Off the coast of Belgium, truly gigantic wind turbines are going up. They’re rated at 6.15 megawatts. The blades of these monsters cover the surface of two soccer fields, according to RWE Innogy, the German company behind the project. The hub holding the gear that makes the electricity? It’s the size of a two-family home. Just one of these things can provide power for 6,000 people.

It’s hard to get a sense from the photo above how big wind turbines like this are, because the sea is so massive. But check out this video of a six megawatt rated wind turbine … it’s just huge.

[youtube http://youtu.be/LQxp6QTjgJg]

Putting these six megawatt turbines out to sea means scaling up the size of the turbines in the wind farm they’ll be part of. (To date the biggest out there were rated at five megawatts.) That offshore wind turbines this big are going into use is just one more clear sign that wind can provide reliable, clean power. But these six megawatt behemoths aren’t the largest wind turbines out there. The Dutch company Vestas has developed a seven megawatt turbine — its blades are “as long as nine London city buses,” according to SmartPlanet. Prototypes for those aren’t coming until the end of this year, though.

In the U.S., we’re way behind on building offshore wind farms, of course — we don’t have any at a commercial scale. Energy Secretary Steven Chu said earlier this month that $180 million will go over six years to support offshore wind. But that’s basically chump change. For comparison, the Army is investing $7 billion into a range of renewable energy technologies.