Transport energy and city density: a case study of how renewable energy can reverse the curve.
Authors: Ho, Anna; Byrd, Hugh
ABSTRACT: A central argument in favour of compact cities has been the inefficient use of transport
energy by dispersed urban forms. However, when the means of transport is predominantly electric vehicles
that are fuelled by renewable energy sources, this argument becomes less valid
The share of renewable sources in New Zealand’s electricity supply is currently over 70% with a policy to
increase this to 90% by the year 2020. In main urban areas, 90% of New Zealand’s vehicles travel less
than 69Km per day. This is well within current ranges of electric vehicles and makes this form of transport
attractive once costs of operating and running electric vehicles are competitive with conventional forms of
This paper will present the findings of research on the total energy supply and consumption in different
urban densities with different dispersal. The total energy use will take account of household transport
energy consumed and the potential energy supplied to housing by photovoltaics mounted on roofs. The
results show that, for transportation in Auckland, suburban development is more energy efficient than
intensifying the city.