Mueller Homes - Trees Competing For the Sun

Shade is the Enemy of the Solar Power Producer

Around 40 Mueller Austin residents are in the process of getting PV solar panels installed on their roofs.  But how do trees affect the picture?

This Statesman article chronicles the progress of the Mueller Mega-Watt project - and talks of the substantial Austin Energy rebates. One comment on the article brings up a potential future challenge - trees and shade.

The first Mueller homes were completed at the very end of 2006, so trees have not yet had chance to grow to 40 feet tall, though my Monterey Oak is growing fiercely towards that goal, and I’ve already had to rein it back.

Most home-owners in more established neighborhoods consider large shade trees a boon - a shade tree over an older roof can cut HVAC bills by up to 40% in summer. The PV panels that Mueller residents are choosing perform dual  functions:

• shading the sunniest part of the roof to reduce heat load on the home
• generating electricity to offset HVAC bills

So as the trees grow up in front of the South and West facing roof surfaces, they bring the enemy of PV panels - shade. And just a little shade can make a huge difference.

Above is an excerpt from Celestial Power’s solar proposal for the array currently on our roof. It shows that a tiny bit of shade can halve the output of the panels.

So the challenge is to keep your tree growth from interfering with the sunlight. Maybe we should get solar trees like these in Vienna!

Garreth Wilcock is an Austin EcoBroker® with Keller Williams Realty.

Specializing in: Green Austin Real Estate and New Green Homes in Austin.

(512) 694 8873