Martha Walden
In response to a column that I wrote several months ago (Must We Electrify Our Homes?) a reader asked if our electrical supply is clean enough to warrant switching our appliances over to electricity. “When will we honestly be able to say that electricity is the substantially cleaner way to go?” Good question! Due to the complexity of the grid, the answer isn’t at all obvious.
We can assume that most of the electricity consumed in Humboldt originates from the natural gas plant on Humboldt Bay because it is the largest local source of electrons. We use whatever electrons are closest. In distant second, third, and fourth places are biomass, solar, and hydropower from Ruth Reservoir.
Our transmission lines carry varying quantities of energy from outside of the county as well, including hydroelectric, solar, nuclear, wind, geothermal, and “unspecified” electricity, meaning that no one knows its source. The ratio between local generation and imported electricity shifts constantly as prices fluctuate according to wholesale energy markets. California Independent System Operator (CAISO) is the traffic operator that directs the energy flows to make sure supply matches demand.
Lacking specific numbers, how can we assess the carbon intensity of our electricity usage? The most prevalent way is to count what load-serving entities purchase. For example, Redwood Coast Energy Authority (RCEA) procures eligible hydroelectricity, solar and wind in equal quantities for its premium plan even though most of this power is generated far away and never physically arrives here. The assumption is that consumers in the vicinity of those generators are using less fossil fuels because they’re using the good stuff instead. Therefore, RCEA’s Re-Power+ customers are entitled to say that the greenhouse gas intensity of their electricity is zero.
In other words, we look at the grid as a whole and assume that the generation of carbon neutral electricity anywhere within the state displaces fossil fuels, and the purchaser gets the credit. Now we know how carbon intensity is calculated, but does that really help us decide when to electrify?
The future of our power usage will be overwhelmingly electric if we are phasing out fossil fuels as we absolutely must. It seems to me that we have to start heading in that direction now because the conversion is a gradual process for householders. It usually occurs appliance by appliance. It would be impractical to wait until the entire grid has become carbon-neutral—which is supposed to be in 2045—and then everybody runs out and buys electrical appliances. Considering that natural gas won’t be available in twenty-one years if California sticks to its plan it would be unwise to buy new natural gas appliances. Weatherizing your house before switching to electric heat could help reduce emissions and your electricity bill.
One more thing: wood heat emits more CO2 than any other fuel. It gets a special pass because trees are renewable, but the greenhouse gas overload in the atmosphere is outstripping the carbon sinks provided by forests and other natural systems. That’s what we call a climate crisis. However, the same thing applies to biomass electricity, which RCEA includes in its regular power mix. A wood stove probably emits more carbon than a heat pump running on a typical power mix that includes 20 percent biomass, but I’m not sure. Burning wood also produces a lot of air pollution.