Power companies are being criticised for failing to make natural gas more available to Auckland homes.
Official figures show that hot water from reticulated gas costs half to threequarters as much as hot water from electricity.
But energy experts say that for many years only 20% of Aucklanders have been offered gas as well as electricity, and as a result, low-income people are paying more for their home heating than they need to.
Price controls that deter the laying of gas pipelines are being blamed, along with the fact that the same companies market both gas and electricity, so do not have an incentive to push gas uptake.