Octopus Go faster changing

If you are on Octopus then you need to get on the new tariff before April and the Government Cap disappears.

Go faster 4 hours 2030 - 0030 is being discontinued which is a bummer cos it's been a very cheap way of having the TV, washing machine tumble dryer etc on during off peak (wife will NOT use Tumble Dryer or Washing Machine on if she aint there). I'm going from 5p to 7.5p off peak 2130-0130. 13.2p to 30.3p peak early march.

My battery only takes 3 hours to charge and my EV is charged once maybe twice per week. I also get to charge it for free at some workplaces I go to.

I am trying to get my head around if there is any benefit to going 5 hours. Overnight at present i use the battery at zero cost from 00:30 at between 250wh - 350wh (fridge, CCTV etc etc). Extending the off peak usage by an hour, not using the battery during that off peak hour may be beneficial later in the day. Theory being for 1 - 2 hour a day I'm not paying the 30p. I'd also go from 7.5p off peak to 8.25p.

Currently I'm running out at 18:30 - 19:00. But it is winter and summer is a coming! When the sun is out at the mo the battery generally lasts all day

Options on offer below

Option 1. Take a 4-hour Go period at 7.5p/kWh and select a start time of 21.30, 22.30, 23.30, 00.30, 01.30 or 02.30

Option 2. Take a 5-hour Go period at 8.25p/kWh and select a start time of 21.30, 22.30, 23.30, 00.30 or 01.30

Thoughts?

mjkelly5a I was on Go 4 hour 0030 - 0430 for a few weeks before deciding to change to the 5 hour 2130 option. Reason being was simply the longer at cheaper rate the better during the winter. My 8.2kw batt does not last from 0230 until 2130 and sometimes was actually out of charge by mid day. So to me the extra 1 hour at 5.5p meant cheaper rate for longer and the battery lasted a bit longer too. Also my washing machine is quick, 32 minute cycle and quiet enough to run over night, dishwasher too and we have tried hard to do loads during the cheaper rate.

When the sun stays out for longer I will not need the 5h option, but this year I will have more questions about tariffs as my EV is due later in the year and I will need to put 14 - 17kw in it daily so need to work out if going back on Agile is an option or staying on Go is better.

mjkelly5a If you are on Octopus then you need to get on the new tariff before April and the Government Cap disappears.

Tariffs like Go aren't subject to the cap. It only relates to SVRs.

browellm Whats an SVR?

THALL I'm coming round to that way of thinking. the extra 0.75p is really no difference to worry about.

Battery is currently charging in the sunshine at 50w :-)

mjkelly5a Standard Variable Rate

mjkelly5a Exactly. For me it made sense to get as much onto cheaper rate as possible, 5 hours at 5.5p plus however long the 8.2kw in the battery lasts. My average pence per kwh this month is 8.1pkwh. The battery now lasts until 5pm ish so not many more weeks and it should last until the cheaper rates kicks in. Cheap average equals good! 😀

It's that effort to keep the average rate as close as possible to your tariff rate and it's really those winter months that need to be factored.

If you are regularly busting your battery with 6+ hours to go before the cheap rate then another hour makes perfect sense.

Load shifting (dishwasher and washing machine) made the difference for me trying to get an 8.2kwh battery to last a day when it's short duration daylight coupled with dull days. Usually managed about a kWh from the PV in those conditions opposed to 10kwh or so I've seen on bright sunny days.

Whilst another battery and more importantly another inverter would see me very close to 5p per unit it's not worth the extra expense versus the return.

I've yet to hit a point with the EV (E-208) where it goes from nearly empty to needing to be fully charged the following morning - 28kwh (45 kWh usable battery) over the 4 hours has always been enough to get it through the following days use.

yandards Can I just ask, does your EV charge at 7kw constantly? Or is it a curve? I will be doing 52 miles per day once I get mine and hoping for 4 miles per kw so will need 13+ kw everyday. So a 2 hour charge would do, but I have been wondering if it is a curve so when it gets close to 80% or 90% (which i may set it to) does it slow?

yandards Yep the sunny days will cover me all day I think but the conundrum for me is we are coming to the spring/Summer. I'm sure I wont need the extra hour until after September. But afterwards i probably will.

Load shifting is not an option with my wife's OCD. We had a neighbour who's Washer/Tumble dryer caught fire and she has been dodgy about it ever since. So she needs to be there. Dishwasher we can get away with.

I may go for the 5 hours and see how flexible Octopus are to reducing it. Currently putting 1kw into the battery.

The sun came out from behind the tree at 12:38 and at 12:41 was supplying a total of 1.4kw to the house/battery, up from 400w

It’s now doing 1.8kw and the battery is taking 1.2kw.
That bloody tree!

My current deal expires at the end of March, currently a fixed rate of 14p per kWh. I don’t have an EV but do plan on buying a second hand at some point in the next year or two. I also don’t think I will ‘need’ a cheap overnight rate during the months when PV generation is considered to be good. I live in the north west of England so have to be realistic on that one, we get plenty of grey and wet days, even in summer. My PV array was only installed in December so I also don’t yet know when I can expect to need that cheap overnight tariff to charge the battery (8.2kw). Lots for me to think about to be fair. I may well sit tight, let my current provider sort out my rate at the end of the deal, enjoy the better solar generation months and make a decision when I know more about the market/government response.

anglefire I had one trimmed last week I'm seeing about another .5kwh today so i guess that's good. Solar generated 4kwh today up battery went from 61% to 86%. In the summer thats going to be 100% and change. I'll be using my granny charger that's for sure too make sure no excess disappears into the grid.

c_squared My PV is on a great FITs rate anyway from 2012. I put all proceeds into my Octopus account and it covers my gas & electric costs over the last couple of years. Will be interesting too see at the new rates.

THALL I get a pretty consistent charge rate of over 7kw for the whole 4 hours of Go even when charging to 100% with our Hyundai Ioniq

The tree in question is not in my garden and it’s not really possible to just trim it. And it’s not my call!

I have had 4.1kwh of solar today which given it went cloudy this afternoon from about 3pm and it dropped to 400-500w from 1800watts.

THALL depends on the car, I've seen some charge rate reductions below 7kw but I think they are tied to cell balancing by the BMS.

50 odd miles a day is easily recoverable on a daily basis although I wouldn't expect to see 400w per mile all year round. The car is used for a lot of start stop stuff (Mrs Yandards is a community nurse) which is less than ideal. It's been between 1.5-2.5p per mile and the short hop, reheat the cabin stuff is brutal.

I aim to charge to around 80% day to day, read some articles that suggest between 50 and 80% is optimal for battery life but they might be out of date.

THALL CURVE. At very low battert, you have lower charge - say 4kw, then after about 20% charge you hit the MAX of your charger - up to say 90% then it drops again and again and again.. Last 10% charge takes as much time as 30 to 70 in my car.

I have a VW id3 life pro performance 58kw on order. I thought the best charge window was 30 - 80% but as a just in case, I intend to charge to 90% and only to 100% when I know I have a long trip to do. But good to know if I stay in that window it will just charge at the 7kw or 7.2 etc.

@anglefire I believe you can trip any branches that hang over your property which might help?

If it helps, I have a Tesla Model 3 that I charge in the 4 hour Octopus Go window and looking at my historical charging stats my charger uses 29.5kWh in the 4 hour window so my car charges at max rate given the charger is 7.5kW. I usually charge between 20 - 80% but looking at stats where I went to 100 due to a long trip I still got full charge rate. Its different if using a high powered DC charger then between 85-100% it drops dramatically.

THALL it’s not branches in the main ( there are some which does knock production back a bit in the afternoon but not a lot - but yes they could be trimmed a bit. We also have a silver birch that is ours. But is not affecting anything yet as the sun doesn’t come that far round in the winter - and the sun should be high enough not to trouble us when it does come around.
The tree in question doesn’t actually overhang our garden. It’s a fir tree so is dense all year around. I’m going to try and work out the angle to the roof to try and predict when the sun will be high enough to clear it.
Today of course the sun is behind the clouds again so we are down to less than 100w at the moment.

THALL , fully charged the E208 last night for the first time in a few weeks.

For reference it was 7kw until the last hour where it dropped down to around 2.5kw - I suspect this is actually the BMS doing a spot of cell balancing work.

22.5kwh into the car over a 4 hour charging slot according to the Zappi and I've seen around 28kwh before for the same time period previously.

Even if that last hour to 100% was just BMS work it's only short of that 2.5kw so even with optional use of around 250wh per mile that's a 10 mile range reduction at worst.

If I am charging my e Niro to 100% then my charge at home only starts to drop off around 97%-98%.

THALL

It depends on the battery chemistry. LiFePo batteries are happy charging to 100% (Tesla actually recommend charging to 100% regularly on their LiFePo packs). "Ordinary" lithium batteries last longer if they arent regularly charged to or held for long periods at 100%.