DOE should focus resources on R&D to advance automated stove technologies

 The Department of Energy Bioenergy Technologies Office (BETO) released a Request for Information (RFI) seeking feedback on defining the goals and objectives for a planned effort to collect in-situ wood heater performance data in the field. The deadline to submit comments was September 30, 2024. John Ackerly, AGH President, submitted the following comment: 

There are a number of small portable
emission testing devices for wood stoves
that can be used in situ, or larger lab
equipment can be moved to a home.

"We believe BETO should minimize its role in funding in-situ testing efforts because in-situ testing is usually very complex and expensive, given BETO’s funding for residential wood heater technology development. There are many distinct objectives and reasons to do in-site testing, and stakeholders could eloquently make the case for any number of them. But given the size of BETO’s budget, we do not feel there is a compelling enough type of in-situ testing that is likely to be undertaken.

BETO’s mandate is to “support the development of cleaner burning, higher efficiency residential wood heaters” and it seems this has been interpreted more broadly over time, which is understandable to some point, given the dearth of high quality applications to develop next generation stove technology.

We would urge BETO to only fund in-site testing to the extent it directly focuses on modern, more automated stove technology. For example, it may be worthwhile doing some in-situ testing with an automated stove side by side with a traditional manually operated one, to provide data about how beneficial automation can be, if at all.

The list of questions in the Four Categories suggest that this RFI is wide-ranging without parameters related to development of cleaner burning, high efficiency residential heaters. In the United States, stoves must be tested for PM 2.5 to be certified for sale. Efficiency, as measured by B415, is not regulated, but tested and an existing IRS tax credit gives an incentive to hit 75% efficiency, HHV. Any new generation of more modern, cleaner and efficient wood stoves will need to focus on these metrics first.

To understand the potential of modern, automated stoves, it may be just as relevant to study pellet stoves, to understand how and why they have such a predictable emissions profile, compared to cordwood stoves. It is also relatively easy to test how clean and efficient pellet stoves are in-situ after 1 to 10 years in operation.

To achieve testing goals of how pellet stoves perform after 1 – 10 years of use, I would recommend simply using a Testo 380 and principally test for PM2.5, enabling more sampling of more devices.

There are a multitude of academic inquiries into residential wood smoke but BETO should first determine what avenues there are to more directly advance an R&D agenda, which could include emissions data showing how automation can reduce emissions. Cordwood furnaces have already made the transition from being manually operated to controlled by sensors, and the evidence is clear that sensors will keep a boiler or furnace far cleaner.

Some stakeholders who are heavily invested in manually operated stoves may want BETO to undertake in-situ testing studies, which can be endless. But one test of this RFI will be whether those stakeholders who are doing R&D on modern, more automated stoves need in situ testing data, and if so, what kind. Similarly, it may be instructive to see what kind of in-situ testing is recommended by stakeholders who regulate wood stoves, or are involved in health related studies.

BETO could consider doing an RFI on how to develop the next generation of wood stoves in the United States. R&D is perhaps the most important avenue but DOE funding in the solar, wind and geothermal sectors address scores of barriers to bringing a renewable technology to scale. Those barriers can also be addressed in the eco-system surrounding the wood heater community. Obviously, the wood heater sector will never have that level of resources, requiring a careful assessment of where scarce resources can best be used.

An RFI that engages this community on how to advance automated stove technology may help better understand why major manufacturers are hesitant or whether there are other initiatives that could be undertaken. In-situ testing may be one of them, but an RFI solely on in-site testing sends a confusing message to the wood heating community unless BETO better explains how it is part of a strategy to develop modern, more automated stove technology.