Columnists: Alan Meier, LBNL

Published on: 21 Dec 2018

Climate Change, Garage Door Openers, and Home Energy

California just approved legislation requiring all new garage door openers to have battery back-ups so that doors would open even when electricity service is interrupted. The legislation – Senate Bill 969 – sailed through with almost no opposition. Curiously, the only group to oppose the law was the industry responsible for manufacturing and installing garage doors, the people most likely to benefit from it. What’s going on here and what does this have to with climate change and home energy? More than you might imagine.

The origin of the requirement for battery back-up of garage doors is easy to explain. The tragic 2017 fires in Northern California trapped residents in their garages after power failures prevented them from opening the doors and driving away from the fast-moving flames. Several people died because they were unable to manually open the doors. (If you think it’s easy to open a garage door, ask an 80-year old relative.) Hence the new law. The 2018 fires were even worse and some California utilities warn that they will shut off power in certain areas as a precautionary measure to prevent their lines from sparking during high wind events.

The climate change connection is almost as easy to explain. The entire western United States (and Canada and Mexico) is becoming drier. The fire season, which traditionally ended in October, now extends into December. Climate change has also changed the character of the fires: a fire storm now better describes their size, speed, and ferocity. Whole communities can be reduced to ashes in minutes (as the 2018 fires demonstrated).

What is the home energy connection? Those batteries need constant re-charging, which adds another continuous load in each new home, perhaps as much as 5 watts (50 kWh per year). That’s only a 0.5% increase in an average California home’s electricity use but it’s moving us in the opposite direction of our net zero goals. Still, it may be justified for the safety benefits it affords the occupants of a new home.

It’s the batteries that deserve scrutiny. These batteries —typically 12 volt lead acid—need replacement every two years. At about €30 each, they cost more than the increased electricity, introduce a maintenance headache, and create a new waste stream. Meanwhile, the garage door industry opposed the law because their products are designed to provide a convenience but not a more robustly-engineered emergency service. Manufacturers fear that they will be held liable when a battery fails to deliver during an emergency. Surely there is a better way to provide a safety service without all these attendant problems.

The better way might be a small Direct Current network operating in the home to service the garage door opener along with other devices. More and more appliances need back-up power in case of power outages. The most important ones involve communications: a modem, a router, and chargers for cellular phones, but sump pumps and medical devices, such as home oxygen generators, often need back-up power in North America. Service providers of Voice Over IP (VOIP) phone connections are already required to make available a battery that can sustain telephone operation for several hours. Everybody keeps flashlights around in case of an outage, but a few emergency lights strategically placed around the home would be even better. Laptops operate very nicely on DC, too. A single, larger battery offers many economies, as well as ease of management. A DC network could include a small, dedicated photovoltaic collector, which would allow these devices to operate mostly grid free. Poorer households and apartment dwellers might find this approach to be a sensible first step into renewables.

It’s easy to think of climate change as something monolithic and all-encompassing whose impacts are difficult to grasp. In fact, the impacts of climate change will first appear in the form of extreme weather events with very specific consequences. The humble garage door opener is an unlikely early flashpoint of climate change’s extremes, but it won’t be the last. With some creativity, though, we can find solutions that make us more resilient while saving energy.  

 

 

 


Other columns by Alan Meier