Why ‘Only Eleven Percent’?

Some excellent work at the University of Cambridge identified that in 2005 the world used 475 exajoules (EJ) of primary energy, oil, coal, gas, renewables and nuclear, and out of that we got 55 exajoules of useful energy services – heat, coolth, motion, light and sound.  That means that, even with our ‘advanced’ technologies we have an overall efficiency of 11% – hence the “only eleven percent”.  We can never achieve 100% but the practical, and even economic, limits to achieving higher energy efficiency are far higher than the levels we achieve today, and improving that performance would bring great benefits in terms of cost reduction, improved energy security, reduced emissions and job creation.

Dr Steven Fawkes

Welcome to my blog on energy efficiency and energy efficiency financing. The first question people ask is why my blog is called 'only eleven percent' - the answer is here. I look forward to engaging with you!

Get in touch

Email Twitter Linkedin Skype

Email notifications

Receive an email every time something new is posted on the blog


Energy Efficiency

Energy Efficiency by Steven Fawkes

My book Energy Efficiency is available to buy now

Outsourcing Energy Management

Outsourcing Energy Management by Steven Fawkes

My book Outsourcing Energy Management is available to buy now

Only Eleven Percent