A Chicago renewable energy firm is powering up a new Denver office downtown.

Invenergy is leasing 29,000 square feet — the entire 19th floor — at 1001 17th St., the company confirmed to BusinessDen.

“We’re excited to be growing our Denver office and team to meet the increased demand across the country for cleaner, more reliable, and affordable energy,” the company said in a statement.

It will cost $1.9 million, or $66 a foot, to build out the space, permit filings show.

Invenergy, which was founded in 2001, opened a Denver regional office in 2005 — its first outside Chicago. It currently operates at 1401 17th St.

The company said it is the “largest privately held owner, operator, and developer of clean energy solutions,” with offices in Japan, Spain, Toronto and Mexico. It has completed more than 200 projects supplying 32 gigawatts of electricity.

For reference, it takes nearly two million solar panels, or nearly 300 wind turbines, to generate a single gigawatt.

Invenergy developed the Spindle Hill natural gas plant, located 30 miles north of Denver, in 2007. It also has six other wind projects around the state, from south of Pueblo to north of Sterling in the Eastern Plains.

The new lease puts a dent in the vacancy rate of 1001 17th St., which BusinessDen reported last year had one of the highest vacancy rates in downtown Denver at 40.5%.

The 20-story, 659,000-square-foot office tower was built in the 1970s and renovated in 2007. Cushman & Wakefield markets the building and states on its website that 164,000 square feet are available, putting the building at about 25% vacant.

The entire 12th, 14th and 15th floors are available, along with sections of lower floors. Asking rents run between $26 and $27 a foot on a triple-net lease.

— Matt Geiger, BusinessDen