APPLETON, WI (WTAQ) – The City of Appleton is wrapping up the installation of a new biogas boiler and gas compression system at its wastewater treatment plant.
Focus on Energy handed the city a check for $167,180 on Wednesday as a financial incentive to help offset the initial cost of the City’s investment in reducing energy waste. Energy Advisor Joe Cantwell has been a part of the process from the start, and has worked with the city on several projects throughout the years.
“This is probably the single largest energy saver that they’ve had. And they’ve had a multitude of them over the past 19 years. It’s working very well for them using it in the boiler. Because they can use it year-round, because the process needs heat year-round,” Cantwell tells WTAQ News, “You pay 40-50 cents depending on the marketplace for natural gas per therm – you’re saving a little more than 200,000 therms – so that’s $100,000 a year.”
As for how exactly the process works, Cantwell let us in on a few details.
“It uses the by-products of the wastewater treatment process of anaerobic digestion – one of those is the production of biogas or methane, and that is what is burned in the boiler as basically a substitute fuel.”
The burning of methane is similar to the burning of natural gas, where there will be exhaust – but the switch simply changes the fuel content.
“It’s beneficial utilization of a by-product in that treatment process, which is basically gas. Whereas before, they were just flaring it – light a torch and burning it and it goes away, it basically just burns,” Cantwell explains, “Now you are containing that torch if you wish to say, and the boiler is heating the hot water to heat their buildings and that process – anaerobic digestion – needs to run at an elevated temperature. So it heats the process.”
The new boiler allows the city to heat anaerobic digesters and buildings at the wastewater treatment facility almost entirely from the biogas produced on-site digesters. That usage offsets natural gas usage, thus saving the city an estimated $103,000 per year.
As for the city, leaders are excited to see the savings in the budget – but they’re also interested to see the environmental impact.
“If we can save money and at the same time, save energy, that’s a win in all directions,” Hanna says, “The more this can become almost self-sustaining in terms of energy, not drawing energy from the grid but using energy generated by the processes here, just demonstrates that we’re being very responsible from an environmental standpoint.”
Hanna also pointed to the community and what the people of Appleton might see when it comes to this change.
“The more efficient we can be with the facility, the more we can contain our costs, which is what this project is all about – the longer we can go without having to raise the rates for people to support this,” Hanna says, “It’s a good opportunity for the public to see the stewardship in action, and really another example of the City of Appleton putting into action our goals of sustainability.”
The estimated energy savings over the life of the boiler is more than 4 million therms of natural gas, which is the greenhouse gas equivalent of taking about 4,700 cars off the road for a full year.
The treatment facility is supplied with natural gas by We Energies, one of the 107 Wisconsin utilities that partner in Focus on Energy. Residential, business and municipal customers of those utilities are eligible for the energy expertise and financial incentive Focus on Energy offers.
A recent third-party evaluation noted Focus on Energy runs the most-cost-effective energy efficiency programs in the nation. It also found every $1 invested in Focus on Energy generates more than $5 in benefits for Wisconsin, including economic benefits, reduced pollution, and reduced energy costs.
