Mixed political messages are putting jobs and investment in the renewable energy industry at risk, a new report has warned.
The Renewable Energy Association (REA) said businesses in the sector are more confident about employment, turnover and business prospects over the next year.
But recent political messages risk undermining progress, the REA said.
Executives in the industry told the association that the Government should stop giving out "contradictory" messages on energy policies, warning that constant changes "destroyed" confidence.
A survey of almost 100 organisations showed that two out of five expected to increase employment.
REA chief executive Dr Nina Skorupska said: "The renewables industry is poised to significantly grow its contribution to employment and economic recovery. The growing confidence in the power sector and the electricity market reform programme is good news as the UK urgently needs new wind, solar and biomass to keep capacity margins healthy. New nuclear, carbon capture and storage and shale gas will not be on-stream until the 2020s at the earliest.
"However, these green shoots are still fragile, and the UK's chances of meeting the binding 2020 targets appear remote. Although Government has confirmed that funding for renewables is not at risk in the 'green taxes' review, consistent messaging on Number 10's commitment to the green agenda is absolutely vital.
"The Government currently opposes a 2030 EU renewables target and is proposing to repeal the Planning and Energy Act. Reversing those stated positions would inject a huge boost into the sector and unlock much-needed new jobs and investments."
A Department for Energy and Climate Change (Decc) spokesman said: " This Government has provided record support for renewables. Since 2010, Decc has recorded private sector announcements of investment in renewables that amount to £30 billion which has the potential to support thousands of jobs and growth across the UK.
"The UK is on track to meet its 2020 renewables target and has more offshore wind installed than any other country in the world. The Energy Bill has the support of all political parties. A key part of this is moving to a low-carbon power sector with renewables playing a key role."