Israel’s largest floating PV plant with inverter tech

Save water, produce green energy, think big: These guiding principles have led Siemens’ KACO new energy GmbH and local partner Altitude to supply Israel’s largest floating solar park with power equipment. The Virtual Central system solution provides an ideal fit.

Water evaporation and an unused reservoir surface

The Habonim water reservoir is in the coastal region south of Haifa, Israel. The reservoir contains 3.3 million cubic metres of water, covering an area of 112,50 acres. The water is used for regional agriculture activities. During hot days, some of the water evaporates from the reservoir, reducing the volume available for agriculture.

Fortunately, Israel has committed to a high use of renewable energy. This goal comes with new challenges. Israel is facing space constraints, for example. Solar energy competes with other important infrastructure projects.

A blue and white Siemens inverter device with a sleek design and a digital display screen.

Solar system stops water evaporation and provides new space

Since September 2021, the Habonim water reservoir has been covered by 51,500 solar modules, with a total power of 23 MW. This floating PV plant generates clean energy for 3,000 households. The system was constructed using the innovative Virtual Central design.

The solar module strings are collected in DC-combiner boxes, which also manage the string monitoring. The DC-combiner boxes are located on the floating structure on the reservoir. From there, DC cables transport the energy to the designated inverter hubs, which are land-based next to the reservoir. This reduces the operation and maintenance activities required on the 120 blueplanet 150 TL3 string inverters from Siemens’ German production facility, which are available in Israel through Siemens' distribution partner Altitude.

The solar modules prevent water from evaporating, meaning more water is available for agricultural purposes. Another major benefit of a floating solar system is the fact that ground-mounted solar systems frequently face space competition with other important infrastructure projects, such as schools or hospitals. Floating solar systems are free from such conflicts; setting them up on water leaves more space for other projects.

Virtual Central approach reduces costs and increases yield

The Virtual Central design offers a host of other advantages for floating solar systems. Because the inverters can be installed next to the reservoir, there is no need for extensive cabling. Single-MPPT inverters by Siemens can be deployed in this fashion. Furthermore, power losses stay on the DC side and a highly efficient energy transport from the reservoir to land at 1500 VDC can occur. Thanks to this, and due to efficiency of up to 99.2%, the single-MPPT inverters can provide higher yields than conventional system designs with multi-MPPT inverters.

This has been confirmed recently by independent research institutes. Because fewer cables are required for this design, the investment costs for the balance of system can be reduced by up to 10%. This leads to overall reduced investment costs.

In summary, the Virtual Central approach reduces investment costs, ensures higher yields, and is advantageous for operating and maintenance activities, especially on floating photovoltaic (PV) systems. Other floating PV systems that rely on the Virtual Central approach are in development and will be deployed soon.

See 'A study on the possible yield gain by inverters with multi-MPPT compared to single-MPPT inverters for different solar system configurations and locations'.