Cogeneration In Woking  

The SMH has an article on use of cogeneration/trigeneration in Woking (on the outskirts of London), which has helped the town become almost self-sufficient for electricity generation and has dramatically reduced CO2 emissions - Flicking the switch from hot air to usable heat. The author is now attempting to implement a similar plan for the whole of London, and recommends Sydney try a similar approach.

The 21st century has been billed as the century of the city. For the first time in history, more than half the world's population is living in cities. It is also the century of climate change and reliable science says we are already on the brink of irreversible damage to our planet.

Cities are our most profligate consumers of scarce resources and our worst polluters. Cities are the primary cause of climate change and are most at risk from climate change, but they also provide the solution to tackling it.

It makes sense, therefore, to begin finding city-wide solutions to the problems of climate change. Solutions do exist. They have been implemented and shown to work. What is needed is the political will and the co-operation of all levels of government and the private sector to implement solutions on a broader scale.

In the 1980s, I was already convinced that global warming was a reality, so when I joined the Borough of Woking in Surrey, I was determined to do something about it.

As chief engineer of this borough of 100,000 people, I introduced the energy efficiency revolving fund that led to replacing the town's electricity and heating systems with cogeneration, also known as combined heat and power generation.

In centralised power stations, two-thirds of the energy generated is dispersed into the atmosphere as heat, and further losses occur in transmission and distribution across the grid. Fifty per cent of Britain's water resources are used to evaporate this waste heat.

In Woking, we installed a gas-fired system (far less polluting than coal), which generates electricity locally. Heat from the generation process is captured and piped underground to supply heating and hot water. This is cogeneration, and in some countries such as Denmark and the Netherlands, more than 50 per cent of their energy comes from cogeneration.

In a further step - trigeneration - waste heat is converted to chilled water for air-conditioning and refrigeration. Trigeneration has a huge impact in reducing carbon dioxide emissions since it displaces electricity that would otherwise be consumed by conventional air-conditioning, generates more low-carbon electricity and does not use greenhouse gas or ozone-depleting refrigerants.

In Woking, trigeneration - supplemented by fuel cells and renewable energy such as solar panels - enabled the town to produce 80 per cent of its own power by 2004 and to drop its CO2 emissions by 77 per cent in 14 years. The power and heat was also cheaper for customers.

I spent almost a year living not that far from Woking and even played for the town basketball team for a couple of months. I couldn't remember any distinctive features about the place whatsoever though (except for a few Formula 1 car operations on the outskirts) - however a quick Flickr search reveals that something strange has occupied the town centre since I was last there...