LONDON – Modern planners are building compact cities, believing tightly controlled zones are better for the environment. New research suggests the opposite: urban sprawl might be a better option, with solar power fitted to suburban houses and the adoption of electric cars transforming the energy needs of a city.

Research in Auckland, New Zealand – the largest urban area in the country and a city built for the age of the motor car – shows that solar panels fitted to the average suburban home can produce enough power for that household, extra to charge an electric vehicle, and still generate enough watts to export a surplus to the grid.

Power for the urban core

Adopting a citywide approach to fitting solar panels and providing charging points for cars would enable suburban homes to provide most of the power for the city center as well as keeping the transport running, according to Hugh Byrd, professor at the School of Architecture at the University of Lincoln in England.

In collaboration with the New Zealand Energy Center and the University of Auckland, Byrd and his colleagues found that detached suburban houses typical of an auto-age city are capable of producing ten times more solar power than is possible from skyscrapers or other commercial buildings. The calculations are based on a detailed cross section of Auckland, which has skyscrapers in its business center but has most of its homes spread out over the surrounding countryside in an urban sprawl.

Although every city is different, the pattern of building in Auckland is repeated in many cities around the globe. Byrd's idea: If planners insist solar panels be fitted to properties and charging points be provided for electric cars, then cities judged to be damaging to the environment could be transformed.

Challenge to conventional wisdom

"While a compact city may be more efficient for internal combustion engine vehicles, a dispersed city is more efficient when distributed generation of electricity by photovoltaic installations is the main energy source and electric vehicles are the principal mode of transport," said Byrd.

The research could have implications for both energy and urban design policies, he added. "Far from reacting by looking to re-build our cities, we need to embrace the dispersed suburban areas and smart new technologies that will enable us to power our cities in a cost-effective way, without relying on ever dwindling supplies of fossil fuels."

"This study challenges conventional thinking that suburbia is energy-inefficient, a belief that has become enshrined in architectural policy," he said. "In fact, our results reverse the argument for a compact city based on transport energy use, and completely change the current perception of urban sprawl."

Byrd concedes that the only way his ideas will work is if planning policy made fitting solar panels obligatory. Planning would also need to require the installation of photovoltaic roofing, smart meters and appropriate charging facilities for vehicles as standard in every household.

The advantages would be a dramatic reduction in carbon emissions, long term energy security, and a reduction in city pollution, he said.

This article originally appeared at The Daily Climate, the climate change news source published by Environmental Health Sciences, a nonprofit media company.