This report was commissioned by New Zealand’s Parliamentary Commissioner for the Environment, Dr Jan Wright, to examine the potential benefits of solar water heating (SWH)in New Zealand and assess the merits of government intervention at both local and central level. This involves a general overview of the history of SWH’s development in New Zealand, and the high levels of subsidies it receives from all levels of government.
The report firmly concludes that SWH substantially reduces CO2 emissions from power plants by replacing baseload electricity, delivering substantial environmentla benefits. However, it also raises two potential shortcomings for SWH in New Zealand compared with warmer climates. Firstly, in New Zealand winter, SWH must use 6 kWh more back up electricity than in summer; and this is when demand for water heating is highest. Secondly, SWH does not reduce the pressure to build new peaking power plants and power lines to compensate for less stable electricity generation elsewhere.
The Parliamentary Commissioner’s conclusion is for New Zealand consumers to evaluate their individual situation when choosing SWH; with the comparative environmental and economic performance of stopgaps such as ripple control and smart meters to be considered. Information and advice from the Energy Efficiency and Conservation Authority (EECA) should be more comprehensive for all technologies (including SWH). The report remains clear that subsidies should be maintained at both central and local level, but that the emphasis should be kept on carbon reduction.
Author: Parliamentary Commissioner for the Environment (New Zealand)
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