Successes achieved in terms of maintenance planning and

implementation-Hydro Power Plants on the Nile River

Nobert MatarutseTechnical DirectorEskom Uganda

LimitedUganda

Introduction and background

• Prior to year 2001 Uganda had a vertically integrated power utility, Uganda Electricity Board, responsible for power generation, transmission and distribution of electricity. No regulatory framework was in place

• Uganda Electricity Generation Company Limited was born out of the de-regulation of the electricity industry in Uganda

Introduction Cont’d

• De-regulation was motivated by among other reasons, the need to improve service delivery, increasing electrification rate and as a way of increasing accountability and provide a fertile environment for investment in this critical industry.

Introduction Cont’d

• Prior to de-regulation power industry was characterised by frequent power blackouts, trips and dwindling plant capacity and high operating costs.

• Eskom Uganda Limited is a wholly owned subsidiary of Eskom Enterprises SA. It was formed in 2002 and won a 20 year concession to operate and maintain two power plants on white Nile, Uganda from 1st April 2003.

Nalubaale and Kiira Power Stations

• Installed Capacity Nalubaale 10 X 18MW= 180MW-Vertical Shaft Kaplan Units

• Ist unit commissioned in 1954. All units uprated and refurbished in between 1992-1998-Uprated from 15MW to 18MW each

• Installed Capacity Kiira 5 X 40MW= 200MW-Vertical Shaft Propeller Units

• Total Installed Capacity For Complex= 380MW

• Peak Generation current 217MW due to hydrological Constraints

Nalubaale and Kiira Power Stations

Nalubaale PS Kiira PS

Rated Head (m)

18.9 20.8

Specific water consumption factor (m3/kWh)

19.8 18.02

Previous Planning Philosophy

• Uganda Electricity Generation Company Limited (UEGCL) being a parastatal was not bound by any Power Purchase Agreement.

• UEGCL had a time based planning philosophy

• UEGCL declared installed capacity and were paid based on same.

• UEGCL’s planning was based on OEM’s recommendations provided soon after rehabilitation

Previous Planning Philosophy

• UEGCL were in charge of the complex for slightly more than 2 years during which time they used a job card system for managing routines and defects

Eskom’s Planning Methodology

• Time and condition based

• Microsoft access based deviation management system was established

• Deviation management system which is still in place is like a manual (s.c.a.d.a) system

• Plant history developed by the creation of the centralised documentation center.

Eskom’s Planning Methodology

• Plant history so developed was key as it enabled proper trending of critical plant parameters and performance of plant.

• Plant history was also utilised to kick start plant intervention programs with a view to stimulate continuous improvement.

• 10 year Technical Plan and Life of Plant Plans developed.

• System Engineering and modification programs established

Service Level Agreements

• Power Purchase Agreement

• Concession and Assignment Agreement

• Generation Licence

• Water Permit

• Support Agreement

• Heads of Agreement

Maintenance Philosophy

• 36 monthly cycle-maintenance outage-30days

• 18 monthly cycle-detailed inspection-15days feeds into 36 Monthly cycle maintenance

• 6 monthly cycle-1day routine

• Using condition monitoring schemes installed, maintenance outages are effected before breakdowns

Maintenance Planning and Implementation

• Outage management procedure in place

• Pre and post outage planning meetings

• KKS plant break down system used for physical assets identification.

• Work packages-for standardisation-doing things right first time.

• Annual plan submitted to system operator 120 days before the following year.

• Annual plan takes into account outage scheduling

Power Generation Performance Indicators

• The following were and are still being measured on a monthly basis in order to guide plant performance and ensure service delivery;

Power Generation Performance Indicators

• Plant Availability

• Plant Reliability

• Unplanned Automatic Grid Separations

• Planned Outage Rate

• Forced Outage Rate (including Mode change failures)

• Plant Load Factor

• Plant Efficiency

Plant Availability Benchmarks

Company CountryAvailability

Mighty River Power

New Zealand 92.4%

Meridian EnergyNew Zealand 94.0%

British Columbia Hydro Canada 96.4%

Eskom Uganda Ltd Uganda 96.0%

Dropping water

levels led to

reduction in

available energy

U2 VT explosion (Trfr 11kV cable

and surge arresters damaged)

outage lasted over 300hrs

- Unit 10 rotor earth fault – outage

lasted approx 100hrs

Performance Outlook

• Conjunctive operation with downstream power plants.

• Commissioning of an integrated computerised maintenance management system that relates to functional areas of the business.

• Increased plant optimisation

Performance Outlook

• Improvement in manpower utilisation

• Increased cost effectiveness

• Further improvement in service delivery

• Focus on quality assurance

• Increased focus on risk management

Intervention measures employed to achieve performance

• replacement of dc systems

• modification of protection schemes

• modification of governing systems

• installation of vibration monitoring

• installation of partial discharge scheme

• transformer replacement

• circuit breaker replacement

• surge arrestors replacement

Intervention measures employed to achieve performance

• System engineering including in-depth incident investigations.

• Standardisation of maintenance tasks and procedures

• Enforcement of statutory maintenance

• Training and development including exposure programs.

• Performance management.

The End

• Thank You

• Siyabonga

• Webale Nyo