ENERGY-AGRO-FOOD STAKEHOLDERS WORKSHOP · ENERGY-AGRO-FOOD STAKEHOLDERS WORKSHOP ENERGY_AGRO-FOOD Energy_Agro-food Synergies in Africa: New Models for African Universities Biogas

ENERGY-AGRO-FOOD STAKEHOLDERS WORKSHOP

ENERGY_AGRO-FOOD Energy_Agro-food Synergies in Africa:

New Models for African Universities

Biogas From Animal By-product (Cow dung)

Institutional Case Study:

College of Agriculture and Veterinary

Sciences,

University of Nairobi

Friday, 26 February 2016 1

Eng. Prof. Ayub N. Gitau

University of Nairobi

BACKGROUND

Livestock waste / by-product is a potential source of domestic and

institutional energy, a major contributor to greenhouse gas emissions and

pollution of surface and ground water resources.

To reduce production of greenhouse gas and pollution from livestock by-

product, biogas production from this by-product is a better solution.

Biogas production from livestock by-product is on the rise in Kenya as a

way of improving access to power as well as reduction of power cost.

The College in partnership with the Ministry of Energy and Petroleum

(MoEP) are promoting use of green energy through the implementation of

a 120m3 biogas pilot project that utilizes cow-dung that is readily

available in the College.

Note: In Kenya we have; individual, communal and Institutional biogas

plants. Currently up to 2 MW plants are available and fed to the

National grid. Hence Bio-fuels production and utilization is on the rise.

2/26/2016

2

PLANT LOCATION

The plant is located at the University of Nairobi, Upper Kabete Campus which is 15 km West of Nairobi, Kenya.


Gas Line 1.3 Km Proposed extension to

Milk Processing plant

The cost of the plant is

KShs 7.5 million (USD

75,000)

Serves approx. 500

students in the college

The unit houses 100 heads

of cattle.

The animals are fed on

Napier grass


Zero Grazing Unit

• The mixing chamber is fed with about 240 kilograms of dung on a daily basis at a ratio of 1:1

Loading


Inlet

• The digester has a capacity of 120 m3

Underground Digester

Water trap

Gas flow Metre


Gas flow Metre


Gas flow Piping

• The gas flows in a

50 mm PVC

underground pipe.

• The distance

between the

digester and the

consumer unit is 1.3

km


Gas flow Piping • Due to Variation in terrain within the

piping system, the line is installed with seven water traps at the lowest points of depressions with the inclination maintained at less than 1%.

Friday, 26 February 2016

• Variation in terrain

9

Suction Pump

• The suction pump pumps the gas into the Biogas bag


Compressor and the desulfurizer ensures the purification is done before storage so that gas usage can continue even during power outages

Plastic Gas Holder Friday, 26 February 2016

11

The gas holder has a capacity of 20m3



12 Friday, 26 February 2016

Biogas Cooking Stoves Friday, 26 February 2016


50-litre cookpot

Biogas Burner


14

Biogas Cooking Stoves


Effluent Storage


FINANCIAL ANALYSIS


Assumptions:

i. Dung production = 10kg/head/day

ii. Total O&M costs = 0.3% of the total

investment cost

iii. Other benefits (C) = KShs 20,000/month

iv. Discounting rate = 12%

DIRECT BENEFITS FROM THE PROJECT


1. Biogas: Number of cattle – 100 heads

Dung produced per day – 1000Kgs

Cost of lpg saved per day = KShs 4,445

Benefits from Biogas (A) = KShs 4,445

Per month KShs. 4,445x30 = KShs. 133, 350

2. BIO-SLURRY (ORGANIC FERTILIZER)


Volume of slurry produced in a day =

(1,000X2) kg = 2,000

Price of artificial/chemical fertilizer = KShs

80/ kg.

Total savings on fertilizer cost assuming 50%

conversion efficiency = (0.5X2,000X80)=

KShs. 80,000.

Benefits from Bio-slurry (B) = KShs. 80,000

Benefits per Month:

30 x 80,000 = KShs. 2, 400, 000

TOTAL BENEFITS


Total financial benefits = A + B + C

= KShs 133, 350 + 2, 400,000 +20,000

= KShs 2, 553, 350/month

Investment cost = KShs 7.5 million

SUMMARY OF FINANCIAL ANALYSIS RESULTS

(WITH PROJECT BASIS)


Year

Total

Investment

Cost

(KShs)

Total

Benefits

(KShs)

Annual

Variable

Costs

(KShs)

Total Costs

(KShs)

Cash Flows

(KShs)

NPV

Coeffi

cient NPV

0 7,500,000 0 0 7,500,000 (7,500,000) 1 (7,500,000)

1 0 3,280,200 18,750 18750 3,261,450 0.9 2,912,009

2 0 3,280,200 18,750 18750 3,261,450 0.8 2,600,008

3 0 3,280,200 18,750 18750 3,261,450 0.7 2,321,436

7,500,000 9,840,600 7,556,250 333,453

FINANCIAL & ECONOMIC INDICATORS


I. Net Present Value = KShs 333,453

II. Benefit Cost Ratio = 1.30

III. Internal Rate of Return = 15%

IV. Pay Back Period = Three (3) Years

CONCLUSION

Renewable energy potentials in Eastern African

are enormous in form of Biomass; Wind; Hydro;

Solar and Geothermal.

The potential are not highly exploited

Expansion and scaling up should be embraced

The pilot project shows that such sources of

energy are economically viable and should be

embraced.

2/26/2016

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ENERGY-AGRO-FOOD STAKEHOLDERS WORKSHOP · ENERGY-AGRO-FOOD STAKEHOLDERS WORKSHOP ENERGY_AGRO-FOOD Energy_Agro-food Synergies in Africa: New Models for African Universities Biogas

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