Study reveals Dunedin’s energy use and high uptake of electric vehicles

Wednesday 10 April 2019 2:43pm

Transport uses half of the energy consumed in Dunedin and produces most of the city's energy-related greenhouse gas emissions, a new University of Otago study reveals. However, it also shows the city boasts the highest rates of electric vehicle ownership in New Zealand.

The Dunedin Energy Study, a joint project between the University's Centre for Sustainability and Dunedin City Council reveals a total of 13.4 petajoules of energy was consumed in Dunedin during the 2018 financial year, a 5 per cent increase from 2017.

Just over half of the city's total energy (53 per cent) came from petrol and diesel, 24 per cent from electricity, 13 per cent from biomass (mainly firewood and wood chips), 5 per cent from coal, 3 per cent from LPG and 2 per cent from sulphur.

Associate Professor Janet Stephenson.

Director of the University's Centre for Sustainability Associate Professor Janet Stephenson says transport energy consumption has grown, and is an important area for action to reduce greenhouse gas emissions.

“However, what is pleasing from an emissions perspective, was to find Dunedin's uptake of electric vehicles tops all New Zealand cities,” Associate Professor Stephenson says.

“Electric vehicle ownership is increasing exponentially, going from around 25 in 2015 to more than 500 today. However, this is still a drop in the bucket – less than half a percent of Dunedin's 104,000 registered vehicles.”

Dunedin boasts highest rates of electric vehicle ownership

Dunedin currently has the highest proportion of electric vehicles of New Zealand's main cities, analysis of the Ministry of Transport's vehicle fleet statistics has shown.  
Electric vehicles per 1000 residents chart (PDF)

Analysis by Carsten Dortans at the Centre for Sustainability shows Dunedin has by far the largest number of pure electric vehicles per 1000 people (3.73), with its closest rival being Wellington (3.19).  When both pure electric vehicles (e.g. Nissan Leafs) and plug-in hybrid electric vehicles (e.g. Mitsubishi Outlanders) are counted, Dunedin still just comes out top (4.34), marginally ahead of Wellington (4.33) which has a greater proportion of PHEVs.

Dunedin's Electric Vehicles owners' group representative Pam McKinlay is delighted with the news. “It's made my day”, she says.  “I think our electric vehicle advocacy and education has probably helped, but Dunedin people are really interested too - we are always in demand for other events and festivals as well as the dedicated EV events we put on.”

Dunedin also has the highest proportion of electric vehicles registered for personal use (as opposed to commercial or other), followed by Wellington and Christchurch.  Dunedin's personal registrations are mostly pure electric vehicles, again at a far higher rate per 1000 people (3.29) than all other cities (2.3 or less).

“This is something for Dunedinites to be very proud of,” Associate Professor Stephenson says. “Electric vehicles have very low greenhouse gas emissions and are also increasingly affordable, and cost very little to run.  I hope Dunedin can keep leading New Zealand.”

The study, commissioned by the Dunedin City Council and undertaken by Warren Fitzgerald from the Centre for Sustainability, is now in its fourth consecutive year and gathers data on all energy inputs into Dunedin.

“It's a real collaboration to pull it all together,” explains Mr Fitzgerald. “We wouldn't be able to do this without the assistance of many businesses and organisations who help us every year by providing information on energy supply or energy use in their sector.”

Dunedin City Council Energy Plan Co-ordinator Jeremy Baker says the Dunedin Energy Study is an important aspect of the Council's Energy Plan and is contributing to an improved understanding of energy consumption within the city.

“Ongoing monitoring and reporting of Dunedin's energy use and related greenhouse gas emissions is important for identifying trends and informing the development of strategies for the future of the city,” Mr Baker says.

In 2014, the council joined the Compact of Mayors, which is a global coalition of city leaders who have pledged to cut greenhouse gas emissions and prepare for the future impacts of climate change.

The first Dunedin Energy Baseline Study was completed in 2014. At the time, there was no single source of information of the amount of energy consumed in Dunedin – including households, transport, businesses, education, farming and industry.

Associate Professor Stephenson says she is not aware of anywhere else in New Zealand where this is done.  “We had to develop a methodology from scratch. It is getting more refined every year and we are starting to see trends.  For example, the 5 per cent increase in energy use compared to 2017 was predominately driven by the increase in diesel consumption.”

Key findings from this recent study show:

• About 35 per cent of the energy used in Dunedin over the past year was from renewable sources. This is slightly less than the national figure of 40 per cent of renewable energy for 2017.
• Electricity and wood are the main sources of renewable energy consumed in Dunedin.
• Solar generation (PV) systems installed in Dunedin have increased by 29 per cent (76 installations) over the past year.
• Twelve per cent of energy used in Dunedin was locally sourced biomass (mainly firewood and wood chips).
• Transport fuels (petrol and diesel) consumed over the past year increased by 9 per cent from the previous year. This follows a 2 per cent reduction in the combined transport fuels in the year prior.
• Energy used in the city resulted in about 680 kilotonnes of CO2-equivalent greenhouse gas emissions. Eight per cent was from coal use, 13 per cent from electricity, 74 per cent from petrol and diesel and 4 per cent from LPG.
• Although the total amount of energy consumed within Dunedin in 2018 has increased by 5 per cent from 2017, the total greenhouse gas emissions have increased by 6 percent. This means Dunedin's overall energy portfolio was more emissions intensive during 2018 compared to the previous year.

The report concludes there is significant potential to reduce energy use and emissions from transport. “As well as the direct benefits of reducing the amount of petrol and diesel consumed, there are also indirect societal and health co-benefits which are possible through the evolution of the city's transport sector.”

These benefits can be achieved through three main mechanisms, the report states:

• Active transport – promoting walking, cycling, and other active modes of mobility through improved infrastructure.
• Technology – promoting the uptake of electric and efficient vehicles.
• Shared mobility – promoting options such as ride and vehicle sharing and public transport.

For further information, please contact

Associate Professor Janet Stephenson
Director Centre for Sustainability
University of Otago
Email janet.stephenson@otago.ac.nz

Jeremy Baker
Energy Plan Co-ordinator
Dunedin City Council
Tel +64 3 474 3403
Email jeremy.baker@dcc.govt.nz

Liane Topham-Kindley
Senior Communications Adviser
University of Otago
Tel +64 3 479 9065
Mob +64 21 279 9065
Email liane.topham-kindley@otago.ac.nz