Is switching to off-peak rate and charging my battery overnight always a good idea?

matt_drummer

Starrfissh said:

matt_drummer said:

I would expect more like 600 Kwh in April of generation based on 7,100 Kwh per annum.

You are like likely to go to bed with a nearly full battery which will get you through the night.

If you need to import it will be during the day, and that will be best at the lowest possible cost, I would stick with a normal standard tariff.

At that level of generation I would have gone for more batteries.

If you have an ev then you could take advantage of cheaper time of use tariffs.

We'll fully charge the battery each day in the summer, but not in the winter. Do you think we should go for a dual rate to charge it in the winter? Or stick to single (cheaper) rate because of daytime use? Thanks     : )

It is not that easy to answer without more information.

I don't know who your energy supplier is but I know that with Octopus you can change between tariffs easily and at no cost (that I know of) to suit the different times of the year.

All you need to work out is when you are likely to run out of sun or battery and where the shortfall of electricity will come from.

If you have to import from the grid first thing in the morning because your battery is empty then it may be worth charging at night on a cheaper tariff but not if you will need to import so much at the more expensive day rate that the savings from the cheaper night time rate are wiped out.

I hope that makes sense.

What is your set up, I am guessing you have Givenergy battery?

Do you have a hybrid inverter?

Hybrid inverters will limit the maximum amount of power you can use in your home without drawing from the grid.

A friend of mine has a Givenergy 3.6 Kw hybrid inverter and a 9.5 Kwh battery.

If he is generating 3.50 Kw of solar and has a full battery you would think he would be able to consume 6.50 Kw without importing from the grid, but you can't as the hybrid inverter can only supply a maximum output of 3.60 Kw.

Something to bear in mind when assessing how much you will import if you have a hybrid inverter.

Starrfissh

matt_drummer said:

Starrfissh said:

matt_drummer said:

I would expect more like 600 Kwh in April of generation based on 7,100 Kwh per annum.

You are like likely to go to bed with a nearly full battery which will get you through the night.

If you need to import it will be during the day, and that will be best at the lowest possible cost, I would stick with a normal standard tariff.

At that level of generation I would have gone for more batteries.

If you have an ev then you could take advantage of cheaper time of use tariffs.

We'll fully charge the battery each day in the summer, but not in the winter. Do you think we should go for a dual rate to charge it in the winter? Or stick to single (cheaper) rate because of daytime use? Thanks     : )

It is not that easy to answer without more information.

I don't know who your energy supplier is but I know that with Octopus you can change between tariffs easily and at no cost (that I know of) to suit the different times of the year.

All you need to work out is when you are likely to run out of sun or battery and where the shortfall of electricity will come from.

If you have to import from the grid first thing in the morning because your battery is empty then it may be worth charging at night on a cheaper tariff but not if you will need to import so much at the more expensive day rate that the savings from the cheaper night time rate are wiped out.

I hope that makes sense.

What is your set up, I am guessing you have Givenergy battery?

Do you have a hybrid inverter?

Hybrid inverters will limit the maximum amount of power you can use in your home without drawing from the grid.

A friend of mine has a Givenergy 3.6 Kw hybrid inverter and a 9.5 Kwh battery.

If he is generating 3.50 Kw of solar and has a full battery you would think he would be able to consume 6.50 Kwh without importing from the grid, but you can't as the hybrid inverter can only supply a maximum output of 3.60 Kwh

Something to bear in mind when assessing how much you will import if you have a hybrid inverter.

We do have a GivEnergy battery, and a 5kw hybrid inverter.

All in all it seems to be a lot more complicated than I hoped and expected! But really appreciate your time  and your advice.

markin

22p Export on octopus Flux, 20p to top up at night if the solar is poor and can't do it.. 

https://forums.moneysavingexpert.com/discussion/6425299/new-octopus-tariff-for-solar-and-battery-users-octopus-flux/p1


Turn off the electric Aga, or fit a timer so it only uses the sun. / Use cheap electric heaters on timers.
Install a Aircon heatpump, for a cop of 3.

matt_drummer

Starrfissh said:

We do have a GivEnergy battery, and a 5kw hybrid inverter.

All in all it seems to be a lot more complicated than I hoped and expected! But really appreciate your time  and your advice.

You're welcome.

The most you will get from your inverter is 5 Kw and that's if the sun is shining, battery only will be 3 Kw.

I you expect to generate 7,100 Kwh per year are you sure the 5 Kw inverter is big enough?

What panels do you have, how many and what orientation?

You need to manage your load to minimise your grid import, a bit like turning stuff on in the right order in the film Apollo 13!

You will have to experiment and learn your usage and what you can achieve to work out the tariff that will suit you best and that might be a different tariff for bright and gloomier months.