Three sprawling development sites in the Twin Cities that are expected to see thousands of new residents and billions in investment in the next decade are planning for a net-zero future.
Each of the sites will likely feature district energy systems, encourage or require efficient buildings and be powered to a large degree by renewable energy. And each of them has an existing thermal heating and cooling source to meet the needs of new apartments, businesses and homes.
In most cases the sites, which are in existing neighborhoods, will be densely developed and have transit options, as well as proximity to retail and business establishments.
Two – a former Ford plant site in St. Paul and the newly named Towerside in Minneapolis – are in older urban areas; the other, a cleaned-up former Army ammunition site now dubbed Rice Creek Commons, is in a suburb.
“If you can integrate thermal and electric (production) at these locations along with having efficiency in a built environment you can do great things and approach very low carbon, if not net zero,” said Ken Smith, chief executive officer of District Energy and its subsidiary, Ever-Green Energy.
Ever-Green has participated in plans and reports on all three sites. The advantage of the Ford site and Rice Street Commons, he said, is that the infrastructure isn’t already constructed so adding a district energy system and encouraging – or requiring – energy efficient buildings still can be done relatively cheaply.
Towerside is an existing neighborhood bordering the University of Minnesota. As new buildings are added to Towerside a district energy system could be built out alongside developments. As aging streets are replaced more existing structures could be added to a district energy network, he said.
Existing neighborhoods come with some built-in problems, however, that may hinder district energy, particularly in Towerside.
“All are large and very well suited to be doing district energy and they should be doing that,” said Tom Fisher, director of the Metropolitan Design Center at the University of Minnesota. “The problem is their ownership structures are different. In some cases it’s easier than in others.
“The Ford site is still owned by one owner, Ford, and it could say (to a future owner) ‘develop this piece of land into district energy,’” he said. “Towerside and Rice Street Commons are a little more difficult because they’re multiple owners.”
Some of the new buildings in Towerside are being created to allow them to be “district energy ready,” Fisher said. The challenge is that buildings are constructed at different times, making district energy more challenging to install.
Ideally, the public sector would fund district energy ahead of development, an option that may not be possible at any of the sites, Fisher argued.
While the technological ability to construct a net zero community exists the will to invest in the public policy and financing required remains a big “if,” he suggested.
So far the United States has not produced a net zero community, though several in Europe come close to achieving that goal. Still, Fisher said the goal seems attainable, especially amid growing concern about climate change.
“It’s a matter of financing and getting the owners to agree,” he said. “There’s the worry of no one wants to be the first to do anything. In other countries the public sector takes the risk – we’ve done that with the Internet and other things that have been huge successes. But it is a bit of a challenge.”
Project leaders in the Twin Cities are collaborating and looking for ways that, by buying collectively, they might save money and share expertise of contractors and consultants, according to Julie Kimble, who leads up the Towerside initiative.
Here’s a closer look at the neighborhoods and their progress in moving forward.
In 2010 a neighborhood planning organization came together to create the 370 acre “Prospect North” project with the idea of creating an innovation district. Part of the plan was to have the area serve as a testing ground for the university’s clean energy research.
One node sure to have development was a Prospect Park light rail transit stop on the Green Line. Since the planning began the district changed names to Towerside and lured a handful of apartment developments, as well as the home to Surly, one the nation’s largest destination craft breweries.
After creating a community development corporation in 2012 the Prospect Park group began investigating the idea of district systems for parking, stormwater management and energy, according to Dick Gilyard, an architect and one of the founders of what became the Prospect North Partnership.
As the group saw it, the idea would evolve from a common heating and cooling system to creating opportunities that to create electricity through solar and other applications, he said.
Eventually, Prospect North brought in Kimble to help raise money and organize all the efforts that today includes more than 30 organizations under the Towerside umbrella.
Kimble calls the Towerside project “master developers with no control.” The organization has raised about half the money for an engineering study of how a district energy system would work using thermal energy from one of the sanitary sewer lines that transverse the neighborhood.
Geographically, Prospect Park is a mixed bag of development, bisected by a major street and light rail line with elegant homes lining hilly streets on one side and commercial and industrial properties on the other.
District heating and cooling will be created in a series of three loops proposed by Ever-Green. Solar electric and solar lighting could be added later. Design guidelines will be given to developers to encourage sustainable, resilient buildings.
Gilyard has begun to see progress on Towerside. Ground will soon be broken for a district stormwater system. Next up is district energy, he said, with under-the-street connections to buildings in parts of Towerside.
Financing for district energy could come from the private market, with Ever-Green handling the operations, Gilyard said. For the original vision to be realized existing buildings and residents would have to see some advantage, from a cleaner environment to access to a district energy system.
“In promoting all these systems there is a broad notion that the benefit of these systems shouldn’t just flow to the new construction but ultimately to the entire neighborhood,” he added.
Ford Plant site
The 157 acre former Ford plant is located in the southwest end of St. Paul. The plant opened in 1925 and began building Model Ts while using electricity created by a nearby hydro dam on the Mississippi River.
By its close in 2011, the plant had produced more than six million cars, primarily manufacturing Ranger trucks at the end of its lifespan. Although the site has been cleared, Ford said in July it would continue environmental testing for at least another two years before placing it up for sale.
The city has had a task force for years looking at various potential developmental configurations, from office and retail to retail, commercial and housing.
Anne Hunt, the city’s environmental director, said the neighborhood could simply buy energy from the 10 megawatt hydro plant and move more quickly toward the net zero goal.
However, the city’s mayor, Chris Coleman, wanted to explore newer energy solutions, such as solar and district energy, she said.
“The mayor said think big and told us to make it a net energy zero site,” she said. “We think a district energy system, in combination with solar thermal and solar PV (photovoltaic) could work.”
That’s among the proposals that came out of a report from Ramboll Group and Krifcon Engineering that studied the potential for renewable energy at the Ford Site, which included suggestions such as combustion (combined heat and power); heat pump technology (electric heat pumps, using river water to cool buildings); and solar, waste heat and storage.
Another study looked at using making all buildings energy efficiency certified. One of the more intriguing options was to re-deploy the site’s underground steam tunnels for a district energy solution.
“Whether they have a good cost-effective role is yet to be determined,” warned city planner Merritt Clapp-Smith. “They may be too deep for putting infrastructure in but they could use for heating and cooling.”
Solar emerged as a potential to power the site. A federal government study showed with modeling that the Ford Site could achieve 63 percent of its electrical needs by installing between seven to 17 MW of rooftop solar – the wide variation accounting for different building and housing configurations.
Conducted by the National Renewable Energy Laboratory, the study suggests that scenario requires highly efficient panels operating at 20 percent efficiency. That number may increase by the time the development gets underway, potentially boosting the output available from solar.
Another promising technology is called “aquifer thermal energy storage.” Ford sits above or close to several aquifers that could be used as part of a geothermal heating and cooling system.
Underground Energy LLC is studying how those aquifers might serve as air conditioners in summer and heaters in winter for the new community to be built above, Clapp-Smith said. A report is due later this year.
While the United States has seen no ATES installations Europe has several systems in place, including several in the Netherlands. “The geologic conditions in this region make ATES a good option,” she said.
“It’s a really exciting and unique opportunity to have a site of this size where you can put in new energy infrastructure and explore emerging technologies and systems,” Clapp-Smith said. “It’s a not to missed opportunity as we look to expand energy solutions in the region and the country. We’ll all so excited about this.”
Rice Creek Commons
The 2,300-acre Twin Cities Army Ammunition Plant produced war materials in World War II, the Korean War and for a time during the Vietnam War.
Ramsey County purchase 427 acres of the site in 2013 and cleaned it to residential standards by 2015, using a variety of funding sources.
As part of the planning, the county and the city of Arden Hills, where the site is located, saw in Rice Creek Commons a rare and large amount of land where they could build an infrastructure from the ground up with the goal of reaching net zero over a decades-long development period.
They expect as many as 3,000 residents and thousands of workers to occupy the site over the next decades.
Key to a district energy approach is capturing waste heat from a groundwater remediation project which pumps two million gallons a day of water, said Heather Worthington, deputy county manager.
Adding to waste heat capture would be a utility-scale solar project to produce electricity for the new neighborhood. Ramsey County earlier this year purchased 62 acres from the federal government – on land near Rice Creek Commons – that could serve as a solar garden to be built by Xcel Energy.
The county is negotiating with Xcel now on a plan for a solar farm of up to 12 megawatt on 40 acres of that land. And it will spend $1.25 million upgrading the site by demolishing buildings and preparing it for the solar farm.
Finally, a town center that is expected to take years to develop could be heated and cooled by a combined heat and power system connected to a district energy district, she said.
“We see this as coming much later in the development,” she said. “I see Rice Creek as a 50-year plan, not a 10- to 15-year plan. It will study how to construct a development that can take advantage of improvements in technology and can respond to changing markets over time and be as energy efficient and as sustainable as possible.”
Kate Knuth, who once represented Arden Hills in the state legislature, studied the site as a policy fellow at the University of Minnesota.
She sees Rice Creek Commons in the largely the same way – a blank canvas to be created to allow for innovation as it occurs in the future.
This will be a decades-long process and what we’re trying to do is ensure the decisions we make now set up that site to be the best it can possibility be in terms of energy resiliency, livability and having a dynamic economy,” she said. “We don’t want to lock in poor decisions at this point.”