Designing homes to conserve energy and use it efficiently, from sources that cause least environmental harm.
A typical New Zealand home consumes 10,500 kWh of energy per year. Approximately 5,800–8,500 kWh of that is electricity (depending on location), with an average house using 7,000 kWh.
All energy consumption has environmental impacts, ranging from the production of greenhouse gases in burning fossil fuels to direct effects on landscapes from dams and other sources of generation.
Most of the total energy consumed in New Zealand still comes from non-renewable sources (fossil fuels), but the story is different for electricity – 85 percent of our electricity is produced from renewable sources.
Energy efficiency measures have also led to energy use in the average New Zealand household falling by 10% since 2000.
This figure comes from a study commissioned by the Equipment Energy Efficiency (E3) programme. There is evidence that people buying more energy efficient appliances explains a large part of the drop. The researchers go on to forecast that household average energy use will continue to fall in the near future, as will greenhouse gas emissions from households.
There are still many opportunities for making our energy use even more sustainable, however.
Sustainable energy use means designing homes to conserve energy, obtaining energy from sources that do the least possible long-term environmental harm and, where energy is used, to use it efficiently. (Find out more about embodied energy.) Energy efficiency will also reduce long-term energy bills for home occupiers.
Energy-efficient design may incorporate small-scale on-site energy production to meet demand.
In its 2018 Statement of Intent, EECA estimated that more than $470 million could be saved each year by improving the quality and energy efficiency of New Zealand’s housing stock. “While the residential sector only accounts for 6% of New Zealand’s total energy-related emissions…households have a significant impact on our peak electricity use when electricity tends to be at its least renewable and most expensive to produce (for example, winter evenings).”
Updated: 17 September 2018