For every small step we take towards responsible living—buying eco-friendly light bulbs, and so on—there are gadgets that help us make giant leaps in our quest for sustainability. This week in our Green Tech series, we examine ocean-harnessing tidal-stream generators, the latest development in hydropower.

The Best of Green Tech: Tidal-Stream GeneratorsS

More predictable than wind or solar power, tidal energy works by converting ocean or river tides into electricity. Research in tidal energy could very well contribute to finding a solution for our global energy consumption problem. Though in the past tidal stream generators were thought to be both cost and location prohibitive, technology has improved enough in recent years that they are now considered a viable means of accessible energy production. Tides have been harnessed in a number of ways over the years—here are a couple of our fave wave makers, past and present:

Ye Olde Tide Mille

The Best of Green Tech: Tidal-Stream GeneratorsS

Tide mills, powered by the ebb and flow of (duh) tides, have existed since the Middle Ages. A number of early mills have been discovered in the UK, including at the Nendrum Monastery on an island off Northern Ireland. Archeologists found remains that date back as far as 619 AD. Another tide mill was recently excavated in Greenwich, England. Wooden beams from the site were dendro-dated at about 1194, which means the mill was likely erected around the time Robin Hood was reportedly making his mischief.

Presenting the Future

The Best of Green Tech: Tidal-Stream GeneratorsS

Even though tide power has existed for quite some time, the technology behind tidal-stream generators is still relatively young. Recently a number of designs have been experimented with and it's thought that there will soon be a model ready for wide-scale use. For those unlucky enough to be currently reading this from Manhattan's Roosevelt Island, please turn your eyes towards the East River. There you might notice stirrings from Verdant Power's prototype "RITE Project", a three-bladed turbine that has been generating power since 2007.

Continued research in sustainable technology is the only way we can responsibly move into the next decade. GE has become a leader in developing and funding projects that help actualize a green future—so GE and its venture capital partners have made a $200 million commitment to invest in the best ideas to develop and deploy digital energy technologies. Head to the GE ecomagination challenge to check out the next great green ideas!

And check back next week when we cover more unique developments in Green Tech!