Photo: SMA

In search of prac­ti­cal solu­tions for island networks

What pos­si­bil­i­ties of sus­tain­able ener­gy sup­ply can be devel­oped for remote areas all over the world? In a research project, the Bib­er­ach Uni­ver­si­ty of Applied Sci­ences (HBC) togeth­er with the Reut­lin­gen Uni­ver­si­ty of Applied Sci­ences and var­i­ous part­ners from indus­try and sci­ence devel­op island net­works and solu­tions from renew­able sources for off-grid areas.

The chal­lenge: PV mod­ules only pro­duce elec­tric­i­ty when the sun is shin­ing, wind tur­bines only when the wind blows suf­fi­cient­ly strong. If they are in full swing under suit­able con­di­tions, the sur­plus­es from the gen­er­a­tion must be saved or redistributed.

Exam­ples of this already exist, such as the Caribbean island of St. Eusta­tius or Bonaire, an island in the Nether­lands Antilles, which is self-suf­fi­cient with renew­able ener­gies such as wind or sun and a bat­tery stor­age sys­tem. With the cur­rent project “PV-Diesel-Glob­al” the devel­op­ers around Volk­er Wachen­feld, pro­fes­sor of grid inte­gra­tion of renew­able ener­gies and ener­gy stor­age at HBC, want to fur­ther expand and improve the exist­ing pos­si­bil­i­ties. In con­crete terms, the par­tic­i­pants in the research net­work want to devel­op hybrid sys­tems that they can link with dif­fer­ent pro­duc­ers of elec­tri­cal energy.

Togeth­er with the project part­ner IEE, bib­er­ach Uni­ver­si­ty of Applied Sci­ences will also design a suit­able set­up for net­work pro­tec­tion, which enables the sta­ble and eco­nom­i­cal oper­a­tion of hybridized island sys­tems even with dis­trib­uted feed-in. With the decen­tral­iza­tion of ener­gy sup­ply by renew­able ener­gies, grid pro­tec­tion is already under dis­cus­sion, but cur­rent grid pro­tec­tion solu­tions are usu­al­ly based on a one-way load flow from the pow­er plant to the con­sumer, explains Pro­fes­sor Volk­er Wachen­feld. The research net­work wants to lim­it the prob­lems to be expect­ed for the island net­work and val­i­date the solu­tions found. For this pur­pose, IEE and HBC will set up sim­u­la­tion envi­ron­ments in which mod­ern net­work pro­tec­tion con­cepts can be designed and test­ed with dis­trib­uted gen­er­a­tion. The IEE will focus more on sim­u­la­tion with soft­ware tools, while HBC will inves­ti­gate these sim­u­la­tion results in a real­is­tic environment.

The island net­works will be mapped by the Bib­er­ach researchers in the Smart Grid lab­o­ra­to­ry. To this end, the lab­o­ra­to­ry will ini­tial­ly be upgrad­ed with addi­tion­al pro­duc­ers in order to meet the spe­cif­ic requirements.

And what remote area could be the geo­graph­i­cal basis for the research project? This has not yet been decid­ed, accord­ing to the sci­en­tist, who describes the ide­al pic­ture of the research net­work for this: a remote sup­ply area, for exam­ple an island, where pro­duc­tion from wind, sun, pos­si­bly also from hydropow­er, is avail­able in dif­fer­ent places and at dif­fer­ent times. Accord­ing to Wachen­feld, this com­plex­i­ty is fun­da­men­tal to the inves­ti­ga­tions, “because the ener­gy sup­ply of tomor­row must be decen­tral­ized and renew­able,” the sci­en­tist describes his conviction.