O&M Requirements for Utility-Scale Solar PV and Energy Storage Nicholas Jewell, Ph.D., PMP Sr. Research Engineer Research & Development LG&E and KU
Overview Overview of E.W. Brown Solar System Design Solar Installation Performance Energy Storage Overview Energy Storage Maintenance Next Steps & Discussion
Background / Timeline December 2013: LG&E-KU requests certificate of convenience and necessity (CPCN) at $36 million December 2014: Kentucky PSC order grants CPCN quoting LG&E-KU testimony that: Moving forward with Brown Solar Facility now will afford the Companies an opportunity to gain operational experience with this type of resource should the economics continue to improve and future CO2 regulations enhance their value to the system. - David Sinclair April 2016: Project completed for $25 million June 2016: Began commercial operation 3
Overview of E.W. Brown Solar EPC contract award to final completion 9 months (completion in June 2016) Approximately 45 acres PV modules ~45,000 modules Fixed tile rack system Each module produces 315 Watts Inverters: 10 x 1,000 kw @ 1,000 volts Anticipated annual production: ~19,000 MWh Assuming a typical home uses 1,000 kwh of electricity per month, the E.W. Brown Solar Facility will power an equivalent of approximately 1,500 home each year. 19,000 MW hours of annual production is equivalent to Brown s 750 MW of Coal generation operating at full output for 25 hours. 4
Typical Solar PV System Design Facts: ~46,000 panels, 45 acres 104 Combiner Boxes 10 re-combiners and inverters ~210 Miles of power cable Up to 24 strings in parallel (~900 Vdc, 6.4 kw) - Up to 12 combiners in parallel (~900 Vdc, 1.5 MW) 5
Typical Solar PV System Design 6
System Design - Panels Qty: ~44,600 (14.056 MW dc ) Manufacturer: Jinko Solar Model: JKM315P-72 Max power: 315 W Max System Voltage: 1000 V Multi-crystalline 72 cells per panel Combination of 3 and 4 collector cells Source: PV-Tech (2017) 19 modules per string 18 or 24 strings per combiner box ~10-12 Combiners per inverter 7
System Design Racking System 100% fixed-tilt racking (20º tilt summer peak) Tracking (SAT, DAT) vs. no tracking Ground requirements Capacity factor Variable Fixed Tilt Tracker Acres Available 40 40 Acres per MWp 2.7 4.3 System Size (MWp) 14.8 9.3 Production Efficiency (MWh/MWp) 1232.1 1490.9 Tracker Advantage 21% Annual MWh 18254 13869 System Cost ($/Wp) $ 1.70 $ 1.85 System Cost ($) $ 25,185,185.19 $ 17,209,302.33 Flat PPA rate ($/MWh) $ 40.00 $ 40.00 Annual Revenue $ 730,160.00 $ 554,751.80 Fixed Tilt Advantage 32% Source: Electric Power Research Institute (2017) 8
System Design - Inverters Qty: 10 Manufacturer: Freesun Model: FS1050CU-24299T Nominal Power: 1,190 kw Administratively limited at 85% (1011 kw) Max Input Voltage: 1000 V DC Maximum Power Point Tracking (MPPT) Output: 390 V AC 9
Weather Stations 2 weather stations installed Available data points: Ambient temperature Barometric pressure Dew point Global horizontal irradiance Plane of array irradiance Rain Relative humidity Wind speed Wind direction 10
Maintenance Grounds maintenance Mowing grass, controlling weeds Erosion control Module replacement Cooling fans Inverters are forced air cooled Inverter modules and controllers Blown fuses Due to lightning and surges No cleaning 11
System Performance E.W. Brown Quick Facts 19.8% capacity factor during 2017 Daily Min: 0% (outage) Daily Max: 37.5% 17,336 MWh 2,157 MWh in June (30% CF) 497 MWh in January (6.7% CF) Output varies considerably by season, month, time of day, and with weather Brown solar production 10 MW (nameplate capacity) - 94 hours or 1% of year Above 9.9 MW - 137 hours or 1.6% of year Offline and parasitic 51.6% of the time (drawing power from the grid, ~ 24.5 kw) 12
System Performance - Monitoring 13
Live Monitoring 3/21/2018 Snow Day Zero Net Output 14
Live Monitoring 3/14/2018 Snow Melting 15
Live Monitoring 8/21/2017 - Solar Eclipse 16
Live Monitoring 7/27/2017 Lightning Strike 17
Live Monitoring 7/27/2017 Lightning Strike 18
Live Monitoring 12/27/2017 Failure of Inverter 1A Blinky 19
LG&E and KU Energy Storage Overview
What is Energy Storage? Energy Storage Systems Mechanical Thermal Chemical Electrochemical Electrical Pumped Hydro Thermochemical Hydrogen Storage Lithium-Ion Supercapacitors CAES Sensible Thermal SNG Lead Acid LAES Latent Thermal NaS Flywheels Redox Flow 21
What is Out There? Pumped Hydro 20.5% Thermal Storage 13.1% # of Projects Rated Power (MW) Avg. Duration (h) Electro-chemical 1055 4008 2.62 Pumped Hydro 353 184196 26.47 Thermal 225 3684 6.84 Electro-mechanical 74 2588 13.02 * Hydrogen 14 21 17.77 Liquid-Air 2 5 3 Other 0.9% Electromechanical 4.3% Electrochemical 61.2% Thermal Storage 1.9% Electrochemical 2.1% Electromechanical 1.3% Other 0.1% ESS Installations - Number of Projects Reference Numbers (as of January 2016) Total battery capacity of electric vehicles on US roads: 11,500 MWh Total battery capacity of consumer electronics sold in 2015: 55,000 MWh Pumped Hydro 94.6% ESS Installations Installed Power 22
Typical Battery Energy Storage System Design 23
Energy Storage Research & Demonstration Site Site Mission: 1. Learn about an emerging technology and how it can be of value to the utility grid and our customers. 2. Promote technological advancement through collaboration with storage vendors, research organizations, regulating authorities, local universities, and other utilities. Better Product Kentucky s first utility-scale energy storage project Storage Vendors ESS R&D Site = Higher Value Constructive Feedback
Project Overview
Site Features Three testing bays Modular construction 1.2 MVA resistive, inductive, capacitive (RLC) load bank Grid-connected or islanded High accuracy metering and data logging User-facility-style site Operational: Dec. 2016
Key Research Objectives Develop integration, testing, and evaluation procedures Evaluate benefit/cost related to battery performance testing for use cases Test application of multiple (stacked) control functions Determine cost-of-ownership, O&M Study integration challenges between multiple battery systems Model energy storage impact at distribution circuit level Screen multiple technologies (plug-and-play design) for short- and long-term testing Transition from R&D to Operations
Kentucky s First and Largest Grid-Scale Energy Storage System 1 MW, 2 MWh Lithium-Ion 340 Battery Modules ~100 lbs. each Smart Inverter Custom, State-Of-The- Art Battery Controls Custom Enclosures Redundant HVAC Built-In Fire Suppression Alarms and Interlocks 28
Dynapower Inverter 480 V Delta 3 ph. output 740-1150 VDC Average ~900 VDC 1000 kw continuous 1000 kvar continuous 96% Efficiency Full Lead/Lag capability up to 1000 kva 4 Quadrant operation 11 control function capability 29
Greensmith Battery Management System 480 V Delta 3 ph. output 740-1150 VDC Average ~900 VDC 1000 kw continuous 1000 kvar continuous 96% Efficiency Full Lead/Lag capability up to 1000 kva 4 Quadrant operation 11 control function capability 30
Energy Storage Maintenance Replaced defective battery module due to bad temperature sensor Replaced air filters on HVAC Replaced carbon filter on inverter coolant line Bad battery backup on controller Firmware updates Replacement of control wire Fire suppression system maintenance 31
Questions? 32