OBJECTIVE
To design an integrated solar and inverter system to power the blower of a biomass gasifier and evaluate the techno-economic feasibility for clean cooking in rural areas.
Week 1 – Understanding initial system design and performed technical calculations for solar panels, inverter and battery.
What is a Biomass Gasifier?
A biomass gasifier is a device that converts solid biomass (like wood, crop waste, coconut shells, etc.) into a combustible gas called producer gas through a process called gasification.
It’s a cleaner and more efficient alternative to directly burning biomass.
How does it work?
A biomass gasifier performs partial combustion of biomass in a controlled oxygen environment.
Step-by-Step Process:
- Feed Biomass (wood chips, shells, crop husk, etc.)
- Ignite it in the combustion chamber (usually with a small amount of fuel or fire)
- Due to limited oxygen, it doesn’t fully burn — instead, it breaks down into gases like:
- Carbon monoxide (CO)
- Hydrogen (H₂)
- Methane (CH₄)
- This gas is called producer gas or syngas
- The gas is filtered and cooled, then used as fuel for:
- Cooking
- Electricity generation
- Heating
What is the Function of a Gasifier?
Convert solid waste into usable energy
Produce clean-burning gas from agricultural waste
Reduce dependency on LPG, diesel, or firewood
Why it’s useful for rural areas ?
- Uses locally available biomass
- Reduces LPG/firewood use
- Creates cleaner combustion
- Can work with solar for hybrid systems
- Low-cost and sustainable in the long run
Gasification Process
Gasification is a thermochemical process that converts solid fuels (like biomass, coal, or wood) into a combustible gas mixture, called producer gas or syngas, by partially burning it in a controlled environment with limited oxygen.
Biomass (CₓHᵧOₙ)+Limited O₂→CO+H₂+CH₄+Heat
CALCULATIONS
Energy needed per day
Blower of the gasifier is of 1 HP = 746W
Operating time = 4 hours
Energy needed per day = 746W*4 = 2984 WH = 3KWH / day approx
Capacity of inverter
746*2 (surge) = 1492 KW = 1.5 – 2KW capacity
Solar PV Capacity
Load = 3KW
Solar hours = 5 hours/day
Assuming 30% loss factor
Solar panels never operate at 100% efficiency due to several real-world losses. To compensate for these losses we multiply by 1.3 (or 30% extra).
Dust and dirt on panels = 5-10%
Panel aging and temperature effects = 5-10%
Inverter and wiring losses = 5-10%
Shading, angle efficiency = 5-10%
Total losses = 25-30% so we multiply by 1.3
PV Capacity = 3000/48 = 62.5 Ah ( E= V*Q )
Battery Capacity
4 batteries of 12 V
Ah = 3000/48 = 62.5 Ah
Lead acid batteries are discharged to 70-80% ( depth of discharge)
Thus 62.5/0.7 = 89.3 Ah = 100 Ah
So we’ll consider 4 batteries of 12V and 100 Ah
Tilt angle
18 to 20 degree facing due south ( latitude of Pabal = 18.7 degree N )
Week 2 – Economic analysis and market survey
Battery back up duration
Blower is of 1 HP
Battery is of 48V and 100 Ah
E = V*Q
= 48*100 = 4800Wh = 4.8 KWH
Safe discharge = 60 – 70 % = 65 %
4.8 * 0.65 = 3.12 KWH usable energy
Back up time = 3.12 KW/ 0.746 KW
= 4.18 hours = 4.2 hours
SAVINGS
Blower = 1 HP = 746W
Usage = 4 hours/day
Daily energy required = 746*4 = 2.984 = 3KWH/day
Monthly power savings = 3KWH/day * 30 = 90 KWH/month
Annual power savings = 90*12 = 1080 KWH/year
If blower runs on grid electricity :
India’s grid emits about 0.713 kg of CO2 per KWH
1080KWH/year * 0.82 = 770.04 CO2/year is avoided
If cooking was done using LPG :
LPG in India contains 14.2 Kg of LPG
1Kg of LPG = 3Kg of CO2
C3H8 + 5O2 = 3CO2 + 4H2O
Molecular mass of Propane = 44g/mol
Amount of CO2 = 3*44 = 132 g
44g propane gives 132g CO2
1Kg of propane gives 3Kg of CO2
So 1 cylinder = 42.6 Kg CO2 (14.2 *3 )
If the kitchen uses 2-3 cylinders per month , yearly usage is approximately 30 cylinders.
30*42.6 = 1278 Kg CO2/year from LPG
Grid electricity for blower = 770.04 Kg CO2
LPG cooking fuel = 1278 Kg CO2
Total = 2048.04 CO2/year
Savings
Grid electricity = 8-10 rupees per KWH
So 1080 KWH/year * 8 = 8640 = 9000 rupees per year approx
1 LPG cylinder of 14.2 Kg costs = 852.5
Assuming kitchen uses 2-3 cylinders per month
So, annually 2.5*12 = 30 cylinders
30*852.50= 25,575
Therefore, total savings = 25,575 + 9000 = 34,575 per year
Pay back period
Total investment / Annual savings = 1,50,000/34,575 = 4.33
Pay back period = 4-5 years
BIOMASS GASIFIER
Cost Breakdown for 1.5 kW Solar + Inverter System
| Component | Specification | Quantity | Unit Price (₹) | Total Cost (₹) |
|---|---|---|---|---|
| Solar PV Panels | 300 W, Monocrystalline | 5 panels | ₹7,500–₹8,000 | ₹37,500–₹40,000 |
| MPPT Charge Controller | 48 V, 60–80 A, solar-grade | 1 unit | ₹6,000–₹8,000 | ₹6,000–₹8,000 |
| Pure Sine Wave Inverter | 2–3 kW, 48 V hybrid inverter | 1 unit | ₹18,000–₹22,000 | ₹18,000–₹22,000 |
| Battery Bank | 12 V, 100Ah tubular lead-acid | 4 batteries (48 V) | ₹9,000–₹10,000 | ₹36,000–₹40,000 |
| Installation & Cabling | Wiring, mounting, labor, fuses | Lump sum | — | ₹10,000–₹12,000 |
Total cost ( including GST and transportation) = 1.2 – 1.5lakhs
