Stirling engines have the potential to help combat climate change. Photo Kew Bridge Steam Museum
A London museum is helping to highlight an eco-friendly way of creating ‘free’ energy that was invented almost 200 years ago.
Stirling engines were commonplace around 1880 to 1920 but fell out of fashion with the advent of the electric motor. Amid concerns over global warming, the Kew Bridge Steam Museum is organising a rally to showcase these engines, which some scientists believe have a role to play in delivering clean energy.
“The thing that makes them so intriguing is because technically it is almost like free energy,” explained Lesley Bossine, who is organising the rally.
“Basically a Stirling engine is unlike a diesel car or steam engine where you have got to put a fuel in. The Stirling engine works on pure heat, so you can power them on solar power, geothermal energy or waste heat.”
Originally invented in 1816 by the Rev Dr Robert Stirling, they are closed circuit combustion engines. They are silent, and work by using heat to warm a cylinder. Within the cylinder, air expands with an increase in pressure that in turn drives the engine.
True Stirling engines also incorporate a heat store called a regenerator, which stores heat energy during one part of the cycle and releases it later, making it even more efficient.
There will be more than 80 engines at the rally, pushing the boundaries of the technology. Photo Kew Bridge Steam Museum
The rally, taking place on March 25 2007 at the museum, will bring together more than 80 working engines made by members of the Stirling Society. It will focus on working models and engines that are designed to stretch the application of this technology. It is thought to be the largest event of its kind ever staged.
Despite their potential, scientists have grappled with the problem of making the engines big enough to create large amounts of power.
“The big problem that everyone has had is scaling the engine up to make it viable on a large scale, like for powering a factory or housing estate,” said Lesley. “There is very divided opinion as to whether the problem of scale can ever be overcome.”
The technology is potentially ideal for developing countries, however, and has already been applied to Combined Heat and Power generators and generators and was used by Phillips in the 1950s and 60s to build a Stirling Engine-powered bus and Stirling-powered radio sets.
“Now that natural resources are running out people are coming back to it,” added Lesley. “There are all sorts of rumours that a guy in America is working on a Stirling-powered car.”
“The person that can crack Stirling technology and scale it up into a viable energy source will become a multi-millionaire.”