Energy Management

Related search terms from www.waterinfolink.com: energy efficiency, energy audit, Schneider Electric

WWD Editorial Director Neda Simeonova spoke with Mark Williams, national sales manager, Water Wastewater Competency Center, Schneider Electric, about how water/wastewater facilities can implement effective energy management practices.

Neda Simeonova: How much energy do water/wastewater utilities use?

Mark Williams: The U.S. Environ-mental Protection Agency (EPA) estimates that 3% of the power generated in the U.S. is for water and wastewater treatment. The usage equates to 56 kWh, $4 billion and 45 million tons of greenhouse gas production.

Pumping is the largest energy user for water treatment and aeration is the largest energy user for wastewater treatment (60% of the total); pumping comes second.

Power consumption for water treatment is about 1,400 kWh per million gal (mg) for surface water and 1,824 kWh/mg for groundwater. Based on the U.S. averages (87% groundwater and 13% surface water) of 1,750 kWh/mg, or just under $17,000 of energy and 600 tons of carbon per mg of freshwater.

Wastewater treatment can be more energy-intensive than freshwater (exceptions exist such as desalination, RO, etc). Power consumption for wastewater treatment is about 1,300 kWh/mg for an activated sludge plant and 1,900 kWh/mg for activated sludge with nitrification. National averages equate to roughly $17,500/mg.

Simeonova: How can facilities gain a better understanding of their energy use?

Williams: Completing an energy audit and establishing an action plan to understand energy usage and develop energy conservation measures will help municipalities better understand energy usage. At the process and pump level, they can install energy monitoring equipment to monitor efficiencies and energy usage.

Simeonova: What is an energy audit and what is its average return on investment (ROI)?

Williams: An energy audit is a comprehensive analysis of all energy consuming processes and equipment in a facility. It includes a facility load profile, utility costs analysis and billing structure and an identification of all cost reduction opportunities.

Audits usually consist of a kick-off meeting with the plant personnel, an evaluation of the utility bill and rate schedule as well as federal, state and local energy conservation measure (ECM) requirements, plant data collection and a field investigation. ECMs and implementation strategies are then developed. The last steps of the audit are monitoring of the plant and follow-up with plant personnel on the progress of ECMs.

The first task is to determine the energy and utility costs for industrial processes and operations areas within the facility. Next, gather utility rate schedules and develop facility profiles. The data required for this study includes consumption history, tariffs, existing supply contracts, growth plans, etc.

The audit will document facility energy usage information and will allow for monitoring progress and performance criteria of the recommended ECMs. The information is used to establish a business case for capital improvement and ROI.

ROI depends on the complexity of the suggested ECM. Simple ROIs should take one to two years, while complex programs could be three to five years. Some facilities can experience significant savings that can pay for themselves in six to seven months.

Simeonova: What type of funding assistance would municipalities receive for projects/upgrades that decrease their energy use?

Williams: In some states, possibilities exist for state funding as well as federal funding. Additionally, some electric utilities offer rebate programs for motor replacement with premium efficiency motors and installation of variable frequency drives.

Another funding option is to enter into a performance contract with an energy services company (ESCO), in which the ESCO determines potential energy savings opportunities, funds the improvements and then shares in the energy savings. This keeps the municipality from having to use their capital budget and can fund it using their existing operating budget, with no out-of-pocket expense.

EPA’s Clean Water and Drinking Water State Revolving funds are an important source of financing for water/wastewater infrastructure. Upgrades to decrease energy use are eligible for funding. These funds may benefit from the pending Economic Recovery Bill; however, there are stipulations in the draft bill for these funds.