Lessons from 5 years of

Operations and Maintenance

of Solar PV in South AfricaLiam May

Operations Manager, SOLA Future Energy, South

Africa

• Introduction to SOLA Group

• Track Record of rooftop solar PV

• Black River Park – No. 1 grid tied with the City

• O&M – 5 years

• Presentation Outline – “Critical Experience” and

“Lessons Learned”

INTRODUCTION

• Ensure financial savings: correlated with tariff ranges

– Maximise energy production

– Maximise demand savings

• Capital investments – ROI

• Environmental – reduce coal usage/CO2

• Client green initiatives – corporate drive/customer

behaviour

PURPOSE OF O&M?

• O&M Contract:

– Stipulates service intervals/inspections

– Response times

• Performance Guarantees – Performance Ratio or Yield (annual kWh)

– Peace of mind to client

– “insurance policy”

• Liability of both parties

– Plant-wide damages (hail storm, severe weather events)

– Within/without warranty• Inverters – not all faults covered (5yrs, 10yrs, extended warranties)

• Panels – covered within bounds

LEGAL GOVERNANCE OF

O&M

• No continuous monitoring, no O&M

• Essential – real-time behaviour + status of the plant

• One single monitoring platform

• Identify faults, diagnose faults, decide on remedy

• Understand scale of fault – severity – determines the

urgency of response and scheduling

FUNDAMENTALS:

MONITORING

• Remote access to remote sites

• Reset comms boards and equipment

• Reset inverters if possible and safe

• Strong comms link + function = good operation

– Critical item – migrogrid operations

– Intermittent comms – missing data - reporting

– Internal network comms – inverters/generators/controller

FUNDAMENTALS:

COMMUNICATIONS

• Site hand-over: completion certificate

• O&M contract signature, or O&M included in EPC?

• Test week report

• Inverters – monitoring + strong comms

• Inverters – performance relative to each other

• Strings – string tests

• Ground Faults

MAINTENANCE

GROUND FAULTS

• Common problem

• Hard to locate – transient – moisture

• Can damage certain inverters – not covered under warranty!

• String tester – methods

• Home runs

• Connectors between panels

• Causes: – improper installation

– DC cables too short

– Expansion/contraction

– Sun damage – UV stable DC cables

REPORTING

• Financials – Budget/Proposal vs Actual

• Client savings

• Expectations

• Display performance of plant

• Reporting = vital

CLEANING 1

• Research on the topic

• Quantification difficult – environmental variance

• Experience:

– Up to 10-15% daily improvement with clean (or more)

CLEANING 2

• Environmental factors – type of dust/grime/open

fields/veld?

• Birds – breeding colony locations (Robben Island)

CLEANING 3

• Climate regime – Summer (JHB) or Winter (CPT) rainfall.

• Clean at the start of the dry season – monitor

• Daily various analysis – comparison to simulation

• Plant running correctly but underperforming?

• Safety of cleaning crew – rope access experience

• Number of cleans a year? Site dependent.

• Water restrictions?

CONCLUSION

• O&M for 20 – 25 years

• Protects the asset, ensures returns – “Run the

powerplant”

• Importance of:

– Accurate monitoring

– Accurate communications links

– Accurate data

– Accurate reporting

– Competent and effective maintenance

QUESTIONS?