Portland State University ‘Lab Roof’

Up on the roof at Science Building 2 at PSU,  there are scientists, professors and researchers conducting all kinds of interesting experiments.  One of them, between a dead whale and a bear carcass,  is one of the most interesting ecoroof installations I have seen in months.   Back when we started Ecoroofs Everywhere, I made sure we were constantly testing different soils, different plants, different designs.  Nowadays, we can no longer turn every project into 4’x4′ test squares anymore now that we’re a legitimate company.  So,  it’s extra exciting for me to be working with researchers whose very reason for having an ecoroof is purely for experimentation.  This  group is measuring the performance of increased solar panel (PV) efficiencies when paired with an ecoroof.  Not only that, but they are testing different plant mixes to see how much different plantings cool the panels.  This will give much-needed quantititative data that exists no where else in Oregon.  Here’s more about the project from Research Assistant Seth Moody, who brought Ecoroofs Everywhere into the team after finding us at the Build It Green tour last month:

“A collaborative effort between Portland State University departments of Chemistry, Biology and Mechanical Engineering is studying the combination of typical and atypical green roof treatments and photovoltaic arrays in the urban roof-top environment of Portland, Oregon. Green roofs and roof-top photovoltaic arrays are two important strategies for enhancing the environmental sustainability of the built environment. Green roofs have increased in popularity because of their favorable impact on building energy utilization, local heat island effects and storm water control.

The manufacture and installation of solar photovoltaics is rapidly growing based on improving economics and their preeminent role in generating renewable, carbon-free energy. Despite the promise of these green technologies, there have been relatively few quantitative studies of the interactions between green roofs and roof-top mounted photovoltaic panels under actual field conditions. Prior studies indicate that green roofs thrive better with partial shading and that silicon solar cells operate at higher efficiency at cooler temperatures, suggesting that the combination of these two systems in the rooftop environment may have favorable reciprocal effects. In this study  we are focused on addressing the fundamental question: Can green roof design and/or management be altered to enhance both photovoltaic energy production and green roof function in a combined technology system?”

More from the ‘Lab Roof’ next week after Dan and I meet with another experimenter with yet another project up on the roof!