District Energy St. Paul has a new look. Please check out our updated website and new brochures. Special thanks to FourFive for their innovative design contributions.
As 2012 comes to a close, it is a time for reflection on the challenges and successes of our past year. This year marks the end of major utility relocation for our heating and cooling services in conjunction with the light rail construction. Certainly this work was a challenge for our organization, but we are pleased to have been a partner in the advancement of this important transit project. We are proud of our team for their exceptional efforts to minimizing disruptions to our customers.
We are celebrating the growth and reinforcement of our customer base. Renovation and new construction created opportunities for us to provide service for the Union Depot, the LRT Operations and Maintenance Facility, the Farmer’s Market Flats, and other new projects for Saint Paul. Our team was dedicated to working with our existing customers to extend the service contracts for many of our customers, including those that have been District Energy customers since the beginning, almost thirty years ago. The combination of growth and recommitment means continued rate stability and a strong system for our customers.
2013 will mark the 30th anniversary for District Energy St. Paul and the 20th anniversary for District Cooling St. Paul. As we enter this landmark year, we are proud to be improving services for our customers, enhancing our metering and monitoring technology, observing the admirable performance of our new solar thermal project, and a thermal storage tank conversion almost complete. We are using our Delta T program to improve energy efficiency for the entire system and to help our customers save money. And we are continuing our commitment to the community through community giving, our strong tour program, and the development of new education partnerships.
We could not have accomplished so much without the strong leadership of our community partners and most importantly our loyal customers. Thank you all for helping us grow and thrive in 2012. We look forward with focus and optimism for 2013.
Ask the Engineer
Why does District Energy require a return temperature of 160°F or lower?
District Energy delivers hot water to its customers for a variety of uses from heating buildings to melting snow on sidewalks and driveways. In order to keep rates down, District Energy requires its customers to maintain a return temperature that is 160°F or lower. The district system is designed for a 90°F temperature difference between the supply and return temperatures. This allowed District Energy to reduce the size of the piping network and to limit the pumping requirement for the central plant.
On the building side, typically buildings that operate air handlers, fan coils, and finned tube radiation maintain a maximum 180° F supply water temperature and a return water temperature of 150° F to the hot water heat exchanger. A proper return water temperature back to the exchanger ensures that the district’s return water temperature will be 160°F or lower. The goal is to keep the district system’s return water temperature at or below 160 °F to lower the flow velocity in the distribution pipes.
When return temperatures are high, distribution losses increase and efficiencies decrease. Capacity diminishes because more gallons of hot water are required to provide the same amount of heating to a customer. More gallons delivered to customer buildings requires more pumping, resulting in higher electricity costs. Higher return temperatures and elevated flows cause more wear and tear on the metering and mechanical equipment. All of this effort to reduce return water temperatures is producing results that benefit all customers. In 2012 we saw our return water temperature average 157.1°F for the year, 2.9°F lower than system design!
Maintaining low return temperatures is a great way customers can reduce maintenance headaches and save money, too. We recommend you review your hot water meter in your building near the service entry point of the hot water lines. The supply and return water temperatures are available for inspection to see how your system is performing. The customer service team reaches out to customers we have identified as having high return water temperatures, but always feel free to contact us if you have any questions about your system – Jeff and Jonathan at 651.297.8955.
Ordway Circle of Stars
District Energy’s community giving program is dedicated to supporting our customers, our community, and the environment. Ordway Center for the Performing Arts is a stellar partner for our program because of their commitment to these same values.
In December, District Energy was a sponsor of the Ordway Circle of Stars event to support the Ordway and its educational programs. The “Putting on the Glitz” event drew more than 500 guests who stepped back in time to enjoy a 1920’s themed evening. Most importantly, the evening raised money for the Ordway’s efforts to bring the arts into the lives of more youth. According to many studies, arts involvement motivates at-risk students to complete high school and increases children’s intellectual capacity, creative abilities, social manners, and coping skills.”
A customer since 1984, the Ordway recently extended its District Energy service agreements with District Energy and we are looking forward to providing exceptional service for decades to come.
We commend the Ordway for the success of the evening and their good work in our community. Visit our new Community page for more information regarding District Energy’s work in the community.
Students, International Visitors, and Local Volunteers Tour District Energy
Our team is committed to keeping District Energy St. Paul at the forefront of creative integration of energy technologies and providing the highest value in service for our customers. As such, we are fortunate to share our story with a wide range of visitors every year. Students from local colleges and universities explore concepts of sustainability, local energy planning and engineering when they visit with our staff at our plants. This fall we hosted visitors from St. Paul College, Macalester College, Hamline University, Century College, the University of Minnesota, and Metro State University. Our international visitors engage in technology and knowledge transfer to learn ways enhance their own district energy systems. In September we welcomed a group of engineers, economic development experts and utility regulators from six countries in the Black Sea region. This fall we also hosted visitors from Japan, Germany and Canada.
A group of National Park Service volunteers who are involved in educating people during tours on the Mississippi River and at the Mississippi River National River & Recreation Area Visitor Center and who clear buckthorn in the Mississippi River Valley toured our plant to see what happens to the buckthorn they collect. We were thrilled to show firsthand how their volunteer efforts support local, renewable energy.
Learn more about our tour opportunities.