Is It Time To Get A Battery?
I got my Electricity Bill the other day which set me wondering if I should invest in a battery for our house.
Our Situation
We live in a retirement unit which is reasonably compact.
As a result our 3.25 kW of Solar Panels takes up most of the available roof space.
The advantage of having a small house is that although we are all electric our daily usage is quite small.
The below graph shows our daily usage and solar export.
From the figures above it would appear that with a battery we should be able to store, and then use overnight 3kw of power almost every day..
Power Company Rates
Our current rates from Powershop are:
$0.2893/kWh Consumption Charge
$0.052/kWh Feed in Tariff
Annual Savings
The annual savings by installing a battery will be:
Consumption Charge minus the feed in Feed In Tariff multiplied by 3kWh multiplied by 365.
$(0.2893 – 0.052) x 3 x 365 = $259.84/year
NB There will be some efficiency loss in the battery but this may be compensated by the battery partially discharging and being recharged during summer days.
Conclusions
Recent industry figures (September 2023) indicate the installed cost of batteries is $1,000 to $1,300 per kW.h
This gives a cost for a 3kWh of $3,000 to $3,900,
Even with the cheapest battery the payback at $259/year is going to be over eleven year,.by which time the battery will have gone through over 4,000 charging cycles.
As I am not convinced that the battery will be in good condition after those 4,000 cycles I think I might not bother with a battery for a while yet.
If I see battery prices drop to around $500/kWh I might rethink..