# Payback Time of Nickel Iron Batteries

What is the payback time of nickel iron electrical storage batteries for homes based on electricity stored - compared to grid cost of energy?

# Notes

- Note this report - [1]
- Conclusions - 100kWhr of energy used total to drive 100k mile lifetime of battery in 1980. Comparison to 28 mpg vehicle? Or 1kWhr per mile. Similar figure for all battery systems from nickel iron to lead acid. It is interesting to note that nickel iron is even considered, as in 2020's standard, nickel iron is considered insufficiently energy dense. Point - not much difference in operating energy requirements - production energy is much smaller than usage energy (10x-30x smaller)

- Nickel Iron at Nickel-Iron Battery Quotes costs 60 cents per watt-hr at the 19.2 kWhr nominal scale. About $12k total. Product itself is $8k, and if open source - we can probably get it down in cost in a Technological Recursion financial model
- At 60 cents per watt-hour, that is $600 per kWhr.
- If we talk of one hour being worth 15 cents on the grid - then assuming a daily cycle of power - this is 4000 days of cycling to pay back the cost. That is 11 years. However, if we consider displacement of heating in the winter - and cooking gas / hot water heating - then the picture becomes much more favorable. A well-insulated home, with good thermal mass, can run on a battery bank alone for heating. Thus we save on the typical $100/mo heating cost - or $600 per year. Thus the overall payback is the reduction of heating and electric bills, where PV panels themselves pay back quickly.
- 20 KW PV panels - cost $10k for life of power if we have open source inverters. If we use these effectively, then we provide all electric + water heat + gas costs + water - $220 per month according to Utility Costs. Each year costs $2640. 2 years till free electricity, assuming Closed Loop Water System. Then to recoup the $12k cost of Nickel Iron bats today - takes another 5 years. Thus, a 7 year payback time for off-grid energy, costing $22k up front. This is peanuts, especially if we share this with car costs with an Open Source Solar Car.
- Bottom line: pending financing of $22k, anyone can use renewable energy. Is there enough nickel to run a solar economy?