Final Price Comparison of Biogas vs. Propane ("A Discouraging Result")

Final assumptions for the price comparison of Biogas vs. Propane

1. 8m^3 chamber produces 1m^3 gas

2. This model requires 65kg of manure, provided by 4 cows

3. 1m^3 of gas covers 18 meals per day (3 meals for a household of 6 people)

4. 1m^3 of biogas = 2.19 lb

5. People use a 25 lb tank for biogas, which can hold 11.4 m^3 that lasts for 12 days

6. Biogas costs $1.36 (34 cords) per m^3, so a 25 lb tank costs $15.58 (390 cords)

7. People use a 25 lb tank for propane that lasts for 30 days

8. Propane costs $11.49 (287 cords) for a 25 lb tank

9. Propane plus cost of obtaining propane: $13.82 (346 cords)

BOTTOM LINE

25lb tank propane costs $13.82 (346 cords for 30 days propane)

       11.52 cords per day of cooking needs

25lb tank biogas costs $15.58 (390 cords) and lasts for 12 days (1023 cords for 30 days biogas)

       34.11 cords per day of cooking needs

ASSUMPTIONS

assumptions of biogas price

-ignore initial cost, but initial cost is $1700, 42,500 cords

-ongoing maintenance: manure, water, labor

• Manure: 65kg added daily, $.005/kg = $.36 daily, 9 cords

• Water: $.325 per m3 or $.000325 per kg = $.02 daily, .5 cords

• Labor: Nicaraguan minimum wage ~ $.49/hour, 25 cords

Assuming 2 hours/daily, 50 cords daily

Total daily cost per household:

biogas: $1.36, 34 cords

propane (without opportunity cost): $.76, 19 cords

firewood: $.43, 11 cords

assumptions of propane price

-$11.49 (287 cords) for 25 lb tank

-plus 6 hours every 30 days for travel time ($2.33 every 30 days) = $13.82 (346 cords)

NOW FOR OUR POSTER TO EXPLAIN THE PROCESS AND FINAL COST ANALYSIS...