Right this moment the California Public Utilities Fee issued a big choice permitting renewable vitality methods to be permitted to interconnect to the electrical grid utilizing an vitality export schedule (often known as a Restricted Era Profile or LGP) that’s designed to keep away from grid impacts. This strategy, which leverages California’s public grid knowledge, can cut back the necessity for pricey infrastructure upgrades and assist larger ranges of renewables on the grid.
The choice is the primary of its type in the USA and is a serious milestone in enabling distributed vitality sources (DERs), like photo voltaic PV and vitality storage, to function in versatile ways in which align with situations on the grid. The choice was considerably formed by suggestions from the nonprofit Interstate Renewable Vitality Council (IREC).
At any given time, the electrical grid can settle for a finite quantity of energy export from producing methods with no need grid upgrades. This quantity, often known as internet hosting capability, varies all through the day and yr based mostly on grid situations. In California, utilities are required to supply detailed hourly fashions of the internet hosting capability for every node on their distribution system (often known as the “Integration Capability Evaluation”). Beneath the Fee’s choice, clear vitality builders can use the Integration Capability Evaluation to design an LGP to make sure that a venture stays inside internet hosting capability limits, moderately than paying for grid infrastructure upgrades that will in any other case be required. As outlined within the order, “Restricted Era Profiles specify the utmost quantity of electrical technology a DER system will export to the grid at completely different instances all year long, making certain that the venture is aware of fluctuating grid constraints at completely different instances.”
Along with ruling that utilities in California should permit venture builders to make use of LGPs based mostly on the Integration Capability Evaluation within the interconnection course of, the fee resolved different key points in its choice together with:
the sorts of management methods that can be utilized to regulate the export of energy from a system;
the allowable format of LGPs, together with what number of instances per yr a venture can change its output;
and the situations during which a utility can be permitted to curtail the output of a system in ways in which differ from the initially permitted LGP.
The Fee dominated that licensed energy management methods, units that electronically management the ability output of producing amenities, would be the major choice that builders can use to handle the LGPs of interconnecting methods. The LGP choice will develop into efficient 9 months after UL consists of the scheduling operate in its certification normal for energy management methods.
One other key situation addressed within the choice issues the format of the LGPs, particularly what number of completely different export ranges a renewable vitality system can be allowed to have all year long, and the way usually these ranges might change (known as an “LGP configuration”). The choice approves utilizing a 24-value configuration advisable by IREC, during which a system’s export ranges can fluctuate as much as 24 instances per yr.
As IREC acknowledged in feedback cited by the Fee, “This strategy will permit initiatives to design configurations that make the most of the particular day by day and seasonal peak durations that come up on the venture’s proposed location on the grid.” This stands in distinction to a competing proposal put forth by utilities that will have restricted LGP configurations to no a couple of completely different worth per thirty days, which might have did not seize the necessary peak load durations through the day, and would have rendered the LGP of restricted worth to DER builders.
The fee adopted three completely different codecs of 24-value configurations; prospects can select the format that makes probably the most sense given the situations at their venture web site. It’s unlucky, nonetheless, that the Fee handed on the chance to make sure the 24-value codecs align with the exact time durations mirrored within the time of use fee it has adopted (for instance permitting blocks from 4 to 9 p.m.). It could be splendid if venture builders may additionally suggest customized schedules (nonetheless restricted to 24 modifications per yr) to higher align with native grid situations and time-of-use charges. However, IREC commends the choice general, as it’s a important development for enabling the flexibleness and grid assist advantages that DERs can present.
A 3rd, vital situation addressed within the choice pertains to situations during which utilities can be permitted to completely curtail the ability output of a renewable vitality system (outdoors of emergency conditions) in ways in which deviate from the agreed-upon LGP as a result of altering grid situations. Utilities expressed issues that if grid situations modified sooner or later grid, grid upgrades may be required after an LGP venture is interconnected to permit it to proceed to export energy on the ranges agreed upon within the LGP.
If such a case arose, utilities wished permission to completely curtail energy technology from affected LGP-interconnected methods or to require the venture developer to pay for the price of wanted upgrades. Aligning with suggestions from IREC, the Fee restricted the situations during which long-term or everlasting curtailment can be allowed, thus higher defending venture builders from monetary danger. Such curtailment might solely be executed in situations when there’s a “sustained load discount.” The Fee moreover asserted that the utility is accountable for upgrades to keep away from such conditions. In distinctive instances, a utility might “apply for a tariff deviation to request permission for everlasting curtailment in the event that they imagine that endeavor an improve is just not an affordable use of ratepayer funds or is unreasonably pricey…”
IREC believes that this consequence is a passable decision that mitigates danger for venture builders whereas offering affordable assurances for ratepayers. The Fee additionally ordered the gathering of information to trace the prevalence of required curtailments and grid upgrades for LGP amenities, and it left open the potential of making future modifications to this coverage.
California’s forthcoming adoption of Restricted Era Profiles within the interconnection course of leads the way in which for extra revolutionary interconnection approaches that unlock the total capabilities of DERs. For extra element on this choice, go to IREC’s detailed web page on-line.
Information merchandise from IREC