Volkswagen Scandal and Wood Heat Technology

The Volkswagen scandal should be a wake-up call to everyone who makes appliances that have to be tested for emissions and efficiency. The new reality is that independent, real-world testing is getting cheaper and more common. Passing a government-mandated test is one thing.  Standing up to scrutiny by others who test is another. 

Pellet stove sales rose 41 percent last year in the U.S. and are likely to outsell wood stoves in coming years. In much of Europe, they already are. If we are going to promote this technology as a more widespread alternative to fossil fuels, we need to be confident that their emissions and efficiency values can hold up once they leave the lab. I think about this a lot because my organization just began independently testing pellet stoves in simulated real-world conditions. We wanted to find out if pellet stoves performed similarly in the real world as they do in the lab. 

Our testing showed that after over a month of intensive use, most of the stoves produced very similar exhaust gases as they did in the lab. This result is radically different than what happens with wood stoves, as manufacturers can coax impressive numbers out of a stoves in labs behind closed doors, numbers that consumers can rarely get in their homes. However, to be fair, wood stove testing is not supposed to approximate emissions in the real world. The artificial lab testing conditions have long been approved by the EPA as a way to test stoves fairly against one another. 

Pellet stoves and their larger cousins, pellet boilers, offer society a cleaner, more controlled combustion that extends beyond the lab into homes, businesses and institutions. Like cars, they are increasingly run by software that can be periodically updated or updated instantly online. Moreover, companies are not allowed to introduce changes in pellet stoves without first retesting them in an approved lab and recertifying, to avoid improving some aspect of performance at the cost of emissions. 

The temptation by companies to tout their green credentials often gets ahead of how green they actually are. In the case of VW, that temptation led to poor decisions by senior management who may now face criminal charges in addition to billions in fines and public shame. Stove manufacturers need to beware of a credibility gap between company claims and how stoves often perform in the hands of consumers. 

Outdoor wood boilers are the main type of wood heater that failed this credibility gap and have thwarted government oversight for many years, in part because regulation was in the hands of an underfunded EPA office that couldn’t afford much independent testing. The EPA took five years to do what should have been done in one or two, allowing tens of thousands of large polluting boilers to be installed in communities year after year. 

Change is brewing in the wood stove world that will reduce the huge differences between emissions recorded in the test lab and emissions measured in the real world.  A few innovative stove manufacturers are voluntarily starting to test and certify their stoves with cordwood, instead of the two-by-fours the EPA protocol required during the past quarter century. The EPA may now be more willing to recognize those companies and steer consumers toward them.  But for this to succeed in the short term, the EPA and state agencies will need to speak out more loudly about new stoves that certify with cordwood.  If the EPA and states promote these stoves, it will help build consumer demand and put pressure on more companies to certify with cordwood.

Closing this credibility gap requires more than just designing and certifying with cordwood.  Now coming to market are stoves that use sensors and microprocessors to deliver the exact amount of air needed to the firebox at each stage of combustion. Quadrafire, a company in Washington, just introduced an automated line of stoves.  A team of University of Maryland engineering students who won awards at the Wood Stove Design Challenge also says it’s bringing a highly advanced stove to market in 2016.

Low-cost mobile testing devices that exposed VW will also be able to keep tabs on various types of wood heat technologies, helping to ensure that all companies play by the same rules.  In addition, low-cost sensors will also help engineers make wood and pellet heating cleaner and cleaner. As biomass heating gets cleaner and testing shows a greater consistency between lab and real-world conditions, the technology will gain legitimacy with policymakers so that clean, renewable energy doesn’t just have to mean solar and wind.


Author: John Ackerly
President, Alliance for Green Heat
[email protected]
301-204-9562