MEDIA RELEASE
BRANZ Reports Massive Increase in Heat Pump Usage
28 March 2008
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BRANZ has released a report which shows a dramatic increase in the country’s use of heat pumps, with potentially
significant consequences for the country’s electricity planners and suppliers.
The study report, titled, ‘Active Cooling and Heat Pump Use in New Zealand’ reveals that New Zealanders are quickly
adopting technology for cooling their houses in summer as well as heating them in winter and in all likelihood, creating
something of a headache for energy planners. One of the implications of this shift in demand is a potential upwards
trend in electricity usage in summer as well as in winter as consumers also move to replace solid fuel burners. The
study has also found that people are using their heat pumps to heat to higher temperatures and for longer hours than the
technologies they have replaced. This will probably result in better occupant health, but will also result in greater
electricity usage.
“The results of the survey have been surprising,” says the report’s author Lisa French. “We knew that heat pump sales
were strong, but last year nearly 78,000 were sold, which is more than double the number sold in 2004, the first year
figures were publicly available.” French is discussing the potential increased demand on the electricity network,
including a potential winter heating increase, with the Electricity Commission.
The implications of this rapid increase in heat pump uptake are not totally clear but findings from earlier BRANZ
research, the Household Energy End-Use Project (HEEP) which ended its collection of appliance data in 2004, underline
concerns. “At that point only 4% of houses had the ability to cool their indoor environment – either by a dedicated air
conditioner or a heat pump. Now, just four years later, that figure has increased to an average of 19%, with regional
variations from 50% to none,” says French. Close to half of all new houses have heat pumps installed during
construction.
More than half of the heat pumps installed are reportedly used for cooling which is a new load on the electricity
network at a time when domestic loads are traditionally at their lowest – during summer.
BRANZ has also discovered as part of the earlier HEEP work that over half of New Zealand’s space heating comes from
solid fuel burners. Until HEEP, the contribution that solid fuel burners make to household heating was largely
underestimated and therefore not fully accounted for in the country’s energy use figures, on which energy planners rely.
The switch from solid fuel burners to heat pumps for winter heating and now summer cooling is a further, unexpected
burden on the nation’s electricity infrastructure. Heat pumps have been installed in greatest numbers in the colder
parts of the country such as Canterbury, Otago and Southland, with up to 50% of houses in the latter having a system.
The report is based on survey information collected by post from 3,400 households throughout New Zealand in August 2007
and has been funded by Building Research. Work will continue on this project until early 2009 and further information
will be published as the project progresses.
The 2008 report can be downloaded for free from the BRANZ website:
http://www.branz.co.nz/branzltd/bookshop/info.php?ask=free=1693
ends