Keene Housing: Harper Acres


Harper Acres is a property with 112 residential units spread among 15 buildings. It was constructed in 1985 and has one master metered electric account servicing all of the facility’s energy needs, with the exception of a small amount of propane that services two buildings. The property had several needs after 30 years of use, but the most pressing opportunities for improvement were the outdated and inefficient lighting and HVAC systems. Keene Housing is fortunate that Harper Acres is serviced by a single commercial electric meter, because its comprehensive energy efficiency upgrades impacted the entire property including common areas, exterior lighting, and residential units.

Harper Acre’s HVAC system is part of the local utility HEATSMART “interruptible rate” program which permits the electricity provider to reroute power away from heating units during high demand times. The participation in this rate savings program is possible because the residential units utilize a combination of wall-mounted ductless and electric thermal storage (ETS) heating units which provide heating when electricity is rerouted from the primary heat pump systems.  Unfortunately, the primary systems are old and inefficient and the ETS units are generally misunderstood and used incorrectly and potential saving opportunities are lost. 



Keene Housing took a multi-step approach to the upgrades over a two-year period. The planned first phase of the energy retrofit involved a comprehensive facility-wide lighting upgrade in order to fully capitalize on the utility program support the properties single utility meter configuration qualifies for. Keene Housing will retrofit all residential units, common area spaces, and exterior lighting with a combination of new lighting fixtures, lamps and lighting controls. 


The state-of-the-art lighting technology will include:

  • LED exterior and decorative pendant mount luminaires
  • LED recessed canisters
  • 2x4 LED recessed troffers
  • LED drum retrofit kits with occupancy sensors
  • Occupancy sensors in offices and other low-traffic areas
  • Astronomic time clocks on exterior fixtures

Keene Housing will substitute high-performance linear T8 lamps and ballast systems for the areas with less foot traffic, where the above measures would be less cost effective. 

Keene Housing’s lighting retrofit is an attractive investment opportunity because it qualifies for incentives through the local utility’s commercial lighting program, a program which covers 50% of the implementation cost.  These cost savings position the lighting retrofits as a low-cost first step toward reducing energy demands at the property. Keene Housing will install the retrofits over a period of two years using more than $90,000 in incentives from its utility; the remaining portion of the project costs were included in Keene Housing’s 2016 budget for capital upgrades. This project has a short payback period of 3.5 years, largely due to its use of incentives.

Since Harper Acres is serviced by a single electric utility meter type and account, it stands apart from the other properties Keene Housing owns that are serviced by multiple meter types and accounts. 



The lighting retrofit at Harper Acres is an initial low-cost effort to reduce the electrical demand of Keene Housing’s portfolio, but Keene Housing has already begun to plan lighting upgrades at three other sites. In addition, the organization is developing a low-cost solution to improve aging HVAC systems. A new training program focused on operation and maintenance of the ETS units will form part of a larger resident engagement program that will help Keene Housing reduce electricity consumption, explore solar options as a way to introduce renewables, and decrease its carbon footprint while exploring available funding options to purchase new heating systems. 


Annual Energy Use

Baseline (2015)
157 kBtu/sf/yr
Actual (2020)
122.6 kBtu/sf/yr

Energy Savings:


Annual Energy Cost

Baseline (2015)
Actual (2020)

Cost Savings:

$ 11,000

Sector Type



Keene, New Hampshire

Project Size

70,100 Square Feet

Harper Acres
Harper Acres