Water and wastewater treatment plants are an untapped market in the world of energy efficiency. For municipal governments, these plants account for 30-40 percent of total energy use and represent the largest controllable expense — yet they’re often overlooked when it comes to conservation efforts. With proper design and analysis, plant operations can be optimized and utility bills reduced, while also providing much needed upgrades to aging equipment.
Studies estimate there are $105 billion worth of infrastructure improvements needed at U.S. plants alone. That’s because many facilities are more than 20 years old, and are using technology that is exceedingly outdated and inefficient.
For the City of Riverbank, Calif., the decision to address its wastewater operations is paying significant dividends, and is a great illustration of the potential that exists for municipalities across the country and globe.
The utility bill for the city’s plant showed excessive energy use — more than 3.5 million kilowatt-hour per year, which is enough energy to power 320 homes on average. So the city and Schneider Electric entered into a construction contract to retrofit treatment ponds with blowers and fine-bubble diffusers for more efficient oxygen transfer. A control system was installed to maintain a dissolved oxygen set point as well.
The work is estimated to save 75 percent of the electricity consumption at the treatment plant. In addition, it will cut the city’s utility bill by 65 percent, saving $240,000 annually.
The energy and utility analysis was done by following a five-step process:
1. Benchmark baseline energy data
2. Analyze baseline utility data and model utility rates
3. Model baseline energy consumption
4. Model estimated energy consumption after the scope of work is installed
5. Determine estimated dollar savings associated with the scope of work
A more detailed look at the process, improvements and outcomes shows how Riverbank is using guaranteed energy savings to address rising costs and antiquated equipment at its wastewater treatment plant. It also showcases the ability to help the city future-proof operations, and prepare for increased state treatment standards and population growth.
Download the full case study.
For more information on self-funding energy projects, visit www.enable.schneider-electric.com.