Definition
Guided charging strategy during wind and solar curtailmentRefers to situations where wind or photovoltaic output exceeds local/export consumption capacity, or when generation is forcibly curtailed due to grid constraints or safety limits, and is managed by power grid companies, trading institutions, or aggregators throughLow-price electricity, temporary subsidies, dispatch instructions, or charging price curves., guiding flexible-timeElectric vehicle charging loadsTo concentrate or accelerate charging within power curtailment windows, thereby improving green power utilization and alleviating power abandonment and peak regulation pressure. The strategy targets include both public/private EV charging station networks as well as fleet centralized control and vehicle ends with connectivity capabilities.
Unlike conventional peak-valley electricity pricing, this type of strategy often binds with real-time or near real-time renewable output, curtailment probability, and regional electricity price signals, and the window may last only tens of minutes to a few hours. Implementation requires the delivery of "whether currently in a curtailment window, available power limit, settlement rules" to the terminal, and the terminal must report back the actual charging power, electricity, and time period, for power consumption accounting, subsidy settlement, and model iteration.
Technical Features
The business chain spans renewable energy forecasting and trading, distribution network constraints, charging operation platforms, and multi-domain coordination of EV charging station/vehicle communication. On the IoT side, support is needed for strategy version number, effective time, revocation, and explanation codes to avoid disputes when instructions conflict with local electricity price tables or OCPP custom extensions. In addition to SOC and power, uplink data often also needs the number of available piles at the site, queue length, and temperature-controlled power reduction events, so that aggregators can decide whether to continue to strengthen guidance.
Areas with a high proportion of new energy sources are prone to minute-level fluctuations : if relying solely on day-ahead electricity prices, the response is delayed; when combined with intraday rolling clearing or dispatch signals, higher requirements are placed on the accessibility, latency, and concurrent delivery of the link. SimtoLink IoT SIM cards provide manageable and controllable cellular access for EV charging station gateways, station controllers, and vehicle modules, making it easy to divide APNs, data pools, and targeted access by station/fleet, isolating strategic channels from high-traffic services such as firmware OTA and multimedia.
Use Cases
Commonly seen in orderly charging and demand response pilots around large new energy bases , centralized distributed photovoltaic parks , and cities with a high proportion of renewable energy ; also seen in independent storage + charging station collaborative scenarios, prioritizing energy replenishment for station-side storage and vehicles during curtailment windows. Large-scale promotion requires alignment with load forecasting, orderly charging, and green power contracts regarding data standards, while explaining to users "why it is cheaper/greener at this time" to reduce complaints and adverse selection.
SimtoLink focuses on providing stable network connectivity and traceable billed-level identification (e.g., ICCID bound to EV charging station assets) for strategy dispatch, metering, and effect feedback, supporting operators in completing connection governance from pilot to replication.
Key points for cooperation with IoT SIM cards
With short curtailment windows and frequent signal updates, cellular connections must ensure timely delivery of strategy and price updates , while avoiding OTA or unrelated services from occupying bandwidth and causing "the command arrives after the window has passed". The following summarizes key implementation points strongly related to IoT SIM cards from the perspective of connectivity and operations.
- Channel Isolation and QoS Awareness: Direct policy/telemetry traffic through an independent APN or targeted domain name, separating it from high-traffic flows like media or advertising screens; refresh and evaluate the data plan tier and concurrent charger scale on a per-minute basis to prevent signaling storms during sudden platform-wide price adjustments.
- Issuance and Return Contracts: The platform issues contracts carrying policy IDs, effective UTC time, revocation flags, and error code enumerations; chargers/vehicles report charging power curves, cumulative energy, and participation response flags to facilitate bilateral reconciliation of green power consumption and subsidies.
- Weak Network and Site Environment: Weak coverage is common in basements and suburban stations, requiring retries, offline caching, and a "last known valid policy" fallback; if necessary, use dual SIM with two carriers or cellular plus dedicated line redundancy to reduce the risk that a single disconnection point prevents price-adjustment guidance.
- Roaming and Cross-Region Fleets: Before vehicles operating across provinces participate in regional power curtailment responses, evaluate roaming fee caps and home-region settlement to prevent uncontrolled pilot costs from being passed on to users or the platform.
- Asset and Audit Binding: Store ICCID, IMEI, charger number, station GIS, and participation contract/green certificate traceability IDs; meets regulatory or grid-side requirements for ledger and log retention of adjustable load resources.
- Security and Integration Boundaries: When interfacing with dispatch, trading centers, or aggregation cloud platforms, align TLS, fixed outbound IPs, whitelists, and session audit policies to prevent exposing policy interfaces on uncontrolled public network paths.