One of the main criticisms of renewable energy is that it is simply unreliable. So what happens to our power when the sun doesn't shine or the wind doesn't blow? Now a group of nine EU nations have come together to draw up plans to make a continental wide green super-grid a reality. 

Just three of the natural resources the European Union hopes to exploit to create renewable energy. 

In 2007, the European Commission suggested a costly push away from fossil fuels. Now there are plans to share across borders. 

A proposed super-grid would link Europe's green energy producers into a continental pool of energy within the next decade. 

Pooling energy means that there is a constant, reliable stream of electricity, that is not weather dependant. 

Christian Kjaer, chief executive of European wind generator Asso., said, "It's really irrelevant what an individual wind turbine does. If the wind is not blowing in one place, it will blow in another if the distance is far enough." 

The European Wind Energy Association is calling for electrical grids to be developed across national borders. 

EU energy advisor for Greenpeace said, "The super-grid, together with a smart decentralized grid, is an essential precondition for a fully renewable energy supply or for even increasing quantities of renewable energy in the system." 

New direct current cables will need to be laid in order to transport the energy over long distances without losing most of the energy in the process. 

The project comes with a steep price tag: 40 billion US dollars. 

The environmental pressure group Greenpeace also supports the project.