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Rank 2
October 22, 2024
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New to solar panels, do they power my home directly?

  • October 22, 2024
  • 30 replies
  • 2558 views

I’ve recently bought a house which has solar panels already installed (no battery storage) along with the FiT Scheme. I have transferred ownership and I just have a few general/basic questions regarding the solar panels/FiT scheme.
 

I’m only querying this as my neighbour in the same size house/same number of occupants (2 adults) is roughly £40 a month cheaper than us in energy bills without solar panels.


I have just submitted my first generation reading to OVO and will receive my first payment in December. OVO have said that I am paid for any excess energy that I generate. Are the solar panels directly powering some appliances in my house and if so why don’t I see the benefits on my energy bill?  On average we use roughly 380kW per month and have a smart meter just for our electricity.

 

Apologies for the basic questions, I just want to make sure I understand it all before selecting our new tariff.

 

Thanks

Best answer by BPLightlog

Hi @CraigM1996 , it will depend on how the control (inverter) is set. 
Usually the setting is to 

  1. power any draw from the home
  2. charge any batteries (if fitted)
  3. export excess to the grid

Of course, this hierarchy varies throughout the day but you should see reduced usage from the grid as you suggest.
The system should have a monitor either via an app or a web portal. This can help to confirm where the generated power is being used. 
You could also check against your half hour usage graphs to show usage vs expected. 
On the FIT scheme you will either be paid for generation plus deemed export or measured. This might also determine what you sign up to. 
If you post the system set up we might be able to help further if needed 

30 replies

Rank 5
October 22, 2024

Wrong part of the forum, but it may get moved. Regardless

380kwh/month = 12kwh/day

The £40/month difference = 181kwh@0.22p/kwh = 5.5kwh/day less

A lot for the “same” and the fact that you have up to 3.6kwhp of solar panels. It’s worth checking that it is the same in terms of using the same fuel for cooking / space heating / water heating as that can make a huge difference. + use of washing machines. 

FIT - I’m not on fit myself. What is your export rate? I believe the FITS were “deemed export” and based on theoretical values. I’m not sure if the actual generation values were measured, but i’m fairly sure they assumed that you only used half and exported the other half. 

SEG - I’m on seg and get 4p/kwh export. 

How do the panels power your house / do they power certain appliances? No, they don’t. The inverter feeds into your consumer box and powers all items connected to it. The inverter measures the incoming mains voltage and always produces a slightly higher output voltage than the mains, forcing electricity back into the grid. When you’re using more than generating, the electricity flows into the house and you use both, or just the grid when there is no generation. 

Panels producing 3.6kw @ midday - House uses 2kw (oven on) - Exports 1.6kw

Panels producing 1kw @ 4pm - Houses uses 2kw - Draws 1kw from grid

 

If you have a smart meter you’ll be able to see on this the energy consumption and it’ll show a negative value when exporting. If you don’t have a smart meter, get one, or get a energy monitor and monitor your mains. 

Makin the most of solar requires you to run equipment when the sun shines, or use a “diverter” to dump energy into the hot water cylinder. Or, charge a car during the day. For me, a battery doesn’t make sense. 

Rank 2
October 22, 2024

@supercitybity 

 

thanks for your reply.

 

I queried my export rate with OVO this morning and they said it was 19.01p/kwh but that is only for ‘any excess generated’. We have only manually submitted our first quarterly reading last month via the generation meter and will be due to receive payment in December.

 

Yes we have a smart meter for electricity - having issues with the app so can’t view daily usage at the moment. However, will be good to check daily usage and to see any negative readings at certain times of the day.

 

thanks again

Rank 7
October 22, 2024

If you are out all day then your panels will during that time be powering the only items that are on - probably a fridge and freezer, perhaps your Internet router and whatever else is on standby.

If it's dark (or darker than the solar panels need) by the time you're home, then sadly you won't be seeing much benefit from them in terms of consumption. You will get the FiT scheme payments which will offset them.

We're in North East England with E/W facing panels. Our latest full year from a 2015 FiT scheme has paid £529. Broadly, December and March quarters total about £80 between them, June £250 and September £200. If we didn't have batteries we'd export more but it wouldn't have made a significant difference for FiT. They do mean negligible grid consumption in summer as we use our own generated electricity all day and night. In winter we charge overnight on economy 7.

3.99kW solar 2015, 12kWh batteries 2022, Tado.
BPLightlog
Super User
Super User
October 22, 2024

 

 

Yes we have a smart meter for electricity - having issues with the app so can’t view daily usage at the moment. However, will be good to check daily usage and to see any negative readings at certain times of the day.

 

Just to note that you won’t see any export or negative readings via your online account - that’s why it’s important to be able to monitor the inverter. 

Bring me Sunshine ~ E&E {Solar PV, Battery Storage, Hybrid EV, ASHP and Home Assistant automation}
Rank 5
October 22, 2024

With such a good FIT payment there is little  incentive to maximise self consumption and no incentive to use it for hot water heating. 

As said, the smart meter won’t show export, the history will just show as no use for that time period.  

Rank 2
October 22, 2024

 

 

Yes we have a smart meter for electricity - having issues with the app so can’t view daily usage at the moment. However, will be good to check daily usage and to see any negative readings at certain times of the day.

 

Just to note that you won’t see any export or negative readings via your online account - that’s why it’s important to be able to monitor the inverter. 
 

will this show on the Solax app once set up? Or will this only show electricity being generated by the solar panels and not the electricity being consumed?

BPLightlog
Super User
Super User
October 22, 2024

 

will this show on the Solax app once set up? Or will this only show electricity being generated by the solar panels and not the electricity being consumed?

It should be able to show a range of parameters once you figure out the detail. 
Although from a different manufacturer, this is an example of mine which I can explore point by point 

 

Bring me Sunshine ~ E&E {Solar PV, Battery Storage, Hybrid EV, ASHP and Home Assistant automation}
Rank 2
October 22, 2024

 

will this show on the Solax app once set up? Or will this only show electricity being generated by the solar panels and not the electricity being consumed?

It should be able to show a range of parameters once you figure out the detail. 
Although from a different manufacturer, this is an example of mine which I can explore point by point

 

Perfect. So in theory as I won’t see a ‘negative’ reading on my graph, any point where my ‘Solar PV’ is showing a higher reading than my ‘consumption’ this is when I am producing/generating more electricity and would be the ideal time to use washing machine/dishwasher etc and my grid should be sitting at 0.

BPLightlog
Super User
Super User
October 22, 2024

 

will this show on the Solax app once set up? Or will this only show electricity being generated by the solar panels and not the electricity being consumed?

It should be able to show a range of parameters once you figure out the detail. 
Although from a different manufacturer, this is an example of mine which I can explore point by point

 

Perfect. So in theory as I won’t see a ‘negative’ reading on my graph, any point where my ‘Solar PV’ is showing a higher reading than my ‘consumption’ this is when I am producing/generating more electricity and would be the ideal time to use washing machine/dishwasher etc and my grid should be sitting at 0.

Yes although you could see a negative grid reading on this output (via the inverter), it’s your supplier account which won’t show the export. 
 

It’s not such a good time of year to show solar which is why many have batteries and charge at an off peak rate 

Bring me Sunshine ~ E&E {Solar PV, Battery Storage, Hybrid EV, ASHP and Home Assistant automation}
Rank 7
October 22, 2024

@supercitybity

 

thanks for your reply.

 

I queried my export rate with OVO this morning and they said it was 19.01p/kwh but that is only for ‘any excess generated’. We have only manually submitted our first quarterly reading last month via the generation meter and will be due to receive payment in December.

 

Yes we have a smart meter for electricity - having issues with the app so can’t view daily usage at the moment. However, will be good to check daily usage and to see any negative readings at certain times of the day.

 

thanks again

That’s a surprise; I’d check again. 

According to the latest tariff update from OFGEM which applies from April this year:  https://www.ofgem.gov.uk/publications/feed-tariff-fit-tariff-table-1-april-2024 the maximum export tariff is 7.14p/kWh.  You get that ON TOP of your generation rate.

Your generation rates will depend on date of installation and the energy rating of the house at that time: 

Ofgem:

Energy Efficiency Requirement Rating:

- Higher tariff rate will be applied if an EPC of level D or above is achieved before commissioning
- Middle tariff rate will be applied if an EPC of level D or above has been achieved but the Generator owns 25 or more installations
- Lower tariff rate will be applied if an EPC of level D or above is not achieved before commissioning. 

There isn’t a rate of 19.01 for generation either.  There is one of 19.02 for installations between July and end September 2015. 

Hope this helps.

 

3.99kW solar 2015, 12kWh batteries 2022, Tado.