The first housing estate in Wales to generate its own energy could be built in Cardiff.
All properties face south to harness heat from the sun
Developers behind a futuristic and award-winning development in London are in talks with the Welsh Development Agency to put 1,000 homes on Brownfield site at Ely Bridge.
If successful, the former paper mill site could be home to Wales' first purpose-built eco village.
Sophisticated solar-powered technology and clever energy-saving devices would mean no energy would have to be drawn from the National Grid.
Waste timber could also be used to power a combined heat and power unit which is environmentally-friendly and does not release carbon dioxide into the atmosphere.
The company behind the scheme developed BedZED - the Beddington Zero Energy Development in Sutton - plans to create many "carbon neutral" communities across the UK.
It is currently looking for clusters of interested people and already has several people registered in the Cardiff area.
The plans for the Cardiff development are revealed in Tuesday's Week In Week Out programme on BBC 1 Wales.
The programme examines the need for a new generation of housing because of mounting concerns about climate change.
The Welsh Assembly Government is committed to finding alternative sources of renewable energy.
It is one of only three governments which has pledged in its constitution to pursue sustainable development in all it does.
Energy-efficient devices are built in to all homes
Developments like BedZED - which was built on the site of a former sewage works - are therefore likely to be of great interest.
The company ensures that, where possible, building materials come from natural, renewable or recycled sources - wherever possible from within a 35-mile radius of the site.
Its homes have an energy-efficient design - they face south to make the most of the heat from the sun, and have insulation and triple-glazed windows.
Water recycling devices ensure that mains water consumption is cut by a third, and each home has a recycling bin.
The developers are keen to reduce the need to travel - so cutting down on carbon dioxide emissions - by means of a green transport plan.
Home-owners are encouraged to use the internet and on-site facilities for shopping, and to use a car pool.
The company has seen attitudes to sustainable development change considerably in recent years.
"We are driven by an absolute determination to show that the future is cool, trendy, fun, desirable and something to really look forward to" said architect Bill Dunster.
"I've just had enough of negative environmental campaigners telling us the end is nigh".
Week In Week Out, Tuesday, BBC1 Wales 2235 BST