Alternatives to electric heating

echo82

Hi all,

Looking for some advice for alternative energy sources. We knew heating/energy costs for our (relatively recently bought) house would be very high and were planning to upgrade / resolve soon, but that's been brought forward by the current energy prices. Background info:

• 2500 square foot pre-18th century barn, converted about 25 years ago. Mostly single storey, brick built with thick walls. Large number of windows / doors (approx. 25 windows, plus 5 external doors)
• Listed building + conservation area
• Both work from home (pre-COVID), so occupied almost constantly
• Current heating: 9 kw + 6 kw electric boiler (system split into two due to size of house I assume) - also used for hot water. I've tried to optimise the system to heat the two parts only as needed (thermostat set at 18C)
• Standard panel radiators throughout (with TRV)
• Current energy use ~22000 - 25000 kwh / year
  
• Main living room (~700 square foot) also has a 14 kW log burner, which we have used more heavily this year (and has decreased cost, as it is cheaper than the electric heating right now it seems!)
• No mains gas available
• Limited access to rear of property (average size garden), no obvious place at front of property to put an oil tank (which most people nearby use)

The current windows/doors are in a very poor state (double glazed timber windows, but poor condition and drafty), we are upgrading ASAP but the council are taking a very long time to grant listed building consent. Also looking to upgrade insulation where possible, but in most of the property this is within the sloping barn roof and would I assume be very disruptive / difficult to do.

So oil and gas are out, electricity is too expensive (I'm not sure if sticking with electricity and upgrading anything is worthwhile, the current boilers are probably 10 - 12 years old). I've heard mixed reviews about an ASHP (particularly given the unknown state of the insulation / general poor thermal efficiency at the moment). It would be tricky to fit a GSHP, but may be possible at the front of the property under the parking area (but that area is in shade most of the day).

The rear of the house faces south, and is on the top of a hill with no nearby trees - I thought it would be perfect for solar panels, but no chance of the council giving permission for that (the rear of the house is classed as a 'protected view' it's difficult to change anything visually. I did see something about 'solar slate' type roof, but know very little about it and it is obviously a lot more expensive than normal panels.

So, is there anything I have missed that would be a better way of doing things? Upfront cost is not a significant issue, but I would want it to 'pay back' and save money in the longer term.

Thanks for your help! 

QrizB

Here's a recent thread on a similar topic:

https://forums.moneysavingexpert.com/discussion/comment/78878157#Comment_78878157

The final post in that thread, by @Gerry1, gives an idea of the relative running costs of various heating systems:

Mains gas (wet radiators)
Mains gas (gas fire)
Oil
Electric Ground Source heat pump
Electric Air Source heat pump
LPG
Electric storage heaters (High Heat Retention, fan assisted) on E7
Electric storage heaters (old style without fan) on E7
Direct electric heating on single rate (e.g. panel heaters / oil filled radiators / fan heaters)
Electric boiler on single rate

You've currently got the bottom (most expensive) option. Literally anything else from the list would be cheaper.

Since you've ruled out pretty much all combustion options form the list, that leaves heat pumps or storage heaters.

• If your current wet heating system is compatible it should be possible to replace your electric boilers with a heat pump(s) without too much disruption. The capital cost will be relatively high.
• If not, storage heaters are the next best option but will require electrical work. The capital cost should be less but might not be, depending on how complicated the installation is and how many of them you need.
  

Mister_G

OP - Have you looked into the possibility of a buried LPG tank in the front garden.  Not as cheap as an above ground one, but could be a worth considering.

The running costs of LPG are currently very similar to Oil.  I pay 6.3p/kWh.

As you already have a wet system, the cost of replacing the electric boiler(s) with a gas one shouldn't be too prohibitive.

Verdigris

A GSHP would probably be the best solution, if you can re-use the existing circulating/emitter components within the barn. The shading at the front shouldn't be a problem but for a place that size you are going to need hundreds of square metres of trench dug to take the collector coils. Will that impinge on others ervices such as drainage? A neater, but generally more expensive option, would be a borehole. If you are lucky with your geology it might not have to go too deep. Otherwise an ASHP; slightly lower capital cost but variable seasonal efficiency - the colder it gets, the lower the efficiency.

matelodave

As said above if you dont have space or dont want an oil or gas tank then the only alternative is electricity and the cheapest form of electrical heating could be a split air-air heatpump - depends on your attitude towards the internal heat exchangers, but they do have the advantage of being a bit more efficient than air to water and you can use them to cool the place in the summer.

You wont get any grant or RHI for them though. They, like an Air-water system, will need an outside unit but they dont take up much space and despite what everyone thinks they aren't as noisy as an oil boiler.

Air to water (ASHP) is probably the easiest if the existing pipework could be utilised but you'll need high output, low temperature radiators to get the most efficient installation. Even though the efficiency drops off a bit when it's everso cold its never going to be anywhere as bad as your present heating system.

Ground Source is an option but you need a lot of land for the ground collectors or very deep boreholes, both of which cost a lot to install.

Alternative you could install storage heaters which like anything else will be a lot cheaper to run than your present system although you'll probably need a fairly big rewiring job to install the extra cabling.

In the end you really need to spend some time finding out the pro's and con's of each type of heating - getting some quotes , doing some very careful sums, although whilst the cost of fuel is as volatile as it is  and the green lobby making and nuisance who knows how the cost of LPG, Oil, or leccy will develop in the long term (or even wood for that matter as the cost of other fuels rise).

Reducing drafts and improving insulation should be your first priority but you do need to get some quotes and get detailed an accurate heat loss info.

Reed_Richards

The trouble with storage heaters is that they rely on cheaper night rate electricity ("Economy 7" or similar) and it's not obvious that this will continue indefinitely in its current form.  Typically the differential of day to night rate charge is now around 2:1 when it used to be about 3:1.     

Verdigris

I suppose biomass might be worth a look. You'd need a bin/silo for the pellets to be blown into but if there was an outbuilding for it to go in the planners/conservation bods might find that acceptable. I suspect the price of wood pellets will follow other fuels inexorably upward, though.

lohr500

As others have said, if there is no opportunity to locate an oil or LPG tank, then I would think an Air Source Heat Pump is going to your best option. Even if you have to upgrade some of the radiators and probably change the hot water storage tank, an ASHP will end up being cheaper to run in the long term than your electric boiler set up. 

I'm not sure, but I believe because you live in a listed building, you may need planning permission for an ASHP, so it is highly unlikely you could get everything in place before the Govt. grant on ASHP's changes at the end of March.

Here is my stab at the costs. Take them as a fag packet calculation as I am no expert !!!

Let's say it cost £15k to £18k to put in an ASHP system, including upgrading some radiators and installing a new hot water store.
If I understand the proposals for the new grant correctly, you could get £5k back.
( I'm estimating an £18k install cost, because that was what we were quoted for a 17kW ASHP install in our own converted farmhouse which included upgrading many of the radiators and putting in a heat store to replace the hot water tank).

Net cost £13k.

Some of your electricity consumption will be on cooking and lighting. Let's say 4,000 kwh
So your heating/hot water usage is currently 21,000kWh.
Assuming £0.22 per kWh as a current SVT, it will be costing you £4620 p.a for heating and hot water.

If an ASHP can deliver a COP value of say 3, that annual cost would in theory drop to £1540.

Annual saving £4620 - £1540 = £3080.

Assuming no change in electricity cost, then the payback on investment will take £13,000 / £3080 = 4 years.

Probably loads of holes in my assumptions and hopefully those with more experience/knowledge can chip in and correct me!!

Verdigris

That's an impressive fag packet you've got! I would say that's well in the ballpark.

One (little?) snagette might be the power supply. Would a 17kW ASHP need three-phase?

Flight3287462

OP in my view needs to sort out insulation, draughts and the dodgy window frames first.  Whilst that is getting done they should be exploring all options.

We rebuilt our house 12 years ago and put in a GSHP which has been great, but you need a company that knows what they are doing.  We have 700m of coil in the field taking up about 1,500m2.  We are very lucky in that we live on the west coast of Scotland so generally have good movement of water in the soil.  Dry areas can be problematic because there is no moisture in the soil and the soil can freeze.

When we laid ours  it was me and my friendly digger man that laid the pipes to keep cost down.  Believe me it is not easy, wants to behave like spaghetti.

If you do go GSHP you probably want underfloor heating to get the best out of it.  But back to the start again get the insulation etc done.

To future proof your house you probably want to look at the newer alternatives.

If decent insulation is tricky then it is all going to get expensive.  

When was the barn converted and to what level of building standards.  At the time we went for the best we could afford (a lot of glass wool) without going full huffhaus so its OK.

lohr500

@Verdigris : On our proposed installation they were going to use a Grant 17kW ASHP.
Just looked at the spec. for said unit and it states a maximum power input of 4.9Kw on 230V single phase, and to be wired with a 32A breaker.
As we already have a very greedy electric AGA which also sits on a 32A supply and charges up overnight, I bet even with just a 17kW unit, we would have been getting close to meltdown on our existing single phase overhead wire supply!!!