Atlantic County Utilities Authority

The Atlantic County Utilities Authority Wastewater Treatment Facility located in Atlantic City is highly visible as the home of the first East Coast, coastal wind farm. The ACUA treatment facility is possibly the first wind powered wastewater treatment plant in the world. When winds are high, the wind farm can generate all the energy required to operate the treatment facility as well as supplying clean renewable energy to the power grid. The wind farm attracted more than 4,000 visitors during its first year of operation. The ACUA has used this opportunity to promote renewable energy and energy efficiency by developing other projects that are more adaptable to other facilities.

Aerator and Centrifuge Energy Efficiency Project
In March of 2006, all 24 of its aerator impellers were replaced with new efficient “Aerophoil” mixers manufactured by Philadelphia Mixing Solutions. A Supervisory Control And Data Acquisition or SCADA system also was installed so the process could be continuously controlled based on the varying dissolved oxygen requirements of the process. Between the increased oxygen transfer rate per KW used and the automatic control of the speed of the aerators there has been a 16 percent reduction in electrical energy use. The new aerators saved 668,910 kWh (more than 8 percent savings) in 2006. Given the average electric price of 11.254 cents per kWh (delivered) the savings equate to $75,279. The savings are expected to increase in 2007, as this will be the first full year of operation with the new style mixers. The new automated dissolved oxygen control system for the aeration process resulted in savings of more than 500,000 kWh in 2006 due to reduced aerator usage. Given our average electric price of 11.254 cents per kWh (delivered), savings equaled approximately $56,270.This was calculated by comparing the actual energy usage during the first year of implementation of the new equipment to the average of the last five years and variation in weather and/or flows are balanced.

During the same time period, the 20-year-old dewatering centrifuges were replaced with automated load controlled Alfa Laval, ALDEC 706 centrifuges resulting in a similar energy reduction at the treatment plant. The new centrifuges are capable of producing a 20% drier biosolids cake that can approach an autogenous burn in its multiple hearth thereby reducing the natural gas or fuel oil required to dispose of the biosolids. The system has resulted in a 23 percent reduction in gas required to incinerate the biosolids. It saved 42,670 decatherms (a 21 percent usage savings) of natural gas in 2006 at our average price of $10.07 per decatherm (delivered), for a savings of $429,690.

Solar Generation Project
The ACUA began operating a photovoltaic solar energy system last year. The 500 kW capacity system has 2,700 panels that are grouped into five arrays. During the first year of operation the solar installation provided the treatment facility with more than 488,000 kWh of clean renewable energy. The installation was purchased utilizing NJ Board of Public Utilities grants and low interest NJ Environmental Trust Fund loans. The first year resulted in more than $55,000 in electrical savings and approximately $112,000 in direct income from the sale of renewable energy credits. Energy production is measured and live data is displayed on the ACUA’s Internet site.

The ACUA also operates an aggressive community education outreach program and includes bringing the energy efficiency message to classrooms and community events throughout Southern New Jersey and providing speakers for professional organizations. Speakers have participated in conferences ranging from Atlantic City, to Chicago and Seattle.