© Fraunhofer ISE

Solar sys­tems learn to swim: Research and indus­try com­bine to put var­i­ous sys­tems through sev­er­al years of prac­ti­cal use.

Float­ing pho­to­volta­ic pow­er plants — so-called float­ing PV plants — enable the expan­sion of renew­able ener­gies with­out tak­ing up new land areas. The Fraun­hofer Insti­tute for Solar Ener­gy Sys­tems ISE, RWE Renew­ables and the Bran­den­burg Uni­ver­si­ty of Tech­nol­o­gy Cot­tbus-Sen­ften­berg (BTU) want to fur­ther devel­op this inno­v­a­tive tech­nol­o­gy togeth­er with oth­er part­ners. The aim of the “PV2Float” research project is to sub­ject sev­er­al float­ing PV sys­tems with dif­fer­ent sys­tem designs to inten­sive prac­ti­cal test­ing. The research project is sched­uled to run for a total of three years. A suit­able open pit lake for imple­men­ta­tion is cur­rent­ly being selected.

Float­ing PV on water sur­faces har­bours a hith­er­to hard­ly exploit­ed pow­er gen­er­a­tion and cli­mate pro­tec­tion poten­tial world­wide. In con­trast to ground-mount­ed sys­tems, the PV mod­ules are installed on float­ing bod­ies and deployed on stand­ing water or the sea. In Ger­many alone, some 500 open­cast lakes have been cre­at­ed as a result of open­cast lig­nite min­ing. Accord­ing to a study by Fraun­hofer ISE, from a pure­ly tech­ni­cal point of view, these have a usable poten­tial in the mid-dou­ble-dig­it gigawatt range*. Thus, the float­ing PV plants open up new per­spec­tives for for­mer cen­tres of lig­nite min­ing, such as Lusatia.
The “PV2Float” project, which is fund­ed by the Ger­man Fed­er­al Min­istry for Eco­nom­ic Affairs and Ener­gy, aims to help tap this poten­tial. The test plants form an impor­tant basis for a pre­cise analy­sis of the tech­ni­cal require­ments, eco­nom­ic effi­cien­cy and eco­log­i­cal effects of float­ing PV pow­er plants in Ger­many. The focus is also on the ques­tion of acceptance.

In addi­tion to the final site selec­tion, RWE is con­tribut­ing to the project with a com­pre­hen­sive poten­tial analy­sis of the Ger­man and inter­na­tion­al mar­ket for float­ing PV. As one of the world’s lead­ing com­pa­nies in the field of renew­able ener­gies, RWE has many years of expe­ri­ence in the con­struc­tion and oper­a­tion of ground-mount­ed solar plants and is cur­rent­ly imple­ment­ing a float­ing PV project in the Netherlands.
Thorsten Miltkau, Senior Man­ag­er Solar Pow­er at RWE Renew­ables, explains: “We see great poten­tial for float­ing PV world­wide. With this research project, we want to deep­en our knowl­edge of the tech­ni­cal pos­si­bil­i­ties of float­ing pho­to­volta­ic sys­tems, such as scal­a­bil­i­ty and ener­gy yield, and trans­fer the find­ings to com­mer­cial projects.”

The exper­i­men­tal plant is being designed and built togeth­er with Vol­ta Solar. Four float­ing instal­la­tions and a ref­er­ence instal­la­tion on land with a total out­put of around 150 kilo­watts are planned. Heck­ert Solar, a solar mod­ule man­u­fac­tur­er from Chem­nitz, will sup­port the project with inno­v­a­tive mod­ule concepts.
VDE Renew­ables eval­u­ates the pow­er plant con­cepts devel­oped with­in the frame­work of the project with regard to con­for­mi­ty with stan­dards and elec­tri­cal safe­ty and checks the plants after con­struc­tion. Fraun­hofer ISE is inves­ti­gat­ing the reg­u­la­to­ry frame­work for float­ing PV sys­tems and is devel­op­ing a pro­ce­dure for the par­tic­i­pa­tion of local actors. The insti­tute also checks the reli­a­bil­i­ty of the indi­vid­ual sys­tem com­po­nents, fur­ther devel­ops PV mod­ules and yield sim­u­la­tions for the spe­cial require­ments of the float­ing appli­ca­tion area, and ana­lyzes the eco­nom­ic effi­cien­cy of float­ing PV. Ste­fan Wieland, head of the project at Fraun­hofer ISE, explains: “The body of water places spe­cial demands on the design, mate­r­i­al, envi­ron­men­tal com­pat­i­bil­i­ty and oper­a­tional man­age­ment of float­ing PV pow­er plants. The project will inves­ti­gate these with respect to the con­struc­tion of large float­ing PV systems.”
The eco­log­i­cal mon­i­tor­ing of the project is car­ried out by the BTU Cot­tbus-Sen­ften­berg and the Insti­tute for Water and Soil Dr. Uhlmann from Dresden.
Dr. Dieter Leß­mann from the Chair of Water Pro­tec­tion at the BTU Cot­tbus-Sen­ften­berg notes: “The eco­log­i­cal com­pat­i­bil­i­ty of float­ing solar plants is a basic pre­req­ui­site for their approv­abil­i­ty. With the PV2Float research project, we want to fur­ther our knowl­edge of the aquat­ic eco­log­i­cal effects.”