Maguy Soldevila is a former art teacher. Some years ago, she quit the frenzy and the pollution of the French city of Lyon to move into a typical house of the 1960s, in the small village of Sail-sous-Couzan.

María Regidor co-owns a mini-hydro power plant in Spain, which produces part of the electricity provided to the residents of the Castile and León region.

It's a brand new sector: the first steps date back to 2012. Today energy crowdfunding is a way of financing solar panel or wind turbine projects.

Cities have started to join forces to become more energy efficient . This trends stems from the findings of the first climate assessment report of the Intergovernmental Panel on Climate Change (IPCC), published in 1990, which was quite alarming.