New solar and battery install - best Octopus tariff

ed110220

Screwdriva said:

I've left it on Flux through the winter. No regrets! 

As long as you have enough batts to avoid the 16:00 - 19:00 peak pricing I think this is probably the best of the non intelligent tariffs. I'm charging up as much as I can in the 02:00 - 05:00 window (about 9 kWh) then discharging the same when the export tariff is highest from 16:00 - 19:00. Now that the flux import price is basically the same as the daytime export rate (accounting for losses) you might as well charge every night.

If I still had the smaller batts I'd be thinking of switching to something else over the winter maybe.

EcoScruples

I've been on Flux for 12 months now and have no intention of swapping. Average import price is way down for the winter period with the battery.
Looking forward to more.

dazjw

Thanks for the reponses.  I'm wondering what peoples regimes (for want of better words) are when on Flux?  Is it just discharge x% between 4pm and 7pm and then just top up overnight?

Our battery is 13kWh and when the weather was rubbish for a few days recently it emptied and we struggled to get much into it purely by from solar generation - need to get my head around what is the best way to deal with it when that happens.

Cheers.

greenbee

It depends on the weather, the forecast, and how you use your electricity. We don't use much at peak rate (I work from home but don't finish work until 7pm so am in my office surrounded by the glow of the monitors!), so if it's been sunny and the battery is full I know I can afford to discharge down to about 50% if it's going to be sunny the next day, or 60% if the forecast isn't so great. If I'm below 50% at that point, then I might do a top up late at night, and will set the top-up level based on the following day's forecast (and what I think we'll be using). It isn't entirely straightforward, and I'm sure there are better ways of doing it. I suspect it'll take me a while to work it out (I'm only about 6 weeks into the solar journey). 

Qyburn

I don't really understand how people without a battery (like Screwdriva) manage on Flux over Winter. Even now production is tailing off by the time you're into the peak time. Ours is a new install so it's guesswork just now, but I don't think we'll see any generation at all during peak time over the Winter.

ed110220

dazjw said:

Thanks for the reponses.  I'm wondering what peoples regimes (for want of better words) are when on Flux?  Is it just discharge x% between 4pm and 7pm and then just top up overnight?

Our battery is 13kWh and when the weather was rubbish for a few days recently it emptied and we struggled to get much into it purely by from solar generation - need to get my head around what is the best way to deal with it when that happens.

Cheers.

With the new Seplos battery I'm mainly limited by the 3 kW charging/discharging limit of the inverter which limits us to getting about 9 kWh into the battery in the 02:00-05:00 Flux period overnight. At the moment I just charge up as much as I can from 02:00-05:00 and discharge as much as I can from 16:00-19:00. That leaves a minimum of about 6 kWh to use until 02:00. As we usually use around 10 kWh/day it should mostly be sufficient, especially as I tend to run the dishwasher in the flux period. When solar output gets really poor I expect we'll have to sometimes import at the 'day' rate after 19:00 but before 02:00.

Solarchaser

I'd say if you are going to stay on flux, you definitely want to be charging the battery in the 3 hour period overnight, and perhaps run a week this month, and see how much battery is left at the end of each day, if for instance you end up with 5kwh left consistenly, it may be worth setting the inverter to discharge for the last 1.5 hours of the peak rate to get the best return.

Be aware though, the solar will drop off significantly over the next month or so, and not return in good numbers for another few months (usually March for those of us a bit further north), so I'd perhaps do the same again in mid October, at which point you may find you don't have enough spare to export excess without costing yourself.

charles_b_2

Qyburn said:

I don't really understand how people without a battery (like Screwdriva) manage on Flux over Winter. Even now production is tailing off by the time you're into the peak time. Ours is a new install so it's guesswork just now, but I don't think we'll see any generation at all during peak time over the Winter.

He's banking as much export payments as possible to pay for the winter months.  I'm new to all of this having only gone live in June.  I chose Agile and fixed 15p export. My battery is my daily usage buffer, and at 15p export, all my excess will pay for the most part all of my winter electric use. By carefully managing battery charging (currently manual) using 'predbat' in Home assistant, I can hopefully take advantage of the very low rates agile has at times.

Screwdriva

Qyburn said:

I don't really understand how people without a battery (like Screwdriva) manage on Flux over Winter. Even now production is tailing off by the time you're into the peak time. 

Not hard to explain. Our consumption is < 1600kWh per year.  Import during the peak 4-7pm Flux window is limited to small appliances. There is typically no export after 2pm in the Winter months after baseload is factored in. The larger appliances run between 2-5am (currently just over 14p per kWh). 

If we were on Agile/ Outgoing 15p, we would have "saved" < £50 over last winter. This helped us decide it wasn't worth the hassle/ risk of switching out of Flux, given how lucrative it has proven for us over the past 2 Summers. 

MallyGirl

Having had a very successful summer on IOF I am now looking for the winter option. I wfh and can be flexible on use of appliances in cheap slots so I think Agile will work for import. I am holding off making that switch till daughter goes back to uni!
I am now pondering what export tariff will be best - Agile or fixed are the only ones that are compatible with Agile import according to the table. We have 13.5kW AIO but daily use in the winter last year was > 20kWh per day.