Circular reasoning (Rolfe's solar energy system)

[Bam Bam]

You think ?

So they wouldn't do this then: ?

View attachment 25748

It seems dependent on the manufacturer releasing the API details and giving access to it.

Bonanza!

Yes they don't seem to limit the export as much for IOG customers, but they do for OG. Assumed it was because they were in control of the battery as well, but they aren't are they?

In other news we are currently over £4 up from today's imports and exports. Easy money. Summer credit = future heating + EV miles.

Octopus and Givenergy have worked together on battery projects before so I'm sure they will sort out the EV Charger, though it might take a little time if Octopus have other priorities.

 

[Ferretusmaximus]

Why do you say the Zappi is a bit over the top?

It's quite expensive. My installer recommended as it has the capability to monitor your batteries and solar panels so as to take any excess (that would go to the grid) and put it in the car instead. As pointed about above it needs 1.4kw excess to start charging the car. If you only have a charger but no panels and no battery then the Zappi becomes an expensive charger. Just to confuse everything I used to be on the Tesla plan (no longer available) which charged up the Powerwall at night and sold back to the grid between 4pm and 7pm (most expensive peak electricity rate). If you go for the full Monty configuration you can use Octopus Flex and charge up your batteries during the night on cheap rate and sell back to the grid during peak rate - the solar panels then charge the batteries (for nothing) and then the electric can be sold back to the grid at peak rate (the more panels you have the better it gets - us old timers are limited to 4kW due to FIT rules, hey ho).

 

[Rolfe]

It's quite expensive. My installer recommended as it has the capability to monitor your batteries and solar panels so as to take any excess (that would go to the grid) and put it in the car instead. As pointed about above it needs 1.4kw excess to start charging the car. If you only have a charger but no panels and no battery then the Zappi becomes an expensive charger. Just to confuse everything I used to be on the Tesla plan (no longer available) which charged up the Powerwall at night and sold back to the grid between 4pm and 7pm (most expensive peak electricity rate). If you go for the full Monty configuration you can use Octopus Flex and charge up your batteries during the night on cheap rate and sell back to the grid during peak rate - the solar panels then charge the batteries (for nothing) and then the electric can be sold back to the grid at peak rate (the more panels you have the better it gets - us old timers are limited to 4kW due to FIT rules, hey ho).

Thanks for all the contributions. Obviously the system I'm pricing up is the Full Monty, and the supplier suggests the Zappi with Octopus Flex. If I was only going for a charger I'd re-think that.

I'm a bit surprised by the scarcity of "it's great, go for it!" posts compared to the "nah, not worth it" ones, especially in this forum section. Where are the enthusiasts?

 

[Bam Bam]

Thanks for all the contributions. Obviously the system I'm pricing up is the Full Monty, and the supplier suggests the Zappi with Octopus Flex. If I was only going for a charger I'd re-think that.

I'm a bit surprised by the scarcity of "it's great, go for it!" posts compared to the "nah, not worth it" ones, especially in this forum section. Where are the enthusiasts?

Flux in the Summer, IOG in the winter. I expect to build up enough credit in the summer to pay all bills through the winter.

It's a big upfront cost, but it will end up paying back more than it cost, especially with an EV, and you don't have to worry so much about bills going up due to wars in the Middle East or Ukraine - you are much more inflation proof.

Personally, I was offsetting my carbon emissions so the solar and EV are saving a fortune on that!

I'd certainly recommend to anyone with a suitable roof!

 

[Rolfe]

I showed my roof earlier, here it is again. The supplier recommends six panels on the garage and twelve on the main roof.

It's always seemed to me to be a bit of a sin not to put solar panels on that.

Simplistically, I look at the current recommendation for my monthly electricity DD, which is £146. Not actually a huge amount in the grand scheme of things. (I'm actually paying a bit less at the moment but the Scottish Power app is recommending an increase, possibly it's realised I'm consuming a bit more than I was.)

The entire quote (including solar panels, battery and Zappi) is £13,710. If I divide the quote by the monthly DD, then that makes 7 years 10 months worth of monthly payments. Obviously not accounting for inflation or lost interest and so on. My supplier is estimating 6-7 years of payback time. This suggests that over the year I'm not simply paying nothing for my electricity, I'm making a little bit.

I appreciate this is highly simplistic, but is this actually possible? And yet people who have the systems seem to be quite satisfied with the return they're getting, on the whole. And my electricity consumption is on the high side of average, so that should actually be advantageous.

 

[Archev]

I showed my roof earlier, here it is again. The supplier recommends six panels on the garage and twelve on the main roof.

View attachment 25750

It's always seemed to me to be a bit of a sin not to put solar panels on that.

Simplistically, I look at the current recommendation for my monthly electricity DD, which is £146. Not actually a huge amount in the grand scheme of things. (I'm actually paying a bit less at the moment but the Scottish Power app is recommending an increase, possibly it's realised I'm consuming a bit more than I was.)

The entire quote (including solar panels, battery and Zappi) is £13,710. If I divide the quote by the monthly DD, then that makes 7 years 10 months worth of monthly payments. Obviously not accounting for inflation or lost interest and so on. My supplier is estimating 6-7 years of payback time. This suggests that over the year I'm not simply paying nothing for my electricity, I'm making a little bit.

I appreciate this is highly simplistic, but is this actually possible? And yet people who have the systems seem to be quite satisfied with the return they're getting, on the whole. And my electricity consumption is on the high side of average, so that should actually be advantageous.

Sounds good to me. Almost a sin not to have panels on such a fine roof.
My roof is not really suitable at all due to flat bits and dormers etc. I’ve considered ground mounted panels along a fence line but never got further with that. I’m about £250 per month with OVO and everything is electric.

 

[bobbarley]

Our bill came in and despite a £180 a month direct debit, they said we used over £400 of gas and electric in February!

 

[johnb80]

The entire quote (including solar panels, battery and Zappi) is £13,710. If I divide the quote by the monthly DD, then that makes 7 years 10 months worth of monthly payments. Obviously not accounting for inflation or lost interest and so on. My supplier is estimating 6-7 years of payback time. This suggests that over the year I'm not simply paying nothing for my electricity, I'm making a little bit.

I appreciate this is highly simplistic, but is this actually possible? And yet people who have the systems seem to be quite satisfied with the return they're getting, on the whole. And my electricity consumption is on the high side of average, so that should actually be advantageous.

I would suggest it's highly unlikely that your panels will provide all of your electricity, especially during the winter months. There are several apps where you can feed in your details, location, panel type etc and it will give you a generation forecast. This is much more meaningful because it takes your location and local weather conditions into account, they are pretty accurate. My 7kW array generated 5.3MW last year which is amazing. Based on 25.6p kWh the revenue from solar is £1356.

Is it worth it? I would say so, if I were to do it all again, I would have a battery only system.

 

[Rolfe]

Obviously the panels are going to provide bugger-all in the winter. So there must be some compensatory mechanism. The system the installer is proposing is predicted to supply 6618 kwh pa, which is actually more than I use at the moment. I'm trying to get my head round how this works.

 

[SimonS]

Thanks for all the contributions. Obviously the system I'm pricing up is the Full Monty, and the supplier suggests the Zappi with Octopus Flex. If I was only going for a charger I'd re-think that.

I'm a bit surprised by the scarcity of "it's great, go for it!" posts compared to the "nah, not worth it" ones, especially in this forum section. Where are the enthusiasts?

We had a 10kWh Libbi battery system (9.2kWh usable) and a Zappi charger installed at the end of November. Disregarding the solar (only 7 panels as it's a new build and the builder refused to add more) using our IOG tariff I've calculated that we are saving £1190 pa on charging our EV versus our previous ICE car (BMW 320i) and £975 pa on the house electricity. Based on the £10k cost we will break even in 4.6 years. (less if you take into account the 15p/kWh we get for the exported solar).

 

[Bam Bam]

Obviously the panels are going to provide bugger-all in the winter. So there must be some compensatory mechanism. The system the installer is proposing is predicted to supply 6618 kwh pa, which is actually more than I use at the moment. I'm trying to get my head round how this works.

Use the electroverse card when DC charging and that gets deducted from your summer credit build up as well.

I expect the great payments rates for export will decline once enough more solar farms are online to cover use, so we've got until then (5 years? 8 years?) to make some money out of solar export. After that it might go back to home-use priority.

An extra panel is so cheap compared to cost of labour etc. it makes sense to maximize as you've said.

This is a good time to get solar I should think.

Another question - are they including micro-inverters (or similar)? We've just got two simple strings but micro-inverters should get you better generation in the winter. We have East-West strings so much less in winter but you've got South facing so not such a big Summer-Winter difference (except you are much further North).

 

[johnb80]

We had a 10kWh Libbi battery system (9.2kWh usable) and a Zappi charger installed at the end of November. Disregarding the solar (only 7 panels as it's a new build and the builder refused to add more) using our IOG tariff I've calculated that we are saving £1190 pa on charging our EV versus our previous ICE car (BMW 320i) and £975 pa on the house electricity. Based on the £10k cost we will break even in 4.6 years. (less if you take into account the 15p/kWh we get for the exported solar).

Youre better off to export all what you generate and then charge EV and batteries from off peak energy.

 

[Bam Bam]

Youre better off to export all what you generate and then charge EV and batteries from off peak energy.

That is currently true with some tariff set-ups such as yours.

For me it doesn't matter - I've got the same price import and export so the timing doesn't matter. I just try to top up the car when the carbon intensity is very low (like right now).

Having smart devices (like a Zappi) means future-proofing.

Whatever the best deal happens to be, the smart equipment can be set up with to take advantage of it.

 

[Rolfe]

That's a useful observation. My financial advisor didn't throw her hands in the air and scream "don't do it!" so I'm still considering.

 

[SimonS]

Youre better off to export all what you generate and then charge EV and batteries from off peak energy.

That's exactly what we do.

 

[Bam Bam]

That's a useful observation. My financial advisor didn't throw her hands in the air and scream "don't do it!" so I'm still considering.

If your Octopus account is in credit you can request a payment. However, you should then be declaring this as taxable income, so I aim to use it on heating and car charging.

 

[Ferretusmaximus]

Thanks for all the contributions. Obviously the system I'm pricing up is the Full Monty, and the supplier suggests the Zappi with Octopus Flex. If I was only going for a charger I'd re-think that.

I'm a bit surprised by the scarcity of "it's great, go for it!" posts compared to the "nah, not worth it" ones, especially in this forum section. Where are the enthusiasts?

Possibly because it all depends on personal circumstances. I invested in a Powerwall when interest rates were 0.1% and house batteries looked as though they could deliver an equivalent interest rate of about 5-10% - not sure if I would have done it if I didn't have the funds. As to "go for it" - if you can afford it then definitely a big yes as you save a lot in the long term, you have some insulation against power cuts and you are being good to the planet.

 

[Archev]

Possibly because it all depends on personal circumstances. I invested in a Powerwall when interest rates were 0.1% and house batteries looked as though they could deliver an equivalent interest rate of about 5-10% - not sure if I would have done it if I didn't have the funds. As to "go for it" - if you can afford it then definitely a big yes as you save a lot in the long term, you have some insulation against power cuts and you are being good to the planet.

Go for it ?

 

[GaryMG4]

Obviously the panels are going to provide bugger-all in the winter. So there must be some compensatory mechanism. The system the installer is proposing is predicted to supply 6618 kwh pa, which is actually more than I use at the moment. I'm trying to get my head round how this works.

Here in Norfolk our 16 panel 4kW array (no battery storage) has produced 3700-4200 kWh pa over the last 8 years. As a result we buy around 3000 kWh pa, currently costing around £82 per month. I expect the DD will need to increase a bit as this time last year I was in credit by £100 or so, this year it's flat. Oil provides heating and hot water.

 

[Rolfe]

Thanks for all the input. Could anyone specifically clarify two things.

First, how come the projected payback time is less than the time it would take me to pay the capital cost for electricity at my current direct debit rate, and

Second, given that solar generation only really happens in the summer, how is it possible not to rack up a lot of expenditure from the grid in winter?