When General Electric Company (GE 1.99%) bought into the wind turbine business, it operated in just eight markets. Today that number is 35, with around 40% of expected 2015 volume coming from the Middle East, Africa, Turkey, and Asia: areas that GE's Jim Rise recently said "weren't even thought about in this wind business" 10 years ago. Now, with its complicated Alstom purchase, GE is clearly trying to step the wind business up another notch, with the offshore market a notable option for expansion. Siemens AG (SIEGY -1.01%) should watch its back in the United Kingdom.

Offshore wind is big where?
Here's a fact that might surprise you: the United Kingdom accounts for roughly 50% of globally installed offshore wind capacity. To some extent that makes sense, given the country's geographic location. But for such a relatively small country to be leading the way like that is notable. The United States, by comparison, is only just starting to look at offshore wind.

Source: CIA Factbook, via Wikimedia Commons

And when it comes to offshore wind farms in the United Kingdom, the standout performer is Siemens. According to industry watcher LORC, Siemens turbines power 13 of the 22 offshore wind farms in the U.K. That's an impressive number of contract wins. GE turbines power a grand total of one offshore farm globally, and that project, off of Ireland, was commissioned in 2004. Siemens turbines operate at 26 of 80 global sites that LORC highlights on its website.

But Alstom could change the offshore wind market's dynamics -- even though GE brass has openly questioned the offshore wind market's prospects. At the end of the first quarter, Anne McEntee, a VP in GE's renewables area, told a conference that, "Offshore continues to be less than 5% of the market and as we look at the cost of offshore as in: 'does it make economic sense?', it's still three to four times higher in price than onshore."

What's the deal then?
So why buy Alstom? GE already has plenty of experience and technological prowess in the onshore market, but it's barely a player offshore.

That doesn't mean it hasn't looked very closely at the space -- GE bought a Norwegian offshore wind turbine manufacturer, Scanwind, in 2009. It had plans to build a European offshore turbine factory in the early part of this decade, too, but put those on hold.

Alstom, meanwhile, sells one of the world's largest offshore wind turbines. It's unlikely that GE will throw away another big offshore wind purchase, especially one that's turned out to be as complicated as the Alstom deal. In fact, GE will be a 50/50 partner with France in Alstom's power business, which means it may not even be able to nix offshore wind expansion, even if it wanted to. So, as other offshore wind players start to partner up to gain scale, GE could be preparing to put its weight behind a reentry into the space.

Protecting the home turf and more
And while it is more expensive and complicated to build offshore wind farms, as GE's McEntee noted, that doesn't mean the company can simply ignore the market. Especially as the domestic U.S. offshore wind market looks like it's ready to take off. Oh, and Alstom is the company supplying the five turbines for the first U.S. project to be fully approved.

Source: ENERGY.GOV, via Wikimedia Commons

So, the U.K. market clearly belongs to Siemens right now, and GE probably doesn't want to give up the U.S. market. But don't think GE isn't gunning for bigger share globally in offshore wind. The U.K. is expected to keep building -- industry watcher GlobalData is projecting the country's offshore wind capacity will increase from roughly 3.7 gigawatts (roughly 3% of U.K. power capacity) at the end of 2013 to 11 gigawatts by 2020. That will more than double the market, and gives GE plenty of room to take on Siemens with its newly acquired offshore wind technology.

Watch this space
When it comes to wind power, onshore is easier, cheaper, and more advanced as an industry. It's why GE has been focused on this space over offshore. But the deal for Alstom could be the event that finally gets GE in the offshore wind game for real. And if it does take the leap this time around, the offshore wind industry could see material changes in leadership. That should keep Siemens on its toes in the U.K. and around the globe. If you own GE, keep an eye on the offshore wind space, it could get interesting.