How Should a Romanian Factory Choose a Solar-Plus-Storage System?

According to Romanian Law No. 255 of 2024, mandatory energy storage is required for all PV systems between 10.8kW and 400kW. Installation must be completed by the end of 2027, otherwise grid transmission capacity will be limited to 3kW. This policy directly drives demand for energy storage, and factories should prioritize energy storage deployment.

Financial Subsidies and Tax Incentives

EU Fund Support: Through the National Recovery and Resilience Plan (PNRR), Romania has received €380 million for energy storage construction, and companies can apply for subsidies covering 25%-50% of project costs.

Green Certificate (GC) Benefits: One GC is awarded for every 1MWh of green electricity generated. The trading price in 2024 was approximately €85-90 per GC. Combined with peak-valley arbitrage, annual returns can reach €120,000 per MWh (using a 10MW storage system as an example).

Phase II of the Power Upgrade Program: Enterprises can receive subsidies of up to €150,000, but must cover 25% of the cost. Support is primarily for 27kWp-150kWp photovoltaic systems and supporting energy storage.

Grid Access Policy: Romania's high-voltage distribution network uses the 690V standard, while energy storage converters (PCSs) mostly operate at 400V input. Therefore, a 690V/400V isolation transformer (such as the ZOERFAN 2500KVA model) is required to ensure safe operation and EU CE certification.

Core Voltage Conversion Equipment

Isolation Transformer: For the 690V high voltage of the Romanian power grid, a transformer with a wide input range (621V-759V) and a stable output of 400V ±1% is required, such as the ZOERFAN 2500KVA model. This transformer can withstand three times the inrush current and is EU EN 60076 certified.

Power Storage Converter (PCS): Prefer models that support 690V input (such as Huawei's 5000kW PCS), or use a transformer to step down the voltage and match it to a 400V device to ensure grid compatibility.

Inverter Compliance Certification: Inverters must be certified by the Romanian National Renewable Energy Agency (RENAR) and meet the following requirements:

Dynamic Response: Supports low voltage ride-through (LVRT) and frequency regulation (50Hz±0.5Hz), with grid disconnection protection within 0.2 seconds during grid fluctuations.

Harmonic Suppression: Total Harmonic Distortion (THD) ≤ 3%, with 20% reactive power support required at night.

Communication Protocol: Compatible with the IEC 60870-5-104 SCADA protocol to facilitate grid dispatch and management. III. Equipment Selection and Supplier: Prioritizing Localization and Reliability

High-efficiency monocrystalline modules: Such as the Chint New Energy ASTRO N5 series (23.5% efficiency) and the JINGSUN 800W HJT Bifacial Module. These modules are suitable for Romania's average annual sunshine conditions of 1600 hours, feature a temperature coefficient as low as -0.29%/°C, and a 30-year power degradation of ≤10%.

Quality Supplier: Jingsun offers modules from brands such as LONGi and JINKO, supporting fast delivery and after-sales maintenance.

Energy Storage Batteries

Lithium Iron Phosphate Batteries: Preferred options include the Jingsun HV Stack Battery, ZETATECH ZT-215kWh, or Huawei's 5000kWh liquid-cooled energy storage system. These batteries offer a cycle life of ≥6000 cycles, IP65 protection for outdoor environments, and are equipped with an intelligent BMS to prevent overcharge and over-discharge. Local Case Study: A 20MW photovoltaic project in Romania employed Huawei's energy storage system. Combined with an isolation transformer, it increased energy storage efficiency by 15% and generated an additional €200,000 in annual revenue.

Smart Scheduling: Jingsun's foldable photovoltaic container system integrates an EMS platform with Modbus support, enabling real-time monitoring of photovoltaic output, energy storage status, and grid electricity prices, automatically optimizing charging and discharging strategies.

Local Adaptation: Compatibility with the Romanian power grid's dynamic pricing mechanism is required, such as charging during peak daytime photovoltaic demand (0.18 €/kWh) and discharging during peak nighttime demand (0.29 €/kWh) to maximize arbitrage.

Cost Structure

Initial Investment: A 1MW photovoltaic + 2MWh energy storage system costs approximately €1.8 million, consisting of 60% for modules, 20% for installation and construction, 15% for transformers and inverters, and 5% for the EMS.

Operating Costs: Annual maintenance costs are approximately 2% of the initial investment, primarily covering battery replacement (every 10 years) and transformer oil maintenance.

Sources of Revenue

Peak-valley arbitrage: Taking a 10MW energy storage system as an example, annual arbitrage income is approximately €1.2 million (price difference of €0.11/kWh, with one charge and discharge cycle per day).

Green Certificates: 1MW of photovoltaic power generation generates 1.2 million kWh annually, corresponding to GCs income of approximately €102,000.

Government Subsidies: Applying for the second phase of the power upgrade program can receive a €450,000 subsidy, directly reducing investment costs by 25%.

Return on Investment: Taking all of the above benefits into account, the cost of investment can be recovered within 5-7 years, and the energy storage system has a lifespan of over 15 years, providing stable returns over time.

Grid Connection Approval Process

Advance Planning: Grid connection applications must be submitted to Transelectrica, the grid company. The average approval process is 14 months, which can be shortened to 6 months by paying an expedited fee of €10,000/MW.

Certifications: Inverters require RENAR certification, energy storage systems require UL 9540 (safety) and IEC 62933 (performance) certification, and transformers require CE certification.

Fire Safety

Battery Cabinet Design: Use an outdoor cabinet with an IP65 fire rating and a HFC-227ea fire extinguishing system that automatically shuts off power when temperatures exceed 50°C.

Clearance Requirements: The energy storage system must be ≥5 meters away from the building, surrounded by a fire wall, and comply with EU ATEX explosion-proof standards.

Local Cooperation

Legal and Tax: Hire a local law firm to handle PNRR fund applications to avoid the impact of the EU carbon tariff (CBAM). Risk can be mitigated by sourcing components with a local content ratio of ≥50%.

Construction Team: Collaborating with local EPCs such as VRC Green Energy to ensure compliance with Romanian building regulations, such as roof load-bearing tests (color-coated steel tiles require ≤1.5kPa).

Project Overview: A 10MW PV + 20MWh energy storage system, equipped with two 2500KVA isolation transformers, was installed at a Romanian automotive parts factory.

Configuration Highlights:

Huawei's 5000kW PCS supports 690V direct connection, reducing intermediate conversion losses.

The energy storage system consists of four 5MWh units, each with independent temperature control, achieving a charge and discharge efficiency of ≥92%.

The EMS platform integrates real-time grid electricity price data to dynamically adjust energy storage strategies, increasing nighttime discharge to 70%.

Revenue Performance:

Annual power generation of 13GWh, 85% green electricity self-sufficiency, and electricity cost savings of €11.7 million. GCs generated €1.1 million in revenue, and the capacity market auction generated €650,000, for a total annual revenue of €13.45 million.

The payback period was 6.2 years, 1.8 years shorter than the conventional solution.

To address grid fluctuation risks, a dynamic voltage restorer (DVR) was deployed to maintain stable equipment operation during grid voltage dips, preventing downtime losses. For example, the Zhuoerfan transformer can withstand voltage fluctuations of ±10%, achieving an output stability of 400V ±0.9%.

Battery degradation management utilizes an intelligent BMS to balance battery pack voltages, with monthly deep charge and discharge cycles, extending battery life to over 6,000 cycles. ZETATECH's 215kWh system comes with a 10-year warranty, with a degradation rate of ≤20%.

Local operations and maintenance signed an annual maintenance agreement with FomCo Solar, conducting quarterly inspections of the PV panels and energy storage system, and stockpiling critical spare parts (such as IGBT modules and fuses) to ensure faults are repaired within 48 hours.

When selecting a PV energy storage system for a Romanian factory, it's crucial to prioritize policy benefits, grid characteristics, and equipment compatibility. Prioritize RENAR-certified modules and energy storage equipment that supports 690V input, and leverage local suppliers to reduce costs. By leveraging peak-valley arbitrage, green certificate trading, and government subsidies, the investment can be recovered in 5-7 years while meeting EU carbon tariff and sustainable development requirements. Factories are advised to initiate project planning as soon as possible to seize this policy window and achieve both energy independence and economic benefits.