The California Public Utilities Fee just lately laid out the subsequent step in the way it plans to fulfill the calls for of 2018 state regulation SB 1339 — making a regulatory construction for commercially viable microgrid initiatives.

That’s a tall order, requiring insurance policies that promote California’s carbon-free vitality targets, give communities a path to safe backup energy amid wildfire and heatwave-driven blackouts, present third-party industrial builders a option to earn revenues for the providers they supply — all whereas preserving utilities’ position as supplier of energy when the grid’s nonetheless up and working. 

Amid the myriad complexities of this coverage puzzle, one crucial but unresolved idea stands out: the necessity to create a microgrid “tariff” that specifies how a system’s a number of applied sciences, possession constructions, and prices and advantages might be utilized to microgrid mission after mission. Piecing that puzzle collectively will probably be crucial to scaling the microgrid market up rapidly and effectively.

Tariffs govern the whole lot from interconnecting energy crops and transmission traces to how utility prospects pay their payments or receives a commission for the solar energy they generate. However microgrids that mix a number of applied sciences, or utility-managed and privately-owned infrastructure, have but to be standardized on this means. 

Final 12 months, the CPUC declined to take up work on a tariff to focus its “Monitor 1” efforts on constructing microgrids in time for the 2020 wildfire season, a decent timeline that the state’s utilities weren’t capable of meet with cost-effective initiatives. In reality, Pacific Gasoline & Electrical ended up contracting for a whole bunch of megawatts of cellular diesel turbines to fill this 12 months’s hole in backup energy as a stopgap measure.  

Final month’s launch of the continuing’s “Monitor 2” features a plan from CPUC workers (PDF) to outline a easy microgrid tariff to bundle funds for a number of distributed vitality assets (DERs) right into a single utility fee construction. The plan is targeted on easy, single-customer microgrids, and delineates how they might keep away from paying “departing load fees” for leaving utility service, and “standby fees” for counting on the utility’s infrastructure for last-resort energy. Exemption from these charges would rely relying on whether or not or not they’re new or current hundreds, serve crucial amenities, or can self-power themselves indefinitely:

However this doesn’t go far sufficient, in keeping with teams making an attempt to construct their very own microgrids. The Microgrid Sources Council, a commerce group representing distributors together with Engie, Eaton, Bloom Vitality, NRG and Scale Microgrid Options, complained in its reply feedback that the tariff proposal “seems to once more be restricted to a slender class of microgrids,” in contradiction with SB 1339’s mandate. 

Vote Photo voltaic and The Local weather Heart agreed of their joint feedback, saying the proposed fee schedule “offers solely with single-user or customer-sited microgrids, and gives nothing to help commercialization of neighborhood microgrids.” What’s extra, its concentrate on cost exemptions “gives no compensation for the worth of providers microgrids can present to the grid.” 

California’s neighborhood selection aggregators (CCAs), main proponents of microgrid improvement, agreed of their joint submitting that the CPUC’s proposal don’t go far sufficient. A “common microgrid tariff,” in contrast, “would cowl all probably microgrid configurations,” together with “utility-sited microgrids that serve a number of parcels/prospects.” 

And the joint CCAs have a mannequin they’d just like the CPUC to develop on: the Redwood Coast Airport Renewable Vitality Microgrid being constructed in Humboldt County. 

Trying on the Redwood Coast Airport instance

The $11.5 million mission, funded by the county’s CCA Redwood Coast Vitality Authority and the California Vitality Fee, is “the primary multi-customer microgrid in PG&E service territory, and one of many solely ones in America so far as we all know,” mentioned Peter Lehman, the founding director of Humboldt State College’s Schatz Vitality Analysis Heart, the group main the mission. 

It combines a number of prospects, together with the Redwood Coast Airport and the U.S. Coast Guard air rescue station, that are crucial amenities for the county, together with 17 different prospects. Whereas RCEA owns and operates the two.2-megawatt photo voltaic array and eight.eight megawatt-hour Tesla battery system that powers the microgrid throughout emergencies, PG&E owns and operates the distribution programs throughout which that energy flows. 

Sharing current infrastructure is less expensive than forcing RCEA or its prospects to purchase and keep a piece of the distribution grid. However it additionally means “there’s acquired to be this vivid, clear line between the distribution system operator and the era system operator,” mentioned David Carter, the Schatz Heart principal engineer managing the mission. 

RCEA’s solar-battery management platform is remoted from PG&E’s grid management platform that runs the microgrid whether or not or not it’s disconnected from the grid at massive. CPUC workers highlighted this as a crucial cybersecurity measure to guard PG&E’s system-wide grid operations from intrusion. 

The “vivid, clear line” additionally applies to the tariff design, when it comes to who’s getting paid for supplying the vitality and the infrastructure it runs over throughout each islanded and “blue sky” circumstances, Carter mentioned. A major funding is required in tools to isolate the system and run it independently, and learn how to cut up these prices continues to be being labored out, he mentioned.


These infrastructure prices will probably be ruled by a Microgrid Infrastructure Value Restoration Tariff. Since RCEA requested the microgrid and its prospects reap the advantages, RCEA can pay for sure upgrades. However as a result of it’s a pilot mission, PG&E can be contributing, Carter mentioned. Future utility-operated microgrids might want to take into account learn how to deal with that cost-sharing problem. 

RCEA’s photo voltaic and battery system generates about seven occasions the electrical energy wanted by the airport, Coast Guard station and different prospects, Lehman mentioned. That may permit the microgrid to run for weeks with out its current diesel backup turbines approaching — therefore the “renewable vitality” in its identify — and it’s additionally consistent with RCEA’s purpose as a CCA to construct native clear vitality mission.  

However to make the economics work, RCEA should promote the ability on the wholesale market, by a hybrid solar-storage tariff (PDF) now being finalized by state grid operator CAISO, Carter mentioned. “In blue-sky circumstances, it is a CAISO-controlled asset,” he mentioned. 

The mission is exploring the complexities of supplying vitality and grid providers to a number of courses of consumers in each islanded and blue-sky states. The entire power-users on the positioning are RCEA prospects, however RCEA itself is a buyer of PG&E, and the electrical car chargers it’s putting in on the positioning will probably be underneath the utility’s tariffs. 

That may present alternative to analyze two various kinds of tariffs to each courses of buyer: an Islanded Grid Providers Tariff with income flowing to each PG&E because the grid infrastructure operator and RCEA for energizing the microgrid, and an Islanded Vitality Tariff payable to RCEA because the supplier of electrons. 

All informed, “the purpose is to get the framework and standardized design that PG&E may settle for quite rapidly” for different initiatives, Carter mentioned. Whereas the Redwood Coast mission is funded by CEC’s EPIC grant program, PG&E is utilizing it as a mannequin for a separate effort to help microgrid improvement for the fire-threatened Northern California communities it serves.

PG&E takes ‘good first step’

PG&E’s “Group Microgrid Enablement Tariff” (PDF) units guidelines for the way native communities, tribal governments or CCAs can construct as much as 20 megawatt programs in excessive fire-threat areas that help crucial amenities and at the very least one different buyer. It’s backed by $27 million by 2022 for PG&E to put in the mandatory utility-side tools and controls. 

The tariff will govern eligibility, engineering research, improvement of the microgrid property, and the island and transitional operation of the microgrid,” in addition to how providers are supplied throughout islanded and grid-connected circumstances, PG&E spokesperson Paul Doherty mentioned. 

Not like PG&E’s rejected plan to put in pure gasoline turbines at its substations, the neighborhood microgrid plan envisions third celebration possession, with a concentrate on clear assets. The Redwood Coast Airport mission is serving as a mannequin, Doherty mentioned, together with how communities’ improvement companions can help the technical challenges of working their energy over PG&E’s traces. 

On the similar time, the programs concerned will probably be eligible to supply distribution providers and take part in demand aspect administration applications and CAISO markets whereas they’re linked to the grid. That’s crucial to permit the photo voltaic, batteries, load controls and different microgrid property to earn revenues throughout blue-sky circumstances to pay again the prices of engineering them to maintain the ability on when they should island from the grid. 

For teams asking the CPUC to create a statewide microgrid tariff, PG&E’s proposal is an efficient first step, Ed Smeloff, Vote Photo voltaic’s director of grid integration, mentioned. However he additionally famous that “PG&E explicitly retains the rights to tug it” if the companions can’t meet the technical phrases of the tariff. “It’s clearly supposed to be testing the waters.” 

Nonetheless, it lays the groundwork for a logical step for microgrids, he mentioned, placing their mixed vitality, capability and grid stabilization providers to make use of not only for their prospects, however for the grid at massive.  

Distribution Assist Providers Tariffs: the way forward for microgrids? 

The CPUC workers paper describes this idea as a Distribution Providers Assist Settlement (DSSA), or a tariff that units localized distribution providers and supplies a market pathway to serve them. These may embody changing grid investments underneath the CPUC’s Distribution Funding Deferral Framework (DIDF), or different providers the place “no particular organized markets but exist,” as with dynamic voltage help to extend a utility’s distributed vitality internet hosting capability. 

The IDEA Schooling Basis in partnership with the Vitality Basis just lately produced a common academic white paper on the idea. The Microgrid Sources Council helps this framework as a logical option to worth the flexibility of microgrids, MRC counsel and board member Christopher Berendt mentioned.  

“With DSSAs you’re including larger controls for utilities to have the ability to conduct the dispatchable DER live performance, to have the ability to dispatch at a segmented degree,” mentioned Berendt. “You need the microgrid to have providers that the utility can name to assist it scale back value of service to the speed base, and supply higher good grid providers that assist communities turn out to be extra resilient and decarbonize.” 

“There are a lot of methods for utilities to help or companion with microgrids and DSSAs are a chief instance,” MRC counsel and board member Baird Brown added. Whereas the MRC sees microgrid commercialization pushed by prospects, “it’s cheap for regulators to reward utilities that may faucet microgrids for grid providers they might in any other case need to spend extra on to acquire themselves.”   

The Schatz heart can be exploring the potential for the Redwood Coast airport microgrid to assist out in these methods, Carter mentioned. The airport is on the finish of a definite PG&E circuit that would face overloads from any extra photo voltaic added to the microgrid’s large-scale system, he famous. But when the microgrid may island and curtail to guard the circuit from the uncommon situations of overgeneration, it may permit PG&E “toincrease internet hosting capability with out having to do costly upgrades.” 

“We all know the grid constraints upstream, so we will monitor the ability in actual time, and proactively by prediction and forecast,” he mentioned. “If PG&E is rolling out an ADMS system over the subsequent 5 years, they’ll have the ability to predict that overgeneration situation, and seamlessly disconnect the microgrid.” 

The CPUC doesn’t embody these extra superior microgrid tariff ideas in its Monitor 2 microgrids proposal. As an alternative, they’re relegated to a separate workers idea paper laying out its plans for Monitor three. However as we noticed from the feedback of events just like the MRC, Vote Photo voltaic and the joint CCAs, there’s apparent curiosity in transferring forward with them as rapidly as doable. 

Leave a Reply

Your email address will not be published. Required fields are marked *