Energy: PEA tariff, electric vs biomass steam, PV vs solar thermal

PEA tariff schedule (May 2023 onward, still current) filed under
docs/finance/pea/; Ft 0.1623 THB/kWh for Sep-Dec 2026 from the PEA Ft page.
The plant falls under Schedule 3.2.2 (Medium General Service, TOU, 22 kV).

New section in sustainability.md: blended ~3.81 THB/kWh for two-shift
production plus 132.93 THB/kW demand charge; electric steam ~4.7M-5.5M
THB/yr at maturity against ~0.35M-0.8M of biomass fuel; self-consumed PV
worth ~3.7 THB/kWh (~4.5-7 yr payback); solar thermal not recommended;
the battery earns little from TOU arbitrage or peak shaving. biomass.md,
scale.md, the utilities CSV note and the README follow.

docs/finance/utilities-investment.csv

@@ -13,6 +13,6 @@ water,Galvanics ZLD evaporator (future),"Small MVR or low-temp vacuum evaporator
 storage,Pallet racking and shelving,"100-200 pallet positions selective/heavy-duty (beams sized 1000-1500 kg/pallet, records are dense) + archive and finished-goods shelving, installed","Jenbunjerd; local fabricators (Sahawatthanakit, UPR, SD Shelf); SSI Schaefer (premium)",800000,1500000,published list prices + engineering estimate,"SSI Schaefer premium tier ~1.5-3M for same scope; ~1000-2000 THB per pallet position at local tier"
 hvac,Whole-factory HVAC,"~1500 m2 at 20-26 C, 35-60% RH, ePM1/F7-F9 filtration sized for burning-season PM2.5, ducting and controls","Daikin Thailand; Trane; Mitsubishi Electric; Carrier; filtration: Camfil Thailand, AAF",7500000,15000000,engineering estimate at 5000-10000 THB/m2,"RH low end of 35% is aggressive for tropics and drives desiccant cost; if 45-60% RH acceptable, cost drops materially"
 hvac,Clean-room-grade zone adder,"Cutting room + galvanics clean room, ~2 x 60 m2, ISO 7/8 with HEPA terminals, positive pressure, airlocks","Same HVAC vendors + clean-room contractors; Camfil HEPA",1200000,3400000,engineering estimate at 10000-28000 THB/m2 adder,Applied only to the two tight zones
-solar,PV rooftop EPC (illustrative 300 kWp),"Turnkey C&I rooftop EPC incl. Deye hybrid inverters, at 25000-35000 THB/kWp","Solar Nicolo (Deye tier-1 distributor); Banpu NEXT; SCG Cleanergy; Sermsang; local Chiang Mai installers",7500000,10500000,market rate per kWp; size illustrative,"Final kWp open until site selection; grid tariff ~3.88 THB/kWh implies ~4-6 yr C&I payback"
+solar,PV rooftop EPC (illustrative 300 kWp),"Turnkey C&I rooftop EPC incl. Deye hybrid inverters, at 25000-35000 THB/kWp","Solar Nicolo (Deye tier-1 distributor); Banpu NEXT; SCG Cleanergy; Sermsang; local Chiang Mai installers",7500000,10500000,market rate per kWp; size illustrative,"Final kWp open until site selection; PEA TOU 3.2.2 plus Ft (Sep-Dec 2026): self-consumed PV worth ~3.7 THB/kWh, ~4.5-7 yr payback (sustainability.md, grid tariff)"
 solar,Battery stack 271 kWh (Gobel),"GP-SRA-HV314 HV LiFePO4 rack, 15 x 18 kWh packs, direct from Shenzhen, 50-60 day lead",Gobel Power (no Thai distributor; integration by solar EPC),1400000,2030000,vendor listed price USD 39900-58000 at ~35 THB/USD,"Confirm Deye BMS protocol compatibility and that the EPC warrants a mixed-vendor DC bus; certs (UN38.3/IEC 62619/CE) to be requested"
 total,BASELINE TOTAL,"Electric steam + oil-injected air + chiller + softener + loop treatment + local racking + HVAC + clean zones + 300 kWp solar + 271 kWh BESS",,23980000,41630000,sum of baseline rows,"~630k-1100k EUR at 38 THB/EUR; excludes options rows (biomass premium, oil-free, tower alternative, RO, ZLD evaporator, SSI premium tier); all figures budgetary +/- 30%, get RFQs before BOI/finance filings"