Normally, wind plant developers buy completed wind turbines, leaving decisions on blades and towers to the wind turbine original equipment manufacturer (OEM). This simplifies the buying process - the OEMs design the tower for their specific turbine and contract tower companies to build them.
However, in China it is commonplace for towers to be bought separately from the turbine and blades. This does not happen in the US for several reasons, including obtaining funding, says Ricky Seung, president of Los Angeles-based Kousa International, an agent for Korindo Wind, an Indonesian tower manufacturer that sells into the US market.
"But we are seeing developers shift towards the Chinese model because these towers are expensive and developers, frankly, can save money," says Seung. The average cost of a tower can be $100,000.
Seung cannot specify what profit margin an OEM typically makes on towers but says: "Generally, when the OEM is selling the turbine as a package it is getting a big profit margin on the tower without doing anything because we provide all the transportation anyway."
Now, in a buyers' market where developers can shop around between turbine makes, they can also push new purchasing ideas, Seung says. "We're seeing this margin shift and the developers wanting to get the turbine OEM out of that because they can save a good amount of money," he says. "This is definitely not something the OEMs want everyone to know."
Stefan Nilsson, president of US tower manufacturer DMI Industries, says he has not seen much evidence of this trend. "Over time there's been talk that it could be a trend but we haven't seen it yet," he says.
Other wind industry officials are hesitant to comment. A spokesperson for a separate domestic tower manufacturer in the US confirms the idea has been picking up speed but says it is a sensitive topic for OEMs.
No project developers who spoke to Windpower Monthly would confirm the trend. A communications official at a tower manufacturer company believes this could be because they are worried about alienating their best customers and suppliers.
Developers may lack expertise
Direct sales are rare but they have occurred, says Patrick O'Keefe, sales manager for Ameron towers, based in Los Angeles, California. He says developers Enxco and NextEra Energy (formerly FPL Energy) have bought packages of towers. Last month, he sold one tower directly to a developer who had to replace one because of a lightning strike.
"I would love to see it happen and I try to tell developers they can buy direct, why pay the extra mark-up," says O'Keefe. He has not seen figures for the OEMs' mark-up.
He adds: "Maybe the developer doesn't have the expertise to know if we're a good tower manufacturer or not, or they may not have a quality team that would go in and research in the way an OEM would." There can be a lot of variation in towers; some heavy-duty towers can weigh 200 tonnes, while others of a similar height weigh 140 tonnes.
Seung-Joo Yang, president of Korean tower manufacturer Win&P, has not yet received direct orders from developers. The closest the company has moved towards working directly with a developer was a discussion with a turbine manufacturer and a developer to revise tower supply cost, Yang says.
Jay Holman, research manager for the renewables markets for IDC Energy Insights, is another who says he has seen scant evidence of a shift. He expresses scepticism that this could occur in the US.
While purchasing towers directly might bring costs down a bit, he says, the OEMs say the pairing of a turbine and tower must be made with care, and developers may not be qualified to carry out that analysis. OEMs claim each turbine creates its own set of harmonics and vibrations that need to be taken into account.
"Having said that, if there are wind farms out there with a given turbine paired with a given tower, I would imagine developers might be comfortable repeating that pairing while sourcing the tower directly from the tower manufacturer," says Holman.
"The question then becomes, what if there are changes made to the turbine sometime during its life: who is responsible for making sure the changes don't cause new harmonics or vibrations that exceed the specifications of the towers?"