Christchurch men’s prison: laundry using free heat from the sun

The decision Christchurch Men's Prison made to use solar water heating in its laundry will help save over $7,000 per year on their hot water bill, with a payback of 7.6 years. With 21 solar panels covering 97m2 the prison has one of the largest solar water heating systems in New Zealand.

Their new solar water heating system will provide much of the hot water (at up to 80°C), greatly reducing the carbon footprint of the site, provide the balance of the hot water using LPG, which has a smaller carbon footprint per unit of heating than the diesel which would otherwise be used, and eliminate the use of chemicals required to treat the water when it was only 45 degrees.