SWIM PC AUTOMATION and MONITORING
CANADIAN RESEARCH and DEVELOPMENT ACTIVITIES
HOT SUN INDUSTRIES LTD.,
The City of Lytton had Hot Sun dealer, Argosy Pools install a Powermat solar pool heater (made by Hot Sun, Powermat was an early version of our current Powerstrip technology) in 1999. Lytton's outdoor pool is covered at night and it has a propane boiler so energy is expensive. The propane tank is 1000 gallons and it costs the city $2000 to fill it each time. According to Lytton City Chief Financial Officer and pool supervisor in the early days of their solar experience, Enid Kier, the propane tank was being filled 7 times a summer. After solar it gets filled once or twice. Like the South Arm Pool its heated at night by the boiler so the setpoint temperature is achieved first thing in the morning. The old solar system continues to operate year after year and with some design tweaks by Ken Wright of Hot Sun as he passed by on his vacations in the summer, the system is quite reliable. Its a town emergency if the solar system is down because the propane tank starts to empty real fast. This positive experience with a summer only municipal outdoor solar heated pool trumps any speculation that the South Arm Pool's Powerstrip system is anything but a viable investment. We'll collect data with a SWIM PC and we'll find out with certainty. We've learned that we just aren't smart enough to speculate.
Lytton has a sister city that got solar first but Lilloett got a Fafco system. Fafco is one of many rigid polypropylene solar collectors. These types are common in the US but in Canada we get more trouble with low temperature. Their investment in solar thermal was a bad investment. The system only lasted a few years before it froze up one evening when air temperatiures 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 Fafco. 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 temperature that wasn't far off air 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 temperatiure 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 using an offline SWIM PC and a year's worth of data proves this to be the most cost effective deployment of solar thermal ever documented.
The Bonsor Community CenterIn 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. We realized after the Minoru experience that the tank carried logistical problems. The realization was that 20,000 l of storage being heated 20C was the same energy as heating the 25m indoor pool up by half a degree. Why not store the solar energy for hot water use in the pool instead of a separate storage tank? That's exactly what we did and the end result is the largest solar thermal system in Canada. Its designed to heat the pool and the hot water. The best part for the solar thermal industry especially Hot Sun and the solar contractor, Renew Energy was that the City allowed us to use our own control and monitoring solution. Our SWIM PC control system is online collecting all the data, displaying some of it in the lobby of the Aquatic Center, allowing us to monitor and commission the system over time ensuring a successful project.
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.
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 busy 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 to come 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. These systems are not monitored so we can't quantify this technology concept quite yet but it is a major goal we currently have. We believe that increasing the energy available for the heat pump to draw from can all happen at low temperatures where Powerstrips are even more efficient and perhaps all of that energy, 100% of it, will translate to additional electricity savings and energy output from the heat pumps.
ConclusionsIn summary we've found so far that there are applications for unglazed solar collectors in municipal indoor and outdoor swimming pool heating and the numbers are somewhat known and soon to be confirmed. 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. Part of our proposed R and D efforts for 2014 include developing a solar assisted heat pump for residential use. We can build a solar heated tank of water for far less money than an equivalent ground loop system and we can deliver more energy with it.
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.
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.