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EEVblog 1502 - Is Home Battery Storage Financially Viable?

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EEVblog:
Running through the numbers to see if home battery storage is viable on my home.

furmek:
Could someone with a battery please tell me how much cycling a day one should expect.

In Dave's case - 10kWh battery - would you expect close to 10kWh in and out every day or more or less?

The other way of looking a the cost of battery is to compare it to "storing" energy with the network.
I get paid \$0.05 for 1kWh exported and pay \$0.25 for 1kWh used which would mean that "storing" 1kWh would cost me \$0.20 - and it's a infinite capacity "storage".
Where as if you assume \$1k per 1kWh battery over 5 years (1826 days) you are looking at \$0.55 and that does not have infinite capacity. Am I wrong here?

* yes I know that you can't store energy within the grid but I'm considering here the financial aspect.

edit:
let's run the numbers on the whiteboard:
let's assume you can fill up the 10kWh battery everyday and use all of that energy every night over 5years 1826days
you will be saving: 1826days * 10kWh = 18260kWh * \$0.3 = \$5478
but you won't get paid for export 18260kWh * \$0.079 = \$1442
so total savings is \$4035
Looks like none of the options would paid itself off within 5years.
And the question of limited capacity remains open.

ssander:
Hi,

While watching this video, I was thinking about bi-directional charging, in other words using the battery in the EV at night to power the house. It seems there are a few different type and dependent on the make model of the EV. Unfortunately this solution seems to be just as expensive at the moment as installing a dedicated battery.

boB:
Probably don't want to wear out your EV battery by cycling it a bunch !

Once in a while for when the power goes out is probably just fine though.

Charging your EV during the night is good and for self consumption use when sun isn't shining are probably the best uses for having a battery... And of course, if your power goes out enough, keeping the lights on and the beer cold.

boB

NiHaoMike:

--- Quote from: furmek on September 26, 2022, 02:09:34 am ---let's run the numbers on the whiteboard:
let's assume you can fill up the 10kWh battery everyday and use all of that energy every night over 5years 1826days
you will be saving: 1826days * 10kWh = 18260kWh * \$0.3 = \$5478
but you won't get paid for export 18260kWh * \$0.079 = \$1442
so total savings is \$4035
Looks like none of the options would paid itself off within 5years.
And the question of limited capacity remains open.

--- End quote ---
A battery system that costs \$400/kWh would break even in 5 years at that rate, the cells go for about \$100/kWh in bulk, there's plenty left for other stuff like the BMS, inverter, and setup/assembly time.