My air source

[SteamyTea]

Just now, tommy12398 said:

Convinced myself out of what?

That it is the ASHP that is gobbling up all the electricity.

 

You have been asked a few questions i.e. number of zones, flow temperature, running regimes, insulation under and over the UFH.

Without knowing the answers to these, it is impossible to help you.

[tommy12398]

9 minutes ago, ProDave said:

There should not be any situation where your ASHP cannot get the water to 45 degrees and it "has" to use the immersion heater.  I am in the Highlands which gets a lot colder than where you are and my ASHP heats our DHW to 48 degrees all year.

 

It should be possible to completely disable the ASHP's use of the immersion heater.

To be fair it's only aback up and hardly ever comes on. The house is nearly at a 1000ft in hight. It does get some bad weather

[tommy12398]

1 minute ago, tommy12398 said:

To be fair it's only aback up and hardly ever comes on. The house is nearly at a 1000ft in hight. It does get some bad weather

Just to add a point I have set it at 45 from 49. Just seeing if it saves any electricity 

[JohnMo]

8 minutes ago, SteamyTea said:

That it is the ASHP that is gobbling up all the electricity.

 

You have been asked a few questions i.e. number of zones, flow temperature, running regimes, insulation under and over the UFH.

Without knowing the answers to these, it is impossible to help you.

As above and your new thread, without this information no one can help

[ProDave]

15 minutes ago, tommy12398 said:

I have been doing that. But don't have a opinion with the ovens. We Try to stagga when appliances are on. But to be fair it's the ashp whats taking the power

Take a daily electricity meter reading at exactly the same time every day and write it down.

 

Then turn off the ASHP completely at it's main power switch (not just the programmer) for 1 day.  That 1 day go without showers and boil the kettle if you run out of hot water.

 

Let us know how much the daily electricity drops without the ASHP running.  Only then will we know if it's "the ASHP whats taking the power"

[tommy12398]

7 minutes ago, SteamyTea said:

That it is the ASHP that is gobbling up all the electricity.

 

You have been asked a few questions i.e. number of zones, flow temperature, running regimes, insulation under and over the UFH.

Without knowing the answers to these, it is impossible to help you.

5 zones all set in winter at 19 through day. Drops to 17 through night

150mm insulation for ufh.

I'm not what you mean by flow temp. The water in the system is at 45.

[TonyT]

I think the best idea now after small tweaks have been made is to fit some electricity meters to the immersion, ASHP these can be purchased for under £20.

 

this will let you know how how much each device is consuming and you can take this off your whole house meter to get a cost of what the rest of the house consumes..

[tommy12398]

My app shows me every half hour what electric is been used. It spikes when ovens are on and when kids have a bath,or we have a shower. 

[ProDave]

3 minutes ago, tommy12398 said:

My app shows me every half hour what electric is been used. It spikes when ovens are on and when kids have a bath,or we have a shower. 

Post some figures from that app so we get a feel for what you are using and when.

 

If the ovens are used in the daytime on a sunny day, I would not expect you to be importing much, the solar PV should power at least one of them.

[SteamyTea]

4 minutes ago, tommy12398 said:

app shows me every half hour what electric is been used

That is just showing the total usage, and the instantaneous power.

Can it show half hour usage as a time series, i.e. for the last week?

[tommy12398]

I Don't think so. Is it possible to fit a meter to the ashp. Any idea of cost

[SteamyTea]

Rather than have two threads on the same topic, shall answer here.

 

The flow temperature is how hot the water is that runs though the pipes.

45°C is quite hot for UFH, expecially if you have 150mm of decent insulation under it.

Is the floor covered.

 

You also seem to have a number of seperate zones, though without seeing the manifold, it may be different.

When your room temperature gets up to the 19°C, zones will start to close down (or the whole system my close down, hard to tell).

What may happen is that if only one small zone is calling for heat, the ASHP starts up, heats it, then closes down, quickly.  If it is doing this most of the day, then the system is short cycling, which is ineficient.  Why buffer tanks are fitted, the allow the ASHP to run for a decent amount of time and temporarilly store some energy.

[Roundtuit]

12 minutes ago, tommy12398 said:

It spikes when... kids have a bath,or we have a shower. 

Why?  Is the ashp set to maintain a full tank of hot water 24/7?

[SteamyTea]

2 minutes ago, tommy12398 said:

I Don't think so. Is it possible to fit a meter to the ashp. Any idea of cost

I bought some for under twenty quid a few weeks back.

But what model of ASHP do you have it may already be in there.

[tommy12398]

Just a few app meter reading

[tommy12398]

Sorry let me do that again!!

[SteamyTea]

Are the days that show over 10 kWh, baking days?

You have a consistant spikes at 11:30 and 20:30, is that the ASHP coming on to heat water.

 

[AliG]

Thanks, this helps.

 

It seems that you are often using large amounts of electricity in the middle of the day when your PV should be generating.

 

It may be that it was a cloudy day of course.

 

It could be that the ovens are on or that the the heat pump is heating your water.

 

The other useful thing to know, but you would have to gather this on a go forward basis, would be how much you generate on a given day versus how much you export.

 

Then you can tell if you are always using a lot of electricity but it is covered by PV, or if your PV is covering a small amount of your electricity. If it is the former then you would expect your electricity usage to go up considerably in the winter. I suspect that is what is happening.

 

It takes a lot of fiddling around to maximise the use of PV and heat pumps. This doesn't work for everyone, my wife doesn't like being told to use the washing machine at night when we have cheap electricity for example.

 

If you are running UFH flow and hot water at 45C then you should have a decent COP and decent performance from the system. In fact I would expect a COP of 3.5-4 at this time of year.

 

To maximise your use of PV you should try to not use the ovens and PV at the same time. The ovens use 1-1.5kWh per hour, but the elements come off and on, so at any one time they could be using 3kW each.  Your heat pump has an input of around 3.5kW. Thus if they all fired up together you would be using around 10kW in the house and start to use a large amount of imported electricity.

 

If there is a time during the day when your wife tends to cook, say 12-2. Then I would set the hot water heating on your heat pump to be 9-12 and 2-5. Thus it is much more likely that your PV covers your ovens and hot water use. If you cannot stick to a specific time for cooking then there is nothing you can do about this except buy an expensive battery.

 

During the summer there is an argument that you should in fact heat the hot water to 50 or 55C during the day when you have PV and turn it off during the evening and night. Again ideally, everyone has showers in the morning and then the PV reheats the water during the day. A lot depends on the size of your hot water tank and the amount of hot water you sue though. During the winter though I would use 45C for the better COP and lack of PV.

 

Ultimately there are many trade offs between cost and convenience. Looking at your usage charts you have quite spiky energy usage. You can try to smooth this out to use more PV which will help in the summer, hence my comment you could maybe save around 1000kWh but that won't help in winter. In winter the only thing that can help is reduced energy use through insulation, draught proofing etc.

 

[ProDave]

You say this house was built in 2014.  Who built it?

 

Who fitted the PV?  The builder or a later retro fit?

 

What is the size of the PV array, how many panels what size inverter for instance? pictures?

 

If the PV was installed in 2014 it should have been eligible for Feed In Tariff payments, do you receive that?

 

If not registered it might be eligible for the Smart Export Payment instead? Ask your supplier.

[SteamyTea]

You also have a baseload of between 100W and 200W.

Do you have lots of entertainment stuff i.e. TV, Sky box, games consoles permanently on, or on standby?

Edited August 8, 2022 by SteamyTea

[Kelvin]

52 minutes ago, SteamyTea said:

You also have a baseload of between 100W and 200W.

Do you have lots of entertainment stuff i.e. TV, Sky box, games consoles permanently on, or on standby?

This is a good exercise to go through. Switch everything off during the day that doesn’t need to be on for a few days and then monitor your usage. It is surprising how much energy is consumed by the house just sitting in ‘standby’. I have a Starlink system as it’s the only way we can get fast internet. The Starlink router powers the dish and it’s surprising just how much power it uses. A standard router is probably using about £17 of electricity PA and I reckon my Starlink router is consuming about £90. 

Edited August 8, 2022 by Kelvin

[SteamyTea]

3 minutes ago, Kelvin said:

A standard router is probably using about £17 of electricity PA and I reckon my Starlink router is consuming about £90. 

I think I read somethign about this.

Seemt o remember that it was 20W, then a bit more when tracking.

Is the service good though?

[tommy12398]

Yeah I have Young kids there's plenty of stuff on stand by. 

I've only just fitted 6kw solar this summer. It was done by a firm called project solar. My first payment is due now. I'm on a variable tariff.  Which means I get paid what the market is paying. They take readings every half hour.

[tommy12398]

Just got my first payment through for July from the solar pannels. They have paid me 24.5p a kW for 511 kw exported. That's £124. I don't think that's too bad.  Mybe more pv could the answer

[Ferdinand]

This is quite a good thread chewing away at the bone of @tommy12398's electricity costs.

 

My comments for Tommy:

 

If your Smart Meter has a 'usage now' mode, that should let you detect what individual appliances are using when you switch them on. Though the solar will act as variable noise on that signal.

 

I think that the ovens sound quite significant. Have you considered that your wife may be able to offset the electricity charges against tax as a business expense? But you would need to know how much was being used, or 'deem' a number.

 

Your EPC is middling to good for all the housing stock of the whole country. The media is how a high D. It was 64-66 in March 2021, and has moved up by 1-1.5 points per year in the long term. For a newbuild from 2014, C does sound lowish, but they could have been making assumptions rather than look at the actual thing.

 

The housing stock across England and Wales varies and this is reflected in the median energy efficiency scores. The median energy efficiency score was 66 in England and 64 in Wales for all records up to March 2021, which is equivalent to band D.

https://www.ons.gov.uk/peoplepopulationandcommunity/housing/articles/energyefficiencyofhousinginenglandandwales/2021

 

Remember that next time you get an EPC, your solar will significantly improve it - remember that if you make comparisons.

 

You may be able to download energy usage in a spreadsheet from your energy supplier - Octopus do that under the "Explore your energy usage" option.

 

For me, I'd have a more detailed look at the usage by ovens - and get that out of the numbers.