Power forever.

July 2016

DER Monitoring and Control and Smart Inverters

SolarCity Confidential Slide 2 2

Voltage &

Reactive

Power

System

Flexibility

Peak

Demand

Shaving

Contingency

Support

DER Aggregation Utilizing customers and DERs to meet grid needs and unlock the benefits of a distributed grid

SolarCity Confidential Slide 3 3

Utility – DER Provider Communications:

Smart Energy Profile 2.0 (SEP 2.0 / IEEE 2030.5)

CA utilities have been required to implement SEP 2.0 for utility-DER

communications.

It would be beneficial for NY utilities to also implement SEP 2.0.

SEP 2.0

SolarCity Confidential Slide 4 4

Remote Communication

Dynamic Volt/VAR Support

Flexible Power Factor

Enables Dynamic Curtailment

Configurable ramp rates

Voltage‐Watt - Modify real power output autonomously in response to local voltage variations

Anti-islanding protection

Low and high voltage ride through

Low and high frequency ride through

Soft start reconnection

Frequency-Watt - Counteract frequency excursions beyond normal limits by decreasing or

increasing real power

Dynamic Current Support - Counteract voltage excursions beyond normal limits by

providing dynamic current support

Smooth Frequency Deviations

Smart Inverter Capabilities

SolarCity Confidential Slide 5 5

Inverter Data Application:

Geographic smoothing can mitigate voltage flicker

Percent max output swing in any

minute decreases as the area

covered increases.

SolarCity Confidential Slide 6 6

User defined inverter Volt/VAR curves for optimal voltage control

‒ Autonomous operation

‒ Remote updating functionality

Dynamic Volt/VAR Support

Source: Draft Input for Voltage Regulation section in the IEEE 1547 Revision. (not published or final document).

SolarCity Confidential Slide 7 7

Volt-Var Control 30% tighter voltage range

SolarCity Confidential Slide 8 8

Feeder Voltage Profile

Flexible Power Factor Field Results: Reactive Power Support

275 inverters and 5 MW PV

Thu 12:0

Fixed Power Factor configuration shifts voltage to remain within ANSI Limits

SolarCity Confidential Slide 9 9

Dynamic Curtailment 190 inverters and 1.8MW PV

Configurable

Threshold

Aggregation of inverters can be controlled to limit substation backfeed

SolarCity Confidential Slide 10 10

Conservation Voltage Reduction (CVR) Smart inverters can improve performance and reduce cost of CVR

See solarcity.com/gridx for a paper describing how to quantify CVR benefits.

SolarCity Confidential Slide 11 11

Using smart inverters to increase hosting capacity

Examples of using smart inverters as a low-cost option to mitigate

interconnection issues and increase hosting capacity:

Colorado – Seasonal fixed power factor allowed an additional 2 MW of PV to

interconnect.

Texas – Fixed power factor used to remove voltage violations.

Hawaii – Fixed power factor increased hosting capacity.

SolarCity Confidential Slide 12 12

DER Aggregation

for Grid Services

Smart Inverter Dynamic

Reactive Power Support

Smart Inverter and Battery

DERMS Pilot

Utility Collaboration Projects

Inverter Volt/VAR

Optimization & Support

SolarCity Confidential Slide 13 13

Thank you