The short version
- $0 fee; required during the Prepaid Energy Service, while Cash/Loan customers (and Prepaid Energy Service customers who later buy out their system) can opt out at any time at no cost without affecting warranties.
- Every dollar your solar and battery save in standard self-consumption mode belongs 100% to you.
- Incremental value earned above baseline (~$30/kWh of battery per year target across TOU arbitrage, bonus export credits, RECs, and grid services) is split 50/50 at the default 20% reserve.
- EMS revenues are computed and disbursed annually, with quarterly revenue updates sent throughout the year.
- You can control your system at any time—including temporarily bumping your backup reserve to 100% for shorter periods (returning to 20%–60% in steady state)—and EMS automatically takes over when you are not actively controlling it.
Historically, rooftop solar was a passive, “set-and-forget” appliance: panels produced power at midday and sent any surplus straight back to the grid. Today's systems—combining large lithium iron phosphate batteries, hybrid inverters, EV chargers, heat pumps, and dynamic California time-of-use tariffs—are interactive energy assets. Reaching their full financial potential requires software orchestration running around the clock, which is why we built the Potrero Energy Management Service (EMS).
Defining the Baseline: Standard Self-Consumption
Under Exhibit B of our Master Customer Agreement, standard “self-consumption” is the baseline, and 100% of your baseline self-consumption savings belong strictly to you.
In baseline self-consumption mode, your solar array powers your site's real-time loads first and charges the battery with excess daytime solar. Whenever solar drops below site demand, the battery immediately discharges to cover the load down to a 20% backup reserve—with no time-of-use price shifting, no scheduled peak-window exports, and no participation in off-bill grid programs.
We define EMS earnings strictly as the incremental economic value created above and beyond that self-consumption baseline. If the EMS does not outperform basic self-consumption, Potrero earns nothing and you owe nothing.
Where Typical EMS Revenues Come From
Across our fleet, the EMS targets roughly $30 per kWh of battery capacity per year in incremental value above the self-consumption baseline (about $858/year total on a typical 2-battery, 28.6 kWh system), split across two on-bill savings streams and two off-bill revenue streams:
Where typical EMS revenues come from
Incremental value generated above and beyond the standard self-consumption baseline (~$30/kWh/year total, split 50/50 at the default 20% reserve). Select any revenue source below to read how it works.
EMS revenue is not committed and varies from year to year based on utility tariffs, weather, and market rules, though grid services opportunities are trending upward.
Enrollment, Annual Disbursement & System Control
All eligible systems are enrolled in EMS by default at $0 upfront cost and $0 monthly fee. Enrollment in EMS is required for systems under our Prepaid Energy Service while Potrero owns and maintains the system. If you purchase your system with cash or a loan—or if you later exit the Prepaid Energy Service by buying out your system—you can opt out of EMS at any time at no cost without affecting your equipment or workmanship warranties.
Because utility Net Billing credits and grid-program settlements finalize on an annual cycle, EMS revenues are computed and disbursed annually, while quarterly updates on revenue are sent out so you can track accrued on-bill and off-bill performance throughout the year.
You can control your system at any time via the mobile app, and the EMS automatically takes over when you are not actively directing it. You can also temporarily bump your backup reserve to 100% for shorter periods (such as ahead of a storm), returning in steady state to between 20% and 60% (see the backup reserve FAQ below for how steady-state reserves interact with revenue sharing).
Beyond the Battery: Whole-Site Load Optimization & Roadmap
Potrero EMS optimizes your economics across not just your solar array and battery, but your entire electrical ecosystem—including your EV charging schedule, heat pump operation, and other network-connected electrical loads. Instead of letting heavy appliances drain your battery during expensive evening hours, the EMS turns them into flexible sponges for abundant midday solar and off-peak power:
Expanding What Your System Can Optimize
Capabilities roll out via over-the-air software updates to your on-site EMS controller at no additional cost.
- Live Today
Solar + Battery Dispatch, Rate Arbitrage & VPP Enrollment
Automated time-of-use (TOU) energy arbitrage, peak Avoided Cost Calculator (ACC) bonus export credit capture, REC monetization, and California DSGS / CCA Virtual Power Plant dispatch.
- Q1 2027
Smart EV Charging (Excess Solar & Dynamic Tariff Routing)
Real-time modulation of EV charging to soak up excess midday solar that would otherwise export for pennies, automatically pausing during 4 p.m.–9 p.m. peak windows so EV charging never drains your battery reserve.
- Q3 2027
Heat Pump & Thermal Load Optimization
Intelligent pre-heating and pre-cooling of heat pump HVAC and heat pump water heaters during abundant solar and off-peak hours—using your building and water tank as thermal batteries so compressors coast through expensive evening peak periods.
- 2028 & Beyond
Access to More Grid Programs & Networked Appliances Over the Years
Continuous enrollment in emerging wholesale capacity, dynamic hourly pricing, bidirectional EV (V2X), and distribution-level DER programs as SB 913 and utility tariffs expand—plus orchestration of additional network-connected electrical loads.
The Hardware Advantage: Our Dedicated On-Site EMS Computer
Software alone cannot unlock maximum grid revenue if it relies on flaky consumer Wi-Fi or delayed cloud APIs. With every system, Potrero installs a compact edge computer directly alongside your inverter with three physical communication interfaces that uniquely position your system to capture more revenue as new grid programs emerge:
Always-On Cellular Telemetry & Out-of-Band Dispatch
Home Wi-Fi frequently drops when routers reboot, passwords change, or local internet fails during a heat wave. Our controller includes a dedicated cellular modem so Potrero maintains an independent, high-uptime link to your inverter and battery at all times.
Virtual Power Plant (VPP) and wholesale capacity programs pay top rates only to aggregations that prove utility-grade telemetry uptime and reliable event response; missing a dispatch or telemetry interval due to a Wi-Fi dropout can dock or forfeit seasonal capacity payouts (see RMI's report on Virtual Power Plant Metering and Telemetry requirements).
Direct Sub-Second Revenue-Grade Meter Streaming
California utility meters (such as PG&E SmartMeters) contain a built-in Zigbee Smart Energy Home Area Network (HAN) radio that broadcasts real-time net import/export wattage every few seconds. Our computer includes a dedicated Zigbee radio capable of binding directly to your utility meter.
Because utility bills and VPP events settle strictly at the utility revenue meter—not at the inverter's internal CT sensors, which can drift by 2%–5%—streaming the SmartMeter directly via Zigbee lets our controller zero out peak imports with Watt-level precision and supplies auditable settlement data (see PG&E's SmartMeter™ Stream My Data / Zigbee HAN overview).
Hardwired Garage Networking for Appliances With Weak Wi-Fi
Garages, basements, and exterior equipment walls often suffer from weak Wi-Fi due to stucco, concrete, and metal enclosures. Our controller provides local Ethernet and RS-485/Modbus ports right at the inverter to hardwire nearby EV chargers, heat pump water heaters, and smart panels without relying on garage Wi-Fi or third-party cloud APIs.
Direct local control over Ethernet and open standards like IEEE 2030.5 and SunSpec Modbus enables sub-second dynamic load management—throttling EV charging to match real-time solar surplus and shifting heat pump loads during demand-response events, which utilities increasingly reward through managed-charging and flexible-load incentives.