Ann Arbor wants to get rid of the gas to help save the planet. Is it possible?

Ann Arbor, Mich. — Ann Arbor science writer Ken Garber recalls being a University of Michigan student taking physics classes in 1977 when University of Michigan physics professor Mark Ross suggested moving buildings from gas furnaces to heat pumps.

“He wrote a report to Congress about it,” Garber said. At that time, climate change was not yet a thing. Ross’ argument was based on thermodynamic efficiency.”

According to the laws of thermodynamics, heat can be transferred even from cold from the outside into the building’s interior, which is the principle behind heat pumps, Garber said, noting that they are more efficient than burning gas. And when powered by renewable energy, they are a way to heat and cool buildings without generating planet-warming emissions.

Ann Arbor City Council

Ken Garber speaks in support of reducing carbon emissions to address climate change at the Ann Arbor City Council meeting on November 4, 2019.Ryan Stanton | Ann Arbor News

Heat pumps are not theoretical. It has been around for a long time – it was not widely adopted in American society as an alternative to gas, in part because of the upfront financial costs.

It is now a key strategy for Ann Arbor’s A2Zero plan to become carbon neutral by 2030 to combat climate change.

as a city Considered a ban on gas for new buildings It aims to offer more financial incentives for residents and businesses to give up gas and transition to all-electric buildings with renewable energy. Some representatives of labor unions and the construction industry argue the city’s plans are too ambitious.

“I think it’s very fast,” said Howard Friese, a Bloomfield Hills-based developer who has two apartment buildings under construction in downtown Ann Arbor that will use gas: a 19-story high-rise behind the Michigan Theater and a five-story utility building next to it.

There may be reasonable alternatives in the future, Friese said, but banning gas in new construction now would have repercussions.

“This will increase the energy costs of any project and make it more difficult to obtain affordable housing,” he said, noting that it could increase the cost of development in Ann Arbor and have a negative impact on the city’s growth.

Michigan high rise theatre

The construction site of a 19-story, five-story high-rise building behind the Michigan Theater off Washington Street in downtown Ann Arbor on December 29, 2022.Ryan Stanton | Ann Arbor News

City officials are listening to and grappling with these concerns, but climate activists and others who support the city’s sustainability goals still believe it is possible.

‘We have a climate emergency’

Garber spoke before City Council recently, trying to dispel the myth that all-electric buildings aren’t realistic. Some are already in Ann Arbor and others are being built by developers who prioritize sustainability.

450 units Arbor is in a prime residential complex About to start on South Main Street to be fully electric with rooftop solar, as well Veridian in the Farm County neighborhood Now running off Platte Rd.

Other works include a A residential complex consisting of 250 units on state street, A residential building consisting of 79 units on maple road and a quadplex in split ave.

Another local builder is building all-electric solar homes with air source heat pumps In Follmer Court.

There are several types of heat pumps to heat and cool buildings without combustion of gas, including air source heat pumps, which have a unit mounted outside much like an air conditioner, and ground heat pumps, also known as geothermal energy, which take advantage of the temperature of Relatively firm ground is via underground pipes, either with deep boreholes or coils buried four to six feet deep.

Air source heat pump

Air source heat pump outside the Wayne Appleyard home from Sunstructures Architects. An outdoor unit plus two indoor air handlers and one sub-box, plus ductwork for the in-home system, cost about $25,000, he said, stating that it is “a little more expensive” than a simpler system.Wayne Appleyard

Garber said that by using an electric motor, heat pumps compress the refrigerant into a liquid, which raises the temperature, and can produce two to four times more heat energy than the electrical energy consumed, noting that the energy efficiency rate ranges from 200% to 400%.

“Compare that to gas ovens with a higher efficiency of 97%—they can’t get to 100%,” he said.

This is why Ross told Congress in the 1970s that they should switch to heat pumps, Garber said.

“Even then, burning gas was a thermodynamically stupid way to heat buildings,” he said. “Fast forward 45 years, we have a climate emergency.”

The 97% combustion efficiency of gas furnaces was cited as a positive by a labor union that backtracked on the gas ban, saying that coal or gas-fired power plants that might have to generate more electricity for all-electric buildings only had 50-60% efficiency. Burning and this can create more emissions.

Garber argues the use of heat pumps more than negates this difference in combustion efficiency.

“When you convert electrical energy into thermal energy with 400 percent efficiency,” he said, “you have fewer emissions.” “Heat pumps—even with dirty DTE energy—are twice as clean as gas-heated buildings.”

There is always heat

Geothermal and solar energy provide sustainable energy for this mid-century Ann Arbor home

John Mirsky shows off the heat pump for his geothermal heating and cooling system and his dual water heating system, which takes advantage of the heat pump output, at his home in Ann Arbor on Wednesday, January 11, 2023.Jacob Hamilton

John Mirsky, chairman of the Ann Arbor Energy Commission, who has a background in mechanical engineering and spent many years working for Bosch, installed a geothermal heat pump system several years ago to heat and cool his 2,400-square-foot, nearly 2,400-square-foot modern home. , where he also has solar panels on the roof and other electrical appliances.

He explained that he had prepared the house so that it would be very comfortable and to heat it economically, noting that work was done on the building envelope to improve efficiency, replace old windows and add insulation.

Mirsky noted that a heat pump isn’t just a replacement for a gas furnace—it also replaces an air conditioner, because it works in reverse. In air conditioning mode it pumps heat out, and in heat mode it brings heat in.

“There is always heat to be drawn,” he said.

He said his house is now fully electric except for a gas fireplace and a propane grill.

“It’s entirely possible that we’re going to get gas,” Mirsky said, referring to cold-climate heat pumps. Work even in sub-zero temperatures.

Geothermal and solar energy provide sustainable energy for this mid-century Ann Arbor home

John Mirsky shows off the inverters for his solar panels and two separate electric meters, one for a geothermal system, at his home in Ann Arbor on Wednesday, Jan. 11, 2023. The extra gauge is the only evidence of the house’s updated heating and cooling systems visible from the outside.Jacob Hamilton

Homeland Solar installed the 14-kilowatt Mirsky solar array in October, so he hasn’t seen the full benefits yet, but he expects it to deliver about 80% of his annual capacity and is considering adding more panels. In the past two years, he said, his maximum monthly energy bill was about $335, noting that that includes charging his electric car.

As for his heat pump system, the cost would be about $50,000 in today’s dollars, Mirsky said, noting that his price is higher than most because he’s drilled deep wells for geothermal energy, which is more energy efficient, and his house is on the larger side. Someone with a smaller home and using an air source heat pump or shallow coil system can do the conversion for about half the cost.

The air-source heat pump system cost about $25,000, said Wayne Appleyard, a former city energy commissioner who owns a home that has no electricity entirely.

Upcoming incentives

Residents and businesses who want to take the leap and invest in renewable energy and go all-electric could soon get five-figure rebates for doing so between the incentives the city plans to offer and those offered by the federal government.

The city also plans to launch its own sustainable energy facility that could lead to the construction of city-owned solar mini-grids to power neighborhoods and the installation of geothermal systems on the streets that residents and businesses can benefit from, significantly lowering individual costs.

Geothermal and solar energy provide sustainable energy for this mid-century Ann Arbor home

A 14-kilowatt solar array on the roof of John Mirsky’s home in Ann Arbor on Wednesday, January 11, 2023.Jacob Hamilton

The city’s sustainability office is exploring the idea of ​​geothermal energy in the Bryant neighborhood, Missy Stults, the city’s sustainability director, said in November, noting that the city was seeking federal funding and it could take about a year to create a detailed design and plan.

“This is an important area of ​​consideration and the staff is just beginning to dive into the nuances,” she said, indicating that she was watching efforts in Massachusetts.

Ann Arbor officials acknowledge that incremental improvements to the power grid will be needed with the move to all-electric buildings, and grid reliability will be important. The city is also promoting battery backup systems to go along with renewable energy Eliminate network outages.

While many Ann Arbor residents can afford to upgrade their homes, the city acknowledges that low-income residents will need more help to make a just transition. To that end, the city is proposing to allocate an additional $750,000 annually from the city’s new climate action to help low-income residents.

The sustainable energy facility that the city plans to construct can also pay the upfront costs and residents can pay these costs through utility bills. Homeowners can also roll improvement costs into or borrow through their mortgages Michigan saves.

our technology

As for the ban on gas in new construction, if Ann Arbor did it alone, some have expressed concerns that it could push development out of the city and work against goals to add more housing in the city.

City Councilwoman Erica Briggs, D-5th Ward, raised the issue at a recent Energy Commission meeting, questioning the impact it could have on sustainability and affordability goals.

“I think as far as we all feel about the gas embargo… we need to make sure that if we take these steps, we do our due diligence, make sure we’re on good legal ground, but also what the ramifications are.”

It is still debated whether the city has the legal capacity to ban the gas.

Geothermal and solar energy provide sustainable energy for this mid-century Ann Arbor home

An electric heat pump dryer at John Mirsky’s home in Ann Arbor on Wednesday, January 11, 2023.Jacob Hamilton

Energy Commissioner Claire McKenna, a doctoral student at UM who is studying the transition from fossil fuels in residential heating, says the city has a responsibility to protect people from the health effects of burning gas in homes and businesses. She said a zoning law to end gas use in new construction is essential to support this and is a realistic and practical strategy for achieving A2Zero’s goals.

“As a structural engineer, I have studied the feasibility and supported the design of all-electric buildings of all levels, from single-family homes to university laboratory buildings, hotels and high-rise office buildings in colder climates,” she said. “We have the technology to provide for heating, hot water, and cooking requirements for all types of uses, and we have modern standards in place for energy efficiency, such as air and insulation. Appropriately, the state of Michigan is looking to pass a more efficient building code this year, which reduces the electricity demand for our buildings and keeps pollution at bay.” Harmful out of the air as the city continues to transition to greener sources.”

McKenna noted that Ann Arbor is a pioneer but would not be the first US city to ban gas in new construction.

“Technical feasibility is no longer the most important question,” she said. “The question now is which developers and builders will step up and deliver?”

More Ann Arbor news:

Ann Arbor hosts Kamala Harris Climate Call at the University of Michigan

Before the vice president’s visit, Ann Arbor thanks the Biden-Harris administration for helping with the transition to solar power

Excavation in downtown Ann Arbor is the next step for the proposed 18-story high-rise

Ann Arbor agrees to annex two additional properties for mega-residence construction

A farm near Ann Arbor gets historic protection, new ownership

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