November 24, 2008 It's an idea we've seen applied to motoryachts, trimarans and even speedboats, but until now, using solar power as an energy source for submarines wasn't on our radar. Swiss energy company BKW has aims to make this scenario a reality with Project Goldfish, a tourist attraction planned for Lake Thun that would see a 20-30 meter long submarine carry groups of visitors on tours of the underwater landscape.

Given that it operates underwater there's not much point attaching solar cells to the vessel itself, so instead the design relies on a floating solar platform to collect and store energy and act as a charging station for the submarine when it returns to the surface. This platform consists of a a central marquee surrounded by five satellites fitted with 300m2 of solar collectors generating around 30kW of energy - enough to power the sub as well as supply energy back to facilities on the lakeshore according to its designers.

This solar island would be automatically positioned using GPS and to complete the zero-emissions picture, a solar shuttle would be used to take passengers to and from the platform for boarding.

The sub itself will be equipped to carry 20-30 people with a crew of two, dive to a depth of 300m and could also be "parked" on the lake bed. The design incorporates a large living-room style passenger area and 60-70cm portholes for viewing

A feasibility study for the project was completed in June this year and BKW, which was responsible for the construction of Europes first large solar plant in 1992 and the world's largest solar powered ship in 2001, is currently seeking investors and hopes to have the facility operational in 2012.

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