California regulators have rewritten the rules for rooftop solar, and batteries are quickly becoming part of the standard package. In the year after the state shifted away from traditional net metering, a Lawrence Berkeley National Laboratory (LBNL) analysis found that about 74% of new residential solar installations included battery storage, with a typical battery priced around $7,000. For homeowners and installers, the stakes are high because the new structure changes how every exported kilowatt-hour is valued.
The latest publicly available update on these market changes came on May 15, 2024, when researchers released an analysis of how solar adoption shifted in the first year after the policy change. That work examined photovoltaic installations over the year since the new rules took effect and offers one of the clearest looks so far at how customers and companies are adapting.
From net metering to net billing
The shift in California began inside a regulatory process known as Proceeding R.20-08-020, which the California Public Utilities Commission uses as the central forum for designing the Net Billing Tariff. The commission describes this as the canonical hub for the tariff and uses it to organize the entire record, from early proposals to final decisions.
Within that proceeding, regulators issued a decision identified as D.22-12-056, which is linked directly from the commission’s main Net Billing Tariff page. That page also connects readers to fact sheets, staff analyses, Q&A documents and other filings that shaped the eventual design. Together, those materials show how the commission moved from the old net metering structure to a new framework that pays customers based on avoided costs.
The same proceeding page is described by the commission as useful for establishing chronology and for locating any later resolutions or implementation changes. That means anyone trying to track how solar credits have evolved since D.22-12-056 can follow the docket entries and see when utilities proposed updates or when the commission clarified how the tariff should operate in practice.
What the new analysis examined
On May 15, 2024, an analysis from Lawrence Berkeley National Laboratory was published to examine how the market had changed during the first year after net metering was phased out. The laboratory’s energy analysts focused on photovoltaic installations that occurred in the year since the Net Billing Tariff took effect and compared them with earlier projects.
The laboratory notes that its analysis was designed to shed light on how the market has evolved one year after the phase out. By looking at PV installs in the year since the new structure, the researchers were able to identify shifts in system design, including the decision by many customers to add battery storage alongside panels.
That work does not just list raw installation counts. It also reflects a methodical approach to comparing projects before and after the tariff change, which helps separate normal market growth from responses tied more directly to the policy shift. The result is one of the first detailed pictures of how California’s solar market is reacting to the end of traditional net metering.
Why batteries are moving to the center
The core finding for many readers is that solar projects completed under the new rules look different from those installed when net metering was in place. Under the earlier system, customers earned retail-rate credits for excess power sent back to the grid, which made standalone rooftop solar financially attractive without storage.
With the Net Billing Tariff, exported power is instead compensated using an avoided-cost based structure that varies by hour. That change makes it more valuable for customers to store solar energy and use it during high-price periods rather than exporting it at lower compensation levels. The laboratory’s analysis of PV installs in the year since the tariff took effect shows that storage has become a much more common feature of new systems, consistent with customers and installers adjusting system designs in response to those price signals.
For homeowners, this shift means a different cost profile. Adding a battery raises upfront spending but offers the potential to reduce bills under time-varying rates and to keep lights on during outages. The analysis released in May 2024 provides evidence that many customers are willing to accept higher initial costs when the tariff structure rewards self-consumption and stored energy.
Inside the CPUC docket
Understanding how this change came together requires a look inside the formal record. The commission’s online docket for Proceeding R.20-08-020, which can be accessed through an apps.cpuc.ca.gov portal, lists all of the filings associated with the Net Billing Tariff. That docket was discovered through the citation trail on the main Net Billing Tariff hub and functions as the official repository for comments, proposals and decisions.
Within that docket, D.22-12-056 appears alongside earlier proposed decisions and later implementation documents. The commission’s description of the hub page as useful for locating the primary documents that informed the final NBT design indicates that these materials were central to choices about export values, grid cost allocation and customer protections. For observers trying to evaluate whether the tariff is meeting its goals, that record provides the baseline.
The commission also explains that the Net Billing Tariff hub is useful for locating documents on any subsequent resolutions and implementation changes. That suggests regulators anticipated the need to adjust or clarify elements of the tariff as real-world data, such as the PV installs tracked by the laboratory analysis, became available.
Household impact and equity questions
For households deciding whether to install solar, the combination of the new tariff and the emerging battery trend raises practical questions. The analysis of PV installs in the year since the Net Billing Tariff took effect confirms that customers are adapting system designs in response to the new export values. At the same time, the higher upfront cost of adding storage could limit who can participate.
Because the latest publicly available market analysis is from May 2024, there is limited data on long term bill savings or on how low income programs are performing under the new structure. The commission’s own description of the Net Billing Tariff hub as useful for tracking subsequent resolutions suggests that any targeted equity measures or program tweaks would appear there, but those documents have not yet been synthesized into widely cited performance metrics.
This gap leaves open questions about whether the shift toward storage will reduce or widen disparities in access to clean energy. If incentives and program design allow lower income customers to pair solar with batteries, then the same tariff signals that are driving higher income adopters to storage could help reduce long term energy burdens. Without that support, the market may tilt toward households that can finance larger systems.
What the first year tells regulators
The combination of the CPUC’s proceeding record and the laboratory’s analysis of PV installs gives regulators a feedback loop. On one side, D.22-12-056 and related filings on the Net Billing Tariff hub spell out the policy logic that led to the current export values and structural design. On the other side, the May 2024 analysis documents how installers and customers behaved in the first year after net metering was phased out.
Because the commission itself characterizes the Net Billing Tariff page as useful for locating documents on subsequent resolutions and implementation changes, the next step in this process is likely to involve comparing those first year outcomes with the goals laid out in the proceeding. If storage adoption is higher than expected, regulators may examine whether export values and rate structures are aligned with grid needs and customer protections.
For now, the main lesson from the first year is that policy design has real power to shift technology choices on rooftops. By changing how exports are credited, the Net Billing Tariff appears to have prompted many customers to rethink what a standard solar installation should include. The analysis of PV installs in the year since the phase out of net metering shows that batteries are increasingly part of that answer, and future updates from both the commission and researchers will reveal how durable that shift proves to be.
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*This article was researched with the help of AI, with human editors creating the final content.
