SUSTAINABILITY : Energy

SOLAR ENERGY

A canopy of photovoltaic cells over the amphitheater seating provides shade and generates direct current electricity which is supplied to the City's electric grid. The panels produce enough solar power to produce 9 kilowatts of energy daily, enough to power two Austin homes on hot summer days. The solar energy system was installed by Janet Hughes, one of only two female Master Electricians in Texas at the time.

GREEN ENERGY

Austin City Hall's power comes from clean, renewable sources from Austin Energy's GreenChoice Renewable Energy Program, the nation's most successful utility-sponsored green energy program.

Using green power generated from renewable sources, like the wind and the sun, helps Austin’s air quality by not adding pollution to the atmosphere.

DAYLIGHTING

Windows have been strategically placed in Austin City Hall for daylighting of all levels of the building to reduce the need for electricity.

The atrium is well-lit by a clearstory, a large windowed wall that is higher than the surrounding roof.

A lightwell, an open space that extends down several levels, provides lighting and a beautiful 3-story water feature for the underground parking garage.

COOLING

Austin City Hall ties into the district cooling system that provides chilled water for air conditioning. Austin Energy's district cooling plant sits on top of the State of Texas parking garage at Third and San Antonio Streets and is connected to over a dozen buildings in the area by a closed loop underground pipe system.

The system works by creating ice at night when energy demand is lowest. During the day, the water in the pipes is chilled by the icy coils and then circulates to the customers’ air handlers. This saves an immense amount of energy demand during the daytime peak hours – enough to equal the demand of over 4,500 homes – and removes the need for noisy and unsightly traditional air conditioning systems that often contain environmentally hazardous gases.

In 2007, District Cooling Plant 1 was renamed the Paul Robbins District Cooling Plant in honor of Paul Robbins, an environmental and green energy activist that frequently addresses the Austin City Council and who was instrumental in driving the cooling plant concept to fruition. Austin Energy has since added additional district cooling systems at Fifth and Sabine Streets near the Austin Convention Center and in the Mueller and Domain redevelopments.

ENERGY EFFICIENCY

The energy systems in Austin City Hall are maintained through a continuous commissioning program. Energy consumption and system performance is monitored through the program and conservation experts provide periodic calibrations and improvement suggestions.

The light switches in Austin City Hall all have occupancy sensors which conserve electricity by turning on the lights when movement is detected in a room and then turning off the lights when no one is present. Compact fluorescent lamps (CFLs) are used instead of incandescent lamps whenever possible because they give the same amount of visible light while using less power and last longer.

All appliances in Austin City Hall are Energy Star rated for energy efficiency.

The air conditioning system and the lights in the parking garage are demand-based, and save electricity by powering down to a minimum level in zones that are not in use. Another demand-based feature is the innovative carbon-monoxide sensing system in the underground parking garage that allows the ventilation system fans to operate at slower speeds when concentrations are low, resulting in yearly energy cost savings estimated at more than $200,000.

A high-efficiency natural gas boiler is used to provide hot water and heating for the building. The hydronic heating system works by heating the water in a closed-loop water pipe system with the boiler and then circulating the hot water to the building air handler to distribute the heat.