When I click on your link to the plot from further up the satellite layer suggests more like 40% of the plot does not have trees due to the ROW. In addition, if you compare the Google satellite image to the developer's current proposal, it looks like the solar panels are will be installed where there currently are trees.

According to the developer's documents, their proposal puts the solar panels and inverters only on the side closest to houses, not the highway. That also brings potential runoff problems from construction much closer to Cambridge's water supply.