.svg)
Let's get one thing clear at the start: energy and electricity are not the same thing. While these terms are often used interchangeably, electricity is a subset of energy and only makes up part of New Zealand’s total energy use.
We are frequently told that New Zealand’s highly renewable electricity grid puts us ahead of the game when it comes to decarbonising our energy system. It certainly helps, but gas to heat our homes and water and cook our meals, petrol and diesel for our cars, and coal and gas for industrial processes make up the vast majority of the country’s total energy consumption.
That means we can’t just focus on decarbonising our electricity grid. It means we need to switch our fossil fuel machines to electric alternatives and run them with renewable electricity. This will increase the amount of electricity we need, but because of the amazing efficiency of electric machines it will decrease our total energy use - and our emissions.
In this explainer, we look at how New Zealand currently uses energy and why using more electricity means using less energy overall.
Let’s plug in.
The whole truth
In 2023, Aotearoa consumed about 156 petajoules of electricity (one petajoule would power about 40,000 average New Zealand homes for one year), of which 88% was renewable [1]. But, total energy consumption was about 547 petajoules, making electricity just 26% of total energy consumption [2].
This means that of all the energy consumed, just 23% is provided by renewable electricity. Aotearoa also gets about 7% of its energy from renewable fuels - like wood - and uses these fuels directly (instead of using them to generate electricity). This brings the proportion of total consumer energy coming from renewables to 30%.
The rest of the story
Over half of Aotearoa’s consumer energy (52%) came from oil in 2023 [3], all of which is imported as petrol, diesel and other fuels from overseas, and about one fifth came from fossil gas. Although a small percentage (23% of gas, of which around half is lost in the generation process) [4] is used to generate electricity, the vast majority of oil and gas are burned in households and businesses across Aotearoa. We also burn a relatively small amount of coal for industrial processes and backup electricity generation.
The vast majority (73%) of our oil consumption comes from the transport sector, most of which is contained in the petrol and diesel used to fuel our vehicles [5]. New Zealand is a car-dependent country. In fact, we are in the top five in the OECD for vehicle kilometres travelled per person [6]. There are some valid reasons for this. We are a long, narrow and sparsely populated country, making public transport costly.
We also have a steady supply of cheap used cars. Finally, our public transport systems really aren’t up to the same level of service of many larger countries, so we rely on the car for most of our regular journeys.
Fossil gas is used mostly in industrial processes such as chemical production, dairy product manufacturing and other processes that require high levels of ‘heat’. The gas used in our homes for heating and cooking is actually a small proportion of overall gas consumption [7]. However, we also use gas to generate electricity to provide support to the grid during periods of high demand. Electricity generated from domestic fossil gas is more efficient and has lower emissions than coal. It is also generally faster and cheaper to dispatch than coal, meaning gas power plants can be switched on during peak periods. But the domestic supply of gas is dwindling faster than expected and this shortage has increased prices and led to fears that suburban customers may not be able to be supplied with gas in a worst-case scenario.
Feel the burn
Our reliance on petrol and diesel vehicles means that our renewable electricity consumption is easily outweighed by fossil fuel-derived energy. But cars themselves aren’t the problem. In many parts of the country, they’re the easiest way to get around. The problem is the way we fuel them. Petrol and diesel cars make up about 98% of our vehicle fleet and light vehicles are responsible for 70% of our petrol and diesel use. If we consider cars as part of a household’s energy use, they account for around 60% of the total and are the largest source of emissions.
When we burn petrol and diesel, around three quarters of the energy created gets lost as waste heat, noise and vibration. This means that a large chunk of our energy use provides no useful service. Electricity does not have this problem. When we use electricity, virtually all available energy is made useful. By shifting to electric vehicles, we can reduce our reliance on fossil fuels and slash our energy consumption.
- Read our previous explainer Electrification is Efficiency
Our Electric Homes report [8], released in early 2024, shows that New Zealanders could save money by switching to electric vehicles and charging them with a combination of electricity from rooftop solar and our highly renewable grid.
If homes also convert their gas heating, hot water and cooking to electric alternatives, they can have virtually zero energy emissions and dramatically reduce their power bills. It also means reducing our reliance on imported and inflationary fossil fuels.
More with less
An average New Zealand home currently uses about 73 kWh of energy each day (including vehicles), and just under one quarter of that is electricity. If households upgraded their vehicles and appliances to electric equivalents, electricity use rises by around two-thirds, but total energy consumption drops by around two thirds to 25 kWh.
This drop in total energy use is due to the fact that electric machines like heat pumps, induction cooktops and EVs are so much more efficient than the gas and oil machines that we use today, and can do the same job with less energy.
If every household in Aotearoa went electric, the country would need a lot more electricity - and the cheapest electricity will come from their own rooftop solar - but over a year we would remove the equivalent of around 80% of the annual energy use in our entire industrial sector, or the current energy requirements of around 1.3 million homes.
We can reduce our energy consumption further by electrifying every industrial process we can, electrifying diesel farm machinery and removing fossil fuels as a fuel source in businesses and government buildings.
Electrification is the energy efficiency we’ve always been looking for. Electrifying as much of our energy use as possible means much more electricity use, but much less overall energy consumption. It means putting an end to wasteful fossil fuels and building a more sustainable and self-sufficient Aotearoa.
.avif)
Related posts
More Watt Now? posts from Rewiring Aotearoa
Energy use in New Zealand
Read More
Closing The Loop
Read More
Electricity means efficiency
Read More
