View
4
Download
0
Category
Preview:
Citation preview
RampingDebbie Lew, PhD
Western Interstate Energy Board
Nov 19, 20141
Informational Seminar Series
Utility Operations – Nov 13, 3pm MT
Ramping – Nov 19, 11am MT
Frequency Response – Dec 2, 11am MT
Transient Stability – Dec 11, 11am MT
Distributed Generation – Dec 18, 11am MT
2
Wind ramps have been an
ongoing issue
3
Steve Beuning, PSCO, 9/2012 UVIG
High-speed cut-out can
lead to wind ramps
4
The Solar Difference
5
C. Loutan, CAISO, CREPC 2014, http://westernenergyboard.org/wp-
content/uploads/2014/10/10-20-14SFF-loutan-system-flexibility-future.pdf
The Duck Curve 6
C. Loutan, CAISO, CREPC 2014, http://westernenergyboard.org/wp-
content/uploads/2014/10/10-20-14SFF-loutan-system-flexibility-future.pdf
7
M. Rothleder, CAISO, http://www.ieee-
pes.org/presentations/gm2014/PESGM2014P-002422.pdf
Up-ramps vs. Down-ramps
Up-ramps are more of an issue because utility-
scale wind and solar have the technical
capability to be curtailed. Wind turbines and PV
can decrease power output faster and easier
than thermal generators.
There may be contractual and financial issues
however.
Wind is already downward dispatched in all the
markets for congestion.
Rooftop solar, however, is not controllable.
8
Ramping solutions
Generation
Imports
Load
Storage
Markets
9
Flexibility in the
conventional fleet
Are there generators that are institutionally
blocked from providing flexibility?
Can you get flexibility from your imports/exports?
10
11
C. Loutan, CAISO, UVIG Anchorage 2013
Flexibility in the
conventional fleet
Are there generators that are institutionally
blocked from providing flexibility?
Can you get flexibility from your imports/exports?
Are there generators that are operated as
baseload that could provide flexibility?
12
13
Lew et al,
WWSIS2
2013http://ww
w.nrel.gov/do
cs/fy13osti/555
88.pdf
Declining gas prices mean
more gas generation…
14
N. Kumar, Intertek, UVIG, San Antonio, 2014
Using data from EPA CEMS, Kumar studied 900+ thermal units in US.
In WECC from 2006 to 2012, Kumar finds
starts of thermal units increased 7% with small coal starts increasing 2x and gas combined cycles by 50%
Load following from thermal units increased 75% (mostly coal)
15
N. Kumar, Intertek, UVIG, San Antonio, 2014
…and more load following
from coal plants
Flexibility in the
conventional fleet
Are there generators that are institutionally
blocked from providing flexibility?
Can you get flexibility from your imports/exports?
Are there generators that are operated as
baseload that could provide flexibility?
Want low minimum turndown levels and fast
ramping capability
16
Actual coal unit minimum
generation levels in the west
17
GE Energy, WWSIS 2010 http://www.nrel.gov/docs/fy10osti/47434.pdf
Coal is flexible… …but there is a cost to it.
Some typical lower bound wear-and-tear costs to cold start a coal plant are on the order of $100-150 per MW capacity of the plant.
Some typical lower bound wear-and-tear costs to ramp a coal plant from 70% to 100% output are on the order of $2-3 per MW capacity of the plant.
Changes in operating practice and retrofits can decrease minimum generation levels, increase ramp rates, and decrease startup/shutdown times.
Some North American coal plants are even able to operate at about 15% output and four-shift.
18
N. Kumar et al, http://www.nrel.gov/docs/fy12osti/55433.pdf
S. Venkataraman et al, http://www.nrel.gov/docs/fy14osti/60862.pdf
J. Cochran et al, http://www.nrel.gov/docs/fy14osti/60575.pdf
Load
Participation
and Storage
19
Teaching the duck to fly20
J. Lazar, RAP, http://www.raponline.org/document/download/id/6977
How can load participate?
Energy efficiency during evening load rise
Active management of water heating loads
Incorporate utility-controlled thermal storage in
new large air conditioners
Pricing incentives to reduce demand during
evening load rise
Demand response programs
21
J. Lazar, RAP, http://www.raponline.org/document/download/id/6977
CSP with thermal storage
APS’s 280 MW Solana plant has 6 hours thermal
storage
Jorgenson analyzed value of CSP/storage vs PV
in CA RPS scenarios:
22
J. Jorgenson et al, NREL, 2014, http://www.nrel.gov/docs/fy14osti/61685.pdf
Demand response is not just
about reducing peak…
23
Demand response is not just
about reducing peak…
…It is also about filling the valley
New loads such as electric vehicles (EV’s)
Smart charging vs. Dumb charging
24
Market products
25
Bigger is better
Increasing geographic diversity of the
wind/solar/load will help to smooth out the
ramping problem
Mix solar-rich with wind-rich areas
Mix winter peaking with summer peaking areas
Mix time zones
Mix hydro-rich with gas-rich areas
“Markets” could take many forms
ISO
Energy Imbalance Market
26
Faster is better
Regulation duty with hourly scheduling
Decreased regulation duty
when 5 minute redispatch
allowed
27
CAISO Flexible Ramping
Product Lack of capability to meet 5 min to 5 min changes – regulation may
need to resolve imbalance caused by frequency deviation or ACE; if regulation insufficient, then CAISO leans on rest of interconnection.
Optimization is so good that there is no margin of error.
Why can’t they just procure more regulation or non-spinning reserve? This is projected to happen frequently enough that:
Locking up more capacity in regulation will lead to more power balance violations which will lead to more price spikes.
They don’t want non-spin to be doubly compensated.
Currently in stakeholder process
28
http://www.caiso.com/Documents/Agenda-
presentation_FlexibleRampingProduct_revisedstrawproposal.pdf
http://www.caiso.com/Documents/RevisedStrawProposal_FlexibleRampi
ngProduct_includingFMM-EIM.pdf
29
http://www.caiso.com/Documents/Agenda-
presentation_FlexibleRampingProduct_revisedstrawproposal.pdf
MISO
13.5 GW wind of 173 GW total capacity
+/- 2 GW/hour wind ramps in last year
Wind ramps are not a 0-10 minute issue but rather a 10’s of minutes to hours issue
Variability less of an issue in MISO because multiple unit commitment processes. Delay decisions as long as possible to deal with forecast errors. Plus MISO has a lot of quick starts.
At 5 GW wind, net scheduled interchange has bigger impact on variability than wind. At 10 GW wind, wind is less than 10% of variability. Majority of variability is from load but the uncertainty of load is lower.
30
M. Keyser, MISO, UVIG, San Antonio, 2014
MISO
Planning for the future: new products for up ramp and down
ramp capability
New ramp product will be inserted into day-ahead market, forward
reliability assessment commitment, intra-day reliability assessment
commitment, look-ahead commitment, and look-ahead dispatch.
Reduces price spikes
Could increase regulation but regulation is expensive and the
increased requirement would raise prices for all regulation.
31
https://www.misoenergy.org/Library/Repository/Communication%20Mate
rial/Key%20Presentations%20and%20Whitepapers/Ramp%20Capability%20
for%20Load%20Following%20in%20MISO%20Markets%20White%20Paper.pd
f
Extra slides
33
34
http://www.caiso.com/Documents/Agenda-
presentation_FlexibleRampingProduct_revisedstrawproposal.pdf
35
http://www.caiso.com/Documents/Agenda-
presentation_FlexibleRampingProduct_revisedstrawproposal.pdf
36
http://www.caiso.com/Documents/Agenda-
presentation_FlexibleRampingProduct_revisedstrawproposal.pdf
37
http://www.caiso.com/Documents/Agenda-
presentation_FlexibleRampingProduct_revisedstrawproposal.pdf
38
http://www.caiso.com/Documents/Agenda-
presentation_FlexibleRampingProduct_revisedstrawproposal.pdf
39
http://www.caiso.com/Documents/Agenda-
presentation_FlexibleRampingProduct_revisedstrawproposal.pdf
40
http://www.caiso.com/Documents/Agenda-
presentation_FlexibleRampingProduct_revisedstrawproposal.pdf
41
N. Kumar, Intertek, UVIG, San Antonio, 2014
42
Recommended