Different swimming pools require different energy efficient solutions. All pools benefit from pool covers.
Pool covers have two main functions. They reduce the heat-loss from the pool, by virtually eliminating evaporation from the pool surface, as well as greatly reducing the conductive and radiative heat-loss. They also help to keep the pool clean by reducing the amount of debris entering the pool, and this reduces the filtration requirements of the pool.
For further information refer to the Guidelines on the performance of solar water heating collectors to heat swimming pools
There are two main types of pool covers.
- The thermal cover is a polyethylene closed cell foam cover with a protective layer of woven polyethylene. The insulation properties are good, but because the cover is not transparent, the pool will not be heated by the sun through it. If the pool is in used most days (and uncovered) then this shouldn't matter.
- The other cover type is the bubble cover. This is a transparent cover made from polyethylene. The cover has a ‘bubble wrap' appearance and primarily prevents evaporative heat losses, with some reduction in conductive and convective losses. However, the cover allows the solar radiation to heat the water. The cover is more suited to pools that are predominantly covered i.e. not in use every day or throughout the day.
The durability of the covers differs due to the construction type. Thermal blanket covers will last longer, and are more suited for pools, indoor and outdoor, where they will be removed most days. Where transparency is not an issue, then the thermal blanket type of cover should be used.
Energy efficient technologies for pools
Read our fact sheet for information on energy efficiency for indoor swimming pools.
Christchurch City Council introduced renewable energy technology to heat the QEII pool by using landfill gas from Burwood landfill resulting in reductions in electricity and LP gas use at QE 11 (energy savings in excess of $1 million a year), carbon dioxide savings in excess of 40,000 tonnes a year and revenue from the sale of carbon credits. See the Christchurch City Council website for further details.
Solar water heating systems for pools
Solar water heating can improve the comfort levels and extend the swimming season for previously unheated outdoor pools. Grants issued for unglazed solar water heating systems swimming pools:
- Coroglen school - Whitianga
- Devonport Primary School - Auckland
- Diamond Harbour School - Lyttleton
- Half moon Bay School - Stewart Island
- Mayfield School - Blenheim Riverina Primary School - Auckland
- Riverina Primary School - Auckland
- Rotokauri school - Hamilton
- Roto-O-Rangi School - Cambridge
- Whakamarama School - Tauranga
- Westland Distrcit Council - Ross public pool, Hokitika
Grants issued for glazed solar water systems swimming pools:
- Oamaru Intermediate School - Oamaru
- Palmerston Primary School - Otago
- South Waikato District Council - Tokoroa Indoor Pools
- Taupo District Council - Turangi Aquatic Centre
Read the case study about five New Zealand schools who have opted to heat their pools using solar energy resulting in an extended swimming season and warmer pool water.
General information on solar water collectors for heating swimming pools in New Zealand can be found in the Guidelines on the Performance of Solar Water Heating Collectors to heat swimming pools. This report discusses the benefits and appropriate uses for both unglazed rubber or plastic mats / panels and glazed collectors in New Zealand.