Industrial Energy Savings    

Water Treatment Plant Receives $1.7 million Energy Grant

Introduction

A new cogeneration system installed at the Budd Inlet Treatment Plant by the LOTT (Lacey, Olympia, Tumwater, and Thurston County) Clean Water Alliance late last year uses treatment by-products as fuel to generate electricity and heat energy. This renewable energy system, combined with an aeration blower retrofit currently underway at the Budd Inlet Treatment Plant, is expected to save LOTT more than $228,000 per year in utility costs.

 

Puget Sound Energy Provides $1.7 million

Puget Sound Energy (PSE) provided a $1.7 million Energy Conservation Grant to install the cogeneration system. PSE is Washington State’s oldest and largest energy utility, with a 6,000-square-mile service area stretching across 11 counties. They serve more than 1 million electric customers and nearly 750,000 natural gas customers. The PSE grant represents 70 percent of an estimated total project cost of $2.4 million for the cogeneration system project. The estimated PSE grant for the aeration blower upgrade is more than $300,000, which represents 70 percent of the total project cost. The combined projects are expected to result in an energy savings of more than 2.8 million kilowatt-hours (kWh) per year, enough to power more than 210 Thurston County homes.

 

The new cogeneration system supports plans to earn LEED Certification for the LOTT Regional Services Center.

The New Cogeneration System

Methane gas is a by-product of the wastewater treatment process. The gas can be used to produce renewable energy through a cogeneration system. LOTT’s cogeneration system converts methane gas to heat and energy for use in the treatment processes at the Budd Inlet Treatment Plant, as well as for heating and cooling of LOTT’s new Regional Services Center.

Staff selected the cogeneration system because it is expected to produce the most usable energy per pound of CO2 released in comparison to the other alternatives studied. Employing the cogeneration process includes adherence to strict emissions standards as well as combusting approximately 99.9 percent of the methane, dramatically reducing LOTT’s greenhouse gas emissions.

Prior to project completion, LOTT’s Budd Inlet Treatment Plant burned off some of its methane gas into the atmosphere. Installation of a cogeneration system allowed the gas to be captured, cleaned and used to produce heat and electricity.

The cogeneration system included the installation of a new gas treatment system, a reciprocating engine with a heat recovery unit and two small natural gas boilers. The new system is expected to save the facility nearly $180,000 per year in utility costs, provide all of the heating required at the site as a “district heating” plant, eliminate the need to burn off excess digester gas, and greatly reduce the emissions of the site.

Heat recovery units capture and transfer heat from the engine to an existing heated water loop at the plant. The loop was extended to the LOTT Regional Services Center and WET Center on the Budd Inlet Treatment Plant site and to the Hands On Children’s Museum, adjacent to the plant. The heat generated from the system is anticipated to be more than enough to serve the new LOTT building, the future Hands On Children’s Museum, and LOTT’s process needs at the plant.

As an innovative, renewable energy technology, the cogeneration system supports plans to earn LEED Platinum certification for the LOTT Regional Services Center.

Anaerobic Digesters

Aeration Blower Retrofit

The aeration blower retrofit replaced one of the large existing blowers with a smaller, high-efficiency, high-speed turbine blower while retaining the remaining three existing blowers to meet future demand. The new blower will become the primary operating unit, serving approximately 95 percent of the plant’s aeration system needs. This will allow the plant to increase overall aeration system efficiency and meet future aeration process demands.

The existing system had several large 200 horsepower motors which could only run at constant speed, producing far more air than was needed. The new system replaced one of the blowers with a high efficiency blower that has a variable frequency drive that can meet variations in demand.

The aeration blower retrofit, scheduled for completion in August 2010, is expected to save more than $48,000 in utility costs for the LOTT Alliance.

Energy Performance Contract with Trane

A Washington State Department of General Administration Energy Performance Contract was used to procure services associated with the design and installation of the two projects. This option provides a method for organizations to manage and optimize their energy use, allowing them to support strategic business objectives.

“As a public wastewater treatment facility, responsible use of community resources represents the core of our work,” said Doug Mah, president of the LOTT Clean Water Alliance board of directors and mayor of the City of Olympia. “We’re pleased that we can further our commitment to environmental stewardship with these improvements and that these upgrades will also benefit our new neighbors at the museum. Even better, we’ll achieve it all with minimal costs to the utility.”

 

About the LOTT Clean Water Alliance

The mission of the LOTT Clean Water Alliance is to preserve and protect public health and the environment by cleaning and restoring water resources for our communities. LOTT is a non-profit corporation formed by the cities of Lacey, Olympia, and Tumwater, and Thurston County, and is governed by a board of directors consisting of one elected official from each of the four partner governments. LOTT provides wastewater treatment and reclaimed water production services for approximately 90,000 people. LOTT owns and operates facilities in all four partner jurisdictions, including the centralized Budd Inlet Treatment Plant, Budd Inlet Reclaimed Water Plant, Martin Way Reclaimed Water Plant, Hawks Prairie Reclaimed Water Ponds/Recharge Basins, three pump stations, and 28 miles of sewer interceptor pipelines. For more information, visit www.lottcleanwater.org.

 

About Trane

Trane, a business of Ingersoll Rand - the world leader in creating and sustaining safe, comfortable and energy efficient environments - improves the performance of homes and buildings around the world. Trane solutions optimize indoor environments with a broad portfolio of energy efficient heating, ventilating and air conditioning systems, building and contracting services, parts support and advanced controls for homes and commercial buildings. For more information, visit www.Trane.com.