Changing from oil central heating

johnbasssimpson

I am in a quandary about renewables at the moment, I have an oil fired boiler but want to move onto renewables, I’m not sure which one would suit our needs, would solar, heat enough water for heating when it’s needed , does the running and maintenance costs of a heat pump outweigh its benefits? When it’s cold we turn on the heating or boost the water when we need more, do any of the new systems offer this flexibility?
 1st time poster be kind thanks.

MforumSManE

https://energysavingtrust.org.uk/

Gerry1

Welcome to the forum.

johnbasssimpson said:

...would solar, heat enough water for heating when it’s needed

No, not on dull cold days in winter.

johnbasssimpson said:

...does the running and maintenance costs of a heat pump outweigh its benefits?

No.

johnbasssimpson said:

When it’s cold we turn on the heating or boost the water when we need more, do any of the new systems offer this flexibility?

No.

The problems are that to a greater or lesser extent, solar, heat pumps, EVs etc are not yet fully developed systems, they're all largely still in their infancy.  They suit some people with somewhat niche requirements but they will be problematic for many others.

Solar is fine if you sell it in the summer and use it for the tumble dryer etc, but not much use when it's dull (or dark) and cold, just when you need heat the most.

Heat pumps aren't flexible.  You can't come back to a cold house after work or a holiday and be warm as toast in 20-30 minutes.

Pure EVs are fine for local runabouts if you have your own driveway, but no good in a high rise flat or Coronation Street.  Long distances and touring holidays are a pain.  Apart from finding chargers that are available and working, with each kWh costing up to 95p or whatever they can be twice as expensive as a fill-up with petrol, and you can't drive off five minutes later.  However, a self charging or plug-in hybrid may be an acceptable compromise.

Ectophile

Gerry1 said:

Welcome to the forum.

johnbasssimpson said:

...would solar, heat enough water for heating when it’s needed

No, not on dull cold days in winter.

johnbasssimpson said:

...does the running and maintenance costs of a heat pump outweigh its benefits?

No.

johnbasssimpson said:

When it’s cold we turn on the heating or boost the water when we need more, do any of the new systems offer this flexibility?

No.

The problems are that to a greater or lesser extent, solar, heat pumps, EVs etc are not yet fully developed systems, they're all largely still in their infancy.  They suit some people with somewhat niche requirements but they will be problematic for many others.

Solar is fine if you sell it in the summer and use it for the tumble dryer etc, but not much use when it's dull (or dark) and cold, just when you need heat the most.

Heat pumps aren't flexible.  You can't come back to a cold house after work or a holiday and be warm as toast in 20-30 minutes.

Pure EVs are fine for local runabouts if you have your own driveway, but no good in a high rise flat or Coronation Street.  Long distances and touring holidays are a pain.  Apart from finding chargers that are available and working, with each kWh costing up to 95p or whatever they can be twice as expensive as a fill-up with petrol, and you can't drive off five minutes later.  However, a self charging or plug-in hybrid may be an acceptable compromise.

I bought my first EV last November.  It's a small city car, not really intended for long road trips.  Nevertheless, it managed a round trip from East Sussex to Somerset and back last week.  Without even trying to shop around, the highest price I paid was 79p per KWh.  Of course I charged at home before I set off, which was far cheaper.

The total cost of public charging was £64.50 for around 516 miles.  Pretty much the price of a small tank of diesel (and nowhere near what I would have paid if I'd taken the Land Rover).

Reed_Richards

An oil boiler is either full on or off.  You can operate a heat pump the same way but it's the least economical mode of operation, more economical to have it heat your house more gently and more slowly.  If you do that I would expect (from my own experience) that your running costs would be similar to those of an oil boiler.  With a heat pump you can certainly boost the hot water if necessary but as with most other heating systems, when you are heating your hot water you are not heating your house.  You can get a grant of £7.5k towards installing a heat pump and the Utility company Octopus seems to offer competitive quotes.

lohr500

How old is your oil boiler? If it is a reasonably modern condensing type, then my advice would be to stick with it.
Oil is currently 53p per litre plus 5% VAT in our area. Call it 56p.

A litre of oil yields 10.35kWh.at 100% efficiency.
A modern condensing oil boiler should achieve 90% efficiency if set correctly.
That gives 9.3kWh per litre = 6p per kWh.

A heat pump might operate at a 3:1 efficiency or even higher if well set up and used correctly. If you assume 3:1 then you need to be feeding it with electricity at 18p per kWh or less to match the equivalent cost of oil.

For me, it's that efficiency variable that worries me. I know when my oil boiler is running, the output vs input is a given. My understanding of heat pumps is that the efficiency of conversion reduces with falling air temperature. And let's face it, when you need most heat in the house, it will be when it's cold outside. (Stand to be corrected on this). 

Then factor in that the capital cost of a heat pump and the fact that you will probably need to change the radiators in your house to higher output ones as heat pumps operate at lower flow temperatures.And possibly the need for a hot water tank/heat store if you currently have a combi boiler.

There is also a little bit of a conspiracy theorist in me that says, once everyone has been pushed to adopt electric vehicles and electric heat pumps, the energy suppliers will have us over a barrel and prices will rise due to the lack of alternatives.

HillStreetBlues

As a oil user I want to stick with oil as a heat pump doesn't do what I want. It's not a money issue I use 1200l a year and rather pay that even if a heat pump provided free heating.
The most important question is why do you want to move to renewables?

Reed_Richards

@HillStreetBlues is wrong, there is nothing you can do with an oil boiler that you can't do with a heat pump. You can set the heat pump to it's maximum operating temperature and with suitably sized radiators it will do everything an oil boiler does, rather expensively.  

The other thing to understand is that whilst a heat pump will be least efficient when it's really cold outside, conversely it will be most efficient when it's not so cold and it's the seasonal average that determines how much your heating costs.  A modern heat pump should give you more than 3 kW of heat per kW of electricity, averaged over the year 

HillStreetBlues

Reed_Richards said:

@HillStreetBlues is wrong, there is nothing you can do with an oil boiler that you can't do with a heat pump. You can set the heat pump to it's maximum operating temperature and with suitably sized radiators it will do everything an oil boiler does, rather expensively.  

The other thing to understand is that whilst a heat pump will be least efficient when it's really cold outside, conversely it will be most efficient when it's not so cold and it's the seasonal average that determines how much your heating costs.  A modern heat pump should give you more than 3 kW of heat per kW of electricity, averaged over the year 

That's the caveat, I haven't suitably sized radiators, I have small rads, large room and large windows.
What I would want from a heat pump is quick output and using the same rads as I have now.

Phones4Chris

Sorry @Reed_Richards my understanding is that Heat Pumps are not as flexible as other boilers, they are slower to respond and certainly not suitable for all properties. You need a well insulated home for them to be at their best.
If you live in a rural area in a house with 2ft thick stone walls then my advice would be stick with your oil boiler especially if it's near 90& efficient. There are some oil boilers that are 90% efficient without them being condensing boilers.
My neighbour had a heat pump installed a couple of years ago now and he's lucky if he gets better than about 2.5x efficiency.

FreeBear

HillStreetBlues said:

Reed_Richards said:

@HillStreetBlues is wrong, there is nothing you can do with an oil boiler that you can't do with a heat pump. You can set the heat pump to it's maximum operating temperature and with suitably sized radiators it will do everything an oil boiler does, rather expensively.  

The other thing to understand is that whilst a heat pump will be least efficient when it's really cold outside, conversely it will be most efficient when it's not so cold and it's the seasonal average that determines how much your heating costs.  A modern heat pump should give you more than 3 kW of heat per kW of electricity, averaged over the year 

That's the caveat, I haven't suitably sized radiators, I have small rads, large room and large windows.
What I would want from a heat pump is quick output and using the same rads as I have now.

Simply put, you will not get a heat pump to work like that.

Your flow temperature is likely around 70°C, and heat pumps just don't run that hot.