Wilders Grove Solid Waste Service Center Geothermal Project

From Open Energy Information

Last modified on July 22, 2011.

Project Title Wilders Grove Solid Waste Service Center
Project Type / Topic 1 Recovery Act – Geothermal Technologies Program: Ground Source Heat Pumps
Project Type / Topic 2 Topic Area 1: Technology Demonstration Projects
Project Description More than 30 years of ceaseless growth in the City’s population have caused a significant increase in the space requirements needed to house City departments. Studies have documented the need to provide state-of-the-art facilities for multiple City departments, including Solid Waste Services. Plans are for these facilities to be de-centralized to remote nodes located in high growth areas of the City, making City services more convenient to the public. The new facilities will relieve severe overcrowding, provide more efficient and cost effective services, and improve the working conditions and morale of City employees.

In their design, the new facilities will reduce fossil fuel consumption in support of the City’s 20% fossil fuel reduction goal, reduce green house gases in support of the Climate Protection Plan, and allow the City to vacate expensive real estate in downtown Raleigh for other uses. The City Council has also expressed a goal for all new City buildings to meet LEED Silver certification. The Council’s ‘Remote Operations Facility’ network plan is an opportunity for the City to take an active and national leadership role in developing green buildings and facilities, promoting energy conservation, and exploring innovative opportunities for renewable energy development.

The Wilders Grove Solid Waste Service Center Facility is one of the initial Remote Operations service facility elements targeted for development. This facility will be located on a 259-acre parcel of City property on the closed Wilders Grove Landfill site and adjacent to the City’s Solid Waste Transfer Station. The facility is located on a former borrow area which was reclaimed by placement of nearly 155,000 cubic yards of clean soil from other construction projects. The fill placement process was carefully controlled to assure suitability for foundation support for the planned structures and roadways. The Wilders Grove site will house all solid waste staff and vehicles for the City. The site for the new facility covers approximately 20 acres, and the facility is approximately 24,000 sf.

Innovative aspects of the City’s proposal include developing a geothermal solution along the Eastern Seaboard where there are relatively few examples, repurposing land that was previously used as a landfill site, using reject heat from the ground source heat pumps to heat domestic water, and using a modified evaporative condenser that can reduce or supplement ground loop size while also helping to meet peak cooling requirements.

State North Carolina
Objectives - Contribute to 20% reduction in the City’s use of fossil fuels

- Meet LEED Silver certification standards in the design and commissioning of new facilities
- Achieve energy savings of 30% over conventional systems, and 4) provide a comfortable work environment for City staff

Awardees (Company / Institution) City of Raleigh
Awardee Website http://www.raleigh-nc.org/portal/server.pt?space=CommunityPage&cached=true&parentname=Login&parentid=0&in_hi_userid=2&control=SetCommunity&CommunityID=208&PageID=0

Funding Opportunity Announcement DE-FOA-0000116
DOE Funding Level (total award amount) $1,298,625.00
Awardee Cost Share $1,298,625.00
Total Project Cost $2,597,250.00

Principal Investigator(s) Fred Battle

Targets / Milestones The HVAC system for the Wilders Grove facility is proposed as a renewable energy geothermal system. Heating and cooling loads for the proposed design are estimated at 100 tons. The system will be comprised of unitary terminal units, utilizing direct expansion water source heat pumps with supply air fans and filters using a geothermal ground loop water source. The water source will be a closed vertical loop piped grid under the facility parking lot. In order to provide sufficient heating supplies, the grid will be a series of wells, approximately 300 ft. deep, on a 25 ft. x 25 ft. spacing. The closed loop piping system will pump water through these wells to reject heat during the summer and absorb heat during the winter. The reject heat will be used to heat water prior to entering the wells. It is anticipated the geothermal ground loop design will provide energy savings of over 30% over conventional HVAC system designs. Hot water heating will provide an additional 20% energy savings. The City will monitor the actual system performance as compared to the energy model for use in future project applications.

Location of Project Wake, NC

Impacts Offers potential to make GHPs a more common feature in industrial process operations. A fully green waste processing center provides a model for other jurisdictions. Also demonstrates a hybrid GHP design that may provide better performance vs. cost-effectiveness in this application.
Funding Source American Recovery and Reinvestment Act of 2009
References EERE Geothermal Technologies Programs[1]


  1. EERE Geothermal Technologies Programs