The whitepaper titled “Contributions of the H2020 RESOLVD project to standardization and regulation” outlines the key technological innovations, stakeholder needs, and regulatory implications of integrating distributed renewable energy resources (DG) into low-voltage (LV) distribution grids. The document consolidates technical achievements and strategic insights from the RESOLVD project, funded under the EU’s Horizon 2020 framework (grant agreement No. 773715), and coordinated by the University of Girona.

Objectives and Context

The RESOLVD project aims to enhance the hosting capacity of LV networks for variable renewable energy sources (vRES) by developing a modular solution combining advanced power electronics, local storage, and ICT-based grid observability and control. It targets optimal, cost-efficient, and secure grid operation through the active management of flexibility, thus avoiding expensive infrastructure reinforcements.

Technological Innovations

1. Power Electronics Device (PED)
   At the hardware core of RESOLVD is a hybridized Power Electronics Device that integrates both lithium-ion (FENECON) and lead-acid (Ultracell) batteries. It supports:

   • Four-quadrant operation (active/reactive power dispatch)

   • Grid-forming capability in island mode

   • Harmonic compensation and current balancing

   • Communication via Modbus TCP/IP and CAN bus

   Notably, the PED employs silicon carbide-based dual active bridge (DAB) converters for compactness and efficiency.

2. Software Platform
   The RESOLVD software architecture, designed on SGAM (Smart Grid Architecture Model) and delivered as a Service-Oriented Architecture (SOA), includes:

   • Enterprise Service Bus (ESB) for integration with SCADA, GIS, and external systems

   • Data Management System with triple store (Apache Jena) and NoSQL (Apache Cassandra)

   • Forecasting Modules for demand, generation, and critical event prediction using machine learning (Random Forests)

   • Grid Operation Scheduler (GOS) for day-ahead optimization of switching and battery scheduling

   • Fault Detection Application (FDA) using PMU-based wide-area monitoring

   • Security Layer for AAA and network-level protection

3. Use Cases
   RESOLVD tested multiple high-level use cases (HLUCs) including:

   • HLUC 01: Congestion and voltage mitigation via storage and grid reconfiguration

   • HLUC 02–03: Voltage control and power quality enhancement using reactive power injection and waveform correction

   • HLUC 05: Self-healing grid functionalities

   • HLUC 06–07: Controlled islanding and anti-islanding capabilities

Stakeholder Insights

The project identified and engaged a broad set of stakeholders—DSOs, BRPs, aggregators, retailers, prosumers, energy communities, CPOs, building operators, and suppliers. Each group demands enhanced observability, flexibility, and cost-efficient grid solutions. Interviews with GEODE (a DSO association) revealed several priorities:

• Investment barriers due to CAPEX-oriented regulation

• Demand for flexibility services and incentives (e.g. time-variant tariffs)

• Long-term demand for technologies like PMUs and battery services

• A need for clear regulatory boundaries for DSOs in future markets

Regulatory Landscape and Recommendations

The whitepaper critically assesses EU regulation, particularly the Clean Energy Package (CEP), including:

• Directive EC 2019/944 and Regulation EC 2019/943, which promote energy storage and aggregation in flexibility markets

• Ambiguities in current Network Codes (NCs) that exclude storage from standard connection rules

• National advancements in countries like Germany, Denmark, and Italy, which have specific codes for Battery Storage Systems (BSS)

Despite progressive directives, DSOs are prohibited from owning storage, leading to calls for regulated flexibility markets where ESS and aggregators can operate under fair conditions. The report also highlights ancillary services markets (e.g., Black Start, Voltage Support, Synthetic Inertia) as key opportunity areas for ESS—especially under balancing markets (FCR, FRR) regulated by EC 2017/2195.

Conclusions

The RESOLVD project demonstrates that integrated hardware/software solutions with intelligent forecasting, storage hybridization, and advanced power control can substantially improve DG hosting capacity and grid efficiency. To scale these solutions, the report advocates:

• Regulatory support for OPEX-oriented innovations

• Clear market models for ESS and aggregators

• Harmonized technical standards for ESS integration at the LV level

By bridging technology development and regulatory foresight, RESOLVD provides a roadmap for flexible, cost-effective, and resilient LV grid modernization across the EU.