Wales has “missed opportunities” to invest in renewable energy and substantially boost its economy, a report has found.
The Institute of Welsh Affairs (IWA) said a significant number of potential projects struggled or did not attempted to attract funding from within Wales.
It said a “lack of ambition and strategy” was holding back investment.
A Welsh Government spokesman said: “We are already delivering on many of the areas highlighted in the report.”
The think-tank wants Wales to get all its energy from renewable sources by 2035.
Shea Buckland-Jones who worked on the report, Funding Renewable Energy Projects in Wales, said: “Wales needs to reach its renewable energy potential by taking advantage of its abundance of natural resources and should do so by investing in a way that ensures wider economic and social benefits are retained locally within Wales.
“Welsh Government, pension funds, local government, private sector and third sector organisations all have important roles to play in this and joined up thinking is required to make it happen.”
The Welsh Government spokesman added: “Our innovative support for local energy has seen us support and de-risk the development of a pipeline of projects, many of which are already generating energy and income. We have made £25m available this financial year to develop a range of projects in the Welsh public and community sectors.”