Home battery - charging question

[Dad]

Looking at having solar installed soon and may opt for a larger battery of around 10KW now that the prices are softening.

Excluding EV consumption, our daily domestic electric consumption is between 10 and 15 KW depending on whether it’s a laundry day or not.

Now we have Intelligent Octopus we have moved our washing to off peak. Give or take, I think we are consuming approx 10 KW daily of peak cost electric. That will reduce a bit with solar.

My plan is to top up the 10 KW battery using the IO off peak rate and then consume that cheaper electricity during peak hours, especially during winter months.

My question is how long does it take to fill up a battery from near empty to around 10 KW from your mains supply? Is this straightforward etc? Any other considerations?

Thx

[Helijock]

I have a 10 kW battery and in winter on GO I could charge the car to 80% and the house battery to full. I am now on Intelligent so no problems are expected.

[Lorttrol]

It depends on the power of your inverter. If you have a 5kw inverter then it'll take around 2 hours to charge the battery from empty to full. If you have a 10kw inverter then it'll take an hour to charge. It also depends on what power the battery can take, the Enyaq can take 135kw of input but can dischage at 150kw if you have the 204ps motor, more if you have the larger power output motor.

From my calculations having a battery with no solar is not cost effective. By the time the battery and inverter have paid for themselves in savings on a cheap overnight rate they will need to be replaced. Things change if you have solar where you have near 0 cost for incoming and can export some back to the grid. As most panels are gaurenteed outputs for 25 years you will be able to save for 25 years, even with the cost of replacement batteries and inverters at year 10 (average warranty of both) you'll be saving a huge amount every year and even sell some back to the grid.

Things have changed recently where you can buy at 7.5p a kw but you can now sell back at 16p a kw. This makes a big difference but each house is unique so its worth trying to get some free quotes and estimates of what you'll generate to see if it works for you. Personally I am looking to fit a 40 panel system at my home pus 15kw of battery storage. This is enough to run our house for free all year round, sell a good chunk back to the grid and run the car for 18,000 miles. Not everyone is able to fit a system of that size as there are hoops you need to jump through with the DNO etc.

Really what it comes down to is knowing your numbers. A few evenings of sitting on google can teach you an awful lot about how the systems work, how much they generate, the proceeds created etc etc.

[Dad]

Thank you both for taking the time. Very informative.