Hennepin Energy Recovery center (HERC)

Collective Resource Services LLC (CRS) team designed the Hennepin Energy Recovery Center (HERC) to convert trash into energy at the edge of downtown Minneapolis on Seventh Street.  Once an isolated location, when the Minnesota Twins began playing at Target Field ballpark, the quiet neighborhood became the center of a growing pedestrian corridor. This proved that waste to energy facilities can co-exist with a thriving section of a growing city.

With a vision of getting to zero waste, Hennepin County was committed to making recycling as convenient as possible and to continue expanding opportunities to compost. A key piece of that vision is the HERC facility. The county residents and businesses generate more than one million tons of waste each year. If you add up all of that waste it is enough to fill Target Field more than 11 times.

Processing 365,000 tons of waste at HERC each year is just one part of the county's waste management efforts that emphasize waste prevention, reuse, recycling and composting. About 45 percent of the waste generated in Hennepin County is recycled or composted. The trash remaining after recycling and composting can either be buried in the ground or burned for energy. HERC generates 38 MW of electricity.

HERC won the SWANA 1995 Gold Award for Waste-to-Energy Excellence and was awarded a National Association of Counties Achievement Award for Integrated Approach to Regional Waste Processing.

How HERC Converts waste to energy?

1) Waste is delivered via garbage trucks, of which 75% comes from Minneapolis and 25% from the surrounding suburbs.

2) Waste is burned as it moves from the waste pit and fed into the boiler with hazardous and problematic waste removed and either recycled or deposed of properly

3) Heat is generated as waste is burned in boilers lined with water filled tubes. The water in the tubes is converted into steam. That steam turns a turbine to generate electricity. A portion of the steam produced is extracted after going through the second stage of the turbine and sent to the steam line. This steam provides heating and cooling to the downtown Minneapolis district energy system and Target Field. This energy system provides heating and cooling needs for 100 downtown buildings. District energy systems are more efficient than buildings operating their own boilers and chillers.

4) Controlling air emissions, recycling metals and disposing of ash rounds out the process. Air emissions are cleaned and treated and are consistently below the Minnesota Pollution Control Agency permitted levels. The material remaining after combustion is non-hazardous ash that is disposed of in a landfill.

Facts:

1. A ton of waste processed at HERC creates electricity to run a house for 21 days, plus steam to heat Target Field and downtown Minneapolis
2. More than 11,000 tons of scrap metal is recovered from the waste stream delivered to HERC and recycled annually as opposed to ending up in a landfill
3. 24/7 monitoring of an air pollution control system captures pollutants
4. Delivered waste is processed close to where it is produced, minimizing the transportation of waste and associated truck emissions
5. It takes 45 high-wage jobs to operate HERC
6. The combustion process reduces the volume of waste by 90 percent
7. HERC produces 38 MW of electricity, enough to power 25,000 homes

Take a virtual tour of the HERC facility