BENEFITS OF LOWERING MASINGA’S MINIMUM OPERATING LEVEL Presented by: Francis Kimolo 2018 G2G GLOBAL INNOVATION SEMINAR, PRIDE INN PARADISE 18TH JUNE - 22ND JUNE 2018

FRANCIS KIMOLO Engineer, Kamburu Dispatch B.Sc. Mechanical Eng. (Hons) from UoN and is graduate member of both IEK and ERB He is currently undertaking an M.Sc. in Climate Change and Adaptation (MCCA) UoN. Based at Dispatch and Control in Kamburu where he has served for five years.

Conclusion & Way Forward 1. JOH-KGN001-20071212-JvW-X1 PRESENTATION OUTLINE Introduction Problem Statement Cost Benefit Analysis Proposed Solution Conclusion & Way Forward 1. 2. 3. 4. 5.

1. Introduction 1.1 Background of study – Masinga Masinga power station which is based in Machakos county was commissioned in 1981 It is a Surface Power Station with 2 Kaplan type hydro power machines The Reservoir is the main storage used to run the seven forks cascade which has a total installed capacity of 599.2 MW 1. 2. 2. 4.

2. Problem Statement 2.1 How do we optimise this important reservoir? By: Raising the Dam wall Operating the Dam at its designed minimum operating level 1. 2. 2. 4.

2. Problem Statement The Machines are designed to operate at a minimum reservoir level of 1033metres above sea level (masl) Minimum Operating Level (mol) was first revised upwards to 1035masl in June 2009 Again to 1037masl in April 2011 Resulted to a loss of 4metres in a short span of 30 years since the commissioning of the dam 1. 2. 2. 4.

2.1 Diagrammatic representation of Masinga 1. 1056.5 self-spilling 1037 2. 1035 2. 1033 4. Low level outlet (LLO)

2.3 Typical Hydroelectric Power Station 1. 2. Reservoir 2. 4.

3.0 Problem statement At the mol, the station is shut and Low level outlet (LLO) opened. 1037masl Opened 30.06.2000 Level 1032.85 2. Opened 26.06.2009 Level 1035.63 4. Opened 15.04.2017 Level 1037.02

3.0 Proposed Solution Revision of the capped minimum operating level of 1037masl to 1035masl and accord the plant extra 2metres of operation Therefore continue earning capacity revenue up to the capped minimum operating level of 1035masl

3.1 Methodology PRACTICAL TEST running to MOL of 1035masl Confirm how much water we actually have between 1037masl and 1035masl. Closely monitor the equipment’s vibrations & turbine temperatures during the test and inspect the runner and mechanical parts after the test.

3.2 Photos during annual maintenance

3.3 Data Graph 1: Operation below 1037masl. Source KenGen

3.3 Data Graph 2: Operation below 1037masl. Source KenGen

Total storage volume Million Cubic Meters (mcm) 3.4 Findings Masinga Level (masl) Total storage volume Million Cubic Meters (mcm) 1037 227.268 1035 173.677 1033 130.000 2. 4. Table 1: Masinga dam storage at various critical dam levels – Source KenGen 2017

3.5 Results Running Days from 1037 to 1035masl (33Days). 227.268 – 173.677 = 53.59 mcm

3.5 Results The vibrations experienced in September/October 2017 were comparable to those experienced during any other period of operation During this period of operations, the machines never tripped on high bearing temperature. The signs of cavitation on runner blades were consistent with operational hydro turbines

September Energy Charge payment = Kshs. 186,363 Sept. Energy (NEO) 5.9GWH Capacity Payment Sept 2017 = 24,506,270.69 Masinga Payment for September 2017. Source KenGen

October Energy Charge payment = Kshs. 129,335.07 Sept. Energy (NEO) 4.089 GWH Capacity Payment Oct. 2017 = 10,634,178.69 Masinga Payment for October 2017. Source KenGen

4.0 Cost Benefit Analysis Energy =315K Capacity = 35M 2. 2. 4. 35.3 MILLION would have been forfeited if the plant was to be shut down at dam level of 1037masl.

Conclusion Revising the MOL based on practical engineering and documented evidence has provided KenGen an extra 2m of Masinga dam storage and 53.591MCM of stored water. Revision of ZBS billing system to capture the levels from 1037 to designed 1033masl.

Way Forward In order to optimize the reservoir further: Establishing the actual sedimentation loads in the reservoir Explore level revision up to MOL of 1033masl

Thank You IMITATION PRECEDES INNOVATION