Photovoltaic power station application cases

Sichuan Aba Photovoltaic Power Station 50 MW / 100 MWh grid-type energy storage project (full capacity put into operation in May 2025)

1 Overall project scale

• Site: Aba Prefecture, Sichuan Province, China, with an average altitude of 3,600 m and an area of 8,000 acres

• Photovoltaic installed capacity: 250 MW (450,000 monocrystalline bifacial modules, 76 arrays)

• Energy storage system: 50 MW / 100 MWh lithium iron phosphate network energy storage

• Access: 220 kV booster station, T connects to Chuanzhusi-Hongyuan 220 kV line

2 Technical parameters of energy storage system

Subsystem Technical Specifications

Battery type Lithium Iron Phosphate (LFP)

Rated capacity 50 MW / 100 MWh (0.5 C, 2 h system)

Battery pack 280 Ah cells → 1P16S module → 8 modules in a cluster → 14 clusters in one → 2.5 MWh per container

Number of containers: 40 20 ft liquid-cooled high cabinets (single container 2.5 MWh / 1.25 MW PCS)

DC link voltage 1000–1500 V

Converter PCS network three-level topology, single cabinet 1.25 MW, overload 1.1 pu@2 min, efficiency ≥ 97%

Networking function: VSG (Virtual Synchronous Machine), inertia support, primary frequency modulation, and black start capabilities

BMS level three (BMU-BCU-BA), SOC accuracy ≤ 2%, supports active balancing

Energy management system EMS NARI PCS-9620EMS, supports 2 charges and 2 discharges within a day, peak shaving/frequency modulation/emergency power backup

Thermal management Perfluorohexanone fire protection + smoke temperature composite detection; liquid cooling temperature control 25 ℃ ± 3 ℃

Cycle life ≥ 6000 times (25 ℃, 0.5 C, EOL 80%)

System response: charge/discharge conversion ≤ 50 ms, inertia response ≤ 200 ms, one frequency modulation ramp 5 MW/min

3 Operation mode and benefits

• Intraday peak shaving: two charges and two discharges per day, the annual discharge is about 40 million kWh, and the peak-valley/spot arbitrage income is about 12 million yuan/year.

• Inertia support: replacing 2×100 MW gas unit inertia, reducing system frequency regulation mileage cost by 8 million yuan per year.

• Black start: The important load on the 35 kV side can be restored within 15 minutes after the 220 kV bus loses voltage.

4 Ecological and people’s livelihood characteristics

• Complementary use of pasture and light: The lowest point of the photovoltaic support is 2 m above the ground, and grass is planted under the board for grazing. The annual increase in pasture yield is 12%.

•Meadow maintenance: Construct an 18,000 m² smart greenhouse and transplant and strip the meadow, with a survival rate of 95%.

5 Monitoring and communication

• Local: IEC 61850 + Modbus-TCP, millisecond data.

• Remote: dispatch direct acquisition of IEC 104, upload power, SOC, SOH, fault recording.