Octopus Free Electricity Sessions

Not sure if anyone else has got this for today (between 1 and 2pm) - I'm truing to work out how I can do these three things to maximise the "free" part.

a) send all the solar generation to the grid instead of to the house
b) charge the battery from the grid
c) stop the battery sending to the house

I can't seem to work out from the app how to do all of them - I can work out a timed charge from 1pm to 2pm but how do you tell the app to send all solar just to the grid for that 1 hour slot + whilst the battery is charing for that hour for it not to send any charge to the house and for it just to use the grid?

AFAIK you cannot both export and import at the same time. If you are charging from the grid home demand will be met from the grid and not from the batteries so you can accomplish #b and #c but not #a.

Right - that's frustrating :-) Because we're getting lots of solar at the moment so that's negating all the benefits from this upcoming "free" session from Octopus!

The reason for the free hour to start with is the amount of wind and solar energy on the grid.
From a physics point of view I am not sure how simultaneously importing and exporting would be possible of the same cable. The net flow of electrons is either towards your property, or towards the grid. I don't believe it is possible for both to be true at the same time. To benefit from both importing and exporting you would presumably need two grid connections.

TheOmnisis That is the problem with these free electricity events. Myself and @PianSom have had the Octopus Power up events in the East of England for a year now, and often the events coincide with sunny weather where we're exporting loads and so its almost impossible to benefit from the free electricity.

If the free period is long enough and your inverter charge rate exceeds your solar generation forecast then it can be worthwhile discharging the battery beforehand and recharging afterwards, but you're talking pence benefits. I earned 54p from the last two events (through one discharge and recharge on a cloudy day) and Piansom, 4p from the last 3 events.

If its windy and not so sunny you can make savings. Last year we had power up events on Christmas day and Boxing day due to excess supply in the grid so they were worth having as I had the ASHP heating on then

First power-up for me starting at 13:00.
It's been cloudy all morning and guess what, the sun comes out just on cue and maximises my PV generation just when I really want to import as much energy as possible from the grid :-)

Can't complain about an abundance of energy.

I'm trying something a bit different. Set charge from 1-2 to fully charge the battery, but also switched on my iboost and pressed the boost function. I

• think this means it charges from the grid if there isn't enough solar to run the immersion heater. Hoping for a full battery and a tank of hot water by 2pm.

We are already in a privilledged position, with solar and storage there is little scope to benefit from the 'free'. Do I want to chance it and loose the 15p per unit on export in favour of putting an hours worth of 'free' in the car which would otherwise have cost me 7p per unit over night? In real terms will that calculation break even or will I be a few pennies up on the deal? If I was paying the peak rate price for my electrons then I would benefit but as it is the average price for my electricty import is running at just over 9p per unit.
Once hour of export and no messing around is my preferred choice.
But, Octopus, do ask again when the sun isn't shining - though of course then you won't have a surplus either!

Icarus It's worked for me in cloudy Leeds

Icarus Exactly the same for me, been cloudy all day, forecast solar around 1kW for 1-2, 10 to 1 sun comes out, basically solid sun for an hour, maxing my inverter. Ah well.

The plan to charge the battery from the grid during the free session came a cropper as the MCB feeding the LORA receiver for the inverter tripped around 11, and I didn't notice until 15 mins ago...

Utterly bizarre - it's never tripped before, and no sign of any problems.

Worked for me - weather in the north west has been miserable all day - generated a grand total of 1kwh so far today (as of 2pm) - so was able to drop a decent 2.4kw into the batteries that'll get us through into the early evening now.

Quite cloudy in South Brum, and I was out the house, so let Predbat take the strain once I added the manual event. I also have a wireless immersion switch so set that to turn on for an hour.

Is the battery not able to charge from solar DC to DC using say 1.8kw that is available and then top up to 3.6kw using the grid?

I found with charging my battery and having the immersion on was limited to about 5kw between them even though I was generating 1.8kw solar. Using GIV-HY5.0

Magdon Is the battery not able to charge from solar DC to DC using say 1.8kw that is available and then top up to 3.6kw using the grid?

Yes, that worked for me - solar was generating around 1kW, and I configured an AC charge which increased that (adjusting the power dynamically as solar changed).

Loads of solar for me today, 54kWh generated and 48kWh exported so no benefit from the free session.

But there’s always tomorrow, and I’ve got another Octopus power up event then as well from 1-3:30, although also forecast to be sunny then as well

Did my first solar charge with Ohme today, using the hopefully free 1 hour window. Paused the battery discharge. Seemed to go OK with some solar and draw from the grid.

That’s the whole reason they’re giving away the electricity, because there is so much!

My house and battery very much appreciated 10kwh of free power 🙂

Interested in the numbers?
You used 0.00kWh overall during the Free Electricity Session
Based on your meter data from the previous few weeks, you normally use 0.00kWh at this time

You used 4.80kWh overall during the Free Electricity Session
Based on your meter data from the previous few weeks, you normally use 0.01kWh at this time

It may only be £1.08, but i'll take it, any save is a save.

Where are you getting the numbers? I haven’t heard anything yet

SimonClarke they're only available by email at the moment, your email will arrive eventually.

I’m not convinced I successfully registered for it so we’ll see. Put about 7kw in the car so I thought I’d risk it

I received my email yesterday

“It looks like you didn’t use any more electricity than usual in our Free Electricity session, so you won't get any free extra power this time. We know it's very possible you weren't home at the time – don't despair, there'll be more opportunities coming up!

Interested in the numbers?

• You used 0.00kWh overall during the Free Electricity Session
• Based on your meter data from the previous few weeks, you normally use 0.14kWh at this time”

Kind of what I expected, it was a sunny day so I was exporting loads.

On the positive front I did get two emails from Octopus giving me a free sausage roll and a free coffee from my participation in the Octoplus snap competition. Would rather have won an EV but I’ll take those

Power ups only work for me if I can go all out. I.e. be at home and have my ev plugged in. And of course charge my home batteries. Otherwise, if sunny, I'm just using the first 4kW of my own PV and missing out on the export.

“

• You used 9.13kWh overall during the Free Electricity Session
• Based on your meter data from the previous few weeks, you normally use 0.00kWh at this time
• You used 223p worth of Free Electricity ⚡️“

Well, at peak rate yes £2.23 but at my usual 7p off peak that’s only 64p of free electricity. Probably 4kW+ of solar went into car/batteries/ toaster during the massive effort to use energy, but I did discharge 4kW extra in the hour before so maybe I did make 64p after all? When my system is back up and working correctly I reckon I could double that to £1.20 - If the main fuse doesn’t blow first. 😂

Negligible financial gains for me as well from these sessions, but I'm happy to participate if it helps to balance the grid.

Look after the pennies and ...

I find it interesting too, so it's not just about the money.

I've just shared details on the Power Up thread of a REST interface that's been made available to the Octopus Power up and now Octopus Free Electricity events https://community.givenergy.cloud/d/2840-octopus-power-ups/140

As I have not imported any electric since June, these sessions in the summer are not for me, I just hope they continue into the winter on windy days as I will definitely take advantage then. Together with any export sessions like last year, I will see if I can getaway with a complete year with no cost for energy or standing charge for me. As I have built up over £600 credit it is looking very possible. I may even reduce my DD to £1 like Geoffrey.

Daveb01 Pretty much in the same situation. I've been on £1 direct debit since last summer and currently have credit of £650, which I expect will increase in the first few days next month when I get the latest bill. Even better, made 4p on my first free electric session, so over the moon with that! 🤣🤣
However, this morning Octopus have decided to send me a random gas bill (Sunday morning) for £11.22, half of which is standing charge, for 3rd August to 23rd August. Wierd!!
Their billing section can't seems to sort themselves out to just send one bill at the beginning of every month to include electric import, export and gas. They'd finally managed it the last 2 months, but looks like it's gone to pot again!
Sorry just a moan and off topic really.

TimHutchings

Are you on Octopus Tracker? This is my bill for the month so far

Daveb01 Hi Dave. No I'm on the Flexible Tariff. Just a combi boiler used for hot water and showers.

TimHutchings

Have a look at the Octoprice app to check your options. I have selected Gas in the Compare Tariffs and get this.

TimHutchings octopus billing is bizarre. They don't get the idea of one bill per month. It's as 8f they font want you to know your monthly costs.

any call you make to them or a random meter reader visit will result in an interim bill to that point. so annoying when you have called to discuss a bill and then end up with multiple ones for a month.

Daveb01 We're a bit off topic for this thread, but Octoprice shows around £1 per week saving on gas Tracker over a year, so nothing to get really excited about, plus you're relying on the vagaries of the gas wholesale market, which could get out of hand if the geopolitical situation changes.
To be honest, as long as my Electric export covers all my gas, import electric and standing charges each year with minimal fuss and bother, so I have no power bills to pay overall, I'm a happy man!

Leeshore
Please can you post the settings changes you used to get this graph?

The strategy I am trying to achieve is to discharge the battery to the grid (+home) before free electricity starts and then to fill the battery to 100% during the free hour. (Also plan to turn on the dishwasher, washing machine, electric oven etc during the free hour). I have tried a few variations of inverter settings (including remote control) but none seem to get as close as what you achieved.

The strategy I am trying to achieve is to discharge the battery to the grid (+home) before free electricity starts and then to fill the battery to 100% during the free hour. (
Since the max charge rate for my 9.5kWh battery is 3600W, then there is no point in pre-discharging below about 5.9kWh or about 62% (unless you can be sure of good solar generation after the free hour) And of course solar generation during the pre-discharging will slow down the battery "discharge to grid" rate because the total instantaneous conversion from DC to AC is limited by the inverter (5kW). If the solar generation is more than 5kW, the battery has no "headspace" to discharge. Remember solar is also FREE so this is not really a problem!
During the free electricity hour, I want grid import to charge the battery at the max rate (3600W), and the home would be supplied from grid import only. But what happens to solar generation during the free hour?

Brassy During the free electricity hour, I want grid import to charge the battery at the max rate (3600W), and the home would be supplied from grid import only. But what happens to solar generation during the free hour?

Solar will always take precendence over grid import. If you're charging your battery, it will use solar in preference to grid. And as you note, if you are discharging your battery, it will first use the solar to generate AC, and will only use battery to make up the difference to the max AC generation (eg 5kW). No point deliberately turning down free solar generation to get some free import - it's not like they're actually paying you to consume.

My strategy has been straightforward: I usually discharge battery down to 40% during the morning anyway, so it has plenty of room for solar charging. I configure an AC charge for the free hour. Then there are two cases:
1) if solar is less than 3.6kW, the battery will consume it all and import the difference from grid, and I'll turn on car charger to also charge car. I could turn the immersion on, but so far haven't bothered. That will give me some free import.
2) if solar exceeds 3.6kW, I just don't bother with the free electricity. I still send first 3.6kW to the battery (whereas I usually export it directly - I'll just export it later), but since the rest would get consumed first if I was to turn on devices, it isn't really worth bothering. (No point load-shifting from cheap overnight import to consume my solar instead of exporting it for 15p.) If there are any dips in solar due to clouds, the AC charging will kick in, so I'll get a small amount of free import.

(In practise, the threshold is probably more like 4kW - there will be some losses, and no point making a fuss about a few hundred watts lost export.)

As Octopus say, these sessions aren't really aimed at those of us with solar.

Brassy I was using PredBat via home assistant. Just inputted the saving session and voila!! PS Thanks to Trevor and @geoffreycoan

Leeshore
Thanks. Unfortunately this means nothing to me (Ah Vienna!)
What is PredBat and which home assistant do you use?

TX200 haven’t heard anything yet. Is anyone else still waiting?

Brassy

Try Wonder Watt it’s free and very easy to use, a step up from the GE app, before you go down the Home Automation route.

https://www.wonderwatt.com/

Surely the battery-charging aspect isn't terribly hard to manage..? It's deciding whether (it makes sense to) turn lots of other devices on that makes it interesting (balancing whether the reduction in export earnings warrants the extra input).

DD If you're charging your battery, it will use solar in preference to grid.

Just out of interest, is that true whether the battery is AC or DC coupled? It makes sense on a DC coupled set-up but not on AC

CW Hmm... I was thinking specifically of hybrid, but I guess it's true for AC-coupled too... if your solar inverter is generating, say, 4kW, there's no way to distinguish that from grid. The inverter has to generate at a very slightly higher voltage to ensure its power is taken in preference to the grid (or will export, if not consumed). So yes, even for AC-coupled systems, solar power will be consumed before grid power.

Brassy There are lots of discussions about this on the forum e.g. https://community.givenergy.cloud/d/3696-first-night-live-on-predbat/1839. WonderWatt is an alternative

Got £1.13 for plugging the car in but never got an email about it

Where is the smart money?
What do you crystal ball gazers, tea leaf readers think? Will there be any more free electricity sessions this season? Assuming it is sunny in the south and windy in Scotland to give 1-2pm slots.

How do these free sessions show up in terms of automation? My understanding is you get a credit for the electricity used over your normal amount within 2 weeks so the unit rate isn't actually zero at the time?

What's the easiest and least manual way to tie these free sessions into the timed charge option on givenergy?

Currently I'm finding I have to change the times for charging and then change it back at th end of the hour.

Would be handier if there was a simple override charging schedule button with a duration for ad hoc sessions like this

Just in tomorrow between 1-2pm

Daveb01 ...and pointless for Agile users as its 0.4p/kWh. I'm not even bothering about these sessions now 🙂

Going to plug the car in and turn hot water on with my new ashp!

I'm drawing 14 kW at the moment 🙂

GeekGrimmy How do these free sessions show up in terms of automation?

I use Home Assistant and GivTCP to control my battery and inverter activity with Predbat and have recently started using the REST service provided here https://github.com/8none1/octopus_powerups to retrieve Octopus Power up and Free Electricity session dates and times.

Basically the author of the service reads his email for the Octopus announcements and then publishes the session details as a JSON file. I poll the JSON file every 15 minutes in Home Assistant, then convert the file contents into date and time that I can use in automations to control my battery, or write to Predbat for it to manage the appropriate activity. If it’s not particularly sunny then it can be worth discharging the battery but on sunny days Predbat will just retain the SoC and let export occur as normal

pmcg

Nice. I was at home at the time, so i discharged my batteries for about 45 mins before the session.
I turned all the electric floors on to boost, charged the car and home batteries. Was drawing about 19kW from the grid. Then the sun came out literally at 1pm and I was generating about 2kW+ which knocked my import down to 17kW.

It warmed the house up a fair bit for an hour and car got filled. Was it worth it for just over a £1 saving though? And I’d have to be at home with the car and there to turn the floors on. I’m not sure I’ll stress too much over it in future. Way prefer the savings session export for £2 a kW compared to save 7p per kW !
There is also a risk of forgetting (or being slow) in turning everything off in time. Especially if you’re doing it all “manually”. Great if you’ve got an ASHP or limited battery capacity for the afternoon/ evening and would have otherwise had to import peak later in the day.

Oh and I guess I “lost” 30p in export, so more like 70p saving. 🤔

I charged the car, house batteries and gave the heat pumps their first real spin up - might have made a couple of quid if I'm lucky so getting to the point of not really being worth the time to do it. Hoping that Octopus are seeing the numerous posts about folk not being ar$ed for a few pence.

sponev but as it says on the faq, not really aimed at people like us who already store cheap electric.
(I plugged in car early in preparation for charging it, and IOG immediately started a charge 1130 to 1200 and then again 1300 to 1400, so that took care of having to do my own scheduling for that. And I got a few extra kW cycled through the battery.)
It's only a few pennies, but then that's all we're getting from importing/exporting per day. It all adds up.

DD yes, but we are using our kit to benefit Octopus in a range of scenarios and the share of the benefit appears to increasingly skew towards Octopus at the moment? Export rates on Flux are markedly down Vs last year and don't really reflect the change in wholesale prices for example. I love Octopus's innovative approach and maybe it's just a bit of a reality check after a couple of good years of dealing with them. Perhaps some of my frustration results from other issues, e.g. an ongoing battle to get IOG car charging working correctly (it was fine, I haven't changed anything and now it glitches a lot), plus very slow support on stuff like my Octopus mini failing even though it shows connected etc. I guess they are dealing with growing pains at the moment. Rant over and all that said, they are still a lot better than the rest!

sponev

How are you getting on with the heat pump? Guess it’s early days…
What equipment did you get installed? Did you have to pay much extra after the grant?

Pete UK We have two heat pumps running 5 internal units - A2A. It's been very good to be fair, heating and cooling and arguably a lot more flexible and cost-effective than A2W. This is because we use it selectively rather than the "always on" of A2W systems (radiators). 19kwh of batteries handled it on 95% of days last year and on the sub zero days we just pop the gas boiler on. It's not that the heat pumps don't handle cold temps, more that at a certain point sub zero, cheap gas on the tracker tariff is actually a bit more cost effective. We've also added a lot of insulation since last year and the house is noticeably cooler/warmer. So looking forward to seeing how it runs over winter. We highly rate A2A but you do need a hot water solution and some prefer the constant heat of A2W. Also no grant unfortunately.

Free Electric 22nd June, 2pm-3pm, how to benefit?
With PV, battery, ASHP, and no grid consumption, how can we load our system?
I could dump a full battery to Grid, say 80p, have a roast dinner (on this heat) 3x13p, and a pot of coffee, 3p. Set my HW to immersion (if I knew how) and save perhaps £2.
Not worth the hassle.

No hassle for me. I'm on intelligent flux.

They'll do it all for me and even if it doesn't charge between 2-3pm they'll still give me a credit for an hour or battery charging (at off peak rates).

There is also a change / tweak this year for those on Flux and Intelligent Go (IOG) which makes it even less worthwhile. Lots of debate elsewhere, but the consensus is so far that single phase IOG customers will get a max 50p benefit..

"
Intelligent Octopus Go or Intelligent Octopus Flux tariffs get an hour's free charging instead of free extra household power. Here's what you need to do:
During the session, just keep your Intelligent device plugged in, and let our smart schedule do its thing. As long as you do, we'll credit you for an hour's free charging – even if your schedule doesn't actually charge you up during the session.
Use household power as normal, that will be charged at your normal rate. Read more info in the FAQs below.
"

We can't have all the benefits.

IOG with 7p? overnight, pretty good. Any extra hour of free charge, good.

Can't charge your home battery 2-3pm (just charge it from solar or overnight).

Can't get free electric for your washing machine (again use solar or battery or time shift).

We can't have it all.

IOF for me - I've not paid for any electric or gas since 1st April. Not paid any standing charges either. Okay technically I am! But the exports are covering all those costs.

TX200 I agree completely, we get plenty of other benefit. I just said it was a change, and hoped to imply that some will have different views on the worth of going out of your way to participate in now. Especially not those on IOG and Flux as it's probably (clearly maybe) not targetted at encouraging us to change behaviour any more.

TX200 I've not paid for any electric or gas since 1st April. Not paid any standing charges either.

Same here and I am only on Cozy which enabled me to get rid of gas. My forecast for the 6 months from April is £17; I expect that to get lower.

[unknown] Over the last 12 months, my exports have been £328 greater than my combined Gas & Electicity charges.
7.5kW panels, AC3.0 interter & 2 x 9.5kW GE batteries.
IOF March to September & IOG September to March
Outlooking 100% return on capital investement in about 4.5 years from install.