1 Large Scale Storage and Demand Resources - Enabler of Transmission Delivery? Paper Number: 14PESGM2398
2 Agenda Drivers for Energy Storage Key Applications of Energy Storage Energy Storage as a Transmission Asset A Study of Congestion Relief in New York ISO using Battery Storage Demand Response and Transmission Conclusions
3 Why Storage? Lowering Greenhouse Gases Integrating renewable generation Making the grid resilient
4 Types of storage Battery Storage Electrical energy is stored for later use in chemical form. Many different battery chemistries are available. Example: 20MW A123 Li-ion battery storage plant in Johnson City, New York Pumped Storage Hydro Electricity is used to pump water to an upper reservoir during off-peak hours. Stored electrical energy is released during on-peak hours. Example: 1500MW Castaic plant near Los Angeles, California Compressed Air Energy Storage Electricity is used to compress air which is stored in tanks or underground caverns. Compressed air is used in gas turbines to produce electricity when needed. Example: 115MW CAES plant in McIntosh, Alabama Flywheel Energy Storage Electricity is stored as rotational energy. Energy is extracted by converting the kinetic energy to electrical energy by slowing the flywheel. Example: 20MW Bacon flywheel project in Stephentown, New York. Thermal Energy Storage Electricity is used to make ice during off-peak hours The stored ice is used in a cooling system to offset electricity consumption during peak hours. Example: 12MW thermal storage, Napa Valley Community College, California.
Energy 5 Energy or Power? Power Pumped Hydro Compressed Air Battery - + Flywheel Ultracap + - Application defines the power & energy needed... Each storage medium has a sweet spot
6 One Size doesn t Fit All! Source: Grid Energy Storage, US DOE, December 2013
7 Cell GE s Durathon Battery Battery Module (Application-Specific) System High Power Durathon High Energy Seconds Minutes Hours
8 Storage as a Transmission Asset Is storage a generation or transmission asset? In 2010, FERC ruled that storage could be a transmission asset The owner/operator of the storage is only responsible for maintaining the state of charge of the device The resource is operated by the transmission owner/system operator as they would operate other assets like transformers The owner/operator pays retail energy prices when taking power from the grid and receives retail credit in releasing energy The resource will not participate in any wholesale electricity markets Example A 4MW, 32 MWh NaS battery was used to support power quality on a 100 km, radial 69KV transmission line that feeds the border town of Presido. The battery s quick response time addresses voltage fluctuations affecting power quality and the 8 hour duration can supply power during an outage. The battery functions as a transmission asset, providing reactive power to support the transmission system, and defers replacement of the transmission line from Marfa.
9 Storage for Mitigating Congestion Transmission congestion is caused due to flow limitations on the transmission network: An import-constrained area may experience shortage of power and higher electricity prices, since more expensive supply side resources inside the area do not face competition from the outside resources. An export-constrained area may experience surplus of power and lower electricity prices, since too many supply side resources inside the area compete to supply power with no possibility of exporting their power out. Transmission congestion prevent efficient allocation of resources in the grid and result in higher system-wide production costs. Traditional way to relieve congestion is to invest in upgrades or new transmission (or build new generation). Storage could be used to mitigate congestion
10 Study Description Objective A high-level demonstrative study of battery storage for mitigation transmission congestion in New York ISO (Leeds- Pleasant Valley constraint) Battery 10MW battery with 4 hours of storage GE-MAPS Production simulation to determine impacts on production costs and load payments for 2017 Full Eastern Interconnection (EI) modeled. Leeds Pleasant Valley
11 Battery Charge/Discharge Profile Flow on Leeds- Pleasant Valley line and Battery Charge/Discharge Profile
12 Study Methodology $20/MWh 100MW A 100MW Limit B SP=$110/MWh $60/MWh 10MW 110MW Load Production Cost 100 MW*20 $/MWh + 10 MW*60 $/MWh = $2,600 Load Payment 110 MW* 60 $/MWh = $6,600
13 Study Methodology $20/MWh 100MW A 1 MW Battery Case 100MW Limit B SP=$110/MWh $60/MWh 9MW 110MW Load Production Cost 100 MW*20 $/MWh + 9 MW*60 $/MWh + 1 MW*40 $/MWh = $2,580 Load Payment 110 MW* 60 $/MWh = $6,600 - + 1MW Battery $40/MWh
14 Study Methodology 15 MW Battery Case $20/MWh A 100MW Limit B $60/MWh 0MW 95MW 110MW Load Production Cost 95 MW*20 $/MWh + 15 MW*40 $/MWh = $2,500 Load Payment 110 MW* 40 $/MWh = $4,400 - + 15MW Battery $40/MWh
15 Study Results Production Cost Savings i.e., Savings in Fuel and Operations & Maintenance (O&M) costs 2.03 Million $ for NYISO 5.95 Million $ for Eastern Interconnection Congestion Impacts Leeds-Pleasant Valley Constraint Limiting hours reduced by ~400 hours
16 Study Results Load Payments in Zones G-H lower by ~3.0 Million $ in 2017 Load Payments in NYISO lower by ~1.5 Million $ in 2017 Load Payments in Eastern Interconnection lower by ~20 Million $ in 2017
17 Study Results Reduction in production costs and load payments are significant for NYISO Even higher if reductions outside NYISO can be monetized Stacking of other services may further increase value Benefit-Cost depends on a lot of factors
18 DR as a Transmission Asset In Import-Constrained Areas: DR resources that respond to higher prices (or other event signals) in import-constrained areas can help alleviate the transmission congestion by decreasing electricity demand or increasing electricity supply, and relieve the need for increased imports Examples are load curtailment and peak reduction, discharging of energy storage, vehicle to grid (V2G) discharge, etc. In Export-Constrained Areas: DR resource that respond to lower prices (or other event signals) in export-constrained areas can help alleviate transmission congestion by increasing demand for electricity, and relieve the need for increased imports. Examples are load shifting, such as delayed operation of smart appliances, charging of energy storage, smart scheduling of electric vehicle charging.
19 Conclusions Strategically placed Energy Storage or Demand Response can lower congestion costs Change in commercial mechanisms may be required to fully realize the value Stacking of services may be required to realize full value