More than two million construction workers are employed in energy-related activities, according to the U.S. Energy Dept’s second annual national energy employment analysis released Jan. 13.

The study found 32% of the construction industry’s workforce is employed on energy projects. The majority, 1.4 million employees, are in the energy efficiency sector. Another 425,000 are working in transmission, distribution and storage construction, while 250,000 are in generation and fuels construction sectors.

DOE classifies construction workers in energy efficiency as those building and designing energy-efficient homes and businesses or workers installing energy efficient features.

According to DOE, over the next 12 months, construction employers expect energy efficiency job growth of 11%.

The entire energy sector added 300,000 net jobs in 2016, a 5% increase, to a total of 6.4 million.