grabowski
9640a4f075
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.
98 lines
4.6 KiB
Markdown
98 lines
4.6 KiB
Markdown
# Biomass Fuel Strategy
|
|
|
|
If the steam boiler goes the biomass route (see the options in
|
|
[sustainability](sustainability.md) and the Getabec candidate in the
|
|
[utilities CSV](finance/utilities-investment.csv)), the fuel comes from two
|
|
sources: the team's own 60 rai of currently unused land, and northern
|
|
Thailand's agricultural waste market. Figures below are planning estimates,
|
|
plus or minus a wide margin, to be refined against the actual boiler choice
|
|
and duty cycle.
|
|
|
|
## Demand: what the boiler would burn
|
|
|
|
The 400 kg/h boiler is roughly 300 kW thermal at full fire. With the heat
|
|
recovery architecture trimming the load and realistic duty cycles:
|
|
|
|
- Mature plant (semi-auto plus automated lines, two shifts, ~300 days/yr):
|
|
roughly **350 to 400 tonnes of air-dry wood per year** (at ~80% boiler
|
|
efficiency and ~4 kWh/kg air-dry wood)
|
|
- Early operations (one press line, single shift): roughly a quarter of
|
|
that, **~90 to 100 t/yr**
|
|
|
|
## The 60 rai: own-grown fuelwood
|
|
|
|
60 rai is 9.6 hectares. Managed as short-rotation coppice (planted once,
|
|
harvested on a 2 to 4 year cycle, regrowing from the stump), fast species
|
|
proven in Thailand (eucalyptus, acacia, leucaena, bamboo) yield roughly 8 to
|
|
14 air-dry tonnes per hectare per year. So the land can sustainably supply
|
|
about **80 to 135 t/yr**:
|
|
|
|
- Enough to cover **most or all of early operations**
|
|
- About **a quarter to a third of mature two-shift demand**
|
|
|
|
That makes the land a meaningful supplement and a strong brand story
|
|
("records pressed with steam from our own trees"), not a complete fuel
|
|
supply.
|
|
|
|
### The classification check comes first
|
|
|
|
The land is currently classified as forestry, and in Thailand that carries
|
|
legal weight. Before a single tree enters the fuel plan:
|
|
|
|
- Verify the parcel's actual status: clean Chanote title vs Sor Por Kor vs
|
|
National Forest Reserve. Planting, harvesting, and transporting trees,
|
|
even self-planted ones, can be restricted depending on classification,
|
|
and some species are restricted regardless.
|
|
- If eligible, register the plantation under the forest plantation
|
|
framework, which legalizes grow-and-harvest cycles and the transport
|
|
paperwork.
|
|
- If the parcel carries actual standing forest, it should not be harvested
|
|
for fuel: that would undercut the sustainability commitments the plant is
|
|
built on. Coppice belongs on the degraded or empty portions.
|
|
|
|
## Filling the gap: the northern biomass market
|
|
|
|
The region fills the remainder easily and cheaply:
|
|
|
|
- **Longan orchard prunings**: Lamphun is Thailand's longan heartland and
|
|
prunings are an established traded fuel
|
|
- **Sawmill and wood-processing residues**
|
|
- **Corn cobs and rice husk**: abundant regional crop wastes; a
|
|
Getabec-class solid-fuel boiler is designed for exactly this fuel mix
|
|
- Buying from local farmers also strengthens the local-sourcing story that
|
|
already runs through packaging and PVC
|
|
|
|
## Logistics on site
|
|
|
|
To reflect in the facility planning: a fuel storage shed (biomass
|
|
must be kept dry; monsoon-season storage sizing matters more than dry
|
|
season), chipping for coppice wood, ash handling, and the emissions stack
|
|
that comes with solid fuel. These are the capex/opex adders that the
|
|
biomass premium in the utilities CSV (roughly 4M to 7M THB for the boiler
|
|
package vs 2.5M to 4M electric/gas) partially reflects; fuel handling and
|
|
storage are additional.
|
|
|
|
## Decision framing
|
|
|
|
- Biomass makes the steam genuinely renewable and pairs with cheap northern
|
|
fuel, at the cost of higher capex, fuel logistics, ash, and an emissions
|
|
point
|
|
- The 60 rai tilts the economics and the story further toward biomass, but
|
|
only after the land-title check clears
|
|
- The electric boiler remains the alternative: cleanest permitting, no fuel
|
|
logistics, but effectively grid-powered steam at a ~300 kW draw. On
|
|
PEA's time-of-use tariff that costs ~4.7M to 5.5M THB a year at mature
|
|
load against ~0.35M to 0.8M of fuel for biomass, and ~1.4M to 1.7M
|
|
against ~0.1M to 0.2M at early load, because the demand charge follows
|
|
the boiler's full-power draw (estimates; see the
|
|
[grid tariff](sustainability.md#grid-tariff-pea-and-what-it-decides)).
|
|
The electric boiler is the more efficient machine; biomass is the far
|
|
cheaper heat
|
|
- A staged path is possible: start electric (fast, clean permitting), plant
|
|
the coppice now (first harvest in 2 to 4 years), and add the biomass
|
|
boiler at the automated-line expansion when demand and the fuel supply
|
|
have both matured. At the tariff above that is a permitting and logistics
|
|
choice, not a cost one: every year on electric steam costs roughly 1.2M
|
|
to 5M THB more than biomass, so the switch should come as soon as the
|
|
permit and a fuel contract are in place
|