Solar Upgrade

[stevec59]

Hi Everyone, Newbie here, so I hope I'm in the right place. I'm looking at upgrading my existing solar panel system, so lets have a look at what I have.
2 bed detached bungalow SSE facing back garden, on the back:- 4 x Hisunage 265W (Black M60PCS) panels, each with Enphase M215 Microinverter, on the side a further 12 Panels and Microinverters, the original quote was for 250w Panels and an estimated annual output of 3836kWh, so I guess with the extra wattage panels a bit higher, I have an Enphase Gateway and everything works fine. This was all installed November 2015, so under the old Fit Scheme, so receive 15.38 Generation and 5.9 Export, they calculate that 50% of what I generate goes back to the grid, on average I have received £650 to £700 a year back, this year I've done well, I guess just more sun. I think I've attached a pdf of generation history for the last year or 2

So, the question is, how can I get more? Do I add more panels? I guess if I do then I would get the new SEG rate of 4.1p per Kw, or do I get a battery? If I go for a battery, what power would I need? I have LoopEnergy app installed and that tells me that currently I use about 8kWh per day currently and about 2.6kWh in June.

Thanks for your help and advise,

Steve

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[Bob Smith]

Hi Everyone, Newbie here, so I hope I'm in the right place. I'm looking at upgrading my existing solar panel system, so lets have a look at what I have.
2 bed detached bungalow SSE facing back garden, on the back:- 4 x Hisunage 265W (Black M60PCS) panels, each with Enphase M215 Microinverter, on the side a further 12 Panels and Microinverters, the original quote was for 250w Panels and an estimated annual output of 3836kWh, so I guess with the extra wattage panels a bit higher, I have an Enphase Gateway and everything works fine. This was all installed November 2015, so under the old Fit Scheme, so receive 15.38 Generation and 5.9 Export, they calculate that 50% of what I generate goes back to the grid, on average I have received £650 to £700 a year back, this year I've done well, I guess just more sun. I think I've attached a pdf of generation history for the last year or 2

So, the question is, how can I get more? Do I add more panels? I guess if I do then I would get the new SEG rate of 4.1p per Kw, or do I get a battery? If I go for a battery, what power would I need? I have LoopEnergy app installed and that tells me that currently I use about 8kWh per day currently and about 2.6kWh in June.

Thanks for your help and advise,

Steve

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Hi
you surely want to keep your FiT agreement. Therefore you cannot make direct changes to your installation.
eg add more panels to your existing inverter.
Replace the panels with more efficient ones.
In other words, anything that you changed upstream of the generation meter is likely to affect your FiT.



Therefore if, like me, you want to have more panels, you need to set up an "independent" system. ie have the new panels connected to a different inverter.

You can still have batteries but if you want your existing system to contribute to charge the batteries, then you need to have a AC coupled batteries. ie the batteries will be placed after the inverter and not before like for a DC coupled.

I am currently doing this type of project.
I have a 4kWp system since 2016 with Fit. I am adding a new system with 21 panels and new inverter. The batteries will be charged from both the new and existing system (and the grid too as and when needed).


Hope this helps.

You will find on this forum discussion about DC vs AC Coupled batteries and many other useful information.

and welcome to the Electrician Forum

 

[stevec59]

Many Thanks for this, I don't have a lot of room left to add panels, so I don't think Panels will work, I did think about upgrading to more powerful ones, but it sounds like that won't be worth it either, I'll be 64 in April, so another 20 - 25 till I pass away I guess :-0
So, if I want to go battery route can I go DC coupled? (I've watched some YouTube Videos on this), I guess it would mean running DC cable from each panel, I assume the Microinverter is under the panel, I can't see them in loft. You don't loose too much with AC Coupled, so it might be worth going that route. but if I use my Existing Panels that have Fit, will that loose me the Fit? It's not a fortune, but a lot more that SEG.

Thanks,
Steve

 

[binky]

Hi
you surely want to keep your FiT agreement. Therefore you cannot make direct changes to your installation.
eg add more panels to your existing inverter.
Replace the panels with more efficient ones.
In other words, anything that you changed upstream of the generation meter is likely to affect your FiT.



Therefore if, like me, you want to have more panels, you need to set up an "independent" system. ie have the new panels connected to a different inverter.

You can still have batteries but if you want your existing system to contribute to charge the batteries, then you need to have a AC coupled batteries. ie the batteries will be placed after the inverter and not before like for a DC coupled.

I am currently doing this type of project.
I have a 4kWp system since 2016 with Fit. I am adding a new system with 21 panels and new inverter. The batteries will be charged from both the new and existing system (and the grid too as and when needed).


Hope this helps.

You will find on this forum discussion about DC vs AC Coupled batteries and many other useful information.

and welcome to the Electrician Forum

You've certainly learnt a lot from this forum Which is great as it saves me repeating myself

 

[Bob Smith]

You've certainly learnt a lot from this forum Which is great as it saves me repeating myself

Hi Binky,
I have learned a fair bit and mainly thanks to you but that bit I knew it even before I knew this forum existed. I have my FiT and no way I am losing it


@stevec59

Effectively, you do not need to add more panels if you want to add batteries. However, as I have said in my previous response, In order to keep your FiT you must not alter your existing system. That ism if you insert a DC couple batteries (ie the batteries are charged directly from the panels), this is likely to be considered a change and you may lose part of your FiT (export for instance or more). I would recommend you to ask your FiT provider.

On the other hand, while, in theory you lose a bit in efficiency with AC Couple batteries, those batteries are connected (coupled) once the current has been converted from DC to AC and therefore do not alter your existing system.

You seem good at maths so I would also recommend you that you do some calculations to check if it will be worth the investment to install batteries.
You can count roughly 1000GBP per kWh of storage knowing that you will never be able to use all the stored energy.


I hope this answers your questions.

 

[stevec59]

Thanks, so AC coupled battery it is, next question, what size? 3kw will cover summer but I need more in the winter, i certainly don’t want to pay £10k to cover me for winter.
If I go for an AC coupled battery it makes sence to go for one that will supply the bungalow if there is a power cut, I guess these are more expensive?
If I don’t want to charge them from the grid and just rely on my panels, obviously that will mean that I won’t charge them a lot in the winter, so 3kw would make sense, is that possible? I’m not sure that dual tariff is the way to go, and little point paying full price to charge them on full price electricity just toe save full price electricity?
Thanks again,
Steve

 

[Bob Smith]

There are many discussions about which size of batteries should someone install. There is no answer that fits it all. It all depends on your consumption and what you want to do.

I can tell you what I am doing
I have a daily average of 15.5kWh (about 5 in Summer and 30 in Winter). I too am not sure how much I will need so I decided to start with 10kWh (actually it will be 11.5 because of the batteries I have chosen).
I keep my options open in the way that the system will be able to accommodate additional batteries.
I originally thought I would go for a lot more storage in order to charge the batteries in summer and use it in Winter. Well, I would need VERY big batteries and this would cost far too much.

While I intend to use as much as I can from the generated electricity, I plan to export some electricity but also go on a night tariff in order to be able to charge the batteries when I know not enough will be generated in the next day.

There are many discussions here about this topic and also youtube videos that may help you see the situations from different angles so you can take an informed decision.

The decision you'll have to make will be down to your usage and expectations.

Hope this helps

 

[binky]

If I don’t want to charge them from the grid and just rely on my panels, obviously that will mean that I won’t charge them a lot in the winter, so 3kw would make sense, is that possible?

I would say 3kw is a little small, but, you can add batteries as required once you have a system installed.

 

[stevec59]

Thanks, ill look at discussions on choosing size, make e 5 or 6 kw would be better, and I’ll see if there are discussions on dual tariff.
I presume I need a professional to install, it’s not just something that I can but myself and plug in a 13A socket?

 

[Bob Smith]

In order to be able to connect it to the grid, which you will have, the installation must be verified by a MCS accredited person.
You can do the installation yourself but you will need to get someone to sign it off (no offense but I assumed you are not MCS approved )

 

[binky]

In order to be able to connect it to the grid, which you will have, the installation must be verified by a MCS accredited person.
You can do the installation yourself but you will need to get someone to sign it off (no offense but I assumed you are not MCS approved )

No MCS registered installer is likely to do that as it means taking responsibility for a DIY installation under MCS rules. Only legal requirement is to notify the DNO/ building control for a new circuit.

So decision is install it yourself and forgoe any smart export tariffs or bite the bullet and pay for a registered installer.

 

[stevec59]

I’ll get some quotes in after checking discussions on size and dual tariff