Science Show

David Fisk asks what efficiencies exist in energy and transport costs when buildings are clumped together in cities, and how additional efficiencies are easily found.

Transcript

Robyn Williams: Research has shown how wasteful our cities can be.
David Fisk is the BP Professor in Engineering at Imperial. So, can you measure a city's efficiency?

David Fisk: Yes, you can, and it's a very unusual thing to do. We often think of a city as just an enormous collection of individual buildings and we never ask ourselves...shouldn't they get some advantage in all being collected together? There's lots of other reasons why we come together in a city, why isn't energy a little bit better, more efficient in cities than in remote communities? And you can certainly look at a city as if it were one very massive process, with raw energy coming in and eventually at some other end waste energy going out, and we know an awful lot about how to handle those processes when they're in industry, why can't we do that in cities?

Robyn Williams: If you do try to do it, say, for London, what sort of figures do you get?

David Fisk: We've tried some 'back of envelope' calculations on some analysis Imperial has done on the big resource flows through a city like London (London is 10 million people or so, a very large city) and we think that probably London is running three to four times higher energy than actually its theoretical optimum, and that's even before we've looked at the transport sector and that's even before we've interfered with lifestyles, it's just simply that very often we're using the wrong energy source for the wrong use and we're never recovering the heat we lose from one building to another.

Robyn Williams: How do other cities compare? Have you looked at other cities at all?

David Fisk: Yes, we have. Certainly transport is one of the areas that's been looked at most intensely right across the globe, and in fact a number of Australian research workers pioneered the idea of trying to understand how city density affects transport energy. And sure enough if you are a very dense city you have a lot more public transport and therefore you have less private car energy use. If you are a very low density city, as long as you have good highways you can get good transfer. But the trick in any of those cities is the removal of congestion. A city with congestion, dense or low dense, is always going to be in trouble. Similarly, cities with very good district heating networks who manage to get their electricity and heating combined do so much better than cities which have individual electricity generation, individual heat generation.

Robyn Williams: Which are some of the worst cities you looked at?

David Fisk: If you were looking at the enormous consumption of energy for almost no benefit, it would certainly be true that nearly every one of the old Soviet cities were phenomenal, and they weren't very comfortable and they consumed vast amounts of coal to do nothing.

Robyn Williams: David Fisk, BP Professor of Sustainable Engineering at Imperial. London; four times more wasteful than it need be.

Guests

David Fisk
BP Royal Academy Engineering Professor in Engineering for Sustainable Developement Imperial College London
http://www3.imperial.ac.uk/people/d.fisk

Presenter

Robyn Williams

Producer

David Fisher