California has opened a new path for home batteries to compete as grid reliability resources. Governor Gavin Newsom signed Senate Bills 913 and 905 on September 30, with fresh reporting on October 2 detailing how the measures connect virtual power plants to electricity affordability and better use of existing wires. For battery suppliers, the important change is not a new cell subsidy. It is a potential expansion of what an installed battery can sell. SB 913, the Clean Local Power Act, directs the California Public Utilities Commission to update the treatment of aggregated distributed energy resources in resource adequacy. SB 905 establishes grid utilization reporting and a route toward utilization targets. Together, they address two different obstacles: recognizing the reliability contribution of customer equipment and measuring whether utilities could use existing infrastructure more effectively before building more. Neither signature creates an immediately available, uniform payment for every household battery. The practical market will depend on regulatory implementation, operating requirements and commercial contracts. That distinction matters for customers comparing a promised future income stream with the price of a system they would buy today. What changed SB 913: A route to value distributed battery exports in grid reliability. SB 905: Reporting and potential targets for better grid utilization. Signed September 30. Implementation remains ahead. Why exports change the battery calculation Resource adequacy is the framework used to ensure electricity providers have enough dependable capacity available to meet demand. It is not simply payment for every kilowatt-hour a device produces. A resource must be capable of helping at the hours and under the conditions the system requires, with an accepted method for establishing how much capacity counts. According to October 2 reporting by pv magazine USA, customer-device fleets have historically been constrained in California's resource adequacy market by receiving recognition for reducing a home's consumption rather than fully valuing exports from customer batteries. SB 913 directs regulators to establish a valuation method for those exports during grid stress. A battery that serves the house and still sends electricity into the neighborhood can therefore have a broader role than reducing one meter's demand. The difference is commercially important. Self-consumption, backup power and grid services are separate uses of the same finite energy inventory. A useful rulebook must distinguish the power genuinely available to the grid from energy reserved for a household, committed to another program or unavailable because the battery is already depleted. Installed nameplate capacity alone cannot answer those questions. The Climate Center, a co-sponsor of SB 913, describes the law as requiring updated rules so distributed resources can fully qualify for resource adequacy. That is the legislative direction, not proof that any particular manufacturer's fleet will qualify at its advertised capacity. Aggregators will still need a dependable operating product, not just a large customer list. The second test is where batteries sit SB 905 connects the discussion to physical grid assets. The new law establishes a utilization metric for distribution and transmission infrastructure, requires reporting by the largest utilities and creates a path for the commission to set utilization targets. Better information about when equipment is heavily loaded could support more targeted use of customer flexibility. For storage, location can be as important as total fleet size. Batteries on one constrained distribution circuit may help with a local evening peak, while an equally large fleet elsewhere may not relieve that particular bottleneck. A statewide capacity contribution and a local network benefit are related, but they are not interchangeable. Programs designed around one should not automatically claim credit for the other. This creates a practical challenge for aggregators. Their dispatch software has to coordinate customer needs, electricity prices, battery availability and any local operating limits. If network utilization becomes a stronger planning criterion, the value of knowing where each device connects and when it can respond could rise. That is an analytical implication of the laws, not an announced new procurement award. Hardware sales are only the beginning Battery manufacturers and installers should read the legislation as a reason to strengthen fleet operations rather than simply raise sales forecasts. Remote controls, communications reliability, accurate metering and usable customer permissions become part of the revenue product. A battery can work perfectly as household backup yet be a poor contracted grid resource if its availability cannot be verified. Customer terms will need equal attention. Households may want a minimum backup reserve, limits on how often the system cycles and clarity about who receives grid-service revenue. Installers need to explain how those choices affect participation. Dispatch that improves an aggregator's revenue but leaves a customer unhappy with backup availability is not a durable business model. Warranty treatment is another constraint. Extra grid-service operation may change energy throughput and operating patterns, depending on the product and dispatch strategy. Suppliers and aggregators should align contracts with the actual warranty rather than assume all grid revenue is incremental profit. The same applies to communications costs, support costs and any equipment required for measurement or interconnection. Competition could eventually favor businesses that can document reliable delivery at a low total cost. That is a different contest from selling the cheapest cabinet. California's policy shift puts more attention on the complete service: equipment, enrollment, controls, customer retention and performance when the grid actually needs help. Implementation, not a guaranteed bill reduction Regulators have until June 30, 2028, to finalize the rules giving these resources a clearer route into the reliability market, according to pv magazine USA's October 2 account. The interval between legislation and implementation is material. Developers should not treat the new laws as a settled tariff, and homeowners should ask whether quoted benefits come from an existing program or an assumption about future rules. The affordability argument is that using already installed customer equipment could reduce the need for some more expensive alternatives. Whether savings reach bills depends on how resources are valued, how reliably they perform and whether program costs remain below the costs they avoid. Supporters' expected savings should not be confused with verified reductions delivered by these two newly signed laws. California's broader package also shows the limits of the policy opening. Newsom vetoed AB 1813, a proposed community solar framework that included provisions relevant to solar paired with storage. The VPP measures therefore should not be described as approval of every distributed-energy business model. Customer batteries received a regulatory route forward while a separate community solar proposal did not. The next useful milestones are concrete: commission proceedings, proposed valuation methods, measurement rules, customer protections and contracts that explain how revenue is shared. For CurrentCells readers, that is where the battery story now sits. California has moved the question from whether customer equipment belongs in grid reliability toward how much dependable service it can provide and what that service should be worth. Sources and image disclosure pv magazine USA, October 2 legislative reporting The Climate Center, September 30 signing announcement (bill co-sponsor) Hero: original AI-generated conceptual illustration for CurrentCells, not a photograph of an op