White Plains Saves Energy and Dollars
By Bud Nicoletti

White Plains has been committed to implementing energy efficiency and pollution reduction improvements for many years. Indeed, it was the recipient of the Governor’s award for Pollution Prevention in May of 1996 for work on fuel efficiency and alternative fuel vehicles that began in 1990. White Plains continues to make ever increasing energy reductions and is reducing costs each year substantially by doing it.

Variable Frequency Drive Motors

The energy and cost savings that occurred already through the use of variable frequency drive (VFD) motors has been, and continues to be enormous. The benefit of such motors is that they can provide very significant energy savings by slowing down or speeding up in response to changing conditions based on the applicable programming so that motors do not have to always run full speed. They are then able to more quickly react to a sudden increase in workload. In White Plains three applications of such motors are instructive.

The most recent is in our maintenance garage for our vehicle fleet, a 60,000 square foot building with 25-foot high ceilings, and a huge structure. Regulations required that the air be circulated 6 times per hour, necessitating a total air exhaust every ten minutes, which means incurring the cost of heating fresh air every ten minutes in the winter. This created an exorbitant electricity and natural gas load, with commensurate furnace chimney emissions.

As we looked for solutions we found that these new motors were the answer. Sensors were installed to measure carbon monoxide, particulates (soot), and other pollutants in order to maintain safe working conditions for our employees. Based on these safety concerns, the new variable frequency drive motors speed up or slow down the fans. This has resulted not only in great savings in energy costs, but has been a great benefit to the mechanics because the facility is now much quieter and less drafty. In addition, the fan and motor bearings and even the furnace burners promise to have a longer operating life.

In a very exciting project, we are nearing completion of the retrofitting of the third of our three City water pump stations, which pump White Plains drinking water up to a storage tank atop a 450-foot hill so that the water can flow by gravity to peoples’ homes. Traditional high horsepower electric motors consume enormous amounts of energy during the motor startup period as they go from being off to full speed. Our new variable frequency drive motors avoid this huge energy demand as they start to pick up speed gradually from a slow speed to meet the actual water demand as flow rates need to rise.

These new motors save us thousands of dollars annually in electricity costs at the water pumping facilities alone. The water pump station operates much more smoothly and the distribution system pressure is more easily maintained within a narrow range. Thirdly, we have installed these new variable frequency motors at our public library as the older AC cooling tower motors required replacement. This pro duced the expected vast energy savings at the library.

Lighting

Lighting retrofits can also produce large energy and cost savings. Our 4,400 overhead streetlights all operate with high-pressure sodium bulbs that are the bulbs with the longest life and the highest lumens per watt. Our new parking garage is designed with light sensors so that the outside rows are not on 24/7 like most garages but are only artificially lit when there is inadequate daylight.

Our library was retrofitted under a New York Power Authority high efficiency lighting program. Existing old fixtures were replaced with compact fluorescents, reflectors were placed behind the lights to make them more effective, and diffusers were cleaned or replaced; following this successful program similar initiatives were undertaken in the other municipal buildings. In the aggregate lighting improvements save thousands of dollars in electricity costs annually.

Vehicle Fleets

White Plains has been in the forefront of using alternative fuels and increasing the efficiency of vehicle fleets. The Department of Public Works successfully operates electric vehicles, compressed natural gas vehicles and alcohol burning vehicles. While having such a variety of vehicles would seem to require some special dedication, in fact there have been and continue to be significant advantages.

The maintenance on these vehicles is considerably less, the cost of refueling an electric car almost nil, and complaints about noise during night street sweeping efforts are considerably reduced as the compressed natural gas trucks used are so much quieter than typical diesel trucks. In addition the environmental hazards and constant monitoring and testing required of underground fuel storage facilities is eliminated for those vehicles.

As we all strive to reduce the levels of car induced air pollution in this non-attainment zone for air quality, continuing efforts with alternative fuel vehicles are a must. It’s also important to squeeze all possible energy from every drop of fuel, by increasing the efficiency of each of our vehicles. We use high efficiency tires and drivelines, and special lightweight body materials (aluminum, fiberglass, high strength low alloy steel) to greatly improve fuel mileage and corrosion resistance of our trucks.

Help Is Available

White Plains has not done this alone. There are tremendous opportunities for co-funding from NYPA, NYSERDA, and the federal government. None of these projects were undertaken without an examination of the payback that in no case exceeded ten years on equipment with a thirty-year life. In short, energy improvements are saving the City of White Plains a lot of money each year while at the same time helping to protect the environment.

Joseph “Bud” Nicoletti,Jr.,P.E. is Commissioner of Public Works/City Engineer for the City of White Plains

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