By Ron Williams and Bill Mitchell
Watts up, everyone? Welcome back to the Village Green Project and learn about science as it happens at EPA! For those just joining us, EPA researchers in North Carolina are designing and building a low-cost air quality monitoring system from the ground up that can be provide local air quality data to a community.
One of our project goals is to design an air quality monitoring system that is fully self-powered and can operate for a long period of time using very little energy.
Our solution: solar power. We have identified a design that will include sustainable energy (solar power) and features that will allow the monitoring system to operate for long periods of time during the night and when it is cloudy.
One of the first things we had to do was determine how much power is needed to run a large number of environmental monitors and to transmit data from the system to our web site where we hope to make data available. Our first design shows that we will need 15 Watts to fully power all of the electrical parts (sensors, fans, control circuits, communication link).
We identified two highly efficient solar panels that we can use that are 26 inches by 41 inches in size. They are small enough for the monitor and can generate up to 60 Watts of power. The extra power that is generated can be stored in a battery for the solar cells to use when conditions are not favorable, like cloudy days. The rechargeable 12-volt battery is about the size of a car battery. This was good news as we wanted to avoid having a field of solar panels that would drive up the operating cost.
We think we worked it out on paper—now the challenge will be to see what happens when we piece it all together. Stay tuned for more updates on our discovery process.
About the Authors: Ron Williams is an exposure science researcher who is studying how people are exposed to air pollutants and methods to measure personal exposure. Bill Mitchell is an electronics expert who provides support to a variety of air pollution research projects.