Which solar seasonable tariffs best?

Qyburn

doctheclown said:

Hi NedS

As far as I am aware it is recording our generation, but still a bit new to this...

If you ever charge from the grid, a simple generation meter will give misleading readings.

doctheclown

Thanks @Qyburn, not sure how all this works, so any advice welcome...

Croft12

debitcardmayhem said:

Screwdriva said:

Octopus just increased the price of Cosy by 14% but has left the Intelligent tariffs (Flux/ Go) relatively untouched. 

I believe trying to get on Octopus Go is worth a shot, despite the tariff arriving considerably before the EV

Great , was thinking of cosy from next month , might have to go back to the drawing board….

Natch might be staying on IOF longer.

Qyburn

doctheclown said:

Thanks @Qyburn, not sure how all this works, so any advice welcome...

We were in that boat with a simple generation meter recording only one direction. I changed it for a "net" meter that cycles round three readings .. Import, Export and Net.

doctheclown

Hi all,

I am now a step closer to getting sorted, but just trying to get over the last few hurdles.

So.. I managed to sign up to Octopus Flux as the overnight import rate looked good at 16p (2am to 5pm) and now my system is working and exporting, but not quite as I had expected.... 

 

Originally I had been told that the house would take from the panels and then the powerwall and then the grid, so I thought I would be able to *fill up the battery at night and then use the solar and battery during the day, export anything I hadn't used and then start again overnight.

However, it is working by filling the PW3 a little overnight (anything from 60 to 80% @16p) and then using the little solar we are getting and then the rest from the grid during the day / evening etc (@27p).  I had a wee look at the tesla info in more depth and this seems to be the way it is set up to work, but I am not sure it wouldn't be better for me to work as * above, making full use of the import at 16p during the day.

I seem to be importing a lot at 27p and then exporting a bit at 29p (as I have a 40% backup reserve), which I recognise was mainly imported at 16p but I am not sending much back and I am not sure that is working out financially in my benefit, but all the many variables make it difficult for my maths brain to calculate.

Is there anyway to change how the PW works so that it doesn't take elec from the grid and instead uses the battery during the day? I was going to do a couple of weeks in two different ways and do a comparision that way, but wasn't sure that was possible?

Any help to amend how the powerwall works, would be gratefully received.  Thanks 

NedS

doctheclown said:

Is there anyway to change how the PW works so that it doesn't take elec from the grid and instead uses the battery during the day? I was going to do a couple of weeks in two different ways and do a comparision that way, but wasn't sure that was possible?

Any help to amend how the powerwall works, would be gratefully received.  Thanks 

Presumably you want the battery to be as full as possible going into the evening peak, so you can export as much as possible, so I would imagine that you'd want to fully charge the battery overnight, then use solar/grid to run the house during the day ensuring the battery is full at 4pm ready to export.

Try making a spreadsheet to model the two alternatives to see which is most cost effective for a typical day.

doctheclown

Thanks NedS,

Although getting some return on investment is part of the plan, it is not my main goal.

Currently my battery does not seem to fill up overnight, I guess it is leaving some room for the solar it anticipates me getting the next day.  Because I would like to go through the winter with a reasonable backup reserve, I know I am not probably going to make full use of the gains through exporting that I could and I am ok with that.

In the winter, what I would like to do however is see if I could get the system to charge the PW at the overnight rate (to at least 80%) and then use the solar and battery during the day.  If there is then some left at 4pm I would be happy to export the remainder back to the grid (while maintaining my backup reserve at 40%), but understand that there may not be much left to export.  Do you know of anyway to get the system to work in this order (House taking from solar then battery then grid)?

Thanks for any advice

pengbo

Hi doc,

Not sure if you got this working but getting a Powerwall 3 to behave can be challenging.

Mine runs in the way you appear to want it to, charge at cheapest rate overnight, discharge during the day export any excess solar whenever it can (rarely but surprisingly it does happen in winter).

I was on Flux during the summer and I set the PW3's utility rate plan to super off-peak during the 3 hours overnight and the rest of the day to Mid-peak and 4 to 7 pm to Peak.  I discovered the only way to get it to work reliably was to tell it the super off-peak was 1p/kwh, and set mid-peak and peak to what octopus charged and then set it to Time of Use with backup of 10% and it got on with it.

It was amazingly good at predicting what it needed to top up during the night, many a time I looked at it and thought I would be having issues, but it nearly always got it right.  It seemed to be better at predicting the sun for our local area than the met office did so i learnt to leave it to the PW3 and stopped worrying about it.  It got to the stage when it didn't top up overnight I knew we were going to have a 100% sunny day.

That all changed in October as we got a lot of overcast days when we were predicted to get sun so I had to micro manage it and eventually moved onto Agile.  It's challenging and I subscribed to netzero and use that but it does work and I would say I am getting about a 40% saving compared to if I had stayed on Flux.

Now the only way to be sure it will charge when it's the cheapest time is to force it to 100% reserve during the cheapest agile times and involves micromanaging it.

Anyway good luck and if you or anyone else out there knows how to make a PW3 behave more consistently happy to listen to tips, or if anyone knows how to make a PW3 export stored electricity to grid I would very much like to know as I can get it to export spare solar instead of charging but not export any it's stored.

JKenH

I am due to get my PW3 next week and will be hungry for advice. I anticipate I will be watching every PW3 YouTube video ever shown but I find videos time consuming and much prefer text that I can skim through to find the info I need. Is there an existing PW3 management thread elsewhere on this board or on the Energy board? If not maybe we need to start one. Anyone with PW3 experience want to provide a good user guide as an introductory post?

Screwdriva

JKenH said:

I am due to get my PW3 next week and will be hungry for advice.

Yes. You will be. 

If you have an EV, it's hard to get a better deal than the Intelligent Go tariff. It's manually programmed in the Tesla App, where you can input export (Outgoing at 15p), Peak and Offpeak (7p) import rates. From there, it will do everything itself. Make sure you enable export in the app immediately after commissioning.

Come mid March 2026, you can switch over to Intelligent Flux for even less control over the system and watch the £ flow into the account