Fraunhofer IZM has been selected for the final round of Google’s Little Box Challenge. The goal of the competition is developing the world’s smallest solar inverter. Of the more than 100 submissions in July, 18 are now still in the running for the prize of one million US dollars.  Fraunhofer IZM’s prototype was developed in collaboration with an ETH Zurich research team headed by Professor Johann Kolar and the Slovenian inventor Franc Zajc. The developers had to meet high benchmarks

• 2 kW, 240 V, 1 phase, efficiency of >95%, a maximum surface temperature of 60°C,
• and a maximum size of 655 cm³, which is equivalent to an edge length of 8.7 cm.
• The device has to reliable operate for 100 hours.

The volume fell below the allowed maximum by a multiple. “It’s the power electronic Olympics.”, says Professor Eckart Hoene, Fraunhofer IZM researcher, who kickstarted the development and brought the international team members together. The collaboration has clearly paid off. “We optimized the cooling bodies, got extremely fast semiconductors up-and-running, experimented with capacitors and developed the best inductors. We really gave it our all.” adds Hoene. Industry also lent a hand by supplying the very latest components. The prototype will be presented to a committee in the USA, by which time the fourth generation of the development will have been completed. The winner will be announced in January 2016. Although this last stage of the development will be very demanding for the researchers, they are entering this development end spurt prepared. “We will be harnessing all available possibilities, resources and powers to prove our institute’s capabilities and expertise.”, explains Hoene.