Octopus export tariff (non-MCS)

[jack]

12 hours ago, Russdl said:

Mind you, I was on a flexible export tariff post Covid and post Russias shenanigans where I was getting crazy amounts per kWh at times - perhaps it is a level playing field. 

When we had our PV installed in 2015, we just caught the last of the decent FITs payments. I think we get around £1100-1200 a year at the moment.

 

Before the Ukraine situation kicked off and prices jumped, the payments easily covered our entire electricity bill. No chance of that now, especially with an EV in the mix.

 

15 hours ago, MikeSharp01 said:

Now that's my kind of electricity bill. We have not decided to invest in a battery yet but probably will once the house if finished so we can use agile octopus, the PV, the battery and the ASHP to optimise everything.

 

I've been watching battery prices fall over the last few years, and I think they've reached the point where they make financial sense for my circumstances. For example, Fogstar is selling a 16.1 kWh battery and BMS for only £1750. Add an inverter for £1k or so and you have something that would have cost many multiples of that only a few years ago.

 

The only thing putting me off buying now is finding the time to research, design, and vaguely model how batteries would work with our current setup (8.5 kWp PV, Zappi EV charger, Eddi immersion diverter, ASHP). There's also the issue of potentially giving up the balance of our FITs in order to access smart tariffs. TBF, it still might work just using the Intelligent Octopus Go tariff, but again, lots of research and thought is required, using bandwidth I just don't have at the moment!

[Russdl]

1 hour ago, JamesP said:

what is your annual consumption out of interest.

Pre battery and hybrid car we were consuming 7.5 to 8.5MWh annually, the figures are a bit skewed now as we’ve become something an energy trader and EV user, 2024 consumption was 14.5MWh. 
 

1 hour ago, JamesP said:

What would you recommend ?

Regarding what? Tariff or battery?  
 

Tariff: I guess you’ll have to see what’s out there in a couple of years time, I’m sure they will continue to evolve.
 

Battery: I’m very happy with the GivEnergy AIO, in the event of a power outage we could run the whole house indefinitely on the proviso that the days were sunny. 

[JohnMo]

54 minutes ago, Russdl said:

GivEnergy AIO, in the event of a power outage we could run the whole house indefinitely on the proviso that the days were sunny

A thing a lot of hybrid inverters will not do. In a power outage the output goes to circuit or two only. Basically configured allowing essential appliances and lights to stay on only.

 

Via a GivEnergy AIO, I've run the heat pump, oven, lights, TV, all in a power cut and my normal string inverters stay online to pass PV to house and battery.

[Wil]

TBF the biggest issue with the Powerwalls is that they aren’t a UPS and can allow a brownout as the power drops which means a lot of stuff switches off.

 

Once they get hold of the load they can output 10kWp (14 for short duration) and keep the basic inverter online so the power keeps running. The power drop almost always gives a big enough spike to take out my main 100mA RCD though, so they can’t return to grid until I reset it.

 

I’m very jealous of some of the consumption figures- I imported 20.1MWh last year…

[JamesP]

2 hours ago, jack said:

The only thing putting me off buying now is finding the time to research, design, and vaguely model how batteries would work with our current setup (8.5 kWp PV, Zappi EV charger, Eddi immersion diverter, ASHP). There's also the issue of potentially giving up the balance of our FITs in order to access smart tariffs. TBF, it still might work just using the Intelligent Octopus Go tariff, but again, lots of research and thought is required, using bandwidth I just don't have at the moment!

Similar to you, original FIT, 3.7kWh PV, ASHP, PV diverter but no electric vehicle, yet.

 

My thoughts were

1. Leave existing PV as is and top up batteries and ASHP on a cheap overnight rate.

2. Use existing 3.7kWh PV to top up batteries when grid is down.

3. Add separate PV system to increase input.

 

1 hour ago, Russdl said:

Pre battery and hybrid car we were consuming 7.5 to 8.5MWh annually, the figures are a bit skewed now as we’ve become something an energy trader and EV user, 2024 consumption was 14.5MWh. 

 Dim question, not sure how this works, you have a tariff which enables you to  buy and sell units at different price points because you can use the batteries.

[jack]

9 minutes ago, JamesP said:

My thoughts were

1. Leave existing PV as is and top up batteries and ASHP on a cheap overnight rate.

2. Use existing 3.7kWh PV to top up batteries when grid is down.

3. Add separate PV system to increase input.

 

I'm thinking vaguely in that direction (except for 3 - I have no more space for additional PV!) 

 

There are a few ways to skin this cat.

 

All of this paragraph is from memory, so I need to confirm that my recollection is correct, but some people have done the maths and concluded that it's best to fill up batteries at the cheap rate overnight. This is slightly at odds with intuition, which is that it's better to leave the batteries in a depleted state when a sunny day is expected, and allow the (free) PV to fill them rather than pay even a cheap overnight rate. Turns out it's often better to pay the cheap rate to charge the batteries and to sell the PV as you generate it.  

 

This is the sort of stuff I want to have a think about before taking action. No individual component is difficult to understand by itself, but the complexity grows exponentially when you start trying to optimise so many variables.

 

I also need to be sure that, however I set things up, there's enough flexibility to implement a reasonable variety of approaches. 

 

And that's before you start trying to predict how things like TOU plans might change over time.

[JamesP]

8 hours ago, jack said:

When we had our PV installed in 2015, we just caught the last of the decent FITs payments. I think we get around £1100-1200 a year at the moment.

We are being paid 74p / kWh at the moment.

Just did a quick calculation , we have a 3.84kW system and it has generated 50000kWh since installation in November 2011.

An average of 3450kWh per year which is very similar to the amount of watts of the panels.

Are others generating a similar amount to the size of their PV array?

 

Trying to understand how the Smart Energy Guarantee works!

Nervous using units incorrectly, @SteamyTea

[SteamyTea]

15 minutes ago, JamesP said:

Are others generating a similar amount to the size of their PV array

Generally they will.

The UK has irradiation of ~950 kWh.m^-2.y^-1.  More down south and east (better sun altitude and less cloud) and less up north and west (less than optimal angles and more cloudy).

So for every kW_p of PV installed, expect around 1 MWh.y^-1 of energy.

 

This does depend on the system efficiency, installation angles, shading etc.

 

[Dillsue]

14 minutes ago, JamesP said:

Trying to understand how the Smart Energy Guarantee works!

Nervous using units incorrectly, @SteamyTea

The SEG is the governments replacement for the FIT scheme but... only pays for actual export and pays a pittance per unit, typically 4-6p/unit. Being on early FIT rates you might be best sticking with your generation and deemed export payments but if you know what you'll likely export in a year you can run the figures. Octopus Outgoing will pay you 15p/unit based on actual export from your smart meter. I don't know what deemed rate you get but you'll probably be better off sticking with what you've got??

[Dillsue]

9 hours ago, jack said:

Before the Ukraine situation kicked off and prices jumped, the payments easily covered our entire electricity bill. No chance of that now, especially with an EV in the mix.

Putin added a bit of fuel to the fire that was already raging with post covid recovery....we were on our 4th eleccy supplier when Russia invaded!!

[JamesP]

8 minutes ago, SteamyTea said:

kW_p MWh.y^-1 

Head explodes!

Thank you.

[Dillsue]

9 hours ago, jack said:

 also the issue of potentially giving up the balance of our FITs in order to access smart tariffs. TBF, it still might work just using the Intelligent Octopus Go tariff, but again, lots of research and thought is required, using bandwidth I just don't have at the moment!

Your FIT generation payments won't get affected by switching to a smart tariff. If it's an export tariff then you'll loose your deemed export but still keep the lucrative generation element.

[JamesP]

4 minutes ago, Dillsue said:

Your FIT generation payments won't get affected by switching to a smart tariff. If it's an export tariff then you'll loose your deemed export but still keep the lucrative generation element.

Thank you, much appreciated.

[Russdl]

7 hours ago, JamesP said:

Dim question, not sure how this works, you have a tariff which enables you to  buy and sell units at different price points because you can use the batteries.

No such thing as a dim question (Joe90 RIP would have told you that)

 

Currently I have 2 tariffs when I buy, cheap overnight expensive during the day. I fill the battery on cheap rate and the battery runs the house for the rest of the day. I buy almost nothing at the higher rate. The particular tariff I’m on was dependent on having an EV (hybrid in our case)
 

When I sell it’s fixed, whatever time I sell it. Excess PV during the day or offloading the battery when I don’t want so much in there. 
 

All of this is likely to change when it suits the supplier which I guess is fair enough because we couldn’t survive a winter without them. 

Edited 15 hours ago by Russdl

[jack]

2 hours ago, Dillsue said:

Your FIT generation payments won't get affected by switching to a smart tariff. If it's an export tariff then you'll loose your deemed export but still keep the lucrative generation element.

 

Ah, I knew one of the components wasn't affected but I've never got around to looking it up. Good to hear it's the lower value component, thanks.

[Dillsue]

9 hours ago, jack said:

 

Ah, I knew one of the components wasn't affected but I've never got around to looking it up. Good to hear it's the lower value component, thanks.

It is the lower value but definitely worth checking your own figures before jumping from deemed to metered as you can't go back for 12 months.

 

One of our systems is 4kw on 2015 FIT rates and it's only because we have a second self installed system that it was worth giving up the deemed element from the 4kw system and going for metered export from both systems.

[jack]

3 hours ago, Dillsue said:

It is the lower value but definitely worth checking your own figures before jumping from deemed to metered as you can't go back for 12 months.

 

One of our systems is 4kw on 2015 FIT rates and it's only because we have a second self installed system that it was worth giving up the deemed element from the 4kw system and going for metered export from both systems.

 

Thanks for that, very interesting. 

 

It was a while ago, but i thought I read that once you gave up the deemed element from the government there was no going back. That's partly what's put me off finding the time to dig into this in more detail. I'll take another look!

 

We're on a 2015 tariff too. From memory, it was from right before the rates dropped significantly. I'd have to look it up, but I think the rate was something like £0.15/kWh generated, and £0.07/kWh for export (deemed 50%).