This topic is sponsored by the Australian Government's National Innovation Awareness Strategy.
Concerns about the greenhouse effect, smog and energy security have led to increasing interest in energy sources such as hot dry rocks, wave power and hydrogen.
The world has changed dramatically over the last 200 years, thanks largely to fossil fuels – coal, oil and natural gas. These have provided us with cheap and convenient energy, which we use to heat and cool our homes and to run our cars, appliances and industries.
But there has been a cost. No city in the world is immune from the polluting effects of fossil fuels, and they contribute vast quantities of greenhouse gases to the atmosphere, something that many scientists believe causes global warming.So, in the last few decades, scientists have been looking for ways to produce energy without adverse side-effects. Promising renewable energy sources such as wind, direct solar and biomass are dealt with in other Nova topics (see links at the end of this page). Now we'll have a look at hot dry rocks, waves and hydrogen. It may be some years before these energy sources make a big impact but they illustrate the diversity of options that are available.