Add solar hardware plan: Deye hybrid inverters + Gobel Power 271 kWh BESS

Includes open engineering checks: battery rack voltage vs Deye model
window, Gobel safety certifications, and peak-shaving-scale framing

README.md

@@ -177,6 +177,17 @@ at 10 bar / 180 °C) and the 250 kW cooling system.
 - A large rooftop/ground PV installation is planned. Northern Thailand's solar
   irradiance is favorable, and daytime-heavy production shifts align well with
   PV output.
+- The chosen hardware direction: multiple large **Deye** three-phase hybrid
+  inverters (30 to 80 kW class, parallelable up to 10 units) paired with a
+  **Gobel Power** high-voltage LiFePO4 battery stack at **271 kWh** (15
+  stacked 18 kWh packs, LFP 314 Ah cells, rated 8000+ cycles). Deye is an
+  officially supported protocol on the Gobel BMS, and Deye has established
+  Thai distribution. Two engineering checks are open: matching the battery
+  rack's DC voltage window to the specific Deye model (a full 15-pack rack
+  can exceed the 800 V window of the smaller Deye series), and obtaining
+  Gobel's safety certifications (not published) for a Thai commercial
+  install. At 271 kWh the stack is a peak-shaving and ride-through buffer,
+  not full off-grid autonomy, against loads like the 250 kW cooling system.
 - The machine load and cooling system are straightforward PV targets.
 - Steam is the open engineering question. Options under evaluation include an
   electric boiler (maximizes the solar share), a biomass boiler (locally