PEA themselves came over and did the assessment. At least the boss from our local PEA office and a team who did the assessment came over. PEA can see my previous bills (better than I can unless I keep my own records, which I do). We would probably be happy with just the one 16kWh battery. Even with the full quote above, payback time is less than 10 years. I'll check them out. Thanks! My wife found Abawatt.com, https://abawat.com/solar-panel-installation/ who quote 3 phase only + 15 kW + 15 kWh battery @ ~ THB 463K PEA 588K - Abawatt 463K = THB 125K cheaper, but PEA offer an extra 3.2 kW nominal + extra 16kWh storage. My Shopee window shopping would price that as 4 x 650W solar panels @ 4200 each = THB 16800 1 x Deye SolarTOP 16kWh @ 80900 = 80900 Total = THB 97700 ~ THB 98K But Abawatt were only THB 125K cheaper, and most of that difference is the THB 98K extra stuff that PEA put in their quote. Conclusion so far (based on a sample size of 2 :)) is PEA are competitively priced. I'll check out Thailand Solar and see what they have...