1. Optimizing Grid Integration of Energy Storage
Community Microgrids
Optimizing Grid Integration of Energy Storage
Craig Lewis
Executive Director
Clean Coalition
mobile
13 February 2018

2. Clean Coalition (nonprofit) Mission
To accelerate the transition to renewable energy and a modern grid through
technical, policy, and project development expertise 2

3. There are Three Vital Grid Services
Key to Delivering Service
Power Balancing
Capacity of real power (W)
Voltage Balancing
Location of reactive power (VAr)
Frequency Balancing
Speed of ramping real power (W)
The Duck Chart only addresses Power Balancing, but Distributed Energy Resources deliver unparalleled location and speed characteristics 3

4. Community Microgrids = the Grid of the Future
A Community Microgrid is a new approach for designing and operating the electric grid, stacked with local renewables and staged for resilience.
Key features:
A targeted and coordinated local grid area served by one or more distribution substations
High penetrations of local renewables and other Distributed Energy Resources (DER) such as energy storage and demand response
Staged capability for ongoing renewables-driven power backup for critical and prioritized loads across the grid area
A solution that can be readily extended throughout a utility service territory – and replicated into any utility service territory around the world

5. UCSB Community Microgrid – Area Map

6. UCSB Community Microgrid – Phase 1
Legend
Color
Description
Research North Feeder kV
Critical facilities- critical loads must be backed up
Non-critical facilities- loads must be shed
Existing Solar
Proposed Solar PV
Switch 565
Eucalyptus Grove
Switch 516
Switch 552

7. UCSB Community Microgrid – Phase 1 + 2

8. Solar Siting Survey (SSS) for Montecito

9. Montecito Community Microgrid map view

10. Montecito Community Microgrid block diagram
Montecito Country Club
Vons cluster
Other Tier 1 Loads
CVS
North of 101
Santa Barbara Substation
Tier 2 & 3 Loads
Tier 2 & 3 Loads
Hot Springs feeder loop 16 kV
Tier 2 & 3 Loads
Transmission
South of 101
Athletic Club
Event Center
Cemetery
Sanitary District
Music Academy
Four Seasons
Coral Casino
Diagram Elements
Autonomously Controllable Microgrid
Relay/Switch (open, closed)

11. Community Microgrids obviate gas peakers
Thanks in part to our analysis, California regulators have rejected Ellwood and signaled their intent to reject Puente as well
“Let’s take this opportunity to move the Oxnard community into the clean energy future — which is here already.” Carmen Ramirez, Mayor Pro Tem of Oxnard
Significant opportunity to leverage this work to prevent future new gas plant proposals across the country
On October 5, at the urging of Clean Coalition, the California Energy Commission halted the Puente Power Project $299 million, 262 MW gas-fired beachfront power plant in Oxnard, CA, which is a Disadvantaged Community as defined by CalEPA’s CalEnviroScreen 3.0.
This follows on the heels of another nearby gas-fired project rejected by the California Public Utilities Commission after Clean Coalition analysis and advocacy.
Our analysis found that this project could be replaced entirely with solar+storage at a lower cost to ratepayers and a significantly reduced local environmental impact.
Our study and model of the alternative to the Puente Power Project using solar+storage can be downloaded here:
Press Coverage:
Utility Dive:
Greentech Media:
PV Magazine:
Clean Coalition filings: Ellwood Peaker -
Puente alternatives -

12. Community Microgrids cheaper than gas peakers
Leveraging our technical and economic expertise, the Clean Coalition conducted an analysis to determine the viability of solar+storage as a better alternative

13. Community Microgrids cheaper than transmission

14. Distributed Voltage Regulation – Location Matters
“The old adage is that reactive power does not travel well.”
Oak Ridge National Laboratory (2008)
T&D lines absorb 8-20x more reactive power than real power.
Prevent Blackouts:
When a transmission path is lost, remaining lines are heavily loaded and losses are higher.
Reactive power does not travel well.
This chart shows that reactive power has 8-20 times higher line losses than real power.
Also shows much higher transmission line vs. distribution line losses.
When a transmission path is lost, remaining lines are heavily loaded and losses are higher.
Expert audience notes:
The zero crossing of the reactive losses lines are the Surge Impedance Loading (SIL) points at which there is a balance between producing and absorbing reactive power.
When conducting power below its SIL, the line is primarily capacitive and supplies reactive power, tending to raise system voltages (same thing capacitor banks are used for). When the line carries more power than the SIL, it tends to absorb reactive power, lowering system voltages (same thing motor loads do).
The reactive impedances in a transmission systems are typically 8-20 times larger than real impedances, hence reactive losses are much higher, especially when lines carry higher power above the SIL.
Source: “Local Dynamic Reactive Power for Correction of System Voltage Problems,” Oak Ridge National Laboratory, September 2008
Source: Oak Ridge National Laboratory (2008)

15. Replace SONGS with Local Solar+Storagevs
SONGS provided a large amount of reactive power for voltage regulation in Southern California.
Local solar PV paired with advanced inverters can cost-effectively both reduce load on transmission lines and provide large amounts of reactive power 247/365 without reducing the amount of real power it provides while the sun shines.
For example, 570 MW capacity of PV with advanced inverters oversized by 10% at 0.9 power factor could provide the same amount of reactive power as the Huntington Beach synchronous condensers.
$80 million
2 Synchronous Condensers
San Luis Rey Substation 450 MVAr
(minus line losses = 300 MVAr)
600 MW of local solar+storage with advanced inverters oversized by 10% set at 0.9 Power Factor = 300 MVAr
CAISO proposed 320 MW DG solar MW storage = 900 MW (plus 1,400 MW of nat gas)

16. EV Charging Infrastructure with Local Balancing
(sw 2, 19 Jan 2012) 16

17. Peek at the Community Microgrid future
Ecoplexus project at the Valencia Gardens Apartments in SF. ~800 kW meeting ~80% of the total annual load. 17