A report has cast doubt on the government’s policy of encouraging the generation of on-site renewable energy.

The study, by architect Broadway Malyan and consultant Fulcrum Consulting, says the requirement that 10% of energy on new developments be generated using on-site renewable sources poses major technical and supply-chain difficulties.

The paper, Renewable energy - A Current Perspective on Planning and Design Options, notes that the most tried and tested renewable options are not always appropriate.

In particular it says that solar water heating is not suitable for high-density apartments with limited roof areas.

The report concludes that Planning Policy Statement 22: Renewable Energy has significant design, cost, practical and technical problems. Other approaches to alternative energy procurement are highlighted in the report.