreed to replace the 3 H HT unit. The total heat requirement is estimated at 30,000 kWh for the year, heating. I'm investigating solar and battery but that's another £13k or so! 

Not really possible to switch tariff at the moment as time of use e.g. Octopus Agile is not really available due to the current situation.

If the COP was where it should be and as was put on the RHI certificate (3.67) I'd be fine!

@chris With respect to does 50 C work with solid walls? you could do what Im doing with my solid wall bungalow, turn down your central heating temperature to 50c on a cold day. Run it all day and see if it is warm enough at night. Obviously there are tweaks you can make such as bigger radiators and pipework and insulating the walls of often used rooms etc. So far although we havent had a very cold day yet, Im optimistic that it will work. I also have a wood stove in the lounge I can use if its not quite cozy enough on a very cold day.

Posted by: @chrislay

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I'm investigating solar and battery but that's another £13k or so! 

Not necessarily. There's another very 'live' topic here called Anyone want to share costs on batteries?

Don't worry too much about the original title. The thread has evolved into an active exploration by enthusiasts who are starting to build/install their own storage batteries for very much less than £13k 😀 

Your figure is more typical of the commercially available storage batteries which are grid-tied and have export capability. These require certification (G98) and permission from the Distribution Network Operator (DNO) for your electricity region. They set export parameters which constrain what your battery may deliver.

But you're never going to need grid export capability. The whole point is to deliver 'mains' voltage to your own HPs.

That's called an off-grid storage battery. It does not require certification, nor an MCS-registered installer.

Have a look at the topic I've linked to and get an idea of what is (and isn't) possible. That will then enable us to have a more informed discussion.

Posted by: @chrislay

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Octopus Agile is not really available due to the current situation.

Yes, that's a short-term measure. I'm looking forward 5-10 years from where we are now.

I'm in active discussion on ToU tariffs with some Energy Suppliers and National Grid Electricity Distribution. Most of the required control/support is already inbuilt to our SMETS2 Smart Meters. Apart from Octopus, it's the domestic suppliers whose billing systems haven't yet caught up with the technology.

Remember that most of these software packages used to do heat loss and running cost calculations are based on the MCS requirement of heating the property to the design temperature (which according to building regs is 21 degrees) 24/7/365.

That’s probably why they’ve come up with the 4.5MWh/annum heat requirement.

If it were me, I’d sell it and move somewhere that isn’t completely impractical to heat 🤣

Posted by: @hughf

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I’d sell it and move somewhere that isn’t completely impractical to heat

Yes, I understand the temptation.

However I was at Energy Show yesterday talking with an engineer who is committed to finding energy-efficient solutions for older properties with solid walls.

It's not just domestic housing stock we need to consider. 99% of our heritage properties fall into this category.

The situation in which @chris finds himself (at the top of this thread) is very similar to that affecting our historic homes, cathedrals and town halls. We can't just retro-fit these stone buildings with 100mm of internal insulation, surface-clad with plasterboard!

• @transparent 
• hi
• the two companies measured house totally,windows,radiators,doors,insulation in roof,I know every inch of house as we lived in a caravan whilst converting it .cost £200 for one company.
• I actually had three companies,one actually said I would need 3 ashp so totally not viable!!
• the whole idea of having ashp was to reduce log splitting and extra work involved with this,have a house where all the rooms are at the temperature required,at a reasonable cost per year,the oil boiler is fantastic,from cold to warm rooms in less than 45 mins,all heating pipes are insulated in insulated floors with big pipes,just not external walls.
• I think unless the kWh is drastically reduced,or oil gets much worse I have no viable option,having batteries charging up from solar (rubbish in winter)is a option but more expense .
• I believe vattenfall are developing a high temperature ashp to directly replace oil/gas boilers in poorly insulated property!
• the biomass is a possibility but will check distance from rd as it’s definitely more than 20m
• green heating oil is available but at double the price.
• insulating the property external walls apparently won’t make a massive difference as there are some big windows to,in all not viable. 

@bontwoody 

hi

yes we have turned boiler down to 50C,it ok  but need to experiment more,the rooms with log burners in are lovely,I can’t imagine not having them,I like to be warm!!

my problem is that having a ashp at £16000(-£5000 grant) then not having a warm house when temperatures drop and with the kWh price now it could all go horribly wrong.

is there anybody out there that had a big house with good insulation in the roof,floors,a good heating oil system,solid walls,that’s changed to ashp that actually works for a similar price to the oil.

my house is 260sqm

@chris

Hi Chris, welcome to the forum.

I'm afraid what you are asking is to defeat the laws of Physics. You wish to keep a largish home, quite warm by the sound of it, using very little energy in the most cost effective manner, and save the planet in the process. So what are your options?

You could keep your oil boiler and wood burners for the time being and spend money on improved insulation. This would be somewhat environmentally friendly, particularly if your use the 'greener' fuel now available. 

You could spend money on installing an ASHP, but without improved insulation this could possibly be quite expensive to run.

You could install a solar PV system to provide hot water and possibly some heating, to help reduce your oil consumption. This could be with or without battery storage.

Where does the air supply for your wood burners come from? Are they drawing warm air from your home and pulling in cold air to replace it?

I don't think that there is a magic solution to your present situation. You can try reducing your energy demand by lowering the indoor temperatures slightly. If you are using your wood burners then try to distribute the heat energy around your home more evenly.

I'm afraid my crystal ball is in for repair, so I cannot tell you what will happen to the price of energy in the future. I feel fairly confident in predicting that it will not go back to pre-energy crises levels, but if recent wholesale prices for electricity and the recent Octopus Agile prices are anything to go by, then the price for electricity may not rise much above its present level and may even fall. Who knows?

Sorry that I could not be of more help.

I agree so much with @derek-m  I'm constantly coming up against the laws of physics as a constraint in designing energy solutions. Social media is currently full of adverts for energy-saving devices which apparently allow the customer to have greater heat output than permitted by the laws of thermodynamics!

Derek is absolutely correct to highlight the issue of insulation. It remains the cheapest and longest-lasting investment we can make in reducing our energy bills.

Much professionally-installed insulation is poorly implemented, as can be seen by viewing the exterior of a property using a thermal camera. I'd be investing further in additional insulation around window-reveals and the edges of bedroom ceilings, where the insulation requires pushing into the gap above the wall-plate.

I do wonder whether the surveys commissioned by @chris gave any alternative calculations for a ground-source heat-pump. This might've been excluded due to the impractability of drilling a borehole in that location. But it would've been cheaper than two ASHPs and has greater efficiency (higher COP).

@derek-m 

hi thankyou for replying.I have 4kw solar,so could look at batteries.log burners do draw internally,so this could be changed.ground,first floor all insulated,roof 100mm celotex,all heating pipes insulated in floors.

vettenfall are developing a high temperature ashp apparently for older properties,a direct swop for gas/oil with high flow temperature,hopefully a possible solution!!

i have no problem with changing over to ashp as long as it works and is viable.£6000 a year,on a pension is not.

Is there anyone who has changed and was in a similar position as me.

@transparent 

hi again 

I agree totally that insulation is the king,something the uk should have tackled 20 years ago,as well as making all new builds have solar,ashp etc.

with regards to gshp it was mentioned as no problem with space but disregarded because of costs (25k)more efficient but by how much per year!!