Create Solar’s core R&D efforts are all centred around providing a full spectrum green energy solution for both residential and commercial clients in northern climates such as Canada. As such, one of the latest developments we have been working on is an in-ground based solar thermal & electric system, which can be installed in locations such as driveways or footpaths. When completed, this system will be the first of its kind in North America. Its full functionality is as follows:
Generate electricity for a net-metered grid connection or off-grid independent system
Have the ability to de-ice the surface of the system in the winter using multiple different heat sources available, such as:
Vertical solar thermal evacuated tubes
Geothermal ground loops
Reverse electrical current from cleared solar electrical panels
Provide individual monitoring and control of small sections of the array for research & development purposes
Be able to cool the solar electric modules in the summer months to have them operate at a higher efficiency level, while at the same time dumping this excess heat into something useful such as the domestic hot water heater or the in-ground pool.
A diagram of this addition to the overall 727 Living Lab system is shown in the image below:
The physical portion of the system has already been installed and can be seen in progress in the following images:
Currently the team is working on making the physical connections to the control room, with next steps being the installation of all the electrical and thermal control circuitry and the geothermal loops. Additional updates will be provided as the project progresses. This is yet another piece of the net-zero home puzzle that Create Solar is aiming to provide for Canadian homeowners in order to alleviate climate change.
One of the core products Create Solar installs on residential and small commercial buildings is a Building Integrated Photovoltaic (BIPV) system. The major technical parameters of this system are discussed in Part 1 of this post. One of the issues arising from these parameters when using microinverters for the DC/AC power conversion, is the high temperatures which are seen by the inverters causing them to shutdown. The previous post describes Create Solar’s first attempt at mitigating this problem by adding a venting channel snaking through the BIPV modules, and then blowing air through the channel on days when the attic temperature was above 30 degC. This provided some relief, however more cooling was needed, and therefore the following two further possible solutions were explored:
Three of the microinverters were moved from directly behind the modules to inside the attic of the roof as shown in the images below:
This modification of the microinverter location seemed to have solved the overheating problem. The image below shows the six modules (2 per microinverter) not shutting down due to temperature overload, unlike the other modules in their vicinity. This solution is continuously being monitored to ensure there are no further issues.
2. The second solution attempted was another type of forced venting like the initial modification discussed in the first post. However, the difference with this change was that it provided a venting path more inherent to how the BIPV combined solar electrical / solar thermal forced air system was originally designed to operate. A basic schematic of this system is shown in the drawing below:
The microinverters were placed in air gap between the BIPV modules and the roof insulation. This is the cavity were the air naturally gets forced through as it heats up between the modules and the roof. Even though the air is warmed to the ambient temperature, there is a constant air flow which provides more effective heat transfer for the microinverters. An image of the retrofit process is shown below:
This solution also proved to be effective, as the 9 modules which were changed did not shutdown like the adjacent modules during the hot summer afternoon. This can been seen from the image of monitoring system below:
The team at Create Solar has embarked on developing a novel new project to demonstrate the multiple different ways of using solar energy in diverse applications. This project will incorporate many different elements, including a solar driveway, backup batteries, an electric vehicle charger, solar railing, portable solar, solar installed on vehicles, and a unique system to optimize all the solar, while at the same time switching between off-grid and grid-connect based on the needs for the demonstration. The image below shows an aerial image of the 727 Living Lab where the system is currently undergoing testing and will be installed over the course of the next few months.
This will be the first type of this kind of system worldwide, and we will be providing detailed updates over the course of its development.
With the co-operation of the University of British Columbia Okanagan and a Mitacs Accelerate grant, Create Solar has been performing R&D on the most effective ways of clearing snow from rooftop Building Integrated PhotoVoltaic (BIPV) modules. Many different types of technical solutions have been explored, including but not limited to: using waste heat from household furnace operations, electrical heat applied along edges, and electrically supplied convection currents behind the modules. The image below shows one of the lab test setups used to carry out this research.
The research has provided valuable insight into the optimal solutions for keeping BIPV systems clear of snow in order to the produce electricity during the crucial winter months of northern climates, such as Kelowna, BC. Many successful tests have been performed and Create Solar now has optimal solutions for a range of different setups and conditions. The image below shows the snow melting off a single module within 1 hour of system activation. The rest of the modules will eventually heat up from the electrical current produced by the cleared module, thus resulting in a snow-free system.
This has become another successful step in the right direction for Create Solar. We are continuosly dedicated to researching and providing customers with all the best possible solutions to effectively implement renewable energy on homes in northern climates such as Canada.
One of the core products Create Solar installs on residential and small commercial buildings is a Building Integrated Photovoltaic (BIPV) system. The major electrical technical parameters to note for this type of equipment are as follows:
The modules are functionally similar to a typical roof shingle with similar aesthetically pleasing features. Therefore, they cannot be as large in size as a conventional PV solar panel.
Since the modules are much smaller, it is a better design practice to use a microinverter system as opposed to a traditional string inverter setup.
Microinverter electrical design is most cost-effective and efficient when the units are installed close to the modules. This poses some issues for a rooftop BIPV system which also operates as a thermal air handling unit for solar HVAC. This is because in the hot summer months the microinverters are prone to thermal shutdown without adequate ventilation and will stop producing power until they cool to within operating temperatures.
These parameters have caused many YC500 microinverters to shutdown for about 3 hours per day in the hot summer months. The inverter dashboard screenshot below shows that 11 PV branches did not work consistently from 2pm to 5:30pm on July 21, 2019 due to thermal shutdown.
Create Solar’s first attempt at mitigating this problem was to add a venting channel snaking through the BIPV modules, and then add a controlled fan to blow air through the channel on days when the attic temperature was above 30 degC. The designed venting route is shown in the diagram below.
An image of the venting system inside the attic is shown in the following image.
The proactive approach of forced venting provided some thermal relief to the microinverters. Performance was better, as evidenced by the inverter dashboard screenshot for a similarly hot day below, which shows that there were less inverter shutdowns.
However, it was noticed that the long venting route reduced the effectiveness of the cooling system, and therefore there were still some inverters shutting down due to temperature. To provide further thermal relief, a new system has been devised by the team at Create Solar, which will be discussed in our subsequent updates.
In order to fully utilize all available space for energy generation, Create Solar has developed a ‘Solar Railing’ product. These Building Integrated PhotoVoltaic (BIPV) modules replace traditional glass pane railing options, and offer customizable levels of privacy while producing power at the same time. The image below shows a real-world installation in Kelowna, BC.
The overall look and feel of the installed product is very minimal, as all cabling can be conveniently tucked away in the aluminum railing. They are designed to be used with micro-inverters, which allow each small group of panels to produce at their maximum output, regardless of shading. Currently they are being manufactured in two standard sizes, 50W & 100W. They are also available in a slanted configuration for sloping/staircase applications as shown in the following image:
These high-end PV modules have been tested to the most stringent industry standards, and have recently received full certification, including CSA, ULC, and TÜV. Further electrical and mechanical specifications are shown in the datasheet below. This ‘Solar Railing’ product by Create Solar is another important step in appropriately integrating renewable technology in order to realize fully net zero homes.
After we had finished installing roof collection panels, air path pipes, air handing unit, system sensors and other related hardware and plumbing parts, we test run the system on daily basis. In the beginning we had problems to run the system in summer night cool air intake mode. After adjusting the system settings and the exterior temperature sensor location, we have successfully run the set C system in the mode.
Beside the blue color on the bottom left corner of the display panel, the true indicator showing the system is working in summer night cool air intake mode is this: the temperature inside the collection panels are LOWER than both the exterior and interior temperatures as a result of the collection panels’ capability of releasing heat further as the cool air is being collected. See two photos of set C’s display on two August 16 and 22: Continue reading “Catching moments of collecting cool air after sunset”
After making all electrical connections involving three system built-in solar panels, air handling control board, exterior and air collection temperature sensors (room temperature sensor is built inside the display panel), WiFi setup and connecting the heat exchanging coil in the air handling unit to a water tank, we test run the system in both the summer hot water production mode and the inside air circulation mode with a photo taken for each mode below. Note that the color on the bottom left corner of the system control and display panel changes after switching to a different mode… Continue reading “Test running CRE solar HVAC system for set C”
After finishing installing heat collector panels for both set A and set C (see two pictures for each finished set), one of our installation team could attend the Solar Canada 2018 expo in Calgary – this expo typically hold in Toronto and this year 2018 is the fist time in Calgary and next year 2019 also in Calgary.