Renewable energy growth is often discussed as a generation technology question. For utility operations and IT teams, it is primarily a systems integration question. The billing, dispatch, and forecasting systems that were built for one-directional power flow and flat residential rates were not designed for a grid with millions of distributed generation endpoints. This article focuses on what that mismatch requires.
Net Metering: Where Renewables Hit the CIS First
Net metering is the policy mechanism by which customers with rooftop solar receive credit for export to the grid. It sounds straightforward and the physics are simple, but the billing implementation is not. The meter must record both import and export in the same interval. The billing system must retrieve both registers, apply the netting logic for the billing period, calculate the export credit (which may be at retail rate, avoided cost, or a separately approved value-of-solar tariff), and produce a bill that is both accurate and legible.
Oracle CC&B handles this through its rates configuration framework. SAP IS-U manages it through the billing master data and rate determination process in FI-CA. Cayenta CIS supports net metering billing for the mid-market utilities it serves. In each case, the capability is real, but the configuration is non-trivial. Utilities that have not invested in updating their rate configuration since their CIS was first deployed often discover that their net metering billing is generating manual exceptions at volume.
For utilities evaluating platform options, our comparison of Oracle and SAP for utilities covers rate engine depth in both platforms.
DERMS and the Grid-Side Integration
Distributed energy resource management systems handle what happens upstream of the meter on the grid side: forecasting DER output, sending dispatch signals to aggregated resources, settling with grid operators, and coordinating with the ADMS for real-time grid stability.
GE Vernova’s DERMS product and Schneider EcoStruxure Grid are active in this space. Both must exchange data with the CIS for settlement and billing purposes. The integration architecture between DERMS and CIS is not standardized, and utilities deploying DERMS for the first time typically underestimate the integration scope. The DERMS calculates what a customer’s DER resource provided during a demand response event; the CIS must translate that into a billing credit and post it to the account correctly.
For a broader view of how smart grid optimization works across these systems, see our smart grid optimization overview.
Load Forecasting Under High DER Penetration
Traditional load forecasting uses historical consumption data, weather data, and economic indicators to predict demand. High DER penetration changes the forecasting problem materially: behind-the-meter solar reduces net load in a way that is correlated with irradiance, not with the consumption patterns that traditional models were trained on. Load forecasting errors increase grid balancing costs and, in deregulated markets like ERCOT, can create procurement imbalances.
Utilities are addressing this through distribution system state estimation (DSSE) that attempts to infer behind-the-meter generation from smart meter residuals. AMI interval data from Itron or Landis+Gyr meters, fed into the MDM and then into a load research platform, provides the input. But the data pipeline quality constraints apply here as they do everywhere: forecasting model accuracy degrades quickly if AMI read completion rates are low or if MDM processing exceptions are high.
Community Solar and Subscription Billing
Community solar programs allow customers who cannot install rooftop solar to subscribe to a share of an off-site solar array and receive a bill credit. The billing complexity rivals net metering: the utility must track each customer’s subscription share, calculate the generation credit for each billing period based on actual output from the array, and apply the credit against the customer’s consumption bill.
This requires CIS features beyond standard residential billing. Oracle CC&B and SAP IS-U can support community solar billing through rate configuration, but implementation projects have been complex enough that some utilities have used separate subscriber management systems alongside their core CIS. Cayenta CIS has deployed community solar billing for customers in its installed base.
The Honest Integration Challenge
The common thread across net metering, DERMS settlement, and community solar is that renewables growth makes the CIS the bottleneck. Generation technology costs are falling; the constraint is whether the billing and customer management infrastructure can handle the resulting rate and program complexity. Utilities that address this proactively, through rate engine modernization and MDM data quality investment, will be better positioned than those that wait for a billing crisis to force the issue.
For sustainability-related software capabilities connected to renewable programs, see incorporating sustainability practices in the utilities industry. For an independent assessment of your billing infrastructure readiness, contact AvanSaber.