For those who like numbers…
The Eco1 Rocket Stove we make has approx 1630 MJ of energy embedded (embodied) in the steel. Add a bit for the manufacturing and transportation we can round that up to about 1800MJ.
The expected lifespan is around 10 years, so we can average that energy expenditure at 180MJ / Yr.
Over the duration of its life, the Eco1 will save approx 2500Kg of wood from being burnt each year. This is based on the following assumptions and actual measured data:
KG of wood used per hour of Burning:
Baseline Usage = 4Kg (typical bhukari in the Himalayas)
Recorded usage in Manali (2000m) = 2.2Kg
Recorded usage in Leh (3500m) = 1.2Kg
Average = 1.7KG / hr
Average Savings on Baseline = 2.3Kg / hr
Hours of Burning per day:
6 (often 3 in morning and 3 in evening, but can easily be more than this depending on altitude and access to wood)
Days of Burning per year:
(depending on altitude more or less half the year, so we average at 180 days)
Wood Burnt to CO2 Ratio:
Each 1Kg of wood burnt releases 1.9Kg of CO2 (that bit of magic happens as a result of the Carbon in wood bonding with O2 in air in the combustion process, thus making up the additional weight of released CO2.)
When multiply out all those numbers, we get this:
2.3Kg x 6Hrs x 180Days = 2484 Kg wood saved per year
2482 x 1.9 = 4720Kg CO2 not released to the atmosphere as a result of direct combustion.
Note: Additional CO2 is saved as a result of leaving the tree in the ground and letting it continue to soak up CO2 as part of its life cycle. So let’s just round up the benefit to 5000Kg / year (or 5 tons per year).
Over 10 years of lifespan of the Eco1 stove, it will reduce CO2 emissions by 50 tons for a total energy impact of 1800MJ. Not to mention all the other associated benefits in leaving more trees in the ground.
So as a genuine question to the wider community, is that a good figure? Is the saving of approx 28Kg of CO2 per MJ of embedded energy a good ratio?
This post is the first part in an ongoing process of analysing the cost / benefit ratio in the implementation of low cost, high temperature combustion technology. We look forward to your input and ideas around this, as we genuinely seek to achieve the best possible outcomes for the Earth and all beings who depend upon her for ongoing sustenance.