Dec. 8, 2022
Hon. Steven Cliff,
Executive Officer
Channel Fletcher,
Deputy Executive Officer, Environmental Justice
California Air Resources Board
1001 I St,
Sacramento, CA 95814
Dear Mr. Cliff and Ms. Fletcher,
Thank you for the opportunity to provide comments on your draft Program Guidelines to reduce wood smoke. Funds to replace older stoves with cleaner sources heat are funds well-spent, especially since many old stoves provide primary heat to homes of marginalized, lower-income households.
1. Focus on households in densely populated areas
Our biggest recommendation is to focus your resources on households in areas that are more densely populated and/or experience frequent weather inversions, where the public health ramifications of older wood stoves are the highest. Stoves in very rural homes with few or no neighbors will have very few public health impacts. This is an area that more change-out programs should explore. Hopefully, homes in these sensitive areas would opt for heat pumps or pellet stoves. For homes in densely populated areas, we would also encourage you to see if the home has a woodshed or a way to store their fuel.
2. Replacement devices
We fully support CARB’s decision to replace older wood stoves with low-carbon alternatives such as heat pumps and pellet stoves. We would be wary to include electric resistance stove heaters because this may burden lower income homes with higher electric bills than they can afford, assuming electric rates rise in the future. We are glad that CARB does not include gas stoves as that would have a counterproductive carbon impact and hinder electrification goals.
We do not have a high level of confidence in catalytic stoves as they often are not maintained or used properly as the years go by, especially in lower income homes who may not be able to pay to replace the catalyst when needed. Hybrid stoves are a far better option, and we would urge CARB to focus on hybrid stoves because they still provide valuable PM reduction technology even if the cat is not engaged. It is important to understand how stoves are likely to work in the real world, once they leave the lab, and cat stoves are a class of stoves that can work even worse than non-cats if they are not maintained or used properly, particularly after the home or stove is sold and the device is being operated by a new owner. Some owners of older cat stove do not even know they have a cat stove.
We are extremely concerned that CARB is only making four models of non-cats eligible for change-outs. The four non-cats selected by CARB may operate better than some with greater testing flaws, but there is no proof that many non-cat stoves are just as good as the four you identify. The process undertaken by the Alaska and NESCAUM was valuable in many ways, but it does not easily lend itself to being used to qualify stoves for change-out programs. If CARB wants to identify non-cat stoves that would burn more cleanly, allowing more single burn rate stoves to qualify may be the best way. However, most households do not want single-burn rate stoves, particularly if the stove is their primary heat source.
A major dilemma for your program is that you are trying to serve many marginalized, lower income households and balance their legitimate energy needs with the impact their smoke will have on neighbors. By choosing only 4 non-cats, you are sidelining the heating needs of these households in favor of a very questionable process to identify only 4 models, some of which are not likely to be available near these homes.
We support the effort undertaken by Alaska and NESCAUM but decisions like this, to select four stoves, takes their data beyond its usefulness. We think there is disconnect between limiting to 4 non-cats and serving low-income households. Though we understand the desire to put Alaska’s work to use, it will likely be ineffectual in reducing PM in this change-out program.
3. Inspection, repair and safety
One of the best ways to start to identify, repair and/or remove old stoves is to ensure that local energy audits and weatherization programs have integrated wood stoves into their work. Most energy auditors still do not have the training or the software to do undertake stove inspections, even though DOE and state regulations claim to require that all heaters are inspected. If they did, they would find many self-installed stoves that are dangerous, higher polluting and in need of replacement or removal. LIHEAP funding and low-income weatherization programs will cover these costs where the stove is the primary heat source. If the stove is a secondary heater, these programs could cover repairs. Few states have demanded that the US Department of Energy develop standards for inspecting wood stoves, like there are for boilers and furnaces, and the DOE is still hesitant to take this on, even though it would have a major impact for lower-income households across the country. We urge CARB to review how wood stoves are inspected during energy audits and weatherization programs in California and see whether they are being repaired, replaced or removed.
4. GHG reductions
We are pleased that CARB is no longer using carbon to justify switching from a wood stove to a gas stove. In its 2016-2017 Woodsmoke Reduction Program Guidelines, CARB stated, ”Switching from an uncertified wood stove to a natural gas or electric heating device reduces GHG emissions.” We find this statement to be without scientific basis. We understand that the GHG calculations are not central to how CARB runs this change-out program, but we want to open a conversation about it.
In the current Program Guidelines, CARB seems to assert that 100% of carbon released from wood and pellets should be attributed to this form of heating. The Guidelines say that “biogenic CO2 is included in the calculation of GHG benefits for these devices.” We agree that some biogenic carbon should be included, as some carbon can be attributed to all energy sources.
To make scientific estimates of carbon released from firewood that would not have been released anyway, there is a lot of data that can be considered. For CARB to start to gain a basic understanding of the carbon cycles from firewood, you could also ask on your change-out application, “where do you get your wood?”. A researcher can also get data from a sampling of California firewood dealers and households who use firewood.
By not engaging in basic research, CARB is putting the burden on low-income households who heat with wood and is inferring their carbon impact of their heating is far higher than it is. This flies in the face of current thinking about energy justice that seeks to remediate social, economic, and health burdens on those disproportionately harmed by the energy system.
Estimating carbon from gas, oil and electricity involves a complex set of assumptions and calculations and there is no reason that similar effort could be made to assess the carbon cycle from firewood.
In California, as in the rest of the country, it is likely that a substantial number of homes who heat with wood acquire their firewood in a very responsible way by using dead and downed wood, as lower-income households do around the rest of the country. A lot of firewood used for home heating could otherwise end up in the landfill where it would produce worse GHG emissions.
The Minnesota Residential Wood Combustion Survey Results, (May 2019) done by the Minnesota Department of Natural Resources is one of the most definitive studies on firewood procurement and use. The report says, “Most of the wood cut (84%) by residential households comes from dead or downed trees, land clearing, and logging residues (Table 15). Approximately 9.3% comes from live standing trees in the forest.” This is a crucial statistic for understanding carbon impacts of firewood. If 84% of wood cut by households comes from dead of downed trees, it means that carbon was already in the process of being released unlike when a live tree is cut.
Household income generally correlates to how firewood is procured and how much firewood is used. The lower the income of a household, the more wood they use and the more likely they gather their own wood, assuming wood is being used for heating, and not for recreation. More urban and higher income families are more likely to purchase wood. The chart below is based on EIA data.
The Minnesota Residential Wood Combustion Survey Results, found that 60% of firewood is cut by households and 40% is purchased.
Table 15, below, provides further detail of where firewood comes from in Minnesota, and these trends are likely to exist in other states.
Table 17 shows a breakdown of firewood from both household and loggers. Even where firewood is provided by commercial loggers, most of it is still from trees that are dead, down or from the residues of a commercial harvest, which usually is for sawlogs (lumber).
In conclusion, we believe that whether firewood comes from a “locally or nationally approved” forestry plan is not as relevant as existing data about where firewood comes, how sustainable it is and how to understand carbon implications. From a carbon perspective, we believe a rigorous look at the carbon footprint across the value chain of gas production and usage will always be higher than the footprint of firewood, across its value chain. The Achilles heel of firewood is the excessive PM that comes from most wood stoves, and it is that PM which fully justifies change out programs like this one.
As we initially stated, we fully support this program and see it is improving over the years, and we hope that our comments help improve it in future years. Thank you for undertaking the program and accepting comments from the public.
Sincerely,
John Ackerly
President
Further reading: State Parks give downed trees to public for firewood (March 2023)
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