Solving high electricity usage and cost using solar + batteries to store off peak power

Patrol

elrao said:

We currently use ~ 15,000 KwH of electricity a year and we are looking to buy an EV which would add ~3000 KwH a year on top.

15000 is a high use, is it a regular 1250 a month or do you have seasonal factors like high winter use with electric heating as that may well influence whether battery, Tesla plan or other options suits you best.

elrao

Patrol said:

elrao said:

We currently use ~ 15,000 KwH of electricity a year and we are looking to buy an EV which would add ~3000 KwH a year on top.

15000 is a high use, is it a regular 1250 a month or do you have seasonal factors like high winter use with electric heating as that may well influence whether battery, Tesla plan or other options suits you best.

About 50 a day May to Sept and 35 a day the rest of the year.  During the summer at least half of that is during the day (constant 4-5Kw for 6 ish hours)

Mikeyboy01443

elrao said:

Patrol said:

elrao said:

We currently use ~ 15,000 KwH of electricity a year and we are looking to buy an EV which would add ~3000 KwH a year on top.

15000 is a high use, is it a regular 1250 a month or do you have seasonal factors like high winter use with electric heating as that may well influence whether battery, Tesla plan or other options suits you best.

About 50 a day May to Sept and 35 a day the rest of the year.  During the summer at least half of that is during the day (constant 4-5Kw for 6 ish hours)

I have to ask... swimming pool? Industrial bakery??

elrao

Mikeyboy01443 said:

elrao said:

Patrol said:

elrao said:

We currently use ~ 15,000 KwH of electricity a year and we are looking to buy an EV which would add ~3000 KwH a year on top.

15000 is a high use, is it a regular 1250 a month or do you have seasonal factors like high winter use with electric heating as that may well influence whether battery, Tesla plan or other options suits you best.

About 50 a day May to Sept and 35 a day the rest of the year.  During the summer at least half of that is during the day (constant 4-5Kw for 6 ish hours)

I have to ask... swimming pool? Industrial bakery??

I'm no Baker....

Magnitio

elrao said:

Mikeyboy01443 said:

elrao said:

Patrol said:

elrao said:

We currently use ~ 15,000 KwH of electricity a year and we are looking to buy an EV which would add ~3000 KwH a year on top.

15000 is a high use, is it a regular 1250 a month or do you have seasonal factors like high winter use with electric heating as that may well influence whether battery, Tesla plan or other options suits you best.

About 50 a day May to Sept and 35 a day the rest of the year.  During the summer at least half of that is during the day (constant 4-5Kw for 6 ish hours)

I have to ask... swimming pool? Industrial bakery??

I'm no Baker....

Bitcoin miner?

Mikeyboy01443

Probably not worth it with current prices 😁

Solarchaser

elrao said:

Patrol said:

elrao said:

We currently use ~ 15,000 KwH of electricity a year and we are looking to buy an EV which would add ~3000 KwH a year on top.

15000 is a high use, is it a regular 1250 a month or do you have seasonal factors like high winter use with electric heating as that may well influence whether battery, Tesla plan or other options suits you best.

About 50 a day May to Sept and 35 a day the rest of the year.  During the summer at least half of that is during the day (constant 4-5Kw for 6 ish hours)

So a solar diverter would divert up to 3kw of excess solar to the swimming pool meaning hopefully very little bought from grid no?

elrao

Solarchaser said:

elrao said:

Patrol said:

elrao said:

We currently use ~ 15,000 KwH of electricity a year and we are looking to buy an EV which would add ~3000 KwH a year on top.

15000 is a high use, is it a regular 1250 a month or do you have seasonal factors like high winter use with electric heating as that may well influence whether battery, Tesla plan or other options suits you best.

About 50 a day May to Sept and 35 a day the rest of the year.  During the summer at least half of that is during the day (constant 4-5Kw for 6 ish hours)

So a solar diverter would divert up to 3kw of excess solar to the swimming pool meaning hopefully very little bought from grid no?

Pool uses 1.1Kw for the pump (constant 8 hours) and the heat pump uses up to 4.25kw over the same period (depends on outside temp and water temp etc).  So could use pretty much all the solar I would be generating during the day as both pumps run during daylight hours.

Over the winter I only need the water pump and can run that anytime I want for 8 hours.

The rest is the house, which is more where the batteries come in - charge at night and use throughout the day as needed.

QrizB

If I was using 15000kWh/yr I'd be seriously considering accompanying your 6kWp solar PV system with a Tesla Powerwall and the Tesla Energy Plan.

Paying 12p/kWh (instead of 28p/kWh) for the 10000kWh/yr of electricity that you will still be importing means a saving of £1600/yr. If prices remain high the Powerwall pays for itself in 6 years; even if they drop back 20p/kWh after a year, it'll pay for itself in 10 years.

elrao

QrizB said:

If I was using 15000kWh/yr I'd be seriously considering accompanying your 6kWp solar PV system with a Tesla Powerwall and the Tesla Energy Plan.

Paying 12p/kWh (instead of 28p/kWh) for the 10000kWh/yr of electricity that you will still be importing means a saving of £1600/yr. If prices remain high the Powerwall pays for itself in 6 years; even if they drop back 20p/kWh after a year, it'll pay for itself in 10 years.

This was part of my original post.  Weighing up the extra upfront cost of Tesla for a flat rate of 11p versus trying to achieve the same by buying additional batteries and charging at 7.5p.

For less than the cost of a Tesla I could get 24KwH of batteries and charge them overnight in the 4hr off peak period.  In theory this is cheaper upfront and cheaper ongoing...if you spec the system correctly to avoid needing to dip in to peak usage.

Also, having an EV that needs more than 28kwh of charge per night would also be a factor, but for me that should not be an issue as I rarely do 100 Miles a day on consecutive days to need to charge more than 4 hours a night.