Hydro Capacity Preservation & Expansion

Transcription

1 Hydro Capacity Preservation & Expansion ALEX D. MOSLEY General Manager Hydro Generation March 1, 2016

2 TVA Overview Tennessee Valley Authority Established 1933 Nation s largest public power system Wholly-owned government corporation Wholly-self funded, no appropriations 7 state service area 37,000 MW Capacity Hydro Capacity Expansion & Preservation 2

3 TVA Hydro System 29 Conventional Plants 109 Units (3,800 MW) Fully automated 1 Pumped Storage Plant 4 Units (1,600 MW) Hydro Capacity Expansion & Preservation 3

4 Hydro Unit Automation ( ) Development Utilized existing: Remote Terminal Unit (RTU) equipment Secure networks ACS System Modified Siemens software and used PLC for plant controls Siemens WinCC Human Machine Interface for operator controls Program Goals: Reduce Operational Cost Optimize System and Unit Efficiency Operators (HDCC) in SOC with BA and TO Hydro Capacity Expansion & Preservation 4

5 Opportunities of an Aging Fleet Hydro Modernization Program (HMOD) Major refurbishments to restore the power train and extend the life of the asset Opportunity to invest in increased capacity to generation that is reliable, affordable, flexible and sustainable Expansion Focus: Completed 56 conventional and 4 pumped storage units Gained 536 MW in capacity Improved average efficiency 5% 53% Of 113 Units have completed HMODs Hydro Capacity Expansion & Preservation 5

6 Conventional Hydro Capacity At Risk - MW Maintaining Life Cycle Hydro Major Maintenance Program (HMM) Present Preservation Focus: Critical assets beyond life cycle Restoration to ensure reliability Prioritized by condition and risk 3 per year necessary to maintain current fleet capacity 100 MW uprate potential on remaining unit HMMs, but not the focus 4,000 3,500 3,000 2,500 3,805 MW Current 3,750 MW 3,805 MW 3 HMM/Year 2,678 MW 1 HMM/Year 2,329 MW Do Nothing 2, Year Hydro Capacity Expansion & Preservation 6

7 NEW Hydro Capacity Opportunities In addition to existing unit capacity and efficiency uprates gained from the HMOD and HMM programs, TVA is evaluating options for new capacity. Expansion at existing power dams Addition at non-power dams Pumped storage capacity TVA operates 17 Non-power dams Hydro Capacity Expansion & Preservation 7

8 Expansion at Existing Power Dams Nickajack Hydro Conceptual Study: Modify retired navigation lock to run-of-river Fixed Blade Array 24 MW capacity Kentucky Hydro Conceptual Study: New powerhouse construction opposite existing in Earthen Dam 43 MW capacity Expansion sites were chosen based on spill rates, sufficient head and flows, dam and powerhouse features, constructability, and other feasibility factors Hydro Capacity Expansion & Preservation 8

9 Expansion at Existing Diversion Dam Ocoee 3 Hydro Spillway modification to capture recreation flows provided July Sept Kaplan or Conduit Turbine 1 Unit, 10 MW Recreation flow commitments began after construction of the 1996 Olympic whitewater course in the riverbed between the diversion dam and powerhouse Hydro Capacity Expansion & Preservation 9

10 Pumped Storage Capacity Existing Hydro units evaluated for functionality based on: Net head of 98 feet, and minimum tailwater to provide Net Positive Suction Head (NPSH) while in pump mode. High cost and uncertainty of ancillary benefit value have kept construction of new pumped storage sites from being economical Only two plants meet the criteria: Hiwassee (HIH) Unit 2, originally designed to provide 90 MW of pumping capacity, but needs restoration to operate in pump mode Project funded FY2016 Wilson Hydro, determined not feasible due to inadequate tailwater depth and flow imbalance with upstream plant in close proximity HIH Unit 2 was installed in 1956 And was the 1 st Hydro power pump storage turbine in the United States Hydro Capacity Expansion & Preservation 10

11 Adding Capacity to Non-Power Dams Nolichucky Dam (ca. 1913) Retired 1972 Kaplan, Siphon to Conduit Turbine 4 Units, 12 MW total Normandy Dam (ca. 1976) Minimum flow unit Kaplan, Siphon with Conduit Turbine 1 Unit, 2 MW Hydro Capacity Expansion & Preservation 11

12 Conclusion Balancing Potential & Sustainability Continue to explore cost-effective expansion opportunities Resources directed to preservation of existing Greatest gains through HMOD/HMM Restoring pump storage Jan 8, 2015 Record 5 day load swing (165%, 20,380 MW) 1,215 MW in wind purchase agreements (400% increase since 2010) Hydro Capacity Expansion & Preservation 12

13 Questions?