New Modelling Shows Renewable Electricity Can Meet NZ’s Future Demand – without Importing Gas

Why It Matters

The findings demonstrate that a 100% renewable electricity system is technically feasible, questioning the economic rationale for an LNG backup and associated levy.

Key Takeaways

• 2023-2025 renewables capacity exceeds 24 GW, meeting demand
• Without offshore wind, hydro shortfalls 474 hours in 2030
• Adding offshore wind cuts hydro use, keeps reservoirs full
• Short‑term storage need ~1.45 GW; long‑term ~1.5 TWh
• Pumped hydro or advanced storage can replace LNG backup

Pulse Analysis

New Zealand’s energy strategy has been dominated by debate over a proposed liquefied natural gas (LNG) terminal, funded through an electricity levy. While the LNG plan aims to bolster energy security amid global price volatility, the country also targets 100% renewable electricity by 2030. Recent modelling, using data from the Electricity Authority on solar, wind, and geothermal projects slated for completion, shows that the existing pipeline of renewable generation—over 24 GW—already positions the grid to meet projected demand, even before offshore wind comes online.

The analysis reveals that without offshore wind, hydro capacity would be insufficient for roughly 5% of the year, translating to 474 hours where demand exceeds the maximum 5.3 GW hydro output. Introducing offshore wind dramatically reshapes this picture: hydro usage drops, reservoir levels stay high, and the grid can rely on a diversified mix of renewables. Storage emerges as a critical component; short‑term deficits require about 1.45 GW of battery power, while long‑term dry‑year scenarios call for roughly 1.5 TWh of pumped‑hydro or comparable storage. Existing regulatory roadmaps and fast‑track consent for projects like the revived Lake Onslow pumped‑hydro scheme provide a clear pathway to meet these needs.

For policymakers, the implications are clear. Investing heavily in LNG infrastructure may lock in fossil‑fuel dependence and impose a levy on consumers for a resource the renewable grid is unlikely to need. Redirecting funds toward offshore wind development and expanding both battery and pumped‑hydro storage would reinforce grid resilience, keep reservoirs full, and align with the 2030 renewable target. As advanced storage technologies such as compressed‑air and flow batteries mature, they could further reduce reliance on gas, ensuring New Zealand’s electricity system remains both clean and secure.