Principal Investigator: Cle-Anne Gabriel
The Otago Baseline Study was commissioned by the Otago Chamber of Commerce to asses how much energy Dunedin uses as a city, and from which energy sources it is most reliant.
While commissioned by the Chamber, the study was co-funded by the Dunedin City Council and the Centre for Sustainability.
The study looked at the energy inputs to the city of Dunedin (including the rural parts of the city) during 2014, some of the main end-uses of the energy, and the greenhouse gas emissions produced.
The Chamber of Commerce wanted to find out how much energy the city used and what is was used for. It believed that information was needed by the city to help plan its future, because energy was such a crucial resource for businesses and households.
Research Assistant, Dr Cle-Anne Gabriel did not find it easy to uncover this information, as this kind of project hadn’t been done before in New Zealand. She spent a lot of time interviewing local companies involved in supplying different fuels, digging into national energy data files, and looking through dusty boxes for fuel tax data. Although there are still a few bits of data missing, like how much firewood people gather themselves, the big parts of the puzzle are in place.
The study found around 86% of Dunedin’s electricity supply was generated from renewable resources. Dunedin’s electricity was predominantly sourced from the national grid (68%), but the power supply from the Waipori (hydro) and Mahinerangi (wind) generation schemes enters the grid within the DCC boundaries at Berwick, even though the electricity is generated with Clutha District. This provided nearly 32% of the total electricity used within the city in 2014.
Within the city there are many sites where small amounts of electricity is generated (including the DCC’s methane-to-electricity scheme at the Green Island landfill, several other industry-based generation schemes, and household-scale wind and solar installations) but these only contributed 0.2% of electricity supplied to the city. However solar generation capacity increased during 2014 by 280% to a total of 119 solar connections (with combined installed capacity of 0.395 MW). This is the main energy supply where significant change was seen during the year.
Almost all of the energy supplies were sourced from elsewhere in New Zealand or from overseas. Dunedin’s liquid fossil fuels (petrol, diesel and LPG) were shipped in; the coal was transported in from various mines in the South Island; and the firewood sold commercially was sourced from forests outside of Dunedin. Less than 0.1% of total energy was sourced from within the city boundaries.
The report also identifies new business opportunities. For example, approximately 1500 tonnes of wood pellets were supplied to Dunedin customers in 2014, and around 150-200 new pellet fires are installed annually. Despite the fact that Dunedin has a number of major forests, there is no local production of pellet fuel; it is all currently imported from manufacturers in Taupo, Nelson, Timaru and Tapanui.