Lytton has a sister city that got solar first but Lilloett got a grid style 4x12 polypropylene collector system. Their investment in solar thermal was a bad investment. The system only lasted a few years before it froze up one evening when air temperatures dipped below 6C and the water in the collectors flash froze and burst the rigid collectors. We've offered to help and tried to recover this bad situation but when rigid polyprpopylene collectors freeze there is no recovery other than full system replacement at full price and nobody likes paying for a major piece of capital equipment twice. Try getting that into the city budget for the following fiscal year! You have to do it right the first time and polypropylene collectors are simply the wrong choice for BC.
The city of Cache Creek BC got a solar pool heater for their outdoor pool in 2010 under the Eco Energy grant program and they too went with polypropylene grid style 4x12s. Here's what we found on a service call in 2013.
The Minoru Aquatic Center
At this facility shown to the right we installed a classic drainback solar hot water heater but we used low pressure storage and lots of it and we used Powerstrips. With 2000 sq ft of solar panel seeing about 950 GJ of energy over the course of 2012 we delivered almost 500 GJ to the showers. The tank never got much over pool temperature. We were always operating the collectors at a low temperature so there was no need for insulation or glazing or evacuated tubes. To use a higher temperature collector on this low temperature application would have reduced the energy output per square foot of collector and it would have increased the cost 4 fold at least. Its almost funny that this basic system was one of the first things ever tested back in around 1976 when the Solar Age began. After the US tax credits expired when the world learned we weren't on the verge of running out of oil after all, the Solar Age quickly faded but what was left behind was an industry called solar swimming pool heating using unglazed collectors. Products like our Powerstrip have been on the market since 1979 and have always enjoyed free market viability competing head on with fossil fuels as a heating choice and not just as a way to displace natural gas economically. Meanwhile the expensive high temperature collectors lobbied for all the free government money and investments in solar thermal meant investments in the tried and proven untrue technologies of yesteryear. Unglazed solar for water heating never got a foothold. Solar thermal that makes sense economically was always possible. Why are we heating cold water up to warm temperatures with fossil fuels or with high temperature solar panels when we can do that with low temperature solar panels and do it in a way that is justifiable economically? The Minoru Aquatic Center's solar water heater is monitored and a year's worth of data proves this to be the most cost effective deployment of solar thermal ever documented.
The Bonsor Community Center
In 2013 we got an opportunity to be involved in solar heating an indoor pool. We took what we learned at Minoru and at South Arm and we used that data to help design something that evolved things one step further. This installation is a combination solar pool and solar domestic water preheating system.
  The 8000 sq ft Powerstrip Solar System in Burnaby BC
The biggest challenge we faced at Bonsor was meeting structural engineering requirements holding the solar panels down on the gravel roof without roof penetrations. We captured the gravel roof ballast and used it to provide adequate solar ballast. Andy Mill, PEng of David Nairne and Associates is a prominent structural engineer in BC and he was absolutely key in pushing the envelope and helping to develop the building codes of the future for this kind of installation.
 
Burnaby mayor Derek Corrigan, MLA Richard Lee, MP Nina Grewal and Hot Sun President Ken Wright show off Powerstrip samples at the opening of Canada's largest municipal solar heating project on November 29, 2013
The Bonsor solar pool and hot water heater is the largest solar thermal system installed in Canada by area at over 8000 sq ft.
Sechelt, Sparwood, Esquimalt and Kimberley Aquatic Centers
This technology development story keeps getting better and better. While Hot Sun was busy in the Lower Mainland getting the above 3 systems conceived and underway, our friends at Renew Energy were working with other engineering companies in rural British Columbia on energy solutions for those Aquatic Centers. Natural gas isn't as cheap outside the Lower Mainland of BC so what we have are electricity instead of natural gas based systems.
  A year round drainback Powerstrip system as the source for a heat pump at a municipal Aquatic Center!
At those facilities and two more in 2014 what we have now are heat pumps assisted by Powerstrips. Instead of trying to suck heat out of the ground or the air these systems are using a tank of solar heated water just like the tank at the Minoru Aquatic Center.
Conclusions
In summary we've found so far that there are applications for unglazed solar collectors in municipal indoor and outdoor swimming pool heating. What we see happening is that water heating is in fact a better application for solar thermal especially in cases where we're up against really low cost natural gas. When we're away from the constraints of cheap natural gas we have enormous potential opportunity marrying this type of solar thermal to heat pumps.
Meanwhile we're back to focussing on heating residential swimming pools all over the world and training our dealer network. Saving the world is a lofty goal but it'll take lifetimes and we have to make a living in the meantime.
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200 m^2 of Powerstrip at the Minoru Aquatic Center
the 20,000l storage tank and piping
Ken Wright, Hot Sun, right rear. Richmond mayor Malcolm Brodie front right.
Charlie Smeenk, Associated Engineering left rear. John Yap, Provincial MLA left. Alice Wong,federal MP front and center
Ken Wright explains the system at the grand opening in mid November 2011 as the system monitor shows 72kw being delivered.
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