Big Green Challenge

Supporting community-led responses to climate change in the UK

What was the Big Green Challenge?

The Big Green Challenge was a £1 million challenge prize to stimulate and support radical new community-led responses to climate change in the UK. 

The prize was awarded based on results; the ten finalists had to put their ideas into action for a year before the winners were selected and the prize awarded. Three winners and one runner-up received a share of the £1 million prize fund, based on evidence of reduced levels of CO2 and community engagement plus potential for further impact. 

There were 355 initial entrants, with 100 groups selected to receive support to develop their idea into a detailed plan. 21 groups then pitched to judges, who selected the ten finalists. 

Finalists received funding of £20,000 plus additional support during the competition delivery year after which winners were announced in February 2010.

What did we learn?

  • Outcome (performance) based funding has the potential to mobilise community resources and to accelerate change.
  • Providing small grants to pilot the delivery of innovative ideas is a useful model for selecting organisations with the most potential; but the administrative burdens on those taking part need to be kept in proportion to the risk that they will get no further funding.
  • Communities provide a resource for real and measurable change that can complement and work alongside ‘top-down’ interventions and behaviour change programmes.

The finalists...

reduced CO2 emissions in their communities by between 10% and 46% in the Big Green Challenge delivery year

12% of entrants...

were brand new groups, with a further 49% having existed for less than five years before entering

Half of entrants...

were looking to take forward an idea they hadn’t previously had an opportunity to progress and 10% were developing completely new ideas

Impact of the Challenge

  • Up to 5,800 people were engaged in the ten finalists’ work, probably around 2,000 of them in some substantive way.
  • The Challenge revealed some notable innovations including new and more effective ways of delivering home energy checks; innovative use of behaviour change tools (such as pledges); entirely new measures to influence energy behaviour (e.g. a voluntary consumption limit); and new legal, financial and governance structures to support community ownership of renewable energy.
  • The finalists cut CO2 emissions by at least 1,770 – 2,059 tonnes. The winners reduced emissions by at least 10% to 46% which is a notable achievement in the context of the UK target of a 34% reduction by 2020.


The Green Valleys

The Green Valleys is a Community Interest Company (CIC) that develops, installs and finances hydroelectric systems for long-term community benefit. The Green Valleys aims to make the Brecon Beacons region a net exporter of energy.

Isle of Eigg

Isle of Eigg sees residents work together to reduce their dependence on diesel generators and their carbon footprint. Local teams deliver a wide range of activities from installing renewables and insulation to sustainable food and transport initiatives.

Household Energy Services

Household Energy Services is a community-based energy service company providing independent energy advice to help households reduce carbon emissions and save money on fuel bills, including training volunteers from the area to carry out free energy surveys.


Low Carbon West Oxford funds and supports local low carbon initiatives, with the objective of achieving a 90% reduction in carbon emissions by 2050. It established West Oxford Community Renewables, an industrial and provident society, which develops renewable energy projects donating surpluses back to LCWO.

Faith and Climate Change brings together a wide range of organisations in Birmingham to address environmental issues in places of worship and in faith communities.

Global Generation gives young volunteers opportunities to develop food growing spaces, biodiverse green roofs and plant-filtered ‘grey water’ systems on office rooftops, school grounds and development sites in London. 

Hackney City Farm and the Back2Earth programme aims to introduce volunteers, visitors and local people to environmental issues as well as reducing carbon emissions on the farm site.

The Meadows Ozone Community Energy Company is a community-owned energy services company in Nottingham providing local people with advice on energy efficiency and interest-free green loans.

St Bede’s High School aims to become one of the first ever carbon-neutral schools by installing renewable energy equipment and creating a green culture throughout the school.

Waste Oil Recycling Project in Prisons is based at HMP Ford in West Sussex, is reducing carbon emissions at the same time as helping offenders to develop new skills by turning waste cooking oil into vehicle fuel.

Similar Challenges

Dynamic Demand Challenge

Reducing carbon emissions by shifting energy demand 

European Social Innovation Competition 2018

Seeking innovative projects to empower young people to participate in a changing economy

Waste Reduction Challenge

Innovating to reduce waste in communities