The Herald reports:
Solar water heaters are not a “silver bullet” for tackling climate change because they are of little help when they are needed most, a report has found.
The 75-page report from Parliamentary Commissioner for the Environment Jan Wright, released today, looked at the extent to which household solar water heaters could help to reduce the need to build more carbon-emitting fossil fuel power plants.
Dr Wright found solar water heaters reduced carbon emissions but were not a “silver bullet” because they did not flatten electricity peaks.
“While solar water heaters save electricity, they are least effective when savings are needed most – on the cold dark days in winter when people have their heaters and lights running and fossil fuel plants are cranked up to meet this peak demand,” she said.
“Flattening this peak demand is needed if we are to avoid building more fossil fuel power plants and meet the Government’s renewable electricity target.”
That is the problem. One has to have capacity to meet peak demand, otherwise you have blackouts, power cuts or restricted hours for heaters etc. And peak demand tends to be on cold, non sunny days.
I like solar power, and how communities like Great Barrier Island are almost entirely solar powered. On an individual household level it can reduce power bills. But at a national level, it is of limited use in reducing the level of non-renewable energy.