The most efficient solar panels are the glass-encased and insulated full copper 1 x 1.2 meter units such as SUNZ (Mike Izzacs (09) 266 3435 or email sales@sunz.co.nz) who claims to be able to produce 27.5°C pool water for up to 8 months of the year (Auckland & north) with a panel density of 25% of pool area. Developed for hot water heating for homes, the panels cost around $2,000 each + Installation, and should be elevated to 50° north by north-west. We can not substantiate the pool temperature claims, but have met with Mike Izzard, and he seems a genuine and very knowledgeable person in the field of solar water heating. Check out his web page at www.sunz.co.nz

Other approaches include a series of PVC tubing or mats that lay flat on your north roof . Not as effective as the encased models, ideally these solar collectors should be 100% of the pool area (ie a 5 x 10 pool would need 50 square meters of solar collectors).

We understand that recent advances in collector technology allow a 75% ratio of collector to pool area, but so far no company has come to us with hard evidence of the efficiency of these types at 75% coverage. (We will publish any evidence in this web page)

COST? A wide range of systems available between $100 to $200 per square meter, or $1200 for the glass-encased models. A booster pump will consume electricity, and you may not extend your swimming season appreciably unless the collectors are angled (50° Northe West) to catch the spring and autumn sun (which means they are not as effective for mid-season or summer use). OSH requirements may mean that an expensive scaffolding erected during installation will add to your costs. Do some homework before you decide. Visit the web pages of SOLAR 60 www.solar60.co.nz for more information on mid-range cost solar panels.