CR_031: NZ backstop genset + biomass heat cost firming 2026 (web

NZ backstop genset + biomass heat cost firming (2026 web synthesis)

Firms the V0.5 bought-fuel cost cells (RT_251–253)

Moves diesel_genset and biomass_boiler from assumed to sourced, and adds a household wood-stove cost. NZ retail/EECA figures; install multipliers inferred → data_quality medium. RT_254 (HVO price) stays open — HVO is not yet sold in NZ.

Source verification (audit 2026-06-22) — MIXED

**biomass_boiler 1,100/kW_th = VERIFIED EXACT** (EECA Insights states "1,100,000 per MW”). **diesel_genset 900/kW = MISMATCH:** the Riequip retail prices are confirmed exactly (66/88/110 kVA = 26.9k/28.9k/31.9k) but are **supply-only (~360–510/kW)**; the 900/kW “installed” is an inferred ×1.5–2.5 multiplier no document quotes → diesel_genset demoted sourcedassumed in model_design.md.

Summary

NZ retail genset prices (Riequip/Cummins silent units, 66–110 kVA) run ~360–510/kW *supply-only*; an installed off-grid standby genset (with automatic transfer switch, day tank, pad, electrical, commissioning) lands ~550–1,300/kW — so the model’s ~900 NZD/kW is a defensible installed midpoint, consistent with OT_063’s international USD 300–800/kW for the bare set. EECA’s September 2025 Insights confirms a new biomass boiler costs ~1,100/kW_th (GIDI average; as low as 750), while converting an existing coal boiler to biomass is far cheaper at ~290/kW_th — so a community with an existing boiler/building has a much cheaper biomass-heat route. A household wood-stove installs for ~4,500–8,000 (≈$6k/dwelling); pellet fires are ULEB-classified and so installable even in polluted airsheds where log/chip burners are restricted.

Key claims

- claim: "NZ diesel genset cost (RT_251). Riequip NZ retail list (Cummins silent, enclosed): 66 kVA = NZD 26,900; 88 kVA = NZD 28,900; 110 kVA = NZD 31,900 — i.e. ~NZD 360–510/kW supply-only (kW ≈ kVA × 0.8), with economies of scale (110 kVA best). An installed off-grid standby genset adds ATS/switchgear, day tank, concrete pad, electrical connection and commissioning (~×1.5–2.5) → ~NZD 550–1,300/kW installed. The model's diesel_genset ~900 NZD/kW is a defensible installed midpoint and is consistent with OT_063's international USD 300–800/kW (bare set). Fuel: diesel ~NZD 3.18/L (MBIE, 25 May 2026); at ~30–35% genset efficiency (~0.28–0.32 L/kWh) the fuel alone is ~NZD 0.90–1.00/kWh — backstop power is expensive, as expected (cf. OT_066 diesel 75.7 c/kWh)."
  source_location: "Riequip NZ diesel-generator catalogue; OT_063; MBIE fuel monitoring; OT_066"
- claim: "NZ biomass boiler cost (RT_252). EECA Insights 'Biomass boilers for industrial process heat' (September 2025, GIDI-fund data): a NEW biomass boiler averages ~NZD 1,100,000/MW = ~NZD 1,100/kW_th (some as low as 750/kW_th) — about the same $/MW as a coal boiler. CONVERTING an existing coal boiler to biomass is far cheaper: ~NZD 290,000/MW = ~290/kW_th (low ~80/kW_th). This confirms the model's biomass_boiler 1,100 NZD/kW_th (previously the CR_028 GIDI floor) from the primary EECA source, and flags the conversion route (~290/kW_th) as a much cheaper option where an existing boiler/building exists. Standards NZ PAS 5311 governs biomass boilers 50 kW–2 MW (the community-scale band)."
  source_location: "EECA Insights (Sept 2025); Standards NZ PAS 5311; corroborates CR_028"
- claim: "NZ household wood-stove / pellet cost + airshed angle (RT_253). A domestic woodburner unit is NZD 1,000–5,000; fully installed (flue, hearth, building consent) ~NZD 4,500–8,000 (≈ NZD 6,000/dwelling). Pellet fires sold in NZ are ULEB (Ultra-Low-Emission Burner) classified and so installable in ANY airshed without restriction — unlike log/chip burners, which polluted airsheds restrict (the airshed_restricted gate). So a household biomass-heat option exists even where the community-scale chip boiler would be airshed-blocked. Warmer Kiwi Homes grants up to NZD 3,450 toward a burner in eligible districts."
  source_location: "Consumer NZ woodburner/pellet guides; Yourstore install guide; MfE authorised-burners; EECA Warmer Kiwi Homes"
- claim: "HVO price (RT_254) — still not retrievable. HVO renewable diesel is not yet sold at NZ pumps or in confirmed bulk (consistent with CR_030); NZ diesel ~NZD 3.18/L (MBIE, 25 May 2026). The model's fuels.hvo ~NZD 4.00/L remains an estimate (~+10–30% over fossil diesel, international norm). RT_254 stays OPEN until HVO reaches the NZ market."
  source_location: "MBIE fuel monitoring; CR_030 (HVO not at NZ pumps)"

Retrieval provenance

  • Upstream: Riequip NZ (Cummins genset retail list); EECA Insights “Biomass boilers for industrial process heat” (Sept 2025, GIDI data); Standards NZ PAS 5311; Consumer NZ + Yourstore (woodburner installed cost); MfE authorised-burners; MBIE weekly fuel monitoring.
  • Retrieved via: WebSearch + WebFetch, 2026-06-12. (Queries + extracts in the _retrieval.md sidecar.)
  • Verification: Genset prices are retail list (supply-only) + an inferred install multiplier; biomass figures are EECA GIDI averages (industrial process heat, applied to community scale); wood-stove is a market range. data_quality: medium.

Neobiome Intelligence relevance

Firms two V0.5 bought-fuel cost cells from assumed → sourced: diesel_genset (~900 NZD/kW installed — D20 backstop) and biomass_boiler (~1,100 NZD/kW_th — with a 290/kW_th coal-conversion alternative worth a future model option). Adds a household wood-stove ($6k/dwelling) as the domestic biomass-heat variant, with the key feasibility nuance that pellet ULEB burners bypass the airshed_restricted gate. Resolves RT_251, RT_252, RT_253. RT_254 (HVO price) stays open — not yet a NZ market product.

Research targets

Research gaps

  • A firm NZ installed (not supply-only) community standby-genset quote (NZD/kW incl. ATS/tank/pad) would lift RT_251 from inferred-install to fully sourced — noted, no new RT.
  • HVO NZD/L once on the NZ market (RT_254, still open).

Connections

Referenced by

Sources (5): CR_032 · LIT_078 · OT_121 · OT_157 · URL_034

EDT domains (1): D01: Renewable Energy & Storage Systems