Makes more sense to export unused solar than use to heat water/charge car

[conor_mc]

How much does a battery cost, how long does it perform at it's max, and how long until it realistically needs replacing..?

The answer seems to be it depends. To remove a 5kWh battery from my quote was -€1250…. great, I’ll add a second, I said… that’ll be +€2,250 then. Wholesaler discount passed on, yadda, yadda.

I see the same unit advertised at €1400+ VAT.

But, I ordered a GobelPower 15kWh battery from China (good rep, see OffGridGarage on YouTube) delivered duty paid for €2300, albeit shipment takes 2-3 months.

Batteries are generally warrantied to retain min 80% capacity for 6000-10000 cycles, so 15+ years at average of 1 cycle per day.

The real value is they protect your Solar PV investment by giving you options - either buy-low-sell-high when gap between night/EV-rate and export rate is favourable (as it generally is currently) or maximise self-consumption if/when it’s not.

 

[Itchy]

About to put in a bigger battery so I can justify 7c/32c on an EV tariff

What are the economics of that? The 7c rate is only available for 4 hours a day? Whats the maximum draw from the grid during that time 9kW/hr? 9*4*(.32-.07) = €9 per day, maximum savings if you store and use everything drawn from the grid, less if you export the unused. If the battery capacity is 15kW then 15*(.32-.07) = €3.75 per day if you consume it all.