Ramping - Western Interstate Energy Board

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

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Wind ramps have been an

ongoing issue

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Steve Beuning, PSCO, 9/2012 UVIG

High-speed cut-out can

lead to wind ramps

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The Solar Difference

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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

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M. Rothleder, CAISO, http://www.ieee-

pes.org/presentations/gm2014/PESGM2014P-002422.pdf

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.

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Ramping solutions

Generation

Imports

Load

Storage

Markets

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Flexibility in the

conventional fleet

Are there generators that are institutionally

blocked from providing flexibility?

Can you get flexibility from your imports/exports?

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C. Loutan, CAISO, UVIG Anchorage 2013

Flexibility in the

conventional fleet




Are there generators that are operated as

baseload that could provide flexibility?

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Lew et al,

WWSIS2

2013http://ww

w.nrel.gov/do

cs/fy13osti/555

88.pdf

http://www.nrel.gov/docs/fy13osti/55588.pdf

Declining gas prices mean

more gas generation…

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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)

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…and more load following

from coal plants

Flexibility in the

conventional fleet




Are there generators that are operated as

baseload that could provide flexibility?

Want low minimum turndown levels and fast

ramping capability

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Actual coal unit minimum

generation levels in the west

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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.

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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

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Teaching the duck to fly20

J. Lazar, RAP, http://www.raponline.org/document/download/id/6977

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

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J. Lazar, RAP, http://www.raponline.org/document/download/id/6977

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:

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J. Jorgenson et al, NREL, 2014, http://www.nrel.gov/docs/fy14osti/61685.pdf


Demand response is not just

about reducing peak…

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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

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Market products

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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

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Faster is better

Regulation duty with hourly scheduling

Decreased regulation duty

when 5 minute redispatch

allowed

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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

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http://www.caiso.com/Documents/Agenda-

presentation_FlexibleRampingProduct_revisedstrawproposal.pdf

http://www.caiso.com/Documents/RevisedStrawProposal_FlexibleRampi

ngProduct_includingFMM-EIM.pdf

http://www.caiso.com/Documents/Agenda-presentation_FlexibleRampingProduct_revisedstrawproposal.pdf

http://www.caiso.com/Documents/RevisedStrawProposal_FlexibleRampingProduct_includingFMM-EIM.pdf

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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.

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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.

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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

https://www.misoenergy.org/Library/Repository/Communication Material/Key Presentations and Whitepapers/Ramp Capability for Load Following in MISO Markets White Paper.pdf

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Contact Debbie at

[email protected]

303-550-1903

mailto:[email protected]

Extra slides

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