Exergy and the city

Exergy is synonymous with the availability of energy and, in the context of this research, is the availability of energy generated by photovoltaics (PVs) mounted on roofs across a city. The research was carried out on Auckland City with the aim of answering the questions: 1) How much energy could be produced if a city fully utilised its rooftops in a practical and efficient manner? 2) If there is any excess energy produced, how could this best be used?3) What implications will this have on the shape of cities?The purpose of looking at the full potential is that it provides a starting point from which to backcast and predict the impact of PVs as they increase penetration into the building stock.The study took a large sample (3 million sqm of floor area) of various types and uses of buildings form high rise city centre developments through to low density suburbs and everything between.