Exporting at 15p - Help please

[GRiLLA]

That's because you can export from the battery. I'm not permitted by my DNO. So my only option is to export solar as I go, and use the battery to power the house.

I can't add batteries to my existing inverter, so that isn't an option, and hence doesn't matter if they're cheaper.

I'm not trying to sell PW, I frankly couldn't give a t*ss if someone gets one or doesn't. I merely provide info on how it works and how I find it so people can make a more informed decision that basic it on sales and marketing info.

The whole solar, battery thing is horses for courses, what works for me won't work for others, and what they prioritise as the most important things will be different for me. As I say, I say the things I say so people can work out if it works for them, or not.

Seems like an odd stipulation, is this because your powerwall can discharge at a faster rate than the solar would generate, and they won't allow a G99 application ?

 

[phil4]

Seems like an odd stipulation, is this because your powerwall can discharge at a faster rate than the solar would generate, and they won't allow a G99 application ?

I think it's quite common with powerwall peeps... If I had to guess it's not the rate that's the problem (it can be rate limited for grid export), but that they don't want "brown power", so they can say no to it, whereas if you have a hybrid with batteries, it's all or nothing, they can't say no battery export, as that'd stop solar too.

Might well see something similar when the Giv AIO is rolled out, as that AC coupled too. But that's just a guess based on a sample of 1

 

[ringi]

As said above, GivEnergy have an AIO solution which is as good as or marginally better then a PW on paper. It's early days though, so some features aren't available yet, or don't work as planned yet. It's cheaper though

Is it as well thermally regulated as a PW to cope with very hot and cold conditions?

I get that this feels right, but it doesn't really offer anything clever. There isn't any difference in price between the power in the battery and that from your panels. I let it keep my battery full in the day then discharge excess from a battery to the grid just before you recharge in the cheap rate, achieves the same or better return

That depends if the PV is export limited, if so letting the battery discharge before sun and then letting the battery charge when PV near export limit would help.

 

[ACarneiro]

Is it as well thermally regulated as a PW to cope with very hot and cold conditions?

The data sheet says it’s air cooled, so I very much suspect far worse thermal regulation than the Powerwalls.
Wether that’s relevant, though, is another matter…

 

[tomorrowman]

About to get a 13.5kWh GivEnergy all in one battery. If I understand this correctly as an Intelligent Octopus customer in the 6 hour cheap rate period I could charge the battery at 7.5p per kWh, discharge back to grid and receive 15p per kWh, then charge battery again. Outcome free electricity for the day ?

Car charging separately at cheap rate and yes aware battery import/export charge rate limits and flexibility of battery SW may not fully facilitate but interesting all the same.

 

[Fursty Ferret]

About to get a 13.5kWh GivEnergy all in one battery. If I understand this correctly as an Intelligent Octopus customer in the 6 hour cheap rate period I could charge the battery at 7.5p per kWh, discharge back to grid and receive 15p per kWh, then charge battery again. Outcome free electricity for the day ?

You could, but that's not in the spirit of the scheme and all you'll do is wear out the battery and potentially lead Octopus to pull the deal for everyone else, for what? A gain of about 50p/day.

 

[tomorrowman]

At least 75p and battery has 12 warranty (unclear if unlimited cycles) .

And as far as spirit of the scheme is concerned - meh.

And before you loose it about me being a selfish tw@t I was making an observation in my post.

The savings achieved off setting my peak rate usage alone result in the battery being paid for in 5 years (at current rates).

All without solar

 

[ACarneiro]

You could, but that's not in the spirit of the scheme and all you'll do is wear out the battery and potentially lead Octopus to pull the deal for everyone else, for what? A gain of about 50p/day.

I disagree with your first point and your conclusion.
Octopus are no idiots and they are well aware that there is a number of customers who have battery storage units and could do just as you said. That is why Outgoing Octopus was previously “not compatible” with any of their EV tariffs.
They have chosen to reverse that decision (and not only reverse it but putting customers on a 12 month guaranteed export contract, so they won’t be changing their minds for at least a year!), which suggests they are grossly prioritising reducing grid load during the day. Increasing the export tariff nearly four-fold suggests to me they REALLY want that day time juice flowing.

One of two scenarios comes to mind, then:
1 - They want the peak-time production so badly that they don’t really care if it comes from solar directly or from batteries filled during the night
2 - The number of customers with battery storage is so small in the grand scheme of things (which it probably is, and many will have export limitations imposed by the DNOs anyway) that they just don’t really care.

Either way, I cannot see how charging batteries during off peak time goes against the spirit of the tariff, they positively encourage it.

And I certainly cannot see that this will lead to scrapping the tariff, as you suggested.

I suspect there is a LOT going on behind the scenes between energy suppliers, generators and distribution network operators that we have no idea about.

 

[GRiLLA]

At least 75p and battery has 12 warranty (unclear if unlimited cycles) .

And as far as spirit of the scheme is concerned - meh.

And before you loose it about me being a selfish tw@t I was making an observation in my post.

The savings achieved off setting my peak rate usage alone result in the battery being paid for in 5 years (at current rates).

All without solar

You might want to check your maths.

75p a day for 5 years = £1368.75

Avoiding peak on 13.5kWh a day rate at 31p and using at 7.5p over 5 years = £5789.92

How much are you quoted, it'll be more than that.

 

[browellm]

I disagree with your first point and your conclusion.
Octopus are no idiots and they are well aware that there is a number of customers who have battery storage units and could do just as you said. That is why Outgoing Octopus was previously “not compatible” with any of their EV tariffs.
They have chosen to reverse that decision (and not only reverse it but putting customers on a 12 month guaranteed export contract, so they won’t be changing their minds for at least a year!), which suggests they are grossly prioritising reducing grid load during the day. Increasing the export tariff nearly four-fold suggests to me they REALLY want that day time juice flowing.

One of two scenarios comes to mind, then:
1 - They want the peak-time production so badly that they don’t really care if it comes from solar directly or from batteries filled during the night
2 - The number of customers with battery storage is so small in the grand scheme of things (which it probably is, and many will have export limitations imposed by the DNOs anyway) that they just don’t really care.

Either way, I cannot see how charging batteries during off peak time goes against the spirit of the tariff, they positively encourage it.

And I certainly cannot see that this will lead to scrapping the tariff, as you suggested.

I suspect there is a LOT going on behind the scenes between energy suppliers, generators and distribution network operators that we have no idea about.

I would agree with this, but I would temper your expectations of arbitrage @tomorrowman as you need to factor in round trip losses of somewhere between 10-20% through the inverter.

The warranty is OK but it covers the battery being 70% of its original capacity during the warranty.

Clearing a net 4-5p/kW doesn't seem like a tremendous money maker but ymmv. It does make sense to max out charging and export the excess solar during the day though.

 

[ACarneiro]

I would agree with this, but I would temper your expectations of arbitrage @tomorrowman as you need to factor in round trip losses of somewhere between 10-20% through the inverter.

The warranty is OK but it covers the battery being 70% of its original capacity during the warranty.

Clearing a net 4-5p/kW doesn't seem like a tremendous money maker but ymmv. It does make sense to max out charging and export the excess solar during the day though.

I agree.
Although I have asked my DNO if I have permission to export from batteries, I think the hit on the system’s longevity isn’t worth the money I’d make.
Now if Flow Batteries ever become “a thing” or if the export tariff increases even more then that may well change.

 

[browellm]

I agree.
Although I have asked my DNO if I have permission to export from batteries, I think the hit on the system’s longevity isn’t worth the money I’d make.
Now if Flow Batteries ever become “a thing” or if the export tariff increases even more then that may well change.

Mine is a DC coupled battery. The only time I ever forced export was when I used to be on Agile and some of the HH slots were over £2/kW

 

[ACarneiro]

Mine is a DC coupled battery. The only time I ever forced export was when I used to be on Agile and some of the HH slots were over £2/kW

Hah!
Them were the days!

 

[tomorrowman]

You might want to check your maths.

Whoops 7 years. Kept telling my darling wife 5 years and it's stuck in my head.

@browellm Good point about the Inverter losses. For simplicity's sake I had not factored them in.

Think it's going to be interesting optimising this thing over the next few months, which based on the info GivEnergy give you via their portal, should not be too hard a task

 

[ringi]

Whoops 7 years. Kept telling my darling wife 5 years and it's stuck in my head

I expecting the difference between daytime and of peak electricity to reduce as more people charge EVs at off peak times. Hence I can't calculate how many years to payback.

 

[tomorrowman]

I expecting the difference between daytime and of peak electricity to reduce as more people charge EVs at off peak times. Hence I can't calculate how many years to payback.

For me it was the £4K annual gas/electric cost that got me started on this. So summer spent getting cavity fill, heatpump (incoming) and battery. Battery acting as insurance in case heatpump efficiency does not meet expectations (I'd rather have a system using too much off peak than peak electricity).

Would love to do solar but cost of a 4kw system that would generate approx 2500kWh annually (shading, roof orientation issues) did not make sense even if it would have saved me VAT on battery

MVHR and triple glazing, new doors etc next (and potentially additional battery)

 

[WannabeOwner]

Would love to do solar but cost of a 4kw system that would generate approx 2500kWh annually

Long shot: If you have an, unshaded, North roof (which you hadn't considered) that would be worth a look - provided not too steeply sloping. Can generate 75-80% of South in Summer.

 

[MrBadger]

Yep. Also overlooked by many installers as they seem to concentrate on pushing peak power to sell rather than maximising useful energy over a longer period of the day.

South good for peak power but E/W has a flatter but wider insolation curve that would often give usable energy over a longer period of the day vs the more peaky south facing curve.

If I wasn’t on FiT (which would require a new separate system to avoid modifying the registered system) I would certainly be looking at adding some E/W facing panels to my setup. It wouldn’t affect peak power (dictated by the inverter) but would spread that peak over a longer period of time and give me usable energy at the start and end of the period.

 

[yessuz]

I disagree with your first point and your conclusion.
Octopus are no idiots and they are well aware that there is a number of customers who have battery storage units and could do just as you said. That is why Outgoing Octopus was previously “not compatible” with any of their EV tariffs.
They have chosen to reverse that decision (and not only reverse it but putting customers on a 12 month guaranteed export contract, so they won’t be changing their minds for at least a year!), which suggests they are grossly prioritising reducing grid load during the day. Increasing the export tariff nearly four-fold suggests to me they REALLY want that day time juice flowing.

One of two scenarios comes to mind, then:
1 - They want the peak-time production so badly that they don’t really care if it comes from solar directly or from batteries filled during the night
2 - The number of customers with battery storage is so small in the grand scheme of things (which it probably is, and many will have export limitations imposed by the DNOs anyway) that they just don’t really care.

Either way, I cannot see how charging batteries during off peak time goes against the spirit of the tariff, they positively encourage it.

And I certainly cannot see that this will lead to scrapping the tariff, as you suggested.

I suspect there is a LOT going on behind the scenes between energy suppliers, generators and distribution network operators that we have no idea about.

in reality, in simple terms, Octopus has plenty of customers paying 20p or more a day rate...

 

[yessuz]

I would agree with this, but I would temper your expectations of arbitrage @tomorrowman as you need to factor in round trip losses of somewhere between 10-20% through the inverter.

The warranty is OK but it covers the battery being 70% of its original capacity during the warranty.

Clearing a net 4-5p/kW doesn't seem like a tremendous money maker but ymmv. It does make sense to max out charging and export the excess solar during the day though.

it is more like 7p difference, but anyway )