PVgoesMV project to demo first medium-voltage PV power plants
With the addition of around 73 terawatts of new PV capacity expected by 2050, large quantities of raw materials will be required, including copper and aluminium for the cables.
But according to the International Energy Agency's Global Critical Minerals Outlook 2024, copper demand will exceed the announced supply from 2025 onwards. While aluminium cables are already being used, its production causes high CO2 emissions and the metal is already classified as a critical raw material by the EU.
Costs, however, can be reduced if the voltage level of the PV system is raised to medium voltage. Now, a three year German-funded project called PVgoesMV aims to demonstrate this with the construction and operation of two pilot plants.
“The move to medium voltage is a key lever for reducing the demand for copper and aluminium in large-scale photovoltaic power plants and thus for the economic viability of the projects,” explains project manager Felix Kulenkampff from Fraunhofer ISE.
Doubling the voltage leads to savings in conductor cross-section of around 75 percent. Thinner cables are easier to lay and also reduce installation costs. In addition, the connected load of transformers and substations can be doubled without changing their size. In large power plants, their number can be halved, leading to further savings in material, investment, and installation costs.
“All of the advantages mentioned are already apparent at low medium voltage. The costs of developing appropriately voltage-resistant components are manageable, which is why many component manufacturers are supporting us in the pilot project,” says Kulenkampff.
Two pilot plants with 3 kV medium voltage
The objectives of the project are to construct and test two pilot plants in Baden-Württemberg and Rhineland-Palatinate with a connected load of approximately 135 kilowatts over a period of several months.
They will be operated at 3 kV on the DC side and 1.2 kV on the AC side. The medium-voltage PV inverter used, based on high-blocking SiC semiconductors, was already developed by Fraunhofer ISE in the MS-Leikra project and is being adapted for use in the field. (The inverter is pictured above).
Two different string connections are being tested in the project: On the one hand, the use of standard solar modules with 1500 V and centre point grounding. Secondly, a 3 kV string with PV module prototypes developed for the higher voltage class.
Based on their experience in planning, construction, and commissioning, the project partners ultimately want to develop a quality assurance and testing concept for medium-voltage PV systems, incorporate findings from the field into their product design, and contribute to international standardization committees.
The project partners of are Pfalzwerke AG, the FEAG Group, Stäubli Electrical Connectors AG, Weidmüller Interface GmbH & Co. KG, Mersen Deutschland Eggolsheim GmbH, Prysmian Kabel und Systeme GmbH, Sumida Components & Modules GmbH, Hanwha Q Cells GmbH, Zimmermann PV-Steel Group GmbH & Co. KG, Infineon Technologies AG, Fluke Deutschland GmbH, and BES new energy GmbH.
They support the project by providing and further developing key components, as well as with expertise and engineering services for setup, commissioning, and monitoring.
The project, which started in December 2025, is funded by the German Federal Ministry for Economic Affairs and Energy as part of the 8th Energy Research Program 'Innovations for the Energy Transition.'
