The Benefits of Stackable Energy Technologies

Introduction

Humanscale focuses on responsible energy management as they work toward a marked reduction in use and waste. They monitor energy use at their own facilities and offices and evaluate improvements against historical baselines. With the goal of achieving a substantial reduction in their energy consumption, Humanscale contacted Pfister Energy to develop a solution.

By evaluating the sources of energy consumption in the facility and identifying opportunities for improved efficiency, Pfister Energy successfully delivered a project that has a greater financial return than a solar array by itself, while providing an improved working environment for Humanscale employees and helping to meet the company’s sustainability goals.

The Humanscale project has received a lot of attention and accolades. Read how Pfister Energy has been featured as both a “Total Solutions Provider” and “Innovator“.

Results

Roof System: Solar-ready PVC cool roof
Renewable Energy: 775KW solar array
Energy Efficiency: 72 daylighting units,
LED lighting, daylight harvesting & occupancy sensing
Total Savings: $1.75 million
ROI: 4.1 years (21.2% IRR after tax)

The Humanscale energy reduction project showcases how Pfister Energy’s unique approach that stacks the benefits of multiple energy efficiency and renewable technologies executed through a single provider delivers greater value to businesses.

Initially, Pfister Energy examined the sources of energy consumption in the facility and identified four primary opportunities for improvement:

Existing dark asphalt roof created significant summer heat gain, resulting inincreased HVAC energy consumption.

Outdated high‐bay lighting was not energy efficient and needed to be updated.

Lack of lighting controls resulted in a large amount of wasted energy throughilluminating non‐utilized areas.

Large open roof area was not being utilized for on‐site generation.

Pfister Energy upgraded the roof through the installation of a solar‐ready PVC roofing system. The new white PVC cool‐roof membrane has a solar reflectivity 12 times greater than the existing black asphalt roof, resulting in significantly less summer heat gain, lower HVAC costs, and improved employee comfort.

In addition, the white roof resulted in significantly cooler rooftop temperatures enabling improved for the solar array, as photovoltaic modules loose approximately .5% energy production per ⁰C in temperature gain.

To address the outdated high‐bay lighting, Pfister installed 72 SolaTube daylighting units over the production floor, illuminating the facility with bright natural daylight. Humanscale employees saw a significant improvement in the amount and quality of light delivered by the daylighting units.

To further improve the lighting efficiency, Pfister upgraded the outdated T‐5 high‐bay fixtures with high efficiency LED fixtures with occupancy and daylight harvesting sensors that dim or brighten the LED’s automatically based upon the light contribution from the SolaTube daylights.

Pfister offset the remaining energy consumption in the facility through the use of a photovoltaic array to produce on‐site renewable energy. By accounting for the reduced energy consumption through the proposed efficiency improvements, Pfister Energy was able to reduce the size of the solar array from 900 kW to 775 kW, reducing the project cost by over $250,000 and providing an improved financial return to Humanscale with a lower capital investment.