A transition to a sustainable energy system is needed. The Energy research Centre of the Netherlands (ECN) is one of Europe’s largest energy research organizations with approximately 550 employees. It has a strong international position on the items solar energy, wind energy, biomass, policy studies and sustainable process and heat technology. ECN develops knowledge and technology together with and for the market enabling a transition to a sustainable energy system. Special attention is paid to reducing energy demand through energy efficiency, energy generation using sustainable resources and efficient and clean use of fossil fuels (the so-called ‘trias energetica’). ECN focuses its research on sustainable energy generation to develop safe, efficient, reliable and environmentally friendly energy systems. Also ECN conducts research on future opportunities and economic backgrounds related to energy.