This document summarizes an executive exchange program organized by the U.S. Energy Association and funded by USAID. A delegation from various Kenyan electricity sector organizations, including KenGen, Kenya Power, Ketraco, and the Energy Regulatory Commission, visited several U.S. electricity providers to learn about integrating wind power and system operations best practices. The visits covered topics like operational challenges with intermittent resources, operations with wind generation, reliability standards, operator training, system frequency and voltage regulation, and protection systems.

1. BRIEF REPORT ON
EXECUTIVE EXCHANGE ON KENYA WIND DISPATCH
August 24 – September 2, 2015
Denver, Colorado and Austin, Texas
Funded by:
U.S. AGENCY FOR INTERNATIONAL DEVELOPMENT
Organized by:
U.S. ENERGY ASSOCIATION
Compiled by:
Joshua M. Chokera

2. DELEGATION
KenGen
1. Eng. Solomon Karanja Kariuki - Technical Services Manager
Kenya Power
1. Eng. Benson Muriithi, General Manager - Network Management
2. John Kimutai Kirui, Assistant Engineer - System Control
3. James Mtoto Rughendo, Planning Engineer - System Control
4. Joshua Muriithi Chokera, Assistant Engineer - System Control
5. Humphrey Omondi Obondo, Assistant Engineer - System Control
6. Moses Kahara Waweru, Assistant Engineer - System Control
Ketraco
1. Eng. Dr. John Muoki Mativo, Chief Manager - Planning And Development
2. Samson Akuto - Senior Electrical Engineer
Energy Regulatory Commission
1. Benson Kimathi - Technical Officer

3. EXECUTIVE EXCHANGE GOALS & OBJECTIVES
Program Goal:
The purpose of the Partnership was to further the institutional development of Kenya Power,
Ketraco and KenGen senior and mid-level managers by providing them the opportunity to learn
“best utility practices” to dispatch wind generation directly from their peers at electric utilities in the
US.
Executive Exchange Objectives:
The objectives of this executive exchange were to discuss best practices in:
 System operations and dispatch
 Operations with wind generation
 Reliability standards, and
 Training operational staff.
PROGRAM COODINATOR
Tricia Williams
Senior Program Coordinator, U.S. Energy Association
twilliams@usea.org
Electric Utilities Visited:
1. Electric Reliability Council of Texas (ERCOT) in Taylor, TX on 2015-08-27
2. Texas Reliabity Entity in Austin, TX on 2015-08-28
3. Wind Energy Transmission Texas (WETT) in Austin, TX on 2015-08-28
4. Cedar Point Wind Energy Project in Denver, CO on 2015-08-30
5. XCEL Energy in Denver, CO on 2015-08-31 and 2015-09-01

4. A. OPERATIONAL CHALLENGES WITH INTERMITTENT RESOURCES
 Wind and Solar integration pose the biggest challenges in System operation and
restoration.
 System studies (simulation by PSSE) best method to establish wind penetration.
 Weather forecasting, day ahead and week ahead, to guide on wind turbine ramping
rates, hence guide dispatch.
 Ancillary services development for System support.
 Simulator training for operational crews e.g. Black-start, dispatch with wind,
thermal, hydro, etc.)
 PMUs like synchro-phasors to monitor transmission flow rates and analyze System
events to develop future solutions.
 Reliability studies to determine revision of PPAs for more wind penetration.
 Curtailment vs. Reliability: No capacity payment in Texas, only energy payments.
Curtailment is done for System Reliability.
B. OPERATIONS WITH WIND GENERATION
Generation forecast can be greatly aided by availability of the following modelling data and
analysis;
i. Numeric Weather Prediction models
ii. Model Output Statistics (MOS)
iii. Power Plant Output model
Xcel Energy operates a Take or Pay PPA. There is an annual energy target for the wind farms
but the System Operator can curtail at no cost to it-self in case of a Scheduling Risk (e.g. high
output at low demand periods).
Availability Risk provides that if output drops, to say 90% from 97%, wind farms are paid to
keep running. They are also paid for output above availability.
If availability drops due to maintenance of turbines then there is no payment (Maintenance
Risk).
*The Kenya Lake Turkana Wind Power Project has a Take or Pay PPA with an annual energy
MWh) target but without provision for capacity payment.
Other operational challenges for the wind farms include galloping during winter (ice forms
on conductors creating an air foil which causes flash-over) and over-speed during tornadoes which
damage the turbines. Lightning strikes also damage turbine blades.
Capacity factor for the Cedar Point Wind Project was 39% (compared to 50% best c.f. in US).
The Plant has an installed capacity of 252MW and the best output has been 250MW at 12 meters
per second wind speed. The average wind speed is, however, 7.8 – 8.0m/s which give 115-120MW
output. The farm has 139 turbine towers and two meteorological towers.

5. C. RELIABILITY STANDARDS AND COMPLIANCE ASSESSMENT
 There exists an inter-agency committee that sets reliability standards, enforces the
standards and issues penalties for non-compliance. The standards are enshrined in
the State Protocol Compliance (the Kenyan equivalent of the Grid Code).
 Professional assessment of violations, as opposed to zero tolerance and penalties is,
however, encouraged.
 Compliance monitoring is done by; Assessing, Investigating, Evaluating and Auditing
violations.
 Compliance enforcement is by issuing sanctions and ensuring mitigation of
violations.
D. OPERATOR TRAINING
NERC standards require a structured approach to operator training for all utilities;
 Initial Training,
 Continuing Training
Operators are certified and receive annual credits (e.g. 200 hours of C.E. per year). This
includes simulation training, voltage control, power flow, frequency regulation, protection
systems maintenance, e.tc. but only one kind of training at a time.
There are penalties for mal-operations in the System.
There is specialized training for Protection Engineers
The following cadre requires certification;
o System Operators
o Control Center Management
o Outage Coordinators
o Training Coordinators
o Real Time Planning Engineers, and
o Generator Operators
In-house training is implemented in six phases, namely;
i. Basic knowledge training
ii. Specific knowledge training – based on specific job
iii. Procedure-based training – based on Control Center procedures applicable to a
specific position (skills & knowledge to perform a task)
iv. Skills and Knowledge Guide – check offs to ensure mastery of the job
v. On Job Training (OJT) Task Qualification Sheets – training and performance
evaluation that is conducted in the work environment
vi. Final Qualification Board and Simulator Examination – to determine the Operator’s
level of qualification.
E. SYSTEM FREQUENCY SUPPORT
The System Operator is required to maintain the Area Control Error (ACE) within
steady state i.e. 59.98 – 60.02 Hz.

6. Balancing Authorities must respond within one minute (per quota) after a large
generator trip event.
Spinning reserve is maintained typically at 3% of load plus 3% of generation or equal
to the biggest unit on-line.
AGC normally incorporates SCADA for generators to help in scheduling curtailment.
This helps to avoid making telephone calls and guess work on how many MW to
reduce or raise. AGC is very critical in wind integration due to the intermittent
nature of the resource. With AGC the generators are graded to provide primary
response, medium response or late response depending on the unit’s ramping rates
capability. The System Operator specifies which units shall be on AGC and for what
period. Other generators may be retained on Frequency Response mode.
The strong interconnectors provide a critical role in frequency regulation as well.
Under-frequency load shedding is also provided for; but is rarely used.
F. VOLTAGE AND REACTIVE POWER REGULATION
 Transmission Operator must invest in ancillary services to support System voltages.
Static reactive reserves and dynamic VAR reserves are controlled and monitored via
EMS to ensure that voltage levels, reactive flows, and reactive resources are
monitored, controlled, and maintained within limits in Real-time to protect
equipment and the operation of the interconnectors.
 Generator operators are required to ensure that Automatic Voltage Regulators on
synchronous generators and condensers shall be kept in service and controlling
voltage.
 Voltage Related Studies and Testing are done during Contracted Capacity Tests for
both leading and lagging p.f.
 Transmission Planning Studies carried out include;
o Feasibility Study – new steady state voltage or frequency violations
o System Impact Study – uses dynamic modelling data
o Facilities Study – ownership, new facilities
o Large Generator Interconnection Agreement provides guidelines and testing
procedures.
o Next Day Studies/Outage Studies are typically performed by outage
coordinators to identify voltage and operational issues before they occur.
Control Modes for Generators;
 Automatic Voltage Regulation (AVR) – generators will automatically adjust MVAR
output to keep the Point of Interconnection (POI) voltage constant.
 Automatic VAR Control – generator will maintain a constant VAR schedule at the
POI.
Power System Stabilizers (PSS) on synchronous generators should normally be kept in
service. A PSS is a supplementary controller whose output is applied to the excitation system
and which is designed to produce a positive damping torque.
G. PROTECTION AND CONTROL
System Protection Coordination between wind farms & off-taker is done by;

7.  Engineering coordination studies
 Field testing locally
 End-to-end Testing
 Testing with impacted neighbouring utilities
Fault currents are injected into relays for testing. Protection grading is done by zoning faults
using Cape Software. There is peer review process for protection schemes. The wind
developer usually sends their protection scheme to the Transmission off-taker for approval.
Protection System Maintenance
 A 5 year cycle – due to the big size of the power system.
 Condition Assessment maintenance
 Operational checks/Functional tests carried out
 End to End checks also done
 May involve neighbouring utilities
 Permissive and Blocking Schemes are the main types
 There is specialized training for Protection engineers
Special Protection Systems (SPS)
Employed during abnormal or determined System conditions to take corrective action other
than isolation of fault to maintain System reliability e.g. change in demand, generation (MW,
MVar) or System configuration to maintain System stability, acceptable voltage, or power
flows.
It does not include;
i) U/F or under-voltage load shedding
ii) Fault conditions isolation
iii) Out of step relaying
It is also known as a Remedial Action Scheme e.g. tripping some geothermal units in the
event of loss of one line to avoid losing the second line on over-load.
H. OUTAGE COORDINATION PROCESS
Transmission work request is submitted two weeks in advance by the field crew to the
coordinator and it specifies;
 Equipment
 Clearance type
 Time frame
 Work Description
Transmission line outages mainly involve;
 Opening breakers
 Hot line work
 Protection schemes testing
System Impact Study Tools

8. 1. State Simulator – An on-line tool that provides accurate model of the System and adjusts
real time flow and interchange data.
2. PSS®E – An off-line tool that is used to model the interconnection and also to study
neighbouring utility impact of the outage.
Outage Study Inputs
 Load forecasts
 Generation forecasts
 Wind forecasts
 Topography (current scheduled/on-going outages)
Contingency Analysis
i. Assess risk to the bulk electric system
ii. Check for thermal violations
iii. Check for voltage violations
iv. Develop mitigation plans for the outage, if required e.g. reschedule generation
v. Allow outage / defer outage
Study Process
 Next Day Study – uses next day forecasted data to study the next day scheduled
outages and helps to develop mitigation plans for the same.
 Real Time Study – Uses real time System data on the day of the outage.
I. WIND PLANT ELECTRICAL MODELS
The specific topologies shown in Figure 1 are:
• Type 1: Induction generator – fixed speed
• Type 2: Wound rotor induction generator with adjustable external rotor resistance –
variable slip
• Type 3: Doubly Fed Induction Generator (DFIG) – variable speed
• Type 4: Full converter system with permanent magnet synchronous generator (PMSG) –
variable speed, direct drive.
Type 1

9. Type 2
Type 3
Type 4
Figure 1: Different types of Wind Turbine Generators
Reference:
Holdsworth, L.; Ekanayake, J.B.; Jenkins, N. “Power system frequency response from fixed
speed and doubly fed induction generator based wind turbines.” Wind Energy (7:1), 2004;
pp. 21–35.)

10. RECOMMENDATIONS FOR KENYA WIND INTEGRATION
1. Carry out wind integration impacts and costs assessment - Variable renewable
energy generation sources, such as wind and solar energy, provide benefits such
as reduced environmental impact, zero fuel consumption, and low and stable
costs. However, their variability and uncertainty—which change with weather
conditions, time of day, and season—can mean increased power system
operating costs. The primary costs come from additional operating (flexibility)
reserves needed to ensure system reliability and impacts on the operations of
non-renewable generation.
2. Provide adequate ancillary services in the existing transmission network for
voltage and reactive power support.
3. Parallel Path Flow – Building of strong transmission inter-connectors with
neighbouring countries.
4. System reinforcement schemes in existing grid such as re-conductoring and
transformation capacity up-grade.
5. Incorporating AGC into the Independent System Operator’s Scada and allowing
for AGC scheduled curtailment as well as setting other units on frequency mode.
6. Requiring all generators to provide spinning reserve by operating at 80% loading
7. Carry out Reliability Studies to determine content of PPA’s for wind penetration
8. Obtain Numeric Weather Prediction mesoscale modelling data from wind
developers for time-synchronization with actual load data, which should include;
Location
Type of turbines
Meteorological data – seek contractual rights from wind plants. Built
turbines wind speed may differ with pre-built (feasibility) wind
speed due to shadowing & turbulence
Wind speed data for day ahead and week ahead dispatch scheduling
9. Training of Operators - System Operators, Control Center Management, Outage
Coordinators, Training Coordinators, Real Time Planning Engineers and
Generator Operators.
10. Introduction of Special Protection Schemes (SPS) to maintain System Reliability.
11. Formation of an inter-agency committee that will set reliability standards,
enforce the standards and issue penalties for non-compliance.
CONCLUSION
The objectives of the visit were fully met. As Kenya prepares to integrate bulk wind energy in the
national grid, this executive exchange provided participants with priceless insights on wind
penetration that will be applied accordingly to our power system. We thank the U.S. Agency for
International Development, U.S. Energy Association, Ms. Tricia Williams, Mr. Charles Maloba, Eng.
Henry Odedeh and our parent organizations for the well organized and coordinated exchange. We
look forward to implementing wind integration in Kenya very soon.

11. Annexures
Photos: The Kenyan Team at Xcel Energy offices & at Cedar Point Wind Farm in Denver, Colorado.