The clamor for more renewable-energy sources in the U.S. is drowning out a much quieter problem stirring over the horizon the lack of skilled workers ready, willing and able to build infrastructure needed for future power. With the average age of U.S. construction workers at about  54 and engineering-school enrollment dropping like a stone, the industry’s labor pool simply will not be able to keep pace with the growing power sector alone, faced with some $25 trillion in global capital expenditures through 2030.

Consider existing power needs: There are 24 new nuclear reactors planned in the U.S., each requiring thousands of workers trained in highly specialized tasks. Meanwhile, current plants are showing their age because repairs have been deferred too long, partly because of labor shortages. The undercapacity within the industry is manifesting itself through rising numbers of accidents and injuries.

Renewable energy holds much promise because some alternatives have matured to the point where the technology is reliable and economical enough to compete with fossil fuels. But Congress’ inability to develop long-term, consistent energy policies that developers can rely on to make investments is a big obstacle, as is the industry’s diminished capacity for building renewables like wind farms. And then there is the fact that the new wind turbines will need to be serviced regularly to keep them operational.

The emerging issue of turbine maintenance may have hit home for viewers of the popular cable-television show on Discovery Channel, “Dirty Jobs.” Aired in early June, host Mike Rowe climbed up a 300-ft-tall wind turbine in Oklahoma to change 35 gallons of oil in the turbine’s nacelle. The show tried to prove you have to get your hands “brown” in order to go “green.”Rowe later added in his Web diary that the wind-farm work ranked among his top-five most physically exhausting jobs, out of some 200 he has sweated so far.

Firms just getting involved in such grueling work not just in the U.S. but all over the world are underestimating the charge of building new power infrastructure. Building powerplants, especially in remote places, tests even the most hardened workers, superintendents and project managers. Speciality training is required to do things like work around expensive and potentially dangerous $8-million cranes that now are renting for $125,000 a month, as well as rappelling down a turbine tower in case of an emergency.

It is worth the effort to explore the environmental and economic issues surrounding renewable power sources. But without a comprehensive solution to the industry skills crisis, some of the benefits of clean power will just blow away.