California wildfires have been in the news over the past few weeks, as have the resulting preemptive blackouts that Pacific Gas & Electric has been implementing. PG&E is clearly in a bind. They are liable for any fires that are started as a result of their power lines—even if extreme flammability of vegetation from heat, drought, and wind is a major factor—so it is not surprising that they shut down their grid pre-emptively.

But then PG&E is blamed for the inconvenience and even grave risk do to those power outages, including residents without power being unable to receive emergency evacuation orders.

So what’s the answer?

Clearly, PG&E needs to maintain its power lines more effectively. Climate change means that a lot of conditions will no longer be the same, and a different level of power line maintenance is clearly called for in this day and age. That will cost money, and the California Public Utilities Commission will probably have to approve rate increases to pay for it. Utility customers can expect their electricity costs to go up.

But there are better, longer-term solutions that have to do with resilient design.

Passive survivability

With the new reality of intentional power outages, we should be designing and building our houses to keep occupants safe during extended power outages or loss or heating fuel. This is an argument I’ve often made, but the motivation in California these days is particularly strong.

Fortunately, the season of wildfire-related power outages does not occur during times of peak heating or cooling—and California’s wildfire-prone region is relatively mild anyway—so keeping people safe in their homes without power is not a big concern. But it is a consideration we should be aware of.

Backup power

More significant in California’s wildfire country is access to power for keeping cell phones charged, water pumping (in areas without municipal water), lighting, WiFi connectivity, and other needs. The risk that residents’ cell phones lose power and become inoperable is a particular concern with more communities relying on cell phones for evacuation alerts and other emergency communications.

Like it our not, we have become dependent on cell phones and, if they lose power we can’t use them. (By contrast, standard phone lines (land lines) use DC power that is carried in the telephone cables—though hand-held land-line phones usually require AC power to operate.)

Fuel-fired backup power, relying on natural gas, propane, diesel, or gasoline, carries its own risks, though. During natural disasters, natural gas pipelines may be turned off to prevent fires. Stored gasoline and diesel degrades over time in storage, and during extended outages may run out. Portable generators used in garages may cause carbon monoxide poisoning, especially if grid power comes on and closes garage doors.

Solar with battery storage the most resilient option

All of this points to an elegant and increasingly cost-effective solution: a solar array with battery storage. Most residential solar systems going in today are grid-connected without an ability to function when the grid is down. For safety reasons, utility companies don’t want solar systems to be able to feed power into the grid when utility workers may be working on the lines—so there are safeguards to prevent that.

In most cases, this means that when the grid goes down, the homeowner can’t draw power from the solar system—even during the day in bright sunlight. An exception to this rule is the inverter that I have in my barn that allows a hard disconnect during a power outage while supplying power to a connected AC outlet. This only works during the daytime, when the sun is shining, but it is a lot less expensive than a battery system.

The most resilient backup power system is a solar system and battery storage that has islanding capability—that is, an ability to be disconnected from the grid and supply power to the house.

Fortunately, such functionality is becoming more common. Battery backup systems like the Tesla Powerwall can be configured to draw power from a solar array without risk that power will be back-fed into the grid. The intentional power outages in California are sure to result in a surge of interest in such systems.

Given a likely surge in demand, costs of battery storage systems are likely to go up in the short term, but the long-term trend is downward for battery storage, and that is likely to continue.

Final thoughts

The wildfires that are occurring right now in California, and the intentional power outages that at least one utility company are implementing, may have a silver lining. They may open the door to far greater installation of solar energy systems with battery storage. This, in turn, will further reduce our contributions to climate change. Plus, it will spur even more rapid growth of the solar industry and continued cost reductions. That bodes well for the future.

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Still time to register for the Building Resilience 2019 Conference!

There is still time to sign up for the Building Resilience 2019 Conference in Cleveland on November 7-8. There will be excellent sessions on passive survivability, backup power, and wildfire resilience—along with lots of other topics related to resilience. This first-of-its-kind conference will be a great opportunity to learn from the experts about the full range of vulnerabilities our buildings face and what to do about those vulnerabilities. I hope to see you there!

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Along with founding the Resilient Design Institute in 2012, Alex is founder of BuildingGreen, Inc. To keep up with his latest articles and musings, you can sign up for his Twitter feed. To receive e-mail notices of new blogs, sign up at the top of the page.