Renewable liquid fuels provide an opportunity for nations to increase energy independency or reduce greenhouse gas emissions by supplying energy-dense fuels which are miscible with petroleum gasoline and diesel. This chapter shows how liquid fuels are the most pragmatic way to increase the renewable energy content in the transport sector, enabling an evolution, rather than a revolution of both vehicle and fuel technology. The historical development and present market penetration of these fuels is discussed, together with aspects of current and future legislation which may incentivise or limit their use. an integrated system is proposed which combines biomass with fuels made from re-cycled CO2 as a means of storing off-peak renewable energy. © 2014 Woodhead Publishing Limited All rights reserved.