Question: What is the most useful energy? And why?

Helen Pritchard-Smith answered on 19 Jun 2013:

All energy is useful but it is up to us as scientist to get the most out of the available energy around us. If it is easier to get at i.e. fossil fuels from the ground using established industry, then that is easiest which is why more people use fossil fuels as all of our machines are set up to use them (cars, boats, planes, power stations). The more efficiently we can extract renewable energy around us the less we will need to rely on depleting fossil fuels.

When we burn fossil fuels it is the energy released from the complete combustion (when enough air or oxygen is present) of carbon hydrogen C-H bonds contained in the petrol that is used to move the car along. If we could use another fuel like biobutanol made from fermenting sugar cane that would be preferable as we are less likely to run out of sunshine to help the sugar grow than fossil fuels.

Solar panels and wind turbines are also useful sources of energy but at the moment, with technology we currently have, we can only extract or use tiny amount of it. For example the earth’s atmosphere absorbes enough energy from the sun in one hour to power the whole planet for a year!! So the closer we get to efficient technology the more useful renewable energy will become.