Photovoltaic Hybrid Systems

Hybrid photovoltaic systems most commonly take the form of photovoltaic systems combined with wind turbines or diesel generators. They would most likely be found on islands, yet they could also be built in other areas. The largest European PV system used as a part of the hybrid system is located on Pellworm Island in Germany. A very large hybrid system was also built on the Canary Islands. The following descriptions depict some of the world most interesting PV-wind or PV-diesel hybrid systems.

hybrid PV system, courtesy SMA

hybrid PV system, courtesy SMA

SMA's inverter Sunny Island used in hybrid systems
(courtesy SMA)

Case Studies - Khythnos Island, Greece

The Kythnos Island hybrid system plant utilizes a 100 kW PV array, a 100 kW wind turbine, and a 600 kWh battery. The entire system is connected to the existing distribution grid, which is fed by a 200 kVA diesel generator. Three 50 kVA inverters operate simultaneously delivering power into the grid. The plant is monitored by control system, which optimises the amount of renewable energy available to the grid.

Name and location Kythnos Island Plant - Kythnos, Greece
PV system type PV-wind-diesel hybrid system
Operates since 1983
Rated power 100 kW PV, 200 kW diesel, 100 kW wind
Storage 600 kWh battery storage
Number of modules almost 60,000
Total PV area 1290 m2
Module mounting Fixed tilt
Inverters Siemens 50 kVA x 3
Utility interconnection 380 V, 3-Phase, 50 Hz
Design energy output 170,000 kWh/year

TABLE 1: Kythnos Island hybrid system, basic features

Pellworm Island

The largest European PV wind hybrid system is located on the Pellworm Island in Germany. The PV array has the capacity of 800 kW (originaly 600 kW). The first 300 kW array was constructed in 1983. System was renewed in 2006 and has peak power of 1,1 MW (PV + wind).

Name and location Pellworm Power Plant - Island Pellworm, Germany
PV system type PV-wind hybrid system
Operates since 1983, repowered in 2006 and 2016
Rated PV power 300 kWp part one, 300 kWp part two, 800 kWp after repowered
Number of modules 17,569 19.2 W modules, 6048 50 W modules, exchanged with Shell Solar and BP Solar modules in 2006
Total PV area 4500 m2 + 3500 m2
Module mounting Fixed tilt
Inverters Thyristor + IGBT inverter
Design energy output 770,000 kWh/year

TABLE 2: Pellworm Island hybrid system, basic features

Wilpena Pound

The Wilpena Pound power station combines 100 kWp PV system, battery storage of 400 kWh, an inverter and 440 kWp diesel generators. At night a computerized smart controller automatically switches between the battery storage and the most-efficient diesel generator combination to match the load. A modem-link provides remote monitoring and control facilities.

Name and location Wilpena Pound PV System - South Australia
PV system type PV-diesel hybrid system
Operates since 1999
Rated power 100 kWp PV + 440 kW diesel genset
Storage 400 kWh, Sonnenschein Gel battery storage
Number of modules 1260, 80 W Solarex modules
Module mounting Fixed tilt
Inverters AES 125 kVA

TABLE 3: Wilpena Pound hybrid system, basic features



IEA PVPS (2013): Rural Electrification with PV Hybrid Systems - Overview and Recommendations for Further Deployment. Report IEA-PVPS T9-13:2013.
IEA PVPS (2011): World-wide overview of design and simulation tools for hybrid PV systems - Overview and Recommendations Report IEA-PVPS T11-01:2011.