Solar use vs export

Telegraph_Sam

So Export is related to solar generation even if not always directly. And there are two sources of income from solar panels.

If Export acts as the overflow does this remove the attraction of solar batteries?

Qyburn

https://forums.moneysavingexpert.com/discussion/comment/81972699#Comment_81972699

That depends on your tariffs. Say you're paid 12p per kWh for export, and charged 22p per kWh for import. In that case each kWh stored in the battery for later use, costs you 12p in lost export, but saves 22p in reduced import.

There are more complex cases where the battery allows you to charge at a cheap rate like an EV tariff at 8.5p or so.

QrizB

So we've established that Sam has all the info he needs to calculate his total domestic electricity use.

Sam, what are the numbers and what's your calculation?

JKenH

https://forums.moneysavingexpert.com/discussion/comment/81972627#Comment_81972627

Sam,

You may be confusing payments for generation and export. Export is paid on top of FiT Generation - in your case it appears by Octopus at 15p for each kWh you export calculated on the kWh exported as recorded by your smart meter. The 24.53p/kWh Scottish Power are paying you is FiT which is separate/additional and is calculated on the number of kWh you generate as shown by your generation meter, which is a totally separate box to your smart meter. (My smart meter is in my outside meter box and my generation meter is inside my house next to my consumer unit).

FIT is a legacy payment for those who installed solar panels before April 2019 and was split into two parts generation and export. Most people opted to receive “deemed export” which assumed you self consumed half your generation and exported half. The export element if FiT was worth about 6p/kWh which if you were on deemed export meant you received 6p/kWh on half your generation total (or 3p/kwh on the total kWh generated). The generation element of FiT is usually much higher. Not every one receives the same FiT generation rate. It depends on when your panels were installed. (Those who installed panels in 2011 receive 70+p/kWh while those who fitted them in 2019 get about 5p/kWh. With the exception of a few very early FiT entrants everyone receives the same FiT “deemed export” rate which is also index linked. Both FiT generation and FiT deemed export rates are set by the government and it does not matter who your FiT provider is, you will get the same rate.

If you are receiving 15p/kWh for export from Octopus then at some point you must have opted out of the “deemed export” scheme and instead opted to have your export paid based on the amount you actually exported. At that time you should have told SP that you were opting out of “deemed export” and your FiT export payments would have cease but you would have continued to receive the FiT generation payment so the overall FiT rate you would have seen would have gone down approximately 3p/kWh. You could, alternatively, have switched your FiT provider to Octopus and they would continue to pay the same FiT rate (minus the deemed export element) as SP were paying.

edited: spelling mistake

Reed_Richards

what determines what / how much goes through my meter labelled export?

You've had a technical answer but the simple answer is that what is metered as export is all the electricity that you generate but don't use yourself.

For example, suppose your fridge-freezer, your router and your TV on standby together draw 100W (which is 0.1 kW) all the time. Nothing else electrical in the house is switched on. It's a sunny day and your solar panels are are generating 3 kW. Your house uses 0.1 kW and the remainder, 2.9 kW, is exported. If this persists for an hour you will have exported 2.9 kWh and the reading on your export meter will have increased by 2.9. Now suppose you want a cup of tea and boil a kettle, which draws 2.5 kW. Whilst the kettle is boiling, your house uses 2.5 + 0.1 = 2.6 kW so you export 3.0 - 2.6 = 0.4 kW. If it takes 6 minutes for your kettle to boil you will have exported 0.04 kWh during that time (6 minutes being one tenth of an hour) and you probably don't have enough digits on your export meter to see a change in the reading if you look at your export meter immediately before and after the kettle has boiled.

jennifernil

We are one of those who had panels fitted in 2011, panels were much more expensive back then, so it took us almost 10 years to recoup our investment.
Now we are well into profit as our generation payment more than covers all our current gas and electricity bills.
Have considered installing batteries, but would take a good while to recoup that cost, so probably not sensible at our age (83 and 77) !!