Australia's renewable energy insurance market has crossed a threshold: it is no longer simply a growth sector where insurer appetite follows investment volume. It is becoming a specialist underwriting class where engineering quality, climate exposure, transmission infrastructure and supply chain resilience determine whether a project secures coverage and at what price. The shift is documented in Willis's Renewable Energy Market Review 2026, which finds capacity available but deployment increasingly contingent on project-specific characteristics rather than sector-wide appetite.
Renewables accounted for about 36% of Australia's electricity generation in 2025, with penetration in the National Electricity Market reaching around 40% in early 2025. During Q4 2025, renewables supplied more than half of NEM electricity over an entire quarter for the first time - a milestone consistent with AEMO's Quarterly Energy Dynamics for the same period.
Two risk categories have driven the specialisation most sharply.
Battery energy storage systems have become the most acute underwriting focus. Thermal runaway - the uncontrolled, self-sustaining chemical reaction that can cause BESS fires to propagate across a facility - presents a risk profile that standard property underwriting was not designed to assess. Insurers are now requiring detailed engineering documentation, fire suppression system specifications, system integration evidence and maintenance protocols before deploying capacity. The claims experience from early BESS deployments, combined with elevated reinsurance costs, has reinforced that requirement. A poorly documented or inadequately specified BESS project can find capacity withdrawn or priced at levels that alter project economics entirely.
Transmission infrastructure has become the second significant underwriting consideration. Grid constraints, planning delays, construction cost overruns and financing pressures are creating project completion risk that flows into coverage questions around delay in start-up, business interruption and construction all-risk policies. AEMO's 2026 Integrated System Plan concludes that major transmission investment is required to connect Renewable Energy Zones, maintain system reliability and replace retiring coal-fired generation. Where that investment is delayed, projects face revenue uncertainty that affects how underwriters assess the financial viability of what they are covering.
John Rae, Pacific renewable energy leader at Willis, framed the market position precisely: "Capacity remains available, but deployment and pricing are increasingly influenced by project location, technology type, and overall risk quality. In this environment, achieving optimal insurance outcomes increasingly depends on strong risk presentation, robust technical design, and a strategic, well-structured approach to insurance programme placement."
Recent catastrophe experience is reinforcing insurer caution across all renewable energy asset classes. The Insurance Council of Australia reported extreme weather events generated approximately $3.5 billion in insured losses during 2025. Globally, Swiss Re Institute estimates insured natural catastrophe losses reached US$107 billion in 2025 - and while that figure sits below the long-term trend, Swiss Re warned that favourable weather variability rather than reduced underlying risk explained the lower total, with secondary perils including severe convective storms and wildfires accounting for a record share of insured losses. For renewable assets exposed to hail, bushfire, flood and wind, that distinction matters: the risk has not declined, the losses were distributed differently across the year.
APRA's 2026 Insurance Climate Vulnerability Assessment warned that climate change could widen Australia's insurance protection gap by reducing affordability and increasing uninsured losses - reinforcing expectations that insurers continue strengthening climate risk management and long-term capital planning. The IAIS 2025 Global Insurance Market Report similarly identifies climate-related risks and global reinsurance markets among its key supervisory priorities.
The convergence of climate risk, infrastructure constraints, engineering complexity and global reinsurance pressures means renewable energy underwriting is becoming less about insuring individual assets and more about assessing the resilience of entire projects - from design and procurement through to construction and long-term operation.
