Working Towards “Zero Green Premium” Stoves

ARC is working on three types of Zero Green Premium biomass heating stoves designed to protect health and climate. “Zero Green Premium” means that the new product costs the same as the dirty one it replaces. As a rough estimate, ARC uses 0.5 grams per hour of PM2.5 at <5% Black Carbon ratio to define the performance and emissions that protect urban health and climate. 

Sixty percent of electricity in the US is generated by burning natural gas (40%) and coal (20%). Utilities are wondering how to meet increasing demand while replacing fossil fuels. Help is very welcome!

When renewably harvested biomass is burned cleanly enough, could it join solar, wind, and hydro as another useful energy resource? Heating a home with wood is ~ 80% efficient. Making biomass into alcohol is ~ 1/5th as efficient. (Energy Primer, 1976)

Is there enough biomass? In 2023, the DOE estimated that the US produces more than 1 billion tons of renewable biomass per year. Providing the needed ~3 tons of biomass per US home (currently heated by burning fossil fuels) requires 420 million tons, a drop in the bucket.

Six steps: Clean burning of biomass      

  1. Optimize heat transfer efficiency 
  2. Control the rate of reactions 
  3. Achieve molecular mixing in the combustion zone 
  4. Maintain temperatures above 850C 
  5. For a minimum of 0.5 seconds 
  6. In an air rich environment.
Three images - Icy tree limbs, a man with a chainsaw, a car full of logs

Ice Storm 2024!

On January 14, ARC staff experienced a catastrophe when ice brought down about one third of the trees in our valley and we had no electrical power for seven days. Depending on the grid for heat and light is great when everything works. However, when the lights go out, a warm house becomes really important. Light is easy to make with photovoltaics, etc. Living for a week in the cold was a great reminder of the importance of a clean burning non-electric biomass heating stove. 

I lived without electricity on a ranch in Mexico for eight years where it was warm pretty much all of the time. Even so, on chilly nights we lit an open fire and sat around it, talking. The old folks pulled blankets around themselves, too.

I do not remember missing refrigeration or lights. It was not a big deal. At the ranch, people had lived for over a hundred years without them and much more energy went into trying to find juice for the little radio.

Going for a week without electricity reminded me that a warm house is important. In response, ARC is building health/climate non- electric pellet heating stoves as winter turns into spring.  If the creek don’t rise, we want to have these stoves in all buildings before next winter.

PS: I am fine reading a book by candlelight as long as my feet are warm.

thermal image of house juxtaposed with daylight image of same house

COP 28: Near-zero emissions in global building sectors

thermal image of a house juxtaposed with daylight image of same house
Heat can constantly leak out of older homes. Photo: Gina Sanders

Aprovecho is investigating how to design and manufacture biomass-heating stoves that protect health and climate when burning renewably harvested biomass. Of course, staying warm depends on many factors including how much energy is being leaked from the building.

Net-zero buildings are usually tight and well insulated. A net-zero home can have a heating load of 10,000 to 15,000 Btuh (or ~3 to 4 kW) in a cold, northern climate. At COP 28, a minority of nations agreed to move towards net zero homes to reduce climate change by heating the better buildings with renewables. Green Building Advisor: 28 Countries Sign Buildings Breakthrough Agreement at COP28

Since the 1970’s, architects and engineers have learned how to dramatically reduce energy losses in buildings. Many net-zero homes take advantage of solar power to assist heating and create electricity. Solar gain helps a tight, well-insulated home to stay warm.

The United Nations found that buildings and construction account for 39% of total carbon emissions annually. Net Zero Homes: Your Guide to the Greenest Housing Option  If a new generation of very clean burning biomass heating stoves can protect health and climate, might they assist COP* countries to move towards near-zero emissions in global building sectors? *COP is the decision-making body of the UN Framework Convention on Climate Change.

Happy Holidays, 2023!

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That the days are shorter is easy to attest to here at Blue Mountain. Our campus is wedged between parallel rows of 100-foot tall Fir trees. Yesterday, the rare sun fell down below the celestial horizon at 2PM.  We envy the valley farmers whose day lasts until around five. On the other hand, being surrounded by the forest up here makes the air sweet and clean. But only when the wood burning heating and cooking stoves that we are developing and testing are protecting health and climate.

It can be so terrible when traditional stoves are belching smoke! I have had pneumonia three times and get nervous when my throat gets sore. Clean burning makes me a lot happier. 

HEALTH: Can biomass be burned cleanly enough to protect air quality when warming houses and cooking food? 

CLIMATE: Can the Global Warming Potential of burned biomass meet the Paris Agreements and join solar, hydro and wind as a renewable energy source? 

Sure, we do both every day.  

Celebrating life and scientific endeavor in the forest becomes pleasant and comforting when we are toasty warm, and the smoke disappears. 

Feels downright civilized.