Micro-power Generation in Africa

Harold Anuta and Andrew CrosslandDecember 2012

About us

Harold Andrew

1. How does the UK power system work?

2. How does that compare to Africa?

3. How can distributed generation be used in Africa?

4. How is our work relevant?

Power stations

Customers

1. How does the UK power system work?

2. How does that compare to Africa?

3. How can distributed generation be used in Africa?

4. How is our work relevant?

Energy Top Trumps

United KingdomPopulation 62.2 million

Area 93,000 sq.miles

Generation capacity 88 GW

DR CongoPopulation 69.6 million

Area 875,000 sq.miles

Generation capacity 3GW

Energy Top Trumps

Rwanda BelgiumPopulation 10.7 million

Area 9,524 sq.miles

Electrical energy per year 240 TWh

Population 10.8 million

Area 11,690 sq. miles

Electrical energy per year 89,000 TWh

Percentage of population with electricity

< 20%

20% - 40%

40% - 60%

<75%

“Only about one-fifth of the Sub-Saharan population has access to electricity”

(AICD Flagship Report, 2009)

Off-grid/microgrid electricity networks may be a viable and affordable alternative to large investments in network

infrastructure

1. How does the UK power system work?

2. How does that compare to Africa?

3. How can distributed generation be used in Africa?

4. How is our work relevant?

Small Power systems

Generation

Solar

Wind

IC Engines

…

Loads

Machines

Lights

…

Storage

Batteries

Flywheels

…

Grid connection

Bulk Power System

GENERATION TECHNOLOGIES

Hydro http://www.youtube.com/watch?v=iHBRf2bUNXU

Concept

• Water drives turbine linked to generator• < 10kW to 1000kW

Advantages

• Low investment• Renewable energy source• Efficient• Controllable • No pollution

Challenges

• Suitable location• Climate

Solar

Concept

• Solar thermal vs Solar PV

Advantages

• Easy to install• Durable• Renewable energy resource• Easy to maintain• No pollution

Challenges

• Uncontrollable• High capital cost (but rapidly falling)• Need storage or a grid for support

(Electric) Generators

Concept

• Internal combustion engine to turn generator• Widely adopted

Advantages

• Established technology• Well understood• Compact• Reliable

Challenges

• Fuel cost and access• Noise and air pollution

Micro Gas-Turbines

Concept

• Gas powered turbine• Up to 300kW

Advantages

• Heat and electricity (lower heat than other generators)• Use natural gas or biofuels with lower emissions

Challenges

• Fuel supply and access• Noise and air pollution• System Reliability• Low power efficiency• Developing technology

Wind Turbines

Concept

• Wind turns turbine

Advantages

• Established• Easy to understand

Challenges

• Need suitable location• Needs storage• Uncontrollable

http://www.youtube.com/watch?v=wGe65xwd-0c

MICRO-GRID VS. MICRO-GENERATION

Micro-generation Micro-grid

Micro-grid

Micro-generation• Microgeneration involves heat

and/or electricity production from mostly low carbon sources by individual households, small businesses or communities

• Makes use of distributed generation technologies• Solar photovoltaics and thermal

systems• Micro-Turbines• Micro-Hydro• Fuel cells• Combined Heat and Power• Internal combustion engine

• Small power distribution system connecting multiple customers to one or more distributed generation units and storage

• Localised power generation independent of bulk power grid

• Micro-grids were main form of power pre 1950 in most parts of the world• Industrialisation and government

policies led to move towards a centralised bulk power system

• Major advantage is multiple fuel sources

Micro-grid

Micro-grid

Distributed generation

Can be cheaper than electrical

grid

Security of supply

Local Production

Need proper design

Control and dispatch

Rural applications

Emissions reductions

Increase generation

capacity JobsPublic

engagement and empowerment

Lower deployment cost to government

Heat and Electricity

Overall Efficiency …

HOWEVER...The reality isn’t so simple

1. What is an electrical power system?

2. How good is the electrical system in Africa?

3. What role can a micro-grid play in Africa?

4. How is our work relevant?

Solar for Healthhttp://www.youtube.com/watch?v=qOxF7Bz8Tso

• High solar irradiance in Rwanda;

• Falling costs;• Low environmental impact;• Easy to maintain;• Can be used off grid with

batteries.

“In stand alone PV systems special attention must be paid to the battery bank… the weakest component of the

system and the highest contributor to its life cycle cost”

(IEA, 2002)

Depth of Discharge

Predicted Lifetime [years]

10% <16 years

25% <6 years

50% <3 years

80% <2 years

100% <1½ years

Technical Study

• Smart meters;• Load surveys;• System surveys.

Social Study

• Interviews.

Background research

• System vendors/ Installers;• Government institutions.

How has access to solar systems affected daily life?

What problems have been encountered with the systems?

What are the perceptions of solar energy use?

Areas of inquiry

Health Centres and Schools

Considering solar systems

Used to have solar systems

Currently use solar systems

Fully functional

Deteriorating

Non-functioning

Social Factors•Limited impact awareness and conscious misuse of systems;•Solar energy viewed as a secondary source of power;•Education is key.

Technical Factors•Poor design and design changes;•Time of use hugely important•Weather effects;•Poor maintenance and training.

• Battery voltages;

• Autonomy;

• Condition monitoring;

• Usage pattern.

0%

20%

40%

60%

80%

100%

00.20.40.60.8

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00:00 06:00 12:00 18:00

Batt

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Current Demand Current battery state-of-charge

2. The batteries are at a very low state-of-charge by the end of the day

1. High demand in the evening from the laboratory equipment

0%

20%

40%

60%

80%

100%

00.20.40.60.8

11.21.41.61.8

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00:00 06:00 12:00 18:00

Batt

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[%]

Pow

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Shifted Demand Current Demand Improved battery state-of-charge Current battery state-of-charge

1. Laboratory work is shifted from evening to the morning

2. The batteries still get fully charged in the day and are not as deeply discharged at night

What next for us?

1. How does the UK power system work?

2. How does that compare to Africa?

3. How can micro-grids be used in Africa?

4. How is our work relevant?

Thank you for Listening

Any questions?