Embed Size (px)
Citation preview
Renewables, DERs and Reliability in the Evolving Grid Paul Wattles Senior Analyst, Market Design & Development CleanTX Luncheon Austin January 12, 2016
CleanTX Luncheon January 12, 2016 2
The interconnected electrical system serving most of Texas, with limited external connections • 90% of Texas electric load;
75% of Texas land • 69,621 MW peak demand (set
August 10, 2015) • More than 43,000 miles of
transmission lines • 550+ generation units
ERCOT connections to other grids are limited to ~1,250 MW of direct current (DC) ties, which allow control over flow of electricity
220 MW with SPP
600 MW with SPP
30 MW with CFE at Eagle Pass
100 MW with CFE at Laredo 300 MW with CFE at McAllen
The ERCOT Region
CleanTX Luncheon January 12, 2016 3
North American ISOs and RTOs
Independent System
Operators and Regional
Transmission Organizations
are the ‘air traffic controllers’ of the
bulk electric power grids
(69kV and up)
CleanTX Luncheon January 12, 2016 4
Fuel Mix on ERCOT’s Peak Day
Note: Does not include DC Tie imports
CleanTX Luncheon January 12, 2016 5
Weather Impacts on Load by Customer Type
• Customer class breakdown is for competitive choice areas; percentages are extrapolated for munis and co-ops to achieve region-wide estimate
• Large C&I are IDR Meter Required (>700kW)
• 15-minute settlement interval demand values
Mon., Aug. 10, 2015 5:00 PM ERCOT Load: 69,659 MW Temperature in Dallas: 107°
Thursday, March 12, 2015 5:00 PM ERCOT Load: 32,955 MW Temperature in Dallas: 69°
~37,000 MW of weather-sensitive load -- 53% of peak
Large C&I 24.7%
Residential 50.4%
Residential 26.2% Small Commercial
24.9% Small Commercial
29.0%
Large C&I 44.8%
3/16/2015 IE 17:00 8/10/2015 IE 17:00
CleanTX Luncheon January 12, 2016 6
Natural Gas on the margin
• Natural gas is the marginal fuel in the ERCOT markets – Gas-fired generation typically sets clearing prices
for energy and Ancillary Services
CleanTX Luncheon January 12, 2016 7
Planning Summary
As of November 30, 2015:
• ERCOT is tracking 262 active generation interconnection requests totaling 62,510 MW
o This includes 24,071 MW of wind generation
• ERCOT is reviewing proposed transmission improvements with a total cost of more than $1.1 billion
o Transmission Projects endorsed in 2015 total $413.3 million
o Transmission Projects energized in 2015 total about $652.9 million
CleanTX Luncheon January 12, 2016 8
Wind Power Queue
• Texas leads the nation in installed wind (~20% of U.S. total) • Record generation: 13,883 MW, 12/20/15 • Record penetration: 44.7% of Load, 12/20/15
• 36.1 million MWh in 2014 • Majority of wind is in West Texas, with top production in
shoulder months and overnight
CleanTX Luncheon January 12, 2016 9
Grid-Scale Solar Queue
193 193 193
7,563
10,153
15 42 82 121 191 288
7,756
10,346
0
2,000
4,000
6,000
8,000
10,000
12,000
2010 2011 2012 2013 2014 2015 2016 2017
Cumulative MW Under Study Cumulative MW Installed
Megawatts
95
Interconnection Agreement signed + financial security posted
902 1,010
CleanTX Luncheon January 12, 2016 10
CREZ Transmission Investment
Source: Oncor/PUCT
CleanTX Luncheon January 12, 2016 11
Changing Resource Mix
The Future More renewables,
especially distributed
Current Ancillary Services were designed for this world
The world has already changed significantly
Installed Capacity by Unit Type
CleanTX Luncheon January 12, 2016 12
Ancillary Services (AS)
• A fundamental role of ISO system operations is to maintain frequency close to 60 Hz
– Accomplished by constantly balancing generation and load
• Load and generation are constantly changing, requiring continual rebalancing
– Especially on a smaller grid such as ERCOT’s
• This balancing is generally accomplished through Security Constrained Economic Dispatch (SCED) in the real-time energy market
– Economic dispatch of generation to match load every 5 minutes
• But, this process alone does not always ensure sufficient resources of the right kind are available
• Ancillary Services are additional mechanisms that ensure ERCOT can balance additional variability not covered by SCED
CleanTX Luncheon January 12, 2016 13
Future Ancillary Services Framework
• Increasing penetration of intermittent resources, including DERs, will require realigning AS to meet the changing technical needs of the ERCOT System
• Goals of Future Ancillary Services: – Flexible suite of resources to accommodate ramps – Remove barriers to entry for new resource types that
could meet fundamental requirements for AS – Improve efficiency in procurement – Market-based, technology-neutral – Based on fundamental needs of
the system, not resource characteristics – Unbundled services
CleanTX Luncheon January 12, 2016 14
ERCOT Operational Demand Response
Responsive Reserve Service Load Resource participation ceiling
Load Resource MW registered
Deployed as Responsive Reserves, via: • Manual dispatch, 10-minute ramp requirement • Instantaneous trip via Under-Frequency Relay Hourly procurement capped at ~1400 MW
Deployed via: • Manual dispatch during grid emergencies • 10- and 30- minute ramp options Special rules for weather-sensitive Loads
Emergency Response Service MW procured
IoT for Utilities
CleanTX Luncheon January 12, 2016 15
Proposed Future Ancillary Services
Regulation Up Fast-Responding Regulation Up
Current Proposed
Fast Frequency Response 1
Primary Frequency Response
Contingency Reserves 1
Synchronous Inertial Response
Supplemental Reserves 1
Mostly unchanged
59.8 Hz, Limited duration
59.7 Hz, Longer duration Fast Frequency Response 2
Contingency Reserves 2
SCED dispatch
Manual dispatch (10 min.)
Supplemental Reserves 2
SCED dispatch
Manual dispatch (30 min.)
Ongoing development
Non-Spin Reserves
Responsive Reserves
Regulation Down Fast-Responding Regulation Down
Regulation Up
Regulation Down
Fast-Responding Regulation Up
Fast-Responding Regulation Down
CleanTX Luncheon January 12, 2016 16
Candidate Resources to provide Future AS
Future AS is designed to be technology-neutral; these resource types are indicative only
Service Dispatch/notes Candidate resource types Reg-Up/ Reg-Down
AGC signals and Primary Frequency Response
Conventional generation Controllable DR
FRRS-Up/Down Auto-deploy <1 sec. Fast-acting, limited duration resources (e.g., storage, DR) FFRS-1
Auto-deploy <1/2 sec. FFRS-2 Demand Response
PFRS Governor response or equivalent Online Generation, Controllable DR
CRS-1 10-minutes/SCED Generation, Controllable DR
CRS-2 10-minutes/manual Demand Response
SRS-1 30-minutes/SCED Offline Generation, Controllable DR
SRS-2 30-minutes/manual Demand Response
SIRS Spinning mass Generators, possibly others (“synthetic”)
CleanTX Luncheon January 12, 2016 17
Distributed Energy Resources
• DERs potentially include…
Residential solar
Commercial solar Storage
…or combinations of the above at single or multiple points of interconnection at distribution voltage (<60kV)
Fuel cells
Fossil fuel generators
CleanTX Luncheon January 12, 2016 18
ERCOT’s Two Primary Goals for DERs
• Data Collection – ERCOT has outlined what data it believes it will need to ensure future
reliability as DER penetration begins to impact the bulk power grid – Mainly, accurately mapping DERs to the transmission grid
• Market Access – Integrating some (especially larger) DERs into the energy and Ancillary
Services markets can improve efficiency – 2 potential new categories:
• DER Light: Passive participation (no ERCOT dispatch) but settled at the Nodal (local) wholesale price, rather than the Load Zone price
– Would require separate metering of gross load and gross generation
• DER Heavy: Active participation in Energy and AS, much like Generation Resources today, settled at the Nodal price
– Would require: » Separate metering of gross load and gross generation » Significant real-time data to ERCOT
CleanTX Luncheon January 12, 2016 19
Zonal vs. Nodal Prices
• The ERCOT Real-Time Market produces over 4,000 Locational Marginal Prices (LMPs) at Load points every five minutes
Prices can vary based on dispatch that solves for congestion Contour map example for illustration purposes only
• Load Serving Entities pay based on the 15-minute weighted average of LMPs across a Load Zone
4 Competitive Load Zones – (North, South, West, Houston)
CleanTX Luncheon January 12, 2016 20
Demand Response in a DER
• Some DER management systems can deploy demand response as a contributor to the DER performance
• However, integrating DR into a DER involves some issues specific to ERCOT
• The PUC Rule that established the Nodal Market Design requires: – Generation to be settled at a (Nodal) Locational Marginal Price – Load to be settled at the Load Zone
• Exception: Load (energy) used to charge a storage device
• This implies that DR cannot be part of a DER that is being settled at a Nodal price, absent a Rule change
• Hence, the need for dual metering for Nodal pricing for DERs Light & Heavy – Gross Load separately metered from gross generation
(and any storage load if storage is present)
CleanTX Luncheon January 12, 2016 21
Retail Trends in Dynamic Price Offerings
Product Type Description/ Example 2013 2014 20151
Time of Use (Residential)
‘Free Nights,’ ‘Free Weekends’ 135,320 290,328 328,642
Peak Time Rebate2 (Resi, C&I)
Rebates for DR during high price intervals 2,468 413,772 499,085
Real Time Pricing (C&I)
Pricing indexed to 15-minute LMPs 4,358 9,700 5,620
Block & Index (C&I)
Fixed prices some hours, indexed others 23,928 6,976 9,536
1. 2015 counts are preliminary. 2. Events not necessarily called, rebates not necessarily issued.
Thanks in large part to the investment in advanced metering, a significant percentage of the retail market now has some kind of incentive for demand response, price response, or a behavioral shift from on-peak to off-peak
