CAISO PUBLICCAISO PUBLIC

Challenges for the 21st Century Grid

Neil Millar

Executive Director, Infrastructure Development

Power Association of Northern California Annual Seminar

May 2nd, 2018

CAISO PUBLIC

California ISO by the numbers

Serves 80% of state

30 million consumers

26,000 miles of wires

72,000 MW plants

50,270 MW record peak demand (July 24, 2006)

240 million megawatt-hours of electricity delivered annually (2016)

$9 billion market

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CAISO PUBLIC

We are facing a rapidly changing mix of resource

types and technologies

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Inverter-based solar setting

the pace and inverter

based storage also

growing rapidly

CAISO PUBLIC

Oversupply and ramping: A new challenge as more

renewables are integrated into the grid

Typical Spring Day

Net Load 11,663

MW on May 15,

2016

Actual 3-hour ramp

12,960 MW on

December 18, 2016

• ISO has already seen the need to

curtail generation

• Oversupply may lead to

curtailment because of dispatch

limitations on some resources,

such as

o geothermal

o nuclear

o small hydro

o combined heat and power

Potential

over-supply

Ramping

needs increase

CAISO PUBLIC

A suite of solutions to address the challenges

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CAISO PUBLIC

The changes to the grid-connected generation fleet are

only part of the picture:

Community

Choice

50% goal

Growth in

Rooftop

Solar

Federal

Policies

Possible

100% goal

Grid

Modernization

Fossil

Retirements

A Regional

Grid

EIM

Growth

Aliso

Canyon

Consumer

Control and

Participation

The T-D

Interface

CAISO PUBLIC

The ISO’s annual transmission planning process

provides a foundation for many of these challenges

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ISO Annual Transmission

Planning Process

CPUC Integrated Resource Planning Process

CEC Integrated

Energy Resource Plan (Demand Side Forecasting)

Reliability needs

Renewable delivery

(policy) needs

Economic needs

Provides basis for special

studies on emerging issues

Includes interregional

transmission planning

coordination with

neighboring planning

regions

CAISO PUBLIC

Beyond the annual planning activities, the ISO is

actively participating in addressing other issues:

• Among the first adopters of the “composite load model” to more accurately represent impacts of customer load with behind-the-meter generation

• Addressing emerging issues with new technologies:

– Supporting NERC and WECC working groups to improve modeling of grid-connected inverter responses to voltage fluctuations during and after transmission line faults

– Worked with industry to address inadvertent loss of inverter-based generation due to frequency calculation issues

– Pursuing a NERC standard to set transient and post-fault performance requirements for inverters

• Participation in testing of solar generation’s ability to provide “inertia-like” response for frequency control

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CAISO PUBLIC

The ISO process also addresses many of the

resilience issues being discussed in the industry

• FERC Order 1000 planning process already considers extreme

events and common mode impacts

• ISO planning standards augment national and WECC

requirements, and, in particular, focus on certain extreme event

considerations such as San Francisco Peninsula concerns and

high density urban load areas

• ISO planning, procurement, coordination, reliability, and other

efforts have produced a robust and diverse infrastructure and

“set of tools” that have helped the ISO to remain reliable and

resilient in the face of significant threats such as Aliso Canyon,

SONGS, severe droughts and fires, and the solar eclipse

• Other special studies consider issues such as risk of early

retirement of the gas fleet, and gas/electric reliability

coordinationPage 9

CAISO PUBLIC

FERC terminates rulemaking on Grid Reliability and

Resilience Pricing

• FERC concluded that the Proposed Rule did not satisfy the statutory regulatory requirements under section 206 of the FPA

• But the effort “shed light” on the continued need to consider the impact that current economic, environmental, and policy drivers are changing the way electricity is procured and used

• To develop a common understanding among FERC, industry, and others of what resilience means and requires

• How each RTO/ISO assesses resilience in its geographic footprint

• To use this information to evaluate whether additional FERCaction regarding resilience is needed

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CAISO PUBLIC

The ISO suggested that FERC take a holistic approach

in defining “resilience” to accommodate regional

differences

• Not practical to guard against every possible event, but the ISO has developed a robust “set of tools” that have helped the ISO to remain reliable and resilient

• Responsibility for resilience does not solely rest with the RTO/ISO

• Proposed definition is general and somewhat vague because it does not provide a clear objective criteria, metrics, or standards to evaluate whether the existing grid is resilient

• No consideration of cost/benefit of addressing extensive resilience efforts

• Proposed definition appears to relate to reliability which is already addressed by well established reliability standards

• Potential overlap between resilience and reliability is not clearly articulated and why a new, wholly separate concept is needed

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CAISO PUBLIC

Questions?

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