Wind turbines are huge, requiring special transport and equipment for assembly. But a German engineer is working on a model made of modular parts, which he hopes will help renewable energy go truly global.
Frank Richert was on a construction team for an offshore wind farm when he first came up with the idea. Looking at the colossus made of steel, the German engineer and inventor thought to himself: Do large-scale wind turbines always have to be made out of by large-scale components?
Richert had experienced personally the downside of the wind turbine construction business. When the parts of steel towers, as well as rotor blades, are transported to the assembly site, heavy-duty trucks jam the autobahn. This, of course, causes extra carbon dioxide emissions.
And for offshore wind farms, ever-larger ships have to be chartered to reach the sites, and tall cranes are required to lift the blades to the top of the steel towers.
For Richert, all this spelled a "race to the top" - because nations with less-developed infrastructure and lacking special equipment are the most likely to be left behind.
Big blocks as basis
The light bulb came on when Richert remembered how he and his son used to like building towers with Lego toy blocks. At that moment, it became clear that the wind turbine of the future should be constructed modular, the aerospace engineer told DW.
So instead of starting with steel components at least 30 meters (98 feet) long, the Lego-style tower - called SkyWind - is assembled out of ready-made concrete plates that are 10 meters long.
"The big advantage of this concept is that a small local company can produce the concrete plates, and bring them with relatively small trucks to the site," Richert told DW.
The concrete tower plates are stacked together in an octagonal shape, up to 85 meters high. For taller towers, small steel pillars can be incorporated. And instead of three rotor blades - which is currently the standard in global wind turbine construction - the SkyWind project uses a two-blade rotor.
The performance of the windmill is not hampered, Richert asserts. He even points out some gains: "One blade rotor less reduces construction costs - and it reduces maintenance costs too."
Reducing carbon footprint
A prototype for this Lego-style wind turbine has been built in a test field near Richert's home in Husum, in far northern Germany on the North Sea coast. There, Richert and his colleagues even managed to eliminate the need for cranes in construction.
A patented self-winding system replaces the crane, lifting the rotor blades - together with the gear and the generator - to the hub 135 meters above ground. No cranes needed, and less heavy vehicle transport: both benefit the environment.
Fewer roads need to be built to access the construction site, and less land has to be cleared around the newly established turbine. "Our approach is particularly beneficial for forest areas, as we reduce interventions to one-third of the usual standard damage," Richert told DW.
The engineer believes that his technology is particularly well-suited for conditions in developing nations, where infrastructure is often weak and heavy machinery is scarce. "This will make it much easier to roll out wind turbines, also to remote areas in developing nations."
'Unique, ambitious, revolutionary'
Some analysts have called the SkyWind project one of the most promising innovations in recent years. Alois Schaffarcczyk, an engineering professor at the University of Applied Sciences Kiel, even called it "unique, ambitious and revolutionary."
Reactions from wind turbine production giants have been more modest. Behind closed doors, market leaders such as Vestas, Siemens, Areva or General Electric are hesitant to endorse the Lego-style approach. Richert thinks he knows why: "It poses a risk to the current technologies, into which they've invested heavily."
Richert's current estimates suggest that the Lego-style wind turbine would reduce the cost of energy for operators by a quarter, compared to current state-of-the-art windmills with 3.5-megawatt capacity.
If Richert's estimates hold, that would make his turbine one of the most efficient technologies available on a global market. "We are convinced that our concept will make clean, renewable energy much more affordable," Richert emphasized.
But small steps are fine with him, Richert told DW. There's a reason he chose the Lego principle, he says, laughing.