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Discussion Starter #1
Ignoring the capital costs completely for the moment...

When I had the Feed in Tariff (FiT) I always considered my solar power to be free. To be used up whenever I have it or lose it forever into the grid. OK, not so bad it going to the grid as someone else can use the green electricity but I then wouldn't benefit personally once it is out there. So my strategy for using my solar power has been use it myself whenever possible if it benefits me in some way no matter how small. So, charging the car for example... charging in the day with solar was preferable to charging overnight.

With the demise of the FiT and the rising of the Solar Export Guarantee (SEG) that is changing...

With the FiT I got the payment per kWh regardless of how I used it as it was deem 50% export. If I used all my solar in the day myself I still got the FiT payment. SEG is different... it is not assumed at 50% export and instead it is paid based on your actual export. This makes a world of difference. Now, if I don't use a kWh of solar and it goes out to the grid then I don't get the 5p (approx) payment for the SEG. now, letting my solar power go out to the grid instead of using it myself means I lose, or rather don't get, the SEG payment.

So what difference does that make? Well, that depends on what electricity tariff you are on. If you are on a traditional fixed tariff, where your fixed rate is high (say, 15p/kWh) then using solar is always cheaper than buying from the grid and while you wouldn't get the 5p for a kWh that is not exported so you would then save the 15p for not having to import that kWh... giving you a net saving of 10p/kWh of your solar that you use yourself. However, I am on the Octopus Agile tariff and it is quite possible that my day rate drops to below 5p (in fact it happened last week) and when that happens it is cheaper for me to buy from the grid than to export.

Of course, it is a theoretical saving. It is only cheaper if I could store that solar in a battery whilst simultaneously importing from the grid and AFAIK that isn't possible with a normal solar PV/battery set up. The solar PV and battery are linked to the house so if you are generating then the house gets first dibs before the battery and also before the grid. It would need a system that stored the solar PV generated energy for use at another time when the import rate is greater than 5p, whilst simultaneously importing what was needed for the house from the grid at the cheaper rate under 5p.

Am I just wittering on here or am I missing something obvious... have I got the principle right...?

So for now then... as we don't have these kinds of clever systems to maximise our financial benefit... all I can do is look on my solar PV power as now costing me 5p/kWh that I use. If I use 1kWh of my solar then it is 5p of SEG that I won't get and so this makes a difference to when I might charge the car. If the night rate is below 5p on Agile overnight, as it often is, then it will be cheaper for me to charge overnight with the cheap Agile power and let my solar go out to the grid in the day. This will have even more of a bearing if you have a battery installed in your home or if you divert your excess solar power to your immersion... in that case it will often be cheaper to let your excess solar go out to the grid in the day, not charging your battery or diverting to the immersion, and then charging the battery or heating your water on the cheaper rate at night.

This is precisely what the grid wants us to do of course... we can provide solar power to the grid in the day when it is needed and we can then use the cheaper, off-peak, power from the grid instead when there is a surplus.

Things are a'changing...
 

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Sounds entirely like a first world problem!

Seriously, have you calculated your net annual "loss" under the scenarios you describe. Is it worth losing sleep over £100 or so a year.

Lastly, a greater societal good arises from your contribution to the grid. Convert some of that into a self satisfaction payment and you will become happier about the whole setup😁
 

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All this complexity still astounds me, if the government simply let us run our meters backward if not using the solar power myself then not only does the grid get needed power but I can also “bank” my KW‘s while I’m at work to use in the evening. This also stops the need for the tax payer to subsidise, as well as stopped all that buying of people’s roof spaces by companies for no other ”green” reason than to make profit.
 

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1st qn; I thought the Fit was a 10? 20? Year fixed contract. Has this been forcibly cancelled against your wishes? Or did you voluntarily give it up and agree to new terms when changing supplier? If the latter, I'd hope your overall bills are now lower. I'm on Fit, and I'd hope to keep that, plus add home battery or V2G some day, and so try to reduce my grid consumption towards zero. I see the Fit as a reward from gvt/supplier for not having to install a new power station to supply my increased total demand.
 

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All this complexity still astounds me, if the government simply let us run our meters backward if not using the solar power myself then not only does the grid get needed power but I can also “bank” my KW‘s while I’m at work to use in the evening. This also stops the need for the tax payer to subsidise, as well as stopped all that buying of people’s roof spaces by companies for no other ”green” reason than to make profit.
That is a terrible idea because the country needs to build excess generation to cater for the evening peaks and then some more for just in case. This extra generation you would not be contributing to and increase the cost for other consumers without PV. To reduce the overall cost we need to flatten the evening peak and not build excess generation. This the country is doing on many fronts and will get a big boost from time of use tariffs and things like smart grids and batteries.

Just imagine if everybody did as you propose - on sunny days excess generation with prices going negative and generation standing idle and ramping up to max for the evening peak -there cannot be a worse way to run a grid system.
 

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1st qn; I thought the Fit was a 10? 20? Year fixed contract. Has this been forcibly cancelled against your wishes? Or did you voluntarily give it up and agree to new terms when changing supplier? If the latter, I'd hope your overall bills are now lower. I'm on Fit, and I'd hope to keep that, plus add home battery or V2G some day, and so try to reduce my grid consumption towards zero. I see the Fit as a reward from gvt/supplier for not having to install a new power station to supply my increased total demand.
For early adopters the FIT was for 25yrs reduced to 20yrs for later ones. The FIT has not changed. What has changed is that when you go on to a Smart Meter, which you usually have to do if you change supplier, you give up the deemed export payment (basaed on 50% of actual production) and get payed for actual export payment which the meter can now measure. The new rate works out slightl better but is of no benefit if you export is low.

The OP makes a valid point and for eg PV users used to divert leccy to water but that does not really stack up now with time of use tariffs.

PV leccy should be used to substitute for other leccy use particularly EVs. but also heat pumps. But not everybody can have a car charging at home during the day but the smart answer in my opinion is to have 2 EVs.
 

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The FIT has not changed. What has changed is that when you go on to a Smart Meter, which you usually have to do if you change supplier, you give up the deemed export payment (basaed on 50% of actual production) and get payed for actual export payment which the meter can now measure. The new rate works out slightl better but is of no benefit if you export is low.
Please can you point me to this information, as I have had a smart meter fitted and heard nothing about my FIT payments been withdrawn.
 

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Which bit did you not understand in " the FIT has not changed". You are aware that you get 2 payments one for the FITS and one for the export (deemed or actual). These 2 payments can come from seperate companys or the same co. as your choice.
 

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Discussion Starter #9
Sounds entirely like a first world problem!

Seriously, have you calculated your net annual "loss" under the scenarios you describe. Is it worth losing sleep over £100 or so a year.

Lastly, a greater societal good arises from your contribution to the grid. Convert some of that into a self satisfaction payment and you will become happier about the whole setup😁
It wouldn't be worthwhile worrying about it but my electricity bill is currently running at somewhere between 4000kWh and 6000kWh per year and due to rise quite a bit when I get an EV, so the savings could be quite significant.

The thing is that when I have surplus solar, and so I can export to the grid, so does everybody else. What we really need is for that surplus to be stored until it is needed more at peak times and without a battery that isn't possible. So solar only satisfies half of the equation.

All this complexity still astounds me, if the government simply let us run our meters backward if not using the solar power myself then not only does the grid get needed power but I can also “bank” my KW‘s while I’m at work to use in the evening. This also stops the need for the tax payer to subsidise, as well as stopped all that buying of people’s roof spaces by companies for no other ”green” reason than to make profit.
What you are describing (meter running backwards) is called net metering. In other words you only pay for the net import. That is of course possible without meters running backwards with smart meters as import and export are metered separately. Export could be subtracted from import and you pay (or are paid) for the difference.

The problem with net metering is that it requires the energy supply companies to have a pricing structure that allows for it. It would mean the energy company buying your electricity at retail prices thereby handing back to you the profits made of what you buy. As it stands, we buy at a retail price and sell back at a rate closer to the wholesale price which makes sense from a business perspective - why would an electricity company buy electricity at a retail price when they can buy it from the generation companies at wholesale prices?

In some states in the USA they use net metering but not many.

1st qn; I thought the Fit was a 10? 20? Year fixed contract. Has this been forcibly cancelled against your wishes? Or did you voluntarily give it up and agree to new terms when changing supplier? If the latter, I'd hope your overall bills are now lower. I'm on Fit, and I'd hope to keep that, plus add home battery or V2G some day, and so try to reduce my grid consumption towards zero. I see the Fit as a reward from gvt/supplier for not having to install a new power station to supply my increased total demand.
I moved house... the old house still gets FiT... I have just installed solar PV on my new house so I only get SEG.

I still want to export power to the grid... I still want to get a battery to reduce my import to near zero (which I could probably get close to for a lot of the year as my solar PV is 9kWp). But the economics of it are certainly changing.
 

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It wouldn't be worthwhile worrying about it but my electricity bill is currently running at somewhere between 4000kWh and 6000kWh per year and due to rise quite a bit when I get an EV, so the savings could be quite significant.

The thing is that when I have surplus solar, and so I can export to the grid, so does everybody else. What we really need is for that surplus to be stored until it is needed more at peak times and without a battery that isn't possible. So solar only satisfies half of the equation.


What you are describing (meter running backwards) is called net metering. In other words you only pay for the net import. That is of course possible without meters running backwards with smart meters as import and export are metered separately. Export could be subtracted from import and you pay (or are paid) for the difference.

The problem with net metering is that it requires the energy supply companies to have a pricing structure that allows for it. It would mean the energy company buying your electricity at retail prices thereby handing back to you the profits made of what you buy. As it stands, we buy at a retail price and sell back at a rate closer to the wholesale price which makes sense from a business perspective - why would an electricity company buy electricity at a retail price when they can buy it from the generation companies at wholesale prices?

In some states in the USA they use net metering but not many.


I moved house... the old house still gets FiT... I have just installed solar PV on my new house so I only get SEG.

I still want to export power to the grid... I still want to get a battery to reduce my import to near zero (which I could probably get close to for a lot of the year as my solar PV is 9kWp). But the economics of it are certainly changing.
It wouldn't be worthwhile worrying about it but my electricity bill is currently running at somewhere between 4000kWh and 6000kWh per year and due to rise quite a bit when I get an EV, so the savings could be quite significant.

The thing is that when I have surplus solar, and so I can export to the grid, so does everybody else. What we really need is for that surplus to be stored until it is needed more at peak times and without a battery that isn't possible. So solar only satisfies half of the equation.


What you are describing (meter running backwards) is called net metering. In other words you only pay for the net import. That is of course possible without meters running backwards with smart meters as import and export are metered separately. Export could be subtracted from import and you pay (or are paid) for the difference.

The problem with net metering is that it requires the energy supply companies to have a pricing structure that allows for it. It would mean the energy company buying your electricity at retail prices thereby handing back to you the profits made of what you buy. As it stands, we buy at a retail price and sell back at a rate closer to the wholesale price which makes sense from a business perspective - why would an electricity company buy electricity at a retail price when they can buy it from the generation companies at wholesale prices?

In some states in the USA they use net metering but not many.


I moved house... the old house still gets FiT... I have just installed solar PV on my new house so I only get SEG.

I still want to export power to the grid... I still want to get a battery to reduce my import to near zero (which I could probably get close to for a lot of the year as my solar PV is 9kWp). But the economics of it are certainly changing.
That's interesting. Did you justify your 9Kw solar installation financially or just do it because you want to?

We have a 4 KW solar set up under the second stage FIT agreement. I was wondering if I can justify getting the same again without the FIT incentive. Being retired a future BEV might charge happily on a summer's day. Might even get into batteries.
 

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Discussion Starter #12
We kinda justified it :)

The thing is that whatever sums we did it was only ever going to be accurate for that moment or for the foreseeable future. Things have changed a lot since we did the sums originally so if we were to try to justify it now then I am pretty sure that, with Agile, we couldn't make the numbers work so well. However, at the time, we reckoned saving 2/3 of our electricity bill over the year and we did the sums on that. As it happens, over the winter period it looks like it is saving us about 1/4 at best... but so far this spring it is saving us between 1/2 and 3/4. We won't know what it is actually saving over the year until we have had it a year (we installed in October last year). Agile is saving us at least 1/2 at the moment (my estimate) on its own so how much extra the solar will actually save us I am not sure because when we have lots of solar the Agile price is low... lower than the 5p we get to export... so we aren't saving anything like as much as we had planned for.

The battery is what is concerning me. We justified the cost of the battery by saving the solar generation and using it in the evenings and overnight. Now, with Agile, the evenings and overnight isn't so expensive (3p - 8p at the moment) so the only big savings we would make if we had a battery is by avoiding the peak 4pm - 7pm and allowing us to cook in that period (right now we are avoiding cooking from 4-7pm). Remember... when the night rate is less than 5p it will be cheaper for me to let our excess solar go out to the grid and for us just to buy electricity overnight at the cheaper rate... a battery wouldn't save us anything... in fact it would cost us money! This is the primary point of my OP... solar, and a battery, are becoming less financially benefitial. The justification for the battery is disappearing.

Our 9kWp solar cost us £10k and the battery (which we have not yet bought) will be about £5k if we go ahead. We worked on a 15 year payback and consider it an investment in our future. We wanted our bills to be a lot less when we are older and can't afford the bills so much. Now all that is looking much less financially beneficial but we are very much still pleased we have it... the money is just one aspect. We are glad to be contributing to a greener grid. But it is looking less and less likely that it will be financially worthwhile in any sensible period.

Will we get the battery? We might get it anyway as there are additional benefits... even less need to avoid 4-7pm, insurance against power outages (which might become more frequent as the grid gets loaded with EVs - or is that just wishful thinking???), ability to reduce our bills further by charging the battery from cheap, mainly overnight, electricity and using in peak or in not peak but slightly more expensive evening, ability to reduce importing on days with plenty of sun but intermittent cloud. I am sure they are other benefits too one is a huge feeling of smugness knowing that we are contributing.
 

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Discussion Starter #13
That's interesting. Did you justify your 9Kw solar installation financially or just do it because you want to?

We have a 4 KW solar set up under the second stage FIT agreement. I was wondering if I can justify getting the same again without the FIT incentive. Being retired a future BEV might charge happily on a summer's day. Might even get into batteries.
Right now, you would probably be financially better off charging overnight than using solar as I described above. Agile turns it all upside down.
 

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Which bit did you not understand in " the FIT has not changed". You are aware that you get 2 payments one for the FITS and one for the export (deemed or actual). These 2 payments can come from seperate companys or the same co. as your choice.
I did not misunderstand, you stated the FIT deemed export has been withdrawn, replaced by actual export if you have a smart meter fitted.
I have no knowledge of this and I wasn't advised. So I was asking where the change from deemed to metered is mentioned. Is it compulsory, because I can find no mention of it in my FIT documentation.
 

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Right now, you would probably be financially better off charging overnight than using solar as I described above. Agile turns it all upside down.
I'm on normal sort of tariff. Anything clever involves getting a smart meter which I have resisted so far as I thought it would bring the deemed 50 percent export allowance to an end and use actual export figures. Eventually It will have to face that. I just hope that the Agile tariff stays as good as it is now.
 

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I opted out of deemed FIT and instead get paid for actual export based on the half hourly agile / wholesale prices, which are currently very low! But it's the fairest way to do things, imo. I still get my generation FIT payments and the system will pay for itself in time, no rush..

 

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I did not misunderstand, you stated the FIT deemed export has been withdrawn, replaced by actual export if you have a smart meter fitted.
I have no knowledge of this and I wasn't advised. So I was asking where the change from deemed to metered is mentioned. Is it compulsory, because I can find no mention of it in my FIT documentation.
I think there is confusion between the Feed-in-Tariff (the old government subsidy for installing solar panels with payment based on the number of kWh your panels generate - for me currently 17.3p/kWh, and which will cease after 20 [or in some cases 25] years after the day it started) and the Export Tariff for the kWh that you export to (or are deemed to export to) the Grid, which for me is currently 5.38p/kWh. Where your electricity meter is not able to separately register the export kWh, it is deemed to be 50% of the generated kWh [for me, this is an underestimate]. When a meter which will not separately register the export kWh is replaced by one which will (such as a new smart meter), it is reasonable that the Export Tariff payments are then based upon the measured Export kWh, rather than the guestimate figure of 50% of the generated kWh. This means that with measured Export kWh, when you use your own solar power, there is a 'cost' to you at the Export rate because that power is not then being exported to the Grid.

What you are describing (meter running backwards) is called net metering. In other words you only pay for the net import. That is of course possible without meters running backwards with smart meters as import and export are metered separately. Export could be subtracted from import and you pay (or are paid) for the difference.

The problem with net metering is that it requires the energy supply companies to have a pricing structure that allows for it. It would mean the energy company buying your electricity at retail prices thereby handing back to you the profits made of what you buy. As it stands, we buy at a retail price and sell back at a rate closer to the wholesale price which makes sense from a business perspective - why would an electricity company buy electricity at a retail price when they can buy it from the generation companies at wholesale prices?
Now, with Agile, the evenings and overnight isn't so expensive (3p - 8p at the moment) so the only big savings we would make if we had a battery is by avoiding the peak 4pm - 7pm and allowing us to cook in that period (right now we are avoiding cooking from 4-7pm).
With smart meters, do they have separate registers for both import and export for every half-hour period, or do they net meter within a single half-hour period? Also, do Octopus Agile have variable export rates (so that you can earn more if you export during the expensive early evening peaks - and even make a profit without solar if you can charge a battery during the cheap periods and export during the expensive periods)?

The thing is that when I have surplus solar, and so I can export to the grid, so does everybody else. What we really need is for that surplus to be stored until it is needed more at peak times and without a battery that isn't possible. So solar only satisfies half of the equation.
What I envisage is the grid being used as a virtual battery. If a record is made of the amount I export when the grid is short (ie. supply frequency <50.0Hz), I would be happy to have that back at no extra cost to me when the grid has a surplus (ie. supply frequency >50.0Hz). I could then arrange for deferable loads (such as car charging and water heating) to be done at times when the supply frequency is >50.0Hz without having to accurately balance such loads with the amount of solar I am generating at that time.
 

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Discussion Starter #19
Don't know about variable export tariffs. I have kept my export with Bulb for the moment.
 

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I did not misunderstand, you stated the FIT deemed export has been withdrawn, replaced by actual export if you have a smart meter fitted.
I have no knowledge of this and I wasn't advised. So I was asking where the change from deemed to metered is mentioned. Is it compulsory, because I can find no mention of it in my FIT documentation.
It is not compulsory to change though if your FiT provider is the same company as your energy supplier they might bring pressure to bear. I had a smart meter fitted last year to go onto Octopus Go. My FiT provider is another company and they have absolutely no idea that I even have a smart meter. As I use much more of my generated PV than I export and my altruism is mostly used up by my day job and a couple of other parts of my life, I will stay on the deemed 50% export rate.
 
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