Much of this potentiality remains unexploited, but continuing improvements in engineering are sanctioning more of the renewable resources to be utilised. Fears regarding "peak oil" and climate change have driven the subject high up the political agenda and are also boosting the use of various biofuels. Although the funds of many projects remain either risky or contingent on subsidies, it is probable that there has been a significant, and in all probability long-term change, in the underpinning economics.
Besides the planned increases in both mass generating capacity and microsystems using renewable sources, various related schemes to reduce carbon emissions are being researched. While there is substantial support from the public, private and community-led sectors, concerns about the effect of the technologies on the natural environment have been expressed. There is also an emerging political debate about the relationship between the siting, and the ownership and control of these widely distributed resources.