Close to Home: All-electric’s time will come, but it isn’t here yet

Berkeley just banned natural gas hookups for many new buildings. A host of communities are looking to follow; in the North Bay, this includes Santa Rosa and Petaluma. Hats off to Berkeley for its shout against methane's greenhouse effect. But it is worth taking a sober look at consequences before hastily enacting more such bans.

First, electric-only buildings may initially worsen, not improve, environmental impact. Natural gas loads - heating, hot water and cooking - peak in the late evening and early morning, and in the winter. Solar power offers little then. Wind is unpredictable. Absent massive electric grid storage, where will the electricity come from?

A single community in theory can only use green electricity, but that doesn't scale. At the top, it's a supply- demand equation. Imbalances will often be sourced from local fossil-fuel plants or imports. “Imports” can be a euphemism for dirty, high-carbon coal from loosely regulated desert states. The fallback sources, after transmission losses, average 30% to 50% efficiency, with a corresponding greenhouse penalty (calculating total cost-benefit can be messy - try comparing mercury from coal with methane's greenhouse effect). Demand for electric vehicle charging will worsen things. Grid storage will develop eventually, but it will take time - and probably massive investment in pumped hydro storage. Battery banks currently provide less than 0.1%.

Second, electric-only buildings have too many eggs in one basket. Fifty years ago, my grandparents in Portland, Oregon, were housebound after a freak blizzard. The electricity was out, but the gas stayed on. They avoided freezing by running the gas oven (on a smart gas appliance, the range top would run without electricity, but not the oven). In today's world of fire-safety power outages, who would want an electric-only building? With gas, you still have hot water, cooking and last-resort heating. With all-electric, you lose everything. Gas hazards in an earthquake, of course, complicate the picture.

Third, physical transport of chemical energy is classically the easiest way to deliver bulk heat. This, for example, is why there are still far more explosive warheads on a battlefield than beam weapons. Electricity is better if you want to make photons or calculations (or, increasingly, drive a car). I have dedicated much of my career to advancing electricity, but I know its limitations. Consider the millions of tons of aluminum and copper in the transmission lines and house wires. How much will that need to increase to carry the heating load of a frosty winter night?

Last, debatably not least, the cooking. Ahhh, the cooking. The dark secret of Wine Country is that for more than a few Bay Area residents, wine may be the third most important reason for visiting. That is, after escaping the fog - and the food! There is no gourmet cook who does not prize a gas range. Let's think about our cuisine and our liberties before too quickly stamping something out.

So, what should we do? Wait a little, and advance grid storage. The natural gas bans aren't without merit. Buildings, once completed, will indeed be around for a long time. But gas service can be turned off. We need first to develop the storage technologies, including novelties such as redox flow batteries, possibly subsidize some deployment - and then use natural gas banning as a hammer to drive their ramp up. Regarding the other challenges, there will be a need for fine judgment and perhaps new technology. The time for all this will come. But it is not yet.

Doug Widney is an electronic design and energy consultant. He lives in Corte Madera.

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