Replacing oil fired central heating with storage batteries and off peak power - is this possible without solar panels?

Thanks for the info and it is these numbers that I need to start checking.
I looked at air source heat pumps when we moved in but we have an old house and was advised at the time that we would probably need to have oil and air source heating for winter conditions. Maybe things have changed, I’ll check. 

Thanks again for the battery numbers, I’ll start checking. 

Hi @Chisi1 - I’m on the OVO Trial of a PowerVault Storage Battery. It can be charged from Solar Panels or the mains. I have lots of data about this which I can post here if required.

My battery has 8kWh capacity, which is a long way short of what you’d need if you required space-heating or domestic hot water (DHW).

I’ve checked the UK Battery Storage market, and the Tesla Powerwall is expensive but has the lowest figure for £_per_kWh.

Other people who live in listed properties have installed ground-mounted PV Solar Panels. These don’t literally have to be at ground-level. As they’re made of glass they also lend themselves to a greenhouse roof because there will still be enough daylight coming through the remainder of the building

As part of your research here on the Forum I suggest you explore two other topics:

1: the possible use of underfloor heating rather than radiators. This uses water at a much lower temperature and is therefore better suited for slow/steady heat sources such as a Heat pump supplemented with solar-thermal.

Start here on a general tutorial about Heating Strategies.

2: The point that @nealmurphy makes about the amount of power you can take from the Distribution Grid is important. If you would be drawing more than 60A at any time then your regional Distribution Network Operator (DNO) may be wanting to supply you with 3-phase. This is particularly the case if you need  consent for Low Carbon Technology (EV charger or Heat pump).

Have a look at the tutorial on Permission for Import and Export.

Finally, please fill out your Forum Profile page. Knowing whereabouts you are in the country will affect what we can suggest. It might also enable us to put you in direct contact with a Community Energy Group in your area.

Hi Transparent

Thanks for the info and I’m slowly building up a picture on the feasibility of my project.

The information about the PowerVault battery and numbers really help but to give you a better idea of where we’re at and what we’re trying to achieve:

• Location:  Somerset TA14 (tried to put this on Profile Page but I’m missing something)
• House built in 1585 with Hamstone and Rubble construction, walls 300mm thick, concrete/wooden floors downstairs 
• Although listed, house double glazed throughout with 300mm roof insulation.
• The stone construction means that if house gets cold, it needs some time to heat up again, so upstairs rooms are kept to minimum 15 degrees 24 hours/day.  Timers and thermostats used to increase temperatures in bedrooms and bathrooms independently of downstairs heating as required.  And, downstairs heating used with thermostat and timers as required.
• Because house is kept warm, upstairs panels only kick in for short periods outside of timed periods on a few days during the winter
• We bought and renovated the house nine years ago. The oil central heating system required complete replacement so looked at simple complete oil replacement, air and ground source heat pumps, electric radiators and ceiling mounted far infrared heating panels.
• Even then I wasn’t happy with oil but was told, then, that using an air source pump would require oil backup heating for winter conditions.
• Electric radiators using standard rates were not cost effective
• I liked the far infrared panels but then they were considered relatively new technology at the time and I couldn’t find enough feedback to be confident enough to use them throughout the house.
• So, we zoned the house.  Downstairs and water heating, oil.  Upstairs, electric far infrared panels which are set to maintain temperature upstairs at 15 degrees 
• These panels really work.  They are controllable, efficient and effective and, considering the comfort factor we achieve set against the cost, good value for money.
• Out of interest we used Sunjoy panels, www.helvetic.ie, Eamon McGrath +353 86 385 3000
• They were easy to fit during the renovation nine years ago but now would be too disruptive.
• If possible, the plan is to remove the oil tank and boiler, remove current wet radiators and water heating system and replace with electrically powered units, fit batteries and tie into existing system and operate using off peak power with facility to occasionally top up at standard rates during the day in extreme conditions if required.

My wife and I are both 75 and plan to stay here for at least the next ten years, or until they take us out in boxes.  We are not ultra-green but like the idea of the long term benefits and convenience of electric power and remove the reliance on oil.

However, we do not want to get involved in large scale renovations again and realise this will limit us as to what we can do.

Now I some good information from the group I will start looking in more detail about equipment and costs but would appreciate comments from the group on the following:

• We do not want to fit solar panels to the old building
• We do not want to fit air source heat pump because of disruption to fit underfloor heating and still have to retain some other form of heating
• Ideally, we would remove the oil tank and boiler creating space for batteries
• Remove the downstairs wet radiators and replace with electric and I will check power requirements.  I realise this option will not be the most cost effective heating method so would appreciate any comments and possible manufacturers from members on their experience.
• The current oil heated water tank has an immersion heater fitted.  It would be easy to use this but I’m sure it will not be economical so I will check operating costs and would appreciate member’s comments.
• Check state of the art, electric powered water heating system and power requirements.  Again, appreciate member’s comments.
• I know the actual current power usage so with the new requirements I will have total power requirements.  With this I can determine:
  • Power requirements and if it’s possible to draw this down at off peak rates
  • Don’t think 3 phase power will be feasible as the local pub was recently quoted a silly number to install this for a new kitchen cooker
  • Battery size and limitations
  • Again, members comments would be appreciated on what I should watch for and important questions to ask

I am realistic about what we are trying to do and the effect of what we don’t want to do, at our age, has on what equipment we can use.

It would be good if we can get it to work but if not the information package I will put together could possibly be useful to members looking at similar projects.

If anything is not clear, please ping me and I look forward to your comments.

I think a good place to start, if you haven’t already, is to get some heat loss calculations for each room. By working out how much heat leaves the property you’ll know how much heat you need to put back into it to keep it at a chosen temperature. This applies to whatever heating system you go for so as not to undersize or oversize the heaters or heating system. What is the floor area of the house?

I still reckon Air Source is worth considering. I have a High Temperature unit that can heat up to 65 degrees if required and is a straight replacement for my old gas boiler. What is your existing central heating pipework like? Diameter of pipes? Are your radiators single/double? If necessary, would there be space to either increase the size of these or convert to double/triple?

That’s welcome background information @Chisi1 

We have a lot of common thinking between us! I don’t think I’d be classed as ultra-green either… but my common-sense practical approach to energy-efficient renovation also ticks so many of the boxes which green-activists favour.

A few bits of good news:

1: You’re on the eastern edge of the Distribution Grid, SW Region, managed by Western Power. They have generously allowed me access to a wealth of their technical background material. I have the entire electricity map of your area including the size of every conductor!

So whatever may have been the case for your local pub can now be re-checked against the actual data for your locality.

There seems to be only 16 ground-mounted substation transformers within TA14 and you’re almost certainly supplied from the Primary (33kV) transformer at either Martock or Montacute.

2: Have a look at the illustrative maps I uploaded recently in the topic about Energy Demand, Supply and Flexibility.

You can view the map for your particular Primary transformer by going directly to Western Power’s page showing their Distribution Future Energy Strategy.

That means we can see what network infrastructure is being planned by WPD for each type of electricity usage for the next 29 years.

For example Martock currently has 237 Heat pumps, and is expected to have 996 within 5 years. This enables you to choose an energy strategy which Western Power is already geared up to support.

3: Have you, or would you consider a ground-source Heat pump operating from a borehole? These are one-third more efficient than an ASHP, and a bore-hole means you don’t have to start by digging up the garden to a depth of 2m!

4: I understand your point about using the thermal mass of the building to retain heat. Although my house has a cavity-wall, I still use this technique for part of the UFH system and one thick internal wall (my heat reservoir!).

5: You have a Transition Towns group to the north of you at Langport. I suggest you send them an email and find out what energy specialist members they might have and what is their strategy post-Covid.

Some Transition Towns groups have members trained to undertake energy assessments of homes. These are free for certain categories of people - so well worth while enquiring about.

That’s not the entirety of my response, but it’s probably enough to be going on with.

If you want more detail on your electricity supply, send me a PM with your full address. I’m not allowed to post the maps here, but I can certainly check if your house has particular constraints.

I’ve just made a few further checks @Chisi1 and I think your constituency is currently represented by Marcus Fysh MP.

If that’s correct, then he lives in a Grade-1 listed 14th century building. I wonder what strategies he’s invested in to heat that?!

Hi

Thanks for all this information which I will start sorting my way through and build a specific plan for the house.

This will be slow as I’m mechanical, not electrical, and am lost when I get past the light switch on the wall.

A couple of good points from your comments in helping me determine best equipment and power requirements are those regarding heat loss calculations and high temperature air source pumps which I will check.

Total area of house is about 2,200 square feet split 1,200 downstairs/1,000 upstairs.

Regarding radiators, we have a mix of single and double but in all cases we have space to increase.

Regarding your high temperature air source pump, realistically how noisy is this?  We live in the centre of a village with a neighbour close to us on the side any heat pump would be located and this would be a big consideration.

Marcus Fysh is our MP and lives a few miles from here and I will ask how he heats his old house.

Thanks for your help so far and any other comments would be appreciated.

Don’t be concerned at your skill-set being limited to mechanical, @Chisi1 - the whole point of a Forum like this is to combine our skills and knowledge.

I’ve also just read the Historic Environment Strategy for your District Council. It’s dated 2017 and contains nothing whatsoever about ‘energy’.

I also live in an area with a high proportion of historic properties. Our (very small) Borough Council has combined the work of its Conservation Officer with a well-qualified engineer from the local Community Energy Group. This has resulted in a guidance document to inform occupants/owners of historic buildings what they can do by way of ‘Conservation of Heat and Power’ (ie Part-L of the Building Regulations).

This pro-active approach reduces the burdon on the Planning Dept who don’t then have to cope with hosts of applications requiring amendments or enforcement.

It might be a good moment to write to your ward-member(s) and ask South Somerset to create a similar energy-guidance document for your area. In any case the current generic Environmental Strategy document precedes  the increase in public awareness of the need to tackle Climate Change in spring 2020.

Looking at South Somerset website, you seem to be one of the few District Councils who have not (yet) passed a motion declaring a Climate Change Emergency. Your Council’s Environment Strategy relates to actions of the council itself rather than providing assistance to its constituents to take action.

There is expertise available, but it will be up to your Council to request the help they need… perhaps through the Local Government Association.

If there needs to be additional funding available to assist those with historic buildings in their quest to install the right types of Zero Carbon Heating, well then that is surely a question for your MP. I doubt that Parliament will want to proceed towards its 2050 target of Net Zero at the cost of degradation of our country’s historic heritage!

Let us know how you get on, and remember that this Forum hosts an abundance of answers.

Honestly, it’s quieter than my old gas boiler’s flue. I’ve walked in front of the outdoor unit and not realised that it was on until I felt a cold blast of air! When background noise is quiet, and I mean very quiet, you can hear a faint hum but there is a quiet mode (that I’ve never tried) if it is an issue.

Heat pumps will need to be 1 metre from the property boundary for permitted development, and a simple noise calculation will be carried out to confirm suitability of location.