IMPLEMENTING LARGE SCALE SOLAR A UTILITY S PERSPECTIVE

Transcription

1 IMPLEMENTING LARGE SCALE SOLAR A UTILITY S PERSPECTIVE By: Fidelis Mubiana Director Generation ZESCO Limited 15th February 2016 Radisson Blu Hotel, LUSAKA

2 TABLE OF CONTENTS 1. INTRODUCTION 2. PROSPECTS FOR UTILITY-SCALE SOLAR 3. UTILITY S PERSPECTIVE FOR SOLAR PV 4. CHALLENGES FACED BY THE GRID OPERATOR 5. INTERVENTIONS TO BE CONSIDERED BY PV SYSTEM DESIGNERS 6. CONCLUSION 2

3 1. INTRODUCTION GRID-CONNECTED INSTALLED GENERATION CAPACITY CURRENTLY STANDS AT MW; ABOUT 98% OF THIS CAPACITY IS HYDRO BASED; IMPROVING THE GENERATION RESOURCE MIX IS NOW MORE IMPERATIVE THAN EVER FOR CLIMATE RESILIENCE; NEED TO EXPLORE VIABLE ALTERNATIVES THAT ARE BOTH TECHNICALLY AND COMMERCIALLY VIABLE. 3

4 1/Representation of Zambian Grid Centralised generation dispatched to meet demand 4

5 1/POSSIBLE RENEWABLE ENERGY TECHNOLOGIES SOLAR- PHOTOVOLTAIC (PV) AND THERMAL BIOMASS AGRICULTURAL/FORESTRY WASTE, INDUSTRIAL/MUNICIPAL ORGANIC WASTE, ENERGY CROPS & PRODUCTS AND ANIMAL WASTE; SMALL/MINI/MICRO HYDRO (SPREAD HYDROLOGICAL RISK); GEOTHERMAL. 5

6 2. PROSPECTS FOR UTILITY-SCALE SOLAR The Energy Regulation Board (ERB) provides a definition for embedded generation as that with an installed capacity greater than 100 kw intended primarily for own consumption, but, can be synchronised to the grid to provide excess power to the grid. Initiatives supporting utility-scale solar projects in Zambia are Scaling Solar Zambia, sponsored by the Industrial Development Corporation(IDC), promoting interconnection of solar photovoltaic (PV) power plants with a total capacity of 100 MW within Lusaka in 2016, Ministry of Energy and Water Development (MEWD) procurement of solar PV independent power producers for the installation of a total 150 MW power plant capacity spread across five (5) districts around the country, and Zambia Renewable Energy Feed-in-Tariff (REFIT) Program - Phase 1 6

7 3. UTILITY S PERSPECTIVE FOR SOLAR PV MAINTAIN GRID STABILITY - o SOLAR PV PENETRATION BENEFITS FROM HAVING A STABLE GRID WHICH IS ESSENTIAL FOR RELIABLE OPERATION OF THE DESIGNED POWER PLANT; THE PV INDUSTRY MUST PROVIDE VALUE TO THE GRID OPERATORS RATHER THAN CREATE NEW PROBLEMS FOR LONG-TERM SUCCESS MAINTAIN SAFE OPERATING ENVIRONMENT FOR UTILITY PERSONNEL & THE GENERAL PUBLIC o INCREASING SOLAR PV PENETRATION PRESENTS CHALLENGES ON THE PROTECTION, MONITORING AND CONTROL OF THE GRID ; GRID SYSTEM MUST EVOLVE TO ACCOMMODATE BI-DIRECTIONAL POWER FLOWS 7

8 4. CHALLENGES FACED BY THE GRID OPERATOR A. VOLTAGE REGULATION Grid Code Upper Limit Grid Code Lower Limit Grid Code Lower Limit Figure 1 Figure 2 Adapted from Renewable Systems Interconnection Study: Advanced Grid Planning and Operations, Sandia report SAND P 8

9 Global Irradiance [W/m 2 ] 4/CHALLENGES FACED BY GRID OPERATOR B. INTERMITTENCY OF SOLAR PV PRODUCTION DEPENDENT ON FLUCTUATING SUNLIGHT LOCAL TO THE AREA IN WHICH IT IS INSTALLED B. C. D. E A Time of Day Figure 3 Real-time Global Irradiance recorded at Mulungushi, Kabwe Weather Station (01/01/2014). Data Source: Zambia Metrological Department (Pyranometer type: hukseflux LP02 ADC) 9

10 4/CHALLENGES FACED BY GRID OPERATOR C. POWER FACTOR CONVENTIONAL PV SYSTEMS OPERATE AT UNITY POWER FACTOR, REGARDLESS OF REACTIVE POWER NEEDS OF THE UTILITY NETWORK. D. SHUT DOWN/CURTAILMENT OF SOLAR PV DURING VOLTAGE AND FREQUENCY DISTURBANCES POSSIBLY REDUCING GENERATION WHEN IT MIGHT BE NEEDED MOST. E. COST REFLECTIVE TARIFF PROSPECTIVE TARIFF FOR SOLAR PV HIGHER THAN CURRENT AVERAGE TARIFF IN THE COUNTRY. 10

11 5. INTERVENTIONS TO BE CONSIDERED PV SYSTEM DESIGNERS AGGREGATING GEOGRAPHICALLY DIVERSE COLLECTION OF VARIABLE ENERGY RESOURCES RAPID CHANGES IN INDIVIDUAL OUTPUT REPLACED BY SLOWER OUTPUT VARIATION IN AGGREGATED RESOURCE. 11

12 5. INTERVENTIONS TO BE CONSIDERED PV SYSTEM DESIGNERS IMPROVE RIDE-THROUGH CAPABILITY OF SOLAR PV PLANT. 12

13 6. CONCLUSION 1) As a prudent commercial utility ZESCO needs to ensure that sufficient electricity supply is available to meet the ever growing demand at a price that the market considers appropriate and affordable incentives needs to enable ZESCO procure electricity from prospective solar PV projects. 2) Integration of variable energy resources (VERs) might require the utility to invest in new technologies and equipment interconnection might require semi-deep and/or deep network upgrades. Important to decide on who meets such associated costs. The utility will always aim to minimise the cost of dispatch given in equation 1 below

14 THANK YOU 14