When someone mentions solar energy, most of us think of rectangular panes attached to the roof of a house. But solar has gone way beyond panels. These days, folks as diverse as clean tech wonks and artists are coming up with innovative uses of solar energy. Some of these projects are still in the design phase, but others are on display or under construction. From artificial lily pads that soak up the sun’s rays to entire cities powered by sunlight, here’s a look at some of our favorite projects.

1. Floating cities. We’ve all heard the scary predictions about sea level rise: The IPCC reported that by the turn of the century, sea level could rise around 20 to 60 cm. However high the waters climb, some folks are sure to suffer. Rather than moving them inland, architect Vincent Callebaut has proposed building Lilypad, “a floating ecopolis for climate refugees.” Entirely powered by solar and other renewable energy sources, one of these structures could hold 50,000 people. The cities could be anchored near the coastline, or float on ocean currents.

2. Solar taxicab. Pedal-powered rickshaws are common sights in many cities, but SolarLab’s solar-run rickshaw could give those hard-working drivers a bit of a break. The vehicle will carry the driver and two passengers. Though it could ultimately be used anywhere, the company says it’s designing the cab for the crowded streets of Central London, with the aim of reducing CO2 emissions there by up to 2 tons per vehicle per year. The driver isn’t completely off the hook: He’ll still have to provide about a quarter of the power, and the solar generator will provide the other 75 percent. The 3.5-meter-long rickshaw is expected to travel up to 20 mph, and cost around $8,000.

3. Sun-inspired sculpture. These 12 metal shafts sitting atop a hill in Cambridge, Ontario, comprise the solar-powered, interactive sculpture, Solar Collector, created by artists Matt Gorbet, Rob Gorbet, and Susan LK Gorbet. The structures move with the angles of the sun throughout the year: At winter solstice, the tallest shaft is perpendicular to the sun, when the star is low in the sky. The flattest shaft faces the high sun at summer solstice. Each night, flowing wave patterns play across the lights that are spaced along the structures (each shaft has three sets of lights, along with three solar panels). The light show changes daily and anyone can create their own pattern on Gorbet Design’s website and watch the performance online. The length of the show changes with the weather and the season.

4. Power plants. We’re suckers for biomimicry--imitating designs and processes found in nature to solve environmental problems--and Lillies might just be one of the most stunning products of the discipline we’ve seen. Scottish designers at ZM Architecture believe their solar-power harnessing faux plants could offset Glasgow’s electricity needs. If the city council moves forward with a pilot project under consideration, the lily pads could float in the city’s River Clyde, tethered to the riverbed, and generate electricity for Glasgow’s grid.

5. A new leaf. ZM Architecture's Solar Lilies may have been on exhibit at New York City’s Museum of Modern Art in May, but it’s much more than a work of art: It’s an alternative energy system. Renewable energy start-up company SMIT (Sustainably Minded Interactive Technology) designed Grow as an attractive alternative to clunky solar panels and wind turbines. The system was inspired by ivy leaves, and, like the plant, could one day cover building exteriors. The individual solar “leaves” are made of flexible photovoltaic cells and small-scale piezoelectric generators that produce energy as the leaves move in the wind. SMIT expects a solar-only version to be available this year.

6. Solar-powered airplane. The Zephyr, an unmanned, ultra-lightweight carbon-fiber aircraft, flies on solar energy alone. The paper-thin solar panels covering its wings generate power, which is stored in rechargeable lithium-sulphur batteries during the day and tapped into after the sun goes down. In September 2007, Zephyr flew for 54 hours and reached an altitude of 58,355 feet. UK-based defense research company QinetiQ says ultimately it hopes to keep Zephyr airborne for months at a time. From the sky it could relay information about what’s happening on the ground below.


7. The world’s first ecopolis. In February, builders broke ground on Masdar City, a $22 billion initiative to construct a zero-waste, zero-carbon community in the United Arab Emirates (UAE), set to be completed in 2016. Located on the shores of the Persian Gulf, Masdar can house 50,000 residents. Though the project will incorporate various renewable energy schemes, it will rely most heavily on solar energy. A canopy of thin-film solar panels will provide shade and half of the Masdar’s electricity. A 500-megawatt concentrated solar power plant will be built in the nearby desert, and water will be desalinated using solar energy. Not a bad showing for one of the world’s largest oil producers.

Story by Alisa Opar. This article originally appeared in "Plenty" in August 2008.

Copyright Environ Press 2008

Our sun-powered future
From cities and airplanes to sculpture and art, some of the coolest-looking applications using solar energy.