Characteristics of Wind and Solar PowerFor Decision Makers

Jay Apt

Tepper School of Business and

Department of Engineering & Public Policy

Carnegie Mellon University

June 13, 2011

Briefing given to 2 sets of decision makers

• FERC staff May 26, 2011– Jamie Simler, the Director of FERC’s Office of Energy Policy

and Innovation;– Arnie Quinn, the Director of the Division of Economic and

Technical Analysis within the FERC Office of Energy Policy and Innovation;

– Ed Murrell, the Deputy Director of the Division of Economic and Technical Analysis

– Aaron Bloom, the "forecasting guy" in that office. 

• Equinox Energy Summit June 5-9, 2011– 17 Ontario and Canada federal government ministers and

staff

2

3

Hydroelectric

Wind

Geothermal

4

Operating Wind FarmsWind farms > 5 MW

5

Land use can be benign

6

Or, Not so Benign

8

Extreme wind events are much more likely than predicted by Gaussian statistics

9

Gaussian (normal) statistics

Actual Texas data

Wind sometimes fails for many days

5 10 15 20 25 30Date in January 2009

250

500

750

1000

1250

1500

WM

BPA Balancing Authority Total Wind Generation

Sum of ~1000 turbines

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15 Days of 10-Second Time Resolution Data

Smoothing by Adding Wind Farms… has diminishing returns

Source: Katzenstein, W., E. Fertig, and J. Apt, The Variability of Interconnected Wind Plants. Energy Policy, 2010. 38(8): 4400-4410.

Hydroelectric Power has Droughts

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Wind Probably Does Too

Source: Katzenstein, W., E. Fertig, and J. Apt, The Variability of Interconnected Wind Plants.

Energy Policy, 2010. 38(8): 4400-4410.

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Operating Solar PVUnits > 5 MW

17

0

1000

2000

3000

4000

1400000 1450000 1500000 1550000

Seconds since 00:00:00 Jan 1, 2007k

W

0

1000

2000

3000

250 750 1250

kW

(b)

Comparison of Wind with Solar PV

4.6 MW TEP Solar Array (Arizona)

Minutes

kW

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Nameplate capacityCapacity Factor: 19%

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CO2 and NOx from natural gas that fills in

+

+

+

1

2

n

=

Firm PowerVariable Power

Compensating Power

Time

Power

Gas

Wind

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Emissions Factors

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

0.05

0.1

0.15

0.2

0.25

0.3

0.35

(Penetration Factor)

CO

2 E

mis

sion

s (t

onne

s/M

Wh)

Expected

Predicted

(a) LM6000

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 10

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

(Penetration Factor)

NO

x Em

issi

ons

(kg/

MW

h)

Expected

Predicted

(b) LM6000

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Final Comments

• None of this means that wind or solar (if costs ever come down) can't be used at large scale, but wind/solar will require a portfolio of fill-in power (some with very high ramp rates, some with slow), good land use planning, and R&D to optimize emissions control for fast and deep ramping.

Thank you.

Jay Apt

apt@cmu.edu

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