DGS works hard to manage and operate its 400 municipal buildings as efficiently and effectively as possible in order to deliver superior service, comfort, and savings to DC residents. Through its energy efficiency initiatives, DGS improves building performance while reducing costs and environmental impact.
At the heart of the Energy and Sustainability Division’s energy efficiency program is a data-driven approach that allows the agency to identify and prioritize low-cost, high impact improvements. On BuildSmartDC.com, the agency provides benchmarking data and 15-minute interval electricity data for all DGS buildings, which helps to inform this decision-making process.
DGS-SE energy efficiency initiatives include:
- Lighting retrofits
- Predictive Energy Optimization (PEO)
- SmartRoof Program
The agency is continually working to replace inefficient light bulbs with new LED bulbs and lighting systems. At Eastern Market, the Comprehensive Lighting Retrofit Project will switch exterior lights to state of the art light-emitting diodes (LEDs), while incorporating a daylight harvesting design. The project is estimated to cost $30,000 and will save $12,000 in energy costs each year. Many similar projects with similar payback periods have been implemented, identified and planned across the DGS portfolio.
Projects sites have included:
- Emery Shelter
- King Greenleaf Recreation Center
- Eastern Market
DGS commissions District government buildings to ensure that existing buildings are operated to the high-performance specifications defined by DGS. Initial building commissioning (for new construction) is managed by the Capital Construction Division of DGS. DGS-SE leads two types of commissioning projects in partnership with the Facilities Maintenance Division
- Constant commissioning
DGS-SE has retrofitted or expanded roughly 100 buildings, or 25% of the portfolio, with building automation systems, monitors, controls, and communication network upgrades. Despite this, many DGS facilities operate inefficiently because the core capital equipment on site is not well monitored, and DGS often lacks visibility into where capital investment will have the best return. DGS seeks to address this issue through retro-commissioning, which enables the ongoing identification and prioritization of specific capital upgrades. This process augments existing mechanical and controls systems through the installation of customized data collection monitors and systems, which collect data including performance information about space temperatures, and asset-level information such as how frequently a boiler, chiller, or air handler is cycling and how often outdoor air is brought into the facility. These data allow hyper-accurate local monitoring of equipment performance and can be used to support long-term planning of capital retrofits, which lead to better building performance and comfort.
The existing building systems are also tuned while their performance is evaluated during the retro-commissioning process.
The collection of equipment and controls performance data is an industry best practice. With the data provided, DGS can target investments to improve energy performance, and through carefully directed, data-driven, follow-on capital upgrades, DGS is able to lower both the immediate and the total lifetime costs of operating a building.
DGS’ constant commissioning program facilitates the speedy resolution of energy performance and comfort issues through active data monitoring and pro-active management of building mechanical systems. Building upon prior DGS capital projects that created new infrastructure to deliver data flows from building automation systems and advanced metering installations, the program aims to leverage technology resources (BAS systems, remote access, communications networks) to deliver increased comfort levels while reducing energy use. This is achieved by empowering on-call and in-house building engineer teams to identify and resolve comfort and energy performance issues in near-real time, allowing occupant needs to be responsively addressed. Constant diagnostics and critical alarms enable data-driven support for occupants and simplify the identification of performance improvement opportunities and tracking of HVAC and controls problems for building engineer teams.
Predictive Energy Optimization
The Predictive Energy Optimization (PEO) platform automatically creates a custom thermal model for each building that predicts energy consumption, cost and comfort based on building characteristics, weather forecasts, energy pricing, and signals from the utility. The software makes real-time changes to each building, directly adjusting heating, ventilation, and air condition system parameters that can reduce heating and cooling costs by as much as 25 percent. This automated, cloud-based solution requires no manual interaction, and thus frees up time for very busy building staff and engineers to accomplish other tasks.
For this project, DGS is working with BuildingIQ, New City Energy, and the Lawrence Berkeley National Lab to deliver annual savings of $600,000 and generate more than $1 million in free cash flow over the term of the partnership, facilitated by the U.S. Department of Energy’s (DOE) grant program. The project delivers on the District’s commitment to lower energy consumption, save taxpayers money, and reduce greenhouse gas emissions.
Roof restoration technology has advanced significantly in the past decade; today, silicone-based fluid-applied membranes offer up to 20 years of roof life extension at less than one-quarter the cost of a new roof, and the latest roof restoration products are low-VOC, making them less harmful to the environment and workers. These products also convert traditional roofs into Cool Roofs, which improve building energy performance through improved insulation and reduce urban heat island effect.
However, the local roofing industry has not been able to stay current on the latest roof restoration technology, owing mostly to a lack of training, equipment, and demand from building owners. For example, in 2013, the District of Columbia (D.C.) had zero Certified Business Enterprise (CBE) roofing contractors certified to install the latest roof restoration technology. DGS has worked to change this through its SmartRoof program.
To meet our energy and sustainability goals, DGS is employing Cool Roofs to reduce building energy consumption, reduce urban heat island effect, and extend roof life – which reduces landfill waste and makes roofs viable for solar PV. The DGS SmartRoof Program trained three CBE roofing contractors in fiscal year 2015, enabling them to install Cool Roof restorations on several DGS buildings that had been designated to receive solar PV systems. Each of the three CBE contractors received on-the-job training on a DC property roof. These three projects totaled 156,000 square feet, bringing the total area of cool roofs on District property to more than 250,000 square feet.