Thanks to solar panels, a geothermal heating and cooling system, and a gift of carbon-offset credits, Rangeview Library District’s new Anythink Brighton, Colorado, branch is believed to be the first carbon-positive library in the United States. The building, which opened in September, offsets 167,620 pounds of carbon dioxide—16% more than it is anticipated to use annually.

The general contractor, Fransen Pittman, donated $2,400 in carbon-offset credits split equally between Brighton and a yet-to-be-built branch, which pushed the Brighton building into its carbon-positive state.

“At every step, we have made our decisions based upon long-term sustainability,” said Director Pam Sandlian Smith in a district press release. “Our goal is to eventually be carbon neutral at all of our libraries.”

The $7.2-million Brighton branch, designed by Humphries Poli Architects, is part of a $40-million project to build four new libraries and renovate three more, Communications Director Steve Hansen told American Libraries. All except one of the buildings will seek Leadership in Energy and Environmental Design (LEED) certification.

A 108 kW photovoltaic system generates more than a third of the building’s power. Hansen said the solar energy system was not part of the initial building plans, but the library added it when it had the opportunity to apply for a $300,000 grant from the Colorado Department of Local Affairs. The district also had to find funds to match the grant, which Hansen said was accomplished with relatively minor changes to the building plans.

Solar energy will save the library about $30,000 a year in energy costs. “For the 10 years it may take to see the return on investment, we’ll also be not emitting tons of carbon in the air,” Hansen said.

Other environmentally friendly features include:

Geothermal heating and cooling . A closed system of pipes carries fluid through the floors to wells 500 feet below the parking lot. While underground, the temperature of the fluid moderates to about 58 degrees Farenheit, year-round; when it’s pumping through the floors, it helps to cool the building in summer and heat it in winter, requiring about half the energy of blowing heated or cooled air.

. A closed system of pipes carries fluid through the floors to wells 500 feet below the parking lot. While underground, the temperature of the fluid moderates to about 58 degrees Farenheit, year-round; when it’s pumping through the floors, it helps to cool the building in summer and heat it in winter, requiring about half the energy of blowing heated or cooled air. Solatubes . These capture natural light outside, and deliver through reflective tubes to illuminate interior spaces, even if there is no window or skylight.

. These capture natural light outside, and deliver through reflective tubes to illuminate interior spaces, even if there is no window or skylight. Lighting controls , including motion sensors and stepped ballasts to regulate the amount of artificial lighting needed.

, including motion sensors and stepped ballasts to regulate the amount of artificial lighting needed. South-facing facades. Windows receive direct light in winter, with awnings to provide shade during summer.

“Without the carbon-offset credits, the Brighton branch emits 345,000 pounds of carbon a year, which for this size of building is darn good,” Hansen said. He added that a comparably sized building would typically have carbon emissions of more than a million pounds annually.