Steam and cooling plant for the five-press fleet; utilities re-based

New page docs/steam-cooling.html (site /demos/steam-cooling/): the
utility plant as a clickable process diagram. Steam side: raw water,
softener and dosing, feed tank with heat-pump feedwater recovery, feed
pumps, a bank of two 500 kg/h boilers (third for N+1 as an option),
separator and metering, optional accumulator, blowdown, the 10 bar
header with a valved, metered branch and trap per press, drip legs and
condensate return. Cooling side: Newbilt's press outlets are open (max.
2 bar), so returns drain to a warm tank, pass the heat pump, an optional
dry cooler and a plate heat exchanger to a cold buffer tank, and VFD
pumps feed the 20 to 25 C header at ~10 bar to every press, the
extruders and the central hydraulic oil cooler; the chiller loop
(three 250 kW air-cooled modules at 40 C ambient, fourth as option) stays
closed and clean. Galvanics cooling (12 to 20 C) is a separate circuit.
Operating cases (launch, Duplex system 1, five presses, one module down)
show demand against installed capacity; design basis with sources,
equipment schedule, RFQ questions. Static SVG, no per-frame work.

Design basis at Newbilt's per-machine figures: steam 750 to 900 kg/h,
cooling 652.5 kW (625 presses, 15 extruders, 12.5 hydraulics), 305 to
540 l/min circulating. Also found: Newbilt's 53 l/min at ~60 C out is
~140 kW, above its 125 kW peak; listed as a re-quote question.

Re-based in the same commit:
- scale.md: electrical table (chiller bank ~210 to 325 kW electrical,
  plant peak ~430 to 700 kW, ~950 to 1,330 kW with electric steam),
  grid 800 to 1,000 kVA (1,250 to 1,600 with electric steam, Schedule
  4 past 1,000 kW), tariff 4.5M to 6.8M THB/yr, battery ~1 h of chiller
  peak, boiler and chiller banks, biomass up to ~550 t/yr at 1.5 M
  records, utilities money line.
- sustainability.md, biomass.md: same figures; electric steam 5.2M to
  6.0M THB/yr mature, 1.6M to 1.8M early; fuel saving 4.0M to 5.4M.
- utilities CSV: boiler bank, chiller bank with HX and tanks, softener
  and loop treatment re-sized; baseline 23.98M-41.63M -> 30.07M-51.33M.
- total-investment.md: re-size as an added-scope row (+185k / +294k
  USD); headline 4.7M to 8.9M unchanged until the investment re-base.
- pressing-line, equipment-suppliers, facility-security, fleet
  calculator (boiler 1000 kg/h, chiller 750 kW), plant page detail
  texts; README, landing page, build.sh.

docs/sustainability.md

@@ -11,9 +11,10 @@ from day one.
 ## Renewable energy: large solar installation
 
 The pressing machinery itself is a modest electrical load: 32 kVA connected,
-~21 kW average for a full Duplex line. The real energy demand sits in the
-utilities around it, above all the steam generator (400 kg/h saturated steam
-at 10 bar / 180 °C) and the 250 kW cooling system.
+~21 kW average for a full Duplex line, ~118 kVA for the five-press fleet.
+The real energy demand sits in the utilities around it, above all the steam
+(750 to 900 kg/h of saturated steam at 10 bar / 180 °C for five presses) and
+process cooling (up to ~650 kW), drawn in [steam and cooling](steam-cooling.html).
 
 - A large rooftop/ground PV installation is planned. Northern Thailand's solar
   irradiance is favorable, and daytime-heavy production shifts align well with
@@ -28,7 +29,8 @@ at 10 bar / 180 °C) and the 250 kW cooling system.
   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 ride-through buffer, not full
-  off-grid autonomy, against loads like the 250 kW cooling system; under
+  off-grid autonomy, against loads like the chiller bank's ~210 to 325 kW
+  peak draw; under
   PEA's time-of-use tariff it earns little from peak shaving
   ([grid tariff](#grid-tariff-pea-and-what-it-decides)).
 - The machine load and cooling system are straightforward PV targets.
@@ -108,9 +110,11 @@ the electric-boiler route is chosen.
 
 The deepest efficiency in this plant comes from its own thermodynamics: the
 steam's job is to heat the molds, and the cooling water's job is to remove
-that same heat again, so roughly 98% of the 250 kW cooling load is heat
-leaving the press molds, put there almost entirely by the steam, and the
-press cooling return exits at ~60 °C. That
+that same heat again, so roughly 98% of the press cooling load (up to 125 kW a
+press, ~650 kW for the five-press fleet) is heat leaving the press molds,
+put there almost entirely by the steam, and the press cooling return exits
+at ~60 °C (Newbilt site requirements; the concept is drawn in
+[steam and cooling](steam-cooling.html)). That
 warm return is a premium heat source, and the architecture is built around
 reusing it before generating anything new:
 
@@ -163,7 +167,8 @@ PEA's [Ft page](https://www.pea.co.th/en/our-services/tariff/ft), both
 checked 7 October 2026. Plant consumption and demand are this repo's
 estimates ([scale](scale.md)).
 
-**Which tariff applies.** At 300 to 750 kW of peak demand the plant is
+**Which tariff applies.** At ~430 to 700 kW of peak demand without
+electric steam (five presses, [scale](scale.md)) the plant is
 Schedule 3, Medium General Service (30 to under 1,000 kW and at most
 250,000 kWh a month on a three-month average). The flat-rate 3.1 is closed
 to customers classified after November 2015, so a new plant is on **3.2,
@@ -183,35 +188,39 @@ transformer adds 2 % to kW and kWh, so meter at 22 kV; the minimum bill is
 70 % of the highest demand charge of the last twelve months; a power factor
 below about 0.85 (reactive demand above 61.97 % of active) costs 56.07 THB
 per kVAR, so the motor loads need correction. With electric steam the plant
-would average ~210,000 kWh a month (estimate) and busy months could cross
-250,000, which moves it to Schedule 4; that schedule's TOU rate 4.2.2 is
+would average ~210,000 kWh a month (estimate) and its ~950 to 1,330 kW
+peak crosses 1,000 kW, which moves it to Schedule 4; that schedule's TOU rate 4.2.2 is
 identical, so the price does not change. Connecting a high-voltage meter
 below 69 kV costs a 15,000 THB inspection fee plus a security deposit of
-400 THB per kVA (PEA tariff page, rates from January 2020): 200k to 400k
-THB for a 500 to 1,000 kVA transformer.
+400 THB per kVA (PEA tariff page, rates from January 2020): ~320k to 400k
+THB for the 800 to 1,000 kVA transformer the five-press plant needs
+without electric steam, 500k to 640k THB for 1,250 to 1,600 kVA with it.
 
 **What it costs the plant.** Two shifts from 06:00 to 22:00 on ~300 days
 (about 243 weekdays and 57 Saturdays, estimate) put ~66 % of process energy
 into peak hours: a blended **~3.81 THB/kWh** including Ft, before the
-demand charge. Without electric steam (1,000 to 1,500 MWh a year, 300 to
-450 kW peak) the bill comes to roughly **4.3M to 6.4M THB a year** before
-solar, 0.5M to 0.7M of it demand charge (estimate).
+demand charge. Without electric steam (1,000 to 1,500 MWh a year, 430 to
+700 kW peak) the bill comes to roughly **4.5M to 6.8M THB a year** before
+solar, 0.7M to 1.1M of it demand charge (estimate).
 
 **Electric versus biomass steam**, for the same heat as in
 [biomass](biomass.md): 350 to 400 t of wood at 80 % boiler efficiency,
-~1,120 to 1,280 MWh of heat a year at maturity.
+~1,120 to 1,280 MWh of heat a year at maturity (about 1.0 million records;
+the start fleet at its full ~1.5 million needs ~1,750 MWh, and both
+columns scale with it).
 
 | | Electric boiler (~98 %) | Biomass boiler (~80 %) |
 |---|---|---|
 | Price of heat | ~3.9 THB/kWh, plus the demand charge | ~0.5 to 0.9 THB/kWh at 1.35 to 2 THB/kg delivered ([reported market prices](biomass.md#fuel-prices-market-check-october-2026), October 2026; no supplier quote yet) |
-| Running cost, mature two shifts | **~4.7M to 5.5M THB/yr**: 1,140 to 1,310 MWh plus 200 to 300 kW of extra peak demand (0.3M to 0.5M) | **~0.6M to 1.2M THB/yr** of fuel, plus fuel handling and ash |
-| Boiler package ([utilities CSV](finance/utilities-investment.csv)) | 2.5M to 4M THB | 4M to 7M THB, plus the fuel store |
-| Grid | peak demand 600 to 750 kW: bigger transformer and deposit | unchanged |
+| Running cost, mature two shifts | **~5.2M to 6.0M THB/yr**: 1,140 to 1,310 MWh plus 520 to 625 kW of extra peak demand for the five-press boiler bank (0.8M to 1.0M) | **~0.6M to 1.2M THB/yr** of fuel, plus fuel handling and ash |
+| Boiler package ([utilities CSV](finance/utilities-investment.csv)) | 4.5M to 7M THB for 2 × 500 kg/h | ~6M to 10M THB, plus the fuel store |
+| Grid | peak ~950 to 1,330 kW: Schedule 4, 1,250 to 1,600 kVA transformer and deposit | unchanged (~800 to 1,000 kVA) |
 
 The electric boiler is the more efficient machine; biomass is by far the
-cheaper heat. At maturity the fuel saving of ~3.5M to 4.9M THB a year
+cheaper heat. At maturity the fuel saving of ~4.0M to 5.4M THB a year
 repays the biomass premium in under a year (estimate). Even early, at a
-quarter of the heat, electric steam costs ~1.4M to 1.7M THB a year against
+quarter of the heat, electric steam costs ~1.6M to 1.8M THB a year (one 500 kg/h
+module) against
 ~0.15M to 0.3M of fuel, because the demand charge is set by the boiler's full-power
 draw, not by its average. Moving electric steam to off-peak hours barely
 helps: the presses need steam while they run, and the peak window covers
@@ -286,7 +295,8 @@ either tank is ordered.
 The reference process schematic shows a conventional open "dirty water"
 cooling loop. We will not build it that way.
 
-- Cooling (up to 250 kW, 220 l/min peak, roughly 98% of it mold cooling) will
+- Cooling (up to ~650 kW and 540 l/min for the five presses, roughly 98% of
+  it mold cooling) will
   run as a closed loop with a cooling tower/chiller, so process water is
   recirculated rather than discharged.
 - Steam condensate will be recovered and returned to the treated feedwater