This report outlines the development of a zoned map for Solar Water Heaters (SWH) and documents the methodology used.

The map characterises the performance of SWHs in differing regions of Australia and New Zealand.  With the intention to display the map on a ZERL it will enable comparisons across and within all residential water heater categories.

Water heating is the second largest household energy user comprising approximately 25% of household energy use in Australia, and 30% in New Zealand.  There is also significant opportunity for consumers and installers of hot water systems to decrease energy use and costs through better selection of technologies.

The E3 Committee sought feedback and views on the technical elements of the methodology for a map for SWHs set out in this report.  A set of questions listed at the end of the Executive Summary will help readers provide feedback on the proposal.  The list is not meant to be exhaustive or exclusive, simply a guide to assist in considering the approach set out here.