Initiatives such as community renewables could make a big difference to climate change and energy security, according to a report from the University of East Anglia (UEA) and University of Sussex.
The Government has launched a new community energy strategy to help nurture small-scale schemes, but the researchers said better policy support was needed to boost grass-roots development.
Researchers looked at 12 small-scale projects including a community island buy-out on Gigha, a solar panel project in Brighton, a home energy programme in Bristol and hydro-electricity generation in Cumbria.
The study, published in the journal Environmental Innovation and Societal Transitions, interviewed people responsible for getting community energy projects going.
It found that: "While community energy has successfully grown up in between the cracks of the mainstream energy system, it needs to be nurtured and supported ... if it is to continue to grow and develop."
Lead researcher Dr Gill Seyfang, from UEA's school of environmental sciences, said: "What is really needed is flexible and tailored policy support at all levels.
"While technical advice is available through handbooks and toolkits, there are some really critical support needs, in particular from decision-making help to financial models."
Alasdair Cameron, renewable energy campaigner at Friends of the Earth, said: "Instead of undermining investment in solar and wind, ministers must do much more to help communities reap the benefits of clean power. A good place to start would be to enable schools to borrow money to afford the up-front cost of solar panels."