The United Kingdom is preparing for a deep decarbonisation of its energy system. The country has decided to halve its greenhouse gas emissions from 1990 to 2027 and to cut them by a total of 80% by 2050. For this to happen, significant private-sector investment in new energy infrastructure is needed. As it seeks concrete solutions to the low-carbon investment challenge, the United Kingdom is leading by example. The UK’s proposed Electricity Market Reform is a pioneering effort that will be closely observed by other countries. Ideally, this complex and ambitious reform would in the long run lead to a more liberalised marketplace in which low-carbon power generation technologies compete to deliver innovative and least-cost outcomes. Security of supply remains a key focus of energy policy. Fossil fuel production in the United Kingdom has peaked, and a fifth of the country’s ageing power generating capacity will have to be closed this decade. However, oil and gas imports are well diversified, and the government intends to promote various technologies to generate low-carbon electricity – renewable and nuclear energy and carbon capture and storage. More efficient energy use is essential to both decarbonisation and energy security. The Green Deal programme, which the UK plans to launch later this year, aims to improve energy efficiency in buildings and public spaces. The programme has the potential to help energy consumers overcome economic challenges, but for it to succeed, the general public must be sufficiently aware of its benefits.