Grant Thornton, in collaboration with Clean Energy Pipeline, is pleased to present the 2026 Renewable Energy Cost of Capital Survey. This publication builds on previous editions of Grant Thornton’s renewable energy discount rate survey and associated market research, continuing our focus on pricing, valuation and investor return expectations across secondary-market renewable energy transactions.
The discount rate, a key proxy for the cost of capital, remains a critical input for investors, lenders and developers when evaluating renewable energy M&A activity. It directly influences valuation outcomes and fair market pricing across operational, late-stage and development assets. Despite its importance, observable market evidence remains limited, requiring market participants to rely on professional judgement, transaction benchmarks and specialist valuation insight.
The report presents a comprehensive, data-led view of current market conditions by combining two complementary research streams. Given the limited transparency of transaction-level pricing, the report provides an important market-led perspective on how investors are currently benchmarking risk and return across renewable energy technologies and geographies. Observed transaction internal rates of return (IRRs) and implied costs of capital derived from comparable market activity remain important valuation reference points to support this.
First, Grant Thornton conducted a global survey of leading investors, lenders and developers to capture prevailing expectations for discount rates applied to secondary-market renewable energy transactions. Respondents were asked what discount rates they would expect to apply to both levered and unlevered investments across a range of technologies, including ground-mounted solar photovoltaic, onshore wind, offshore wind and battery energy storage systems. The results shown relate to geography and technology combinations which presented a minimum number of responses to infer meaningful conclusions. Participants also provided commentary on key valuation assumptions, such as merchant risk premiums and co-location considerations.
Second, the report incorporates a detailed analysis of Clean Energy Pipeline’s transaction database, focusing on observed enterprise value per megawatt (EV/MW) metrics for commercial operations date and ready-to-build projects. This transaction dataset covers deals announced or completed during 2024 and 2025 and draws on publicly disclosed information, including sponsor announcements, lender communications and market disclosures, alongside selected private bilateral transactions, early-stage development trades and balance-sheet financings that are not publicly reported. Together, this approach is intended to provide a representative view of market values during the period under review.
The research covers countries that rank among the top 20 global markets for renewable energy investment over the 2024–2026 period and spans a broad range of mature and developing markets across Europe, Asia, Africa and the Americas. All survey data was collected prior to the onset of the Iran conflict in the Middle East and should be interpreted accordingly.
Please follow the link to download the survey here.