Portland soon could be joining a growing number of U.S. communities looking to track and reduce energy consumption by large commercial and residential users.

But the city is at a crossroads. Should the public disclosure of energy use be voluntary or mandatory?

It’s a question that must be answered in the coming year. Right now, there are diverging efforts being undertaken.

On Wednesday night, the City Council unanimously referred an ordinance to its Energy and Sustainability Committee that would require some large commercial and public buildings to report their energy usage to the city. At the same time, the Greater Portland Council of Governments is trying to establish a national voluntary energy reporting program, known as 2030 District, in Portland.

“I think it comes down (to) a philosophical question about whether there’s a role for government to be doing this,” City Councilor and Energy and Sustainability Committee Chairman Jon Hinck said Thursday. Hinck supports mandatory reporting requirements and publicly posting the energy use online. “When the effort is strictly voluntary, not enough of the population of buildings ends up being included.”

The Energy and Sustainability Committee will hold a public hearing on the proposed ordinance at its July 20 meeting, he said.

But City Councilor Edward Suslovic, along with area businesses, believes the city should wait and see how the voluntary 2030 District program goes before enacting regulations. The program aims to cut energy use in half by 2030.

“I hope we would not step on the toes, so to speak, of such a voluntary effort,” Suslovic said at Wednesday’s council meeting. “Maybe we ought to give that voluntary effort a little time to get their legs under them and see how that’s going.”

The goal of each program is to collect baseline data about energy use in large buildings, whether it’s electricity, natural gas, steam, water or heating oil. That data would be used to gauge trends in energy use and to measure the effectiveness of efficiency upgrades.

Utility benchmarking – a technical term for tallying and comparing similar things – is a process promoted by the U.S. Environmental Protection Agency through its voluntary Energy Star efficiency program.

Cities track the utility performances of larger commercial and residential properties through the EPA’s Energy Star Portfolio Manager, a website tool that allows users to compare energy use, water consumption and greenhouse gas emissions of similar buildings nationwide.

At least 20 citiesaround the country, including San Francisco, Seattle, New Orleans, Atlanta, Minneapolis, Chicago, Philadelphia, New York City and Boston, have some sort utility benchmarking requirement.

So far, no community in Maine has adopted such an ordinance. South Portland is considering one that would apply to about 30 buildings in the Mill Creek area that have over 5,000 square feet of gross floor area, as well as 23 municipal and school buildings citywide. It would also apply to residential properties in Mill Creek with 10 units or more, of which there are currently none.

Portland’s ordinance is modeled after one passed in Cambridge, Massachusetts, Hinck said. It would apply to most public buildings and privately owned buildings larger than 20,000 square feet of gross floor area, or with more than 50 residential units. By comparison, the city’s Central Fire Station is roughly 15,000 square feet. Failure to report usage could result in a written warning, followed by $150 a day fine.

City officials on Thursday estimated that 225 commercial buildings larger than 20,000 square feet would be affected, as well as 30 municipal buildings, 19 apartment complexes and 10 condominium developments.

Both ordinances would require energy use to be posted online.

The Portland Community Chamber of Commerce is urging a cautious approach to the proposed ordinance. Chamber CEO Chris Hall said some businesses may have concerns about having their energy usage posted online, as well as the costs of implementing a process for collecting information from building tenants.

“I don’t think the concept is a bad one, but they need to go at a pace people are comfortable with,” said Hall, who supports a voluntary program. “We just don’t want to add extra costs that aren’t necessary.”

The Greater Portland Council of Governments, a regional council of 26 area municipalities, will begin conducting outreach to Portland businesses on Aug. 10. At least five businesses need to sign on to the 2030 District before it would be recognized by the national organization.

There are currently thirteen 2030 Districts in the U.S., primarily in larger cities such as Los Angeles, Denver, San Antonio, Pittsburgh, Cleveland and Seattle. Portland is among four “emerging” districts and is in the process of establishing an advisory board, according to council Director Neal Allen.

Allen said the council’s Environmental Action Team has been working on the 2030 District for about a year. The district would largely cover the peninsula and there’d be no size requirements on the buildings that can participate. Participants would benefit from educational forums, best management practices and bulk purchasing rates on system upgrades that could improve the efficiency of their buildings, he said.

Allen thinks the city should hold off on enacting an ordinance.

“On the private sector side there is no interest in an ordinance,” Allen said. “Whenever you come in and require something, that will sometimes lead to a stalemate and a lack of forward direction.”

Jeffrey Packard, who owns the energy efficiency company Alodyne and serves as co-chair of the council’s Energy Action Team, said the group is working with the utility companies to get easier access to energy data in a consistent format. Once that process is streamlined, collecting data will be less onerous than having each property owner manually report usage, he said.

“Personally I think our method of working with the utility will be better,” Packard said. “There are already a ton of regulations and adding an additional layer is going to be an overly cumbersome thing to have to deal with.”

But Hinck said that sometimes businesses will not act on reducing energy use, even if it is in their financial interest, without an ordinance. He noted that Maine has relatively high energy costs and Portland has old housing stock. Through efficiency, businesses could save money and invest it back into the community, he said.

“We get so much more of a return on doing this than do municipalities that have lower relative energy costs,” he said.