Myren Consulting and AGH apply for Department of Energy R&D Grant

Down drafting stove would be open-source

Myren Consulting and the Alliance for Great Heat, along with Stonybrook University and German experts from DBFZ (Deutsches Biomasseforschungszentrum) are seeking to build an open-source wood stove that can help any manufacturer adopt the innovative approaches used by this stove. The goal is to make an ultra-clean wood stove that will consistently burn around 1 gram an hour without a catalyst and 0.5 grams with a catalyst, regardless of who loads and starts the stove.

The stove will use a downdraft airflow that brings the flames through the coal bed, and it will have a fan that induces the draft until the flue gases are hot enough to shut it off. The team will employ Computational Fluid Dynamics (CFD) to optimize the design and the air flow. The stove will also have a robust, multi-purpose data logger that can engage the operator via lights on the stove or through a sophisticated smart phone app. The app will feature content from our partner groups and walk consumers through all stages of the purchase, installation, operation, troubleshooting and maintenance. The consumer can choose if they will be the only one with access to the data, or whether they are willing to share it with the manufacturer, the retailer and/or a chimney sweep, for example.

Throughout the entire project, if funded, the team will share R&D decisions, designs, and data with the stove industry, regulators, and the public. The team will also seek to “crowd-source” solutions to problems and issues that may emerge by regularly seeking input from a range of stakeholders, from industry players to public health and low-income advocates. The stove will undergo a series of rigorous tests in Ben Myren’s lab over a 3-year period because a novel, top-notch stove needs that amount of time to get the design, airflow and other features just right. The stove will be tested to the traditional EPA reference Method 28, and the more recently approved ASTM 303-5 and IDC protocols. The stove will also undergo in situ real world testing, round-robin lab testing and be tested to the rigorous Blue Angel standard in Germany (not with DOE funds) to understand how it can handle a variety of loading and testing methods. 

Current certified stove design configurations have been developed since the mid 1980’s and are all based upon the draft generated by an EPA freely communicated lab chimney that is 15 ±1 ft. These designs have been developed somewhat over the years using a vast number of prototypes that have had many design changes made to them during this multi-year, multi-prototype R&D process. However, R&D in the stove community has not been robust and most manufacturers simply follow a well-known design pattern that has proved to be successful enough. We are attempting to disrupt that design pattern by maximizing secondary combustion in the upper part of the firebox but then drawing the gases down through the coal bed for an even more efficient secondary (or tertiary) emission reduction process.

With the change in draft proposed in this proposal, that entire body of knowledge becomes questionable.  And the project’s timeframe doesn’t provide for the typical long, slow development of a stove that will meet the current emissions standards. Thus, we propose to build upon a technique that we have been successfully using where some stove components are bolted together, rather than being welded together. This technique will allow us to rapidly make design changes which will hasten the entire R&D process. It will also enable us to fine-tune the combustion system in the stove by changing known critical components, e.g., the internal cross-sectional area of secondary air side manifolds, to facilitate the reduction of particulate matter (PM) emissions. The following table contains a (partial) list of critical components known to affect emissions.  Almost all of these features will still be relevant for a downdraft stove, but their size, shape and placement may change based on the downdraft design and the results of computational fluid dynamics (CFD) analysis.

  

• LPAO: Lower primary air orifice
• Horizontal throat gap: shortest distance between the front edge of the baffle and the backside of the air wash
• Vertical throat gap: shortest distance between the top of the baffle and the bottom of the top

All equipment used in the revised dilution tunnel system will be maintained and calibrated using current EPA criteria. Our stove will first assess how consistently we can operate under 1 gram an hour without a catalyst, but we plan on designing a model with a catalyst as well. Wood stoves are often not sufficiently optimized in terms of low-emission combustion, so that the catalyst is subjected to excessive overloading.

The initial group of expert advisors who wrote letters of commitment include the Tribal Healthy Home Network, the German Biomass Research Centre, the Danish Technological Institute, the Hearth, Patio & Barbecue Association (HPBA), the National Fireplace Institute, Industrial Chimney Company-Renewable Solid Fuel (ICC-RSF), Masonry Heater Association, Sunstein Intellectual Property Law Firm, and 509 Fabrications.

The $2 million price tag would include $1.3 million expenses at Myren lab, $300,000 at AGH, $215,00 at Stony Brook University, $125,000 by the German team working at Myren labs (no DOE funds will be spent abroad) and about $70,000 for other vendors and subcontractors.  We are requesting $1.6 from the DOE’s Bioenergy Technology Office.

In the spirit of this open source project and collaboration with other teams, the following materials can be downloaded:

The full technical volume 

Letters of commitment

Summary slide

Resumes

Diversity, Equity and Inclusion Plan

Hearing on Maryland Wood Heat Legislation

The Economic Matters Committee of the Maryland House of Delegates heard testimony on HB 829, the Renewable Energy Act for All, on March 16. HB 829 has the support of the Maryland Energy Administration, who would implement it and scores of organizations and businesses.

HB 829 has secured broad support because it combines and balances a number of important goals in Maryland, including promoting renewable energy, helping low and middle-income residents to affordably heat their homes, changing-out older wood stoves, etc.

HB 829 would provide a grant of up to $1,500 for pellet stoves and for wood stoves for families that live in rural areas and heat with one of the expensive heating fuels: electricity, propane or oil. Families with household incomes over $75,000 would be eligible for a 30% rebate and under $75,000 would be eligible for 40%. HB 829 would

· Only incentivizes new wood stove installations in rural areas

· Provide greater benefits for lower income families

· Target families who use the most expensive heating fuels (oil, propane and electricity) to provide them a more affordable option

· Requires professional installation (thus creating more jobs and ensuring safety)

· Encouraging the removal old, non-EPA certified stoves

· Set lower emission standards than most other incentive or change-out programs

HB 829 has a wide range of industry, environmental, forestry and renewable energy support including: American Wood Fibers (Columbia), Baltimore Biomass, Chesapeake Climate Action Network, Courtland Hardware, Maryland Clean Energy Center, Maryland Energy Administration, Maryland Forests Association, Metropolitan Council of Governments, SOS Corn Heating Cooperative (Takoma Park), Survival Products (Salisbury) and scores of others.

Contemporary Wood Heat Trends in Maryland

Many low-income families rely on wood heat because they can harvest it at very low cost and avoid the fossil fuel bills that cause the ‘heat or eat’ dilemma in many poor communities. Wood heat provides a means by which rural, low-income households can afford to heat their homes in the winter and can also stay off of public heating assistance programs such as LIHEAP.

In Maryland, as in the rest of the US, rural families using wood avoid using more fossil fuel than all the Maryland families using wind, solar and geothermal combined.

Based on US census and national trends, there are probably about a 242,000 Marylanders who use wood or pellets for heat. Another 594,000 Maryland homes have fireplaces. Of the 242,000 homes with stoves, 90% of that population uses wood as a secondary heat source and only about 10%, or 23,000, use it as a primary or sole heat source. Based on national trends, Marylanders burn about 400,000 – 500,000 cords of wood per year[1] 75% of this is burned for heat in stoves and 25% in fireplaces or campgrounds.

Typically, only 1/3 of firewood is purchased and the rest is self-harvested. Based on this national trend, Maryland businesses likely sell around $19 million by the cord, and $32 million is smaller packaged bundles.[2]

1. Counties with per-capita income below the Federal Poverty Line have almost 3 times more wood heat users than counties above the Federal Poverty Line.

To measure the disparity in wood use between high and low-income communities, we examined a total of 196 counties in six states; Oregon, Maine, New Hampshire, Montana, West Virginia and Maryland. The states selected were chosen for their geographical spread, high percentage of forest land and high levels of residential wood heat use; five of the chosen states are in the top ten highest wood use states.

We analyzed the per capita income for each county to determine if families below the Federal Poverty Line (FPL) of $22,050 (for a family of four, 2009-2010) were more likely to use wood heat than families above the FPL. When the two groups were compared, we found that counties with a per capita income below $22,050 were 2.8 times more likely to have wood heat users than other counties (P=.001). Counties with a per capita income below the FPL had an average of 10.7% wood heat use as a primary or sole heat source compared to 3.8% in higher income counties.

Since counties with per-capita income falling below the Federal Poverty Line are almost three times as likely to heat with wood, we can conclude that the financial benefits of wood heat are a significant benefit to low-income areas. This analysis underscores the function of wood heat as a vital resource for lower income communities to heat their houses affordably

2. Maryland counties show a 42% correlation between higher wood use and a higher percentage of families below the poverty line.

We examined Maryland to determine the correlation between the percentage of families in a county living below the Federal Poverty Line and the percentage of wood use. Maryland is geographically well suited to take advantage of forest resources, and the counties have a wide range of incomes. Maryland counties have percentages of families living below the FPL ranging from 2.6%-13.3%. Analysis reveals a positive correlation between rising percentages of wood heat users and percentage of families in that county below the poverty line (Fig. 1).

Figure 1: % of Families below the Federal Poverty Line vs. % of wood use in 23 Maryland Counties

The predictable converse of this is visible in Figure 2. Counties with higher per-capita incomes are correlated with less wood heat use.

Figure 2: Per capita income vs. % of wood use in 23 Maryland Counties

Maryland’s counties reinforce the existence of a connection between families living below the Federal Poverty Line and wood heat use. This data suggests that low-income families consistently turn to wood heat as a heating source.

3. Preliminary analysis suggests wood heat users are less likely to turn to LIHEAP funds\

Federal LIHEAP statistics indicate that while over 3% of low-income households are likely to use wood heat nationally, only 1.2% of LIHEAP recipients receive funding for wood heat. This could suggest a number of things including: qualified wood heat users don’t apply for LIHEAP assistance or despite being qualified for LIHEAP funds, wood heat users can afford to remain off public assistance. The Alliance for Green Heat is currently examining the LIHEAP programs in Maryland and West Virginia to further explore this question.

Wood heat not only benefits the community by keeping heating dollars in the local economy, and benefits the state by potentially allowing LIHEAP eligible families to remain off heating assistance. It also may help the borderline LIHEAP eligible demographic save money and avoid becoming qualified for LIHEAP.

4. Emissions from wood stoves can be significantly reduced with incentive programs

The major drawback of wood heat is emissions. In most areas of the US, 65 – 80% of stoves used were made prior to 1988 when the EPA started regulating stoves for emissions. Those older stoves typically emit 30 – 40 grams of particulates per hour, and justifiably cause concern. Since 1990, the EPA has limited wood stoves to a maximum of 7.5 grams an hour. While technology and state regulation has advanced, EPA’s emission limits have stayed the same, rendering them somewhat irrelevant. Today, about a quarter of wood stoves produced are under 3 grams an hour. Pellet stoves have never been regulated by the EPA but states have provided some necessary regulation, and about a quarter or a third of pellet stoves today are under 1.5 grams per hour. Moreover, emissions from pellet stoves are consistent over time, unlike wood stoves that can vary depending on the moisture content of the wood and other factors.

An incentive program is likely to steer most consumers to the eligible stoves, resulting in much cleaner stoves being sold and installed. Moreover, if combined with an additional rebate to turn in older, non-EPA compliant stoves, it gets those stoves out of circulation instead of onto the second hard market. Under the proposed legislation in Maryland, half the population that lives in more densely populated areas and heats with gas is only eligible for a rebate for a pellet or corn stove, not wood. That is likely to lead to people in densely inhabited areas installing low-emission pellet or corn stoves, instead of wood stoves. This too will lead to an improvement in air quality, if this program is adopted.

[1] This is based on national averages of each wood stove using an average of 1.5 cords per year and each fireplace using an average of .25 cords. It also conforms to US Forest Service estimates on wood usage per capita nationally.

[2] Based on national averages of how much wood is sold in bulk by the cord and sold in higher priced small packages in retail stores.