Solar Plus: Improving Performance in Distributed Clean Energy Systems

This fall, we are kicking off a new “Solar Plus” (Solar+) project to investigate how real-time coordination between clean energy systems can yield performance improvements that benefit both building owners and utility operations. Research and development over the past decade has successfully reduced the cost of solar arrays, batteries, building controls, and electric vehicles. Many of the emerging challenges we now face are related to the large-scale deployment and integration of distributed clean energy components. For example, electrical distribution circuit capacity is limited (in order to prevent power lines from overheating), which in turn limits the downline capacity of distributed generation systems. This Solar+ project will develop control strategies to coordinate onsite resources to reduce their combined footprint on the power system, effectively increasing the capacity of the grid to host clean energy technology.

Our pilot site is a gas station and convenience store at the Blue Lake Rancheria (BLR) in Blue Lake, California. Convenience stores typically have sizable loads, including HVAC and refrigeration, which require backup power. Many of the sites also have significant potential to host rooftop solar. By working with a very common building type (there are 12,000 convenience stores in California alone), we can design with replication in mind.

Over the next two and a half years we will design and install a Solar+ system at the BLR and measure the value of distributed energy coordination. Our project will develop: (1) a hardware design guide for integrated Solar+ packages, (2) open-source software for controlling the technology, and (3) guidelines to determine the best locations for investment, given local insolation and onsite potential for system coordination. Our outcomes will be focused on integrating solar, batteries, and advanced building controls into packages that are market ready and can make positive impacts on the future trajectory of California’s built environment.

Photo of the Blue Lake Rancheria gas station and store


The Rancheria gas station & convenience store

This project is funded by the California Energy Commission through the Electric Program Investment Charge (EPIC) program. Our key partners are the Blue Lake Rancheria, which owns the gas station, and Lawrence Berkeley National Lab, where a team of researchers is developing open-source “Solar+ Optimizer” software.

Project partners also include Southern California Edison, whose refrigeration system test center data is helping us to develop algorithms, and Pacific Gas & Electric, the local energy utility.

Blue Lake Rancheria Microgrid: project update

The Blue Lake Rancheria (BLR) renewable energy microgrid received full permission to connect to the Pacific Gas & Electric grid on July 28, 2017. Designed and implemented by a team led by the Schatz Energy Research Center at Humboldt State University, this new microgrid powers critical infrastructure for the BLR tribal community and the Humboldt County region.

A microgrid is an independent power generation and management system which can operate both while connected to (parallel) or disconnected from (islanded) the electric power grid. In the event of a power outage, a microgrid enters islanded mode and balances all power generation and electrical loads independent of the utility.

The BLR microgrid breaks new ground in its seamless transition between grid-paralleled and grid-islanded states and by demonstrating stable islanded operation with a high percentage of renewable energy.

This project heralds the first deployment of the Siemens Spectrum 7 based microgrid management system (MGMS) and the first multi-inverter Tesla battery energy storage system (BESS) utilized in a microgrid application. The MGMS and the BESS were integrated using foundational relay control programming developed at the Schatz Center.

At 420 kWAC, the Rancheria’s PV array is also the largest installed in Humboldt County. The BLR microgrid has a total of 1.92 MW of generation capacity, including the PV array, a 500 kW, 950 kWh Lithium-ion Tesla battery, and a legacy 1.0 MW backup diesel generator.

Sun on panels at the Blue Lake Rancheria microgrid

Panel Array at the Blue Lake Rancheria

The microgrid powers numerous building and facility loads, including heating, ventilation and cooling; lighting; water and wastewater systems; communications; food production and storage; and transportation. The BLR green commuter program and electric vehicle infrastructure for the tribal government fleet are supported by the microgrid.

The BLR campus has also been certified to serve as an American Red Cross emergency shelter. The microgrid can maintain stable electricity for the shelter during extreme natural events such as an earthquake, tsunami, flood or wildfire. During an extended grid outage, the Rancheria can designate and shed non-critical energy loads as needed.

By coupling renewable generation with battery storage, the BLR microgrid achieves significant reductions in both utility cost and greenhouse gas emissions. The microgrid is now saving the Blue Lake Rancheria $250,000 annually and has allowed the Rancheria to increase tribal employment by 10% with new clean energy jobs.

The Blue Lake Rancheria microgrid was developed through funding from the California Energy Commission’s EPIC program. Major partners on this project included Pacific Gas & Electric, Siemens, Tesla Energy, Idaho National Laboratory, GHD Inc., Colburn Electric, REC Solar, and Kernen Construction.

• For more information about the Blue Lake Rancheria microgrid and upcoming projects at the Schatz Energy Research Center, call (707) 822-4345 or email serc@humboldt.edu.

• For more information about Blue Lake Rancheria’s sustainability and green energy initiatives, please email info@bluelakerancheria-nsn.gov.

Microgrid Feasibility Study for UCSC

The Schatz Center is working with GHD, an international engineering firm, to conduct a microgrid feasibility study for the University of California, Santa Cruz (UCSC). The study is focused on a former semi-conductor manufacturing facility that was acquired by UCSC and is being converted to offices and research lab space. UCSC wants to install a microgrid with renewable energy generating capacity of 2 to 4 Megawatts, allowing the facility to island and operate independently of the Pacific Gas & Electric grid as well as parallel with and provide support to PG&E’s grid in Santa Cruz. Another important objective is to use the microgrid as a teaching and learning laboratory by including both commercially mature and emerging/experimental technologies as well as advanced supervisory control and data acquisition systems.

The study includes:

  • evaluating microgrid technologies,
  • assessing space requirements for generation and storage technologies,
  • developing a design load profile for full occupancy,
  • selection of recommended technologies,
  • developing a site plan and one line diagram,
  • estimating construction costs,
  • evaluating interconnection requirements/constraints,
  • developing an implementation plan including potential funding sources,
  • identifying educational curriculum opportunities, and
  • evaluating how to connect the facility with the adjacent UCSC Coastal Sciences Campus to create one large microgrid that could support both of these facilities.

This project is currently active and scheduled to be completed by the end of 2017. The project is funded by the UC Regents.