Captain Nemo, eat your heart out. The Nautilus doesn't have anything on Project Goldfish.

That's the code name for a solar-powered submarine – and the floating solar power platform that would charge it – on the drawing boards at BKW FMB Energy. The Swiss energy company wants 10 million Swiss francs ($8.4 million) to advance the project, which it hopes to launch on Switzerland's Lake Thun.

BKW envisions a greenhouse-gas emission-free U-boat that could carry up to 24 passengers as deep as 300 meters (984 feet) on underwater tourist jaunts. The floating solar power platform could charge the submarine and also provide power to customers on shore, the company says.

BKW finished its feasibility study for Project Goldfish in June and unveiled it in September at the Expo 2008 event in Zaragoza, Spain. It envisions an all-solar water adventure, featuring a solar-powered shuttle boat to carry tourists to the sub's loading platform, "from where the submarine trips into a fascinating underwater world begin," according to the company's Website.

One possible customer for the green submarine could be the Burj Al Arab Dubai, the luxury hotel that's part of the massive luxury resort being built in the Persian Gulf state of Dubai, BKW said. Dubai already has an indoor ski slope and man-made islands and others are contemplating an underwater hotel there. A solar sub wouldn't seem too out of place.

The company is also pitching the floating solar platform as a way to power ships on China's Yangtze River and to send juice to Australia's famed Sydney Opera House.

BKW generates and sells power from hydroelectric, nuclear, wind and solar power plants, and built its first solar power plant in 1992. It has laid claim to some firsts in the solar power field, including the 2001 launch of what it calls the world's largest solar-powered ship, now sailing on Swiss lakes, and the 2007 installation of the highest-altitude solar power station in the world on the Jungfraujoch, a 3,454-meter (11,332-foot) high railway station in the Swiss Alps.

Whether BKW's waterborne solar power schemes take hold of investor interest is an open question, given the economic turmoil now gripping world markets.

BKW itself hasn't been immune to that turmoil. The company reported in September that, despite rising electricity sales, declines in global stock markets drove down its profit for the first half of 2008 to 63 million Swiss francs ($53 million) a 52-percent decline from the same period last year.

The idea of floating platforms for renewable power isn't completely new. In October, renewable-project developer Principle Power told Greentech Media that it was raising $20 million to finance a 150-megawatt wind park off the Oregon coast. Principle planned to use a technology licensed from Marine Innovation & Technology for WindFloat, a floating foundation to support offshore wind turbines (see Blowing Offshore Power Into Oregon).

Then, of course, there's the field of harnessing power from the motion of ocean waves, which has drawn a number of startups with competing technologies (see Ocean Power Technologies Goes Hawaiian, California Sinks Its First Wave Energy Project and Trawling for $500M in Ocean Power). Some futurists have also talked about erecting offshore platforms that would harvest wave power to produce hydrogen.