NSCC Waterfront Solar Monitoring (Part 1)
June 6, 2011
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We are working on an electronic monitoring system for the solar thermal gear on the roof of the NSCC Waterfront Campus. The roof has 2 arrays of Thermodynamics flat plate collectors as well as 2 arrays of Thermomax evacuated tube collectors. We will be monitoring the glycol temperatures, outside air temperature, and solar radiation. The data logging will be done using the Web Energy Logger (WEL) over the Wel Server. I have installed the temperature sensors and programmed the logic for the calculations inside the WEL. We are interested in adding flow meters to this project if we can find ones within our price range and get permission from facilities management to install them.
The challenge with working on the roof is that there isn’t power or wired network access. The campus has a very weak wireless signal on the roof and I will be connecting the WEL to the internet that way by using a wireless bridging router. The router runs off 12V and the WEL can also run off of 12V. For now I will power the entire setup off of a large deep cycle battery and it will need to be changed and charged from time to time. NSCC Applied Research may add a photovoltaic panel to the roof to power the equipment and charge the battery at a later time.
This project is unique from the residential and commercial installs I have done in the past because it will be used primarily for research. An electronics student at the college was able to design us a voltage to milliamp converting circuit board that will allow us to connect a pyranometer with a voltage output to the 4-20 mA input on the WEL. By using a pyranometer and air temperature sensor I will be able to match the energy output to the solar radiation and determine the energy efficiency of the gear. I will also be able to do statistical analysis over time. The lab will be very interested in the variance of the different readings and how they relate to each other. By comparing sunny days in the winter to days with the same amount of solar radiation in the summer we will be able to determine the effect of outside air temperature on the output of the different types of collectors. This is of particular interest because our winters are cold but the sun is usually shining.
I will be posting more information as this project progresses.
The Thermomax evacuated tube collectors are the dark blue tubes on the left of the roof. The Thermodynamics flat plat collectors are the small grey rectangular panels with the black border.