Tariffs, is there a way to really work out which is best for ones own home?

[ericmark]

I am on Octopus Go, not the smart version, and it does seem to work well for me. But there are so many tariffs, it seems near impossible to work out which is best.

It is not helped by the fact we can change when and what we use, to line up with the tariff we have, and also the inverters are often limited in what they can do, I can't even if I wanted, give control to my supplier.

The Smart meter is rather useless, as the most important fact I need to know is state of charge, if I could set my oil filled radiator to turn on at (set time) only if my state of charge is over (x kWh) I could use the energy, but any device which can auto decide when to use the energy, like my iboost+ is one expensive, and two a small change in tariff can make it redundant.

So in the main we look at what was included with our appliances, so my washing machine, tumble drier, and dish washer have a delay start built in, but my old tumble drier could be set and turned on with an external socket adaptor, so it was set to 00:30 and if the drier had been filled and turned on, it would start at 00:30, but the sequence of button presses required with my new one, is not that intuitive, and as a result I have a problem getting my wife to use it. And also tumbles the clothes every so often while the delay elapses.

So my wife will use it mid day using solar at 12p/kWh if not used, rather than over night at 8.21p/kWh and the difference is so little hard to say don't do that.

With other options over night is not cheaper than solar, so change tariff and we also need to change how used, so very hard to work out costs.

 

[martygturner]

Home assistant goes quite a way to sorting that, it would deal with the oil fired rad when fitted with a smart plug. You can set actions to turn off and on dependent on a range of variables eg battery state, tariff , predicted solar production etc. Load shifting is pretty much a default to maximising the go tarriff.

You could start by making sure both the charging slot AND the discharging slot for any battery is set on the inverter. Whats the point in charging the battery between say 00.30 and 03.00 and then letting it discharge straight away when it hits 100%, you need to set the discharge to 05.30 so that any overnight use comes from the cheap rate.

As for washing, again a smart plug will sort out the cycling, set the washing to 00.30 and the smart plug to off then on at say 02.00 when the cycle is complete, the washer will reset and sit idle.

We do that for our boiling tap, it turns off a 8pm and comes on a 6am, saves 0.6kwh a day and makes it economical.

 

[ericmark]

The inverter is set to charge battery until 5:30 am, starts at 1:30 am as not sure if UTC or BST on tariff, so being on the safe side.

Since off-peak costs less than export, no need to limit off-peak used, if off-peak costs more than export, then need to limit to what level the batteries are charged, and it seems my only control is time, so then I would need to stop charging before 5:30 am.

I had this problem when I was with British Gas when they were not paying me for export, getting the second battery, made it worse rather than better, as they were too full to take the solar when it came out.

This in real terms means the Flux tariff does not suit me, even when made with solar in mind.

It is hard enough looking around one suppliers tariff, start looking at the competition, and can't really work out how they compare. Even the smart meter app, shows the export independent from import, and with one ½ hour slot one can have both import and export.

As it stands, a third battery in winter would pay, but change the tariff, and that can change.