OT_056: Miller (2020) — The Economics of Utility-Scale Solar in Aotearoa New Zealand

Source

Summary

The Economics of Utility-Scale Solar in Aotearoa New Zealand (Dr Allan Miller, Allan Miller Consulting Ltd, for MBIE, May 2020) is a primary NZ-government-commissioned techno-economic study forecasting where and when utility-scale solar (1–200 MW, transmission/distribution-connected, ground-mounted single-axis-tracking crystalline silicon) becomes economic across New Zealand out to 2060. At the time of writing no utility-scale solar had been built in NZ. Using a bottom-up capital-cost component model (after NREL Fu et al. 2018), worldwide-production learning curves, NZ solar-resource data (NIWA CliFlo + SolarView, MERRA-2, Global Solar Atlas 2.0) and Transpower GXP capacities, it finds NZ utility-solar capacity factors of 0.12–0.20, land-use efficiency ~35 Wp-ac/m², and capital costs falling with scale (NZ2.12/Wp-ac at 1 MW → 1.27 at 200 MW in 2018). The first regions to become economic are the Mackenzie and Tasman Districts; rate of return is most sensitive to electricity price and capital cost. For Neobiome Intelligence the value is the NZ solar-resource envelope and methodology — explicitly not the utility-scale cost/transmission economics, which do not transfer to community rooftop scale.

Key claims

See key_claims frontmatter (7 claims, cited to section/figure). All cost and forecast figures are utility-scale (1–200 MW) and 2020-vintage projections — see the scope caveat below.

Neobiome Intelligence relevance

  • NZ solar capacity-factor envelope (D01). The 0.12–0.20 CF range cross-validates MBIE’s ~14% CF and CR_010’s Nelson-Tasman yield. Community fixed-tilt rooftop (no tracking) sits at the lower end — a direct sanity bound for NI solar-yield estimates. OT_056
  • Reusable engine assumptions. Module degradation 0.8%/yr and DC:AC inverter loading ~1.2 are directly transferable to the NI solar model regardless of scale. Land-use ~35 Wp-ac/m² bounds ground-mount area estimates (rooftop differs). OT_056
  • Regional resource ranking — pilot-relevant. The model ranks Tasman (the Lower Moutere pilot region) and Mackenzie as NZ’s first economic utility-solar districts, an independent confirmation that the pilot sits in a top-tier NZ solar resource. OT_056
  • Data-source provenance. Grounds NZ solar resource in NIWA CliFlo + SolarView and Global Solar Atlas 2.0 — corroborates the canonical NZ solar-irradiance sources already used via CR_010 and OT_055. OT_056
  • Cost benchmark floor (use with care). The NZ$/Wp-ac capital-cost series and the IRENA global benchmark (USD 1,210/kW 2018 → 340–834/kW 2030) are a useful floor for what large-scale solar can cost, and the learning-curve method is reusable — but community rooftop PV is materially more expensive per Wp and carries no GXP/transmission economics. Quarantine the utility costs as a floor, not a community input. Companion to OT_055’s grid-scale-vs-rooftop national least-cost finding. OT_056
  • ⚠ Scope. Utility-scale (1–200 MW) only; 2020 vintage, pre-dating NZ’s first built utility solar (RD_001); cost figures are 2020 forecasts. Transfer the resource envelope, degradation/loading assumptions, regional ranking and data sources — not the project economics.

Research targets

Documents to retrieve

  • (none new — this report was itself the document retrieved for RT_103)

Research gaps

  • A NZ community / distributed-scale PV capital-cost benchmark (this report explicitly excludes distribution-end community rooftop economics; only ~5–15%-of-transmission distribution-connected utility solar is covered). Needed to anchor the NI community-PV CAPEX where the utility-scale floor does not apply. (RT_217 — national-data preference.)

Connections

Links to

Sources (3): CR_010 · OT_055 · RD_001

Referenced by

Sources (6): CR_059 · LIT_055 · LIT_071 · LIT_073 · OT_077 · OT_154

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