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Carbon Free Boston policy options

We’re analyzing our options in the City’s efforts to go carbon neutral by 2050.

Carbon Free Boston is the City's long-term initiative to achieve carbon neutrality by 2050. We're currently analyzing how different policies and technologies can help us reach our climate goals.

The list below introduces some of the different policy options our research team will model over the next couple months. This list is not exhaustive. Carbon Free Boston is an ongoing initiative. We may look into other policies and technologies as we continue our work.

Do you see something missing? We’re always listening for more ideas to reach carbon neutrality by 2050. If you have any suggestions or questions, please email us at

Still have questions? Contact:
1 City Hall Square
Room 709
Boston MA  02201-2031
United States
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Energy sector policy options

Energy policy options

Carbon Free Boston is studying district energy policy options. District energy systems produce energy in a central location. They then distribute that energy to a local building network. Distributed generation can boost the resiliency of Boston’s energy system. District energy systems that run on clean energy can further Boston’s climate goals. The 2016 Community Energy Study found more than 40 possible areas for district energy solutions. Here are some of the district energy policy options the team is looking at:

Force the retirement or conversion of in-boundary and neighboring fossil-fuel district energy plants

Most district energy systems run on fossil fuels. But, they can switch to use renewable energy sources. For example, the Kendall Station in Cambridge used to dump heated water into the Charles River. Now, the plant uses that heat to generate steam. That steam heats Boston’s central business district and the Longwood Medical Area.

District energy plants can use a variety of non-fossil fuel energy sources. These include renewable energies, like geothermal heat and solar power. District systems can also use waste heat from:

  • sewage water
  • factories, or
  • data centers.

District energy systems that run on renewables can provide Boston with low-carbon power.

Reduce regulatory barriers

For a district energy system to work, it must be legal for it to sell power to neighboring parcels. To do so, the district energy owner might have to register as a utility. Clarifying the rules for district energy systems is an important part of this process.

Invest in large- and medium-scale distributed generation (district energy, microgrids, combined heat and power systems, trigeneration districts)

District heating and cooling systems generate can heat, steam, and chilled water. They then distribute that energy through underground pipes to a network of buildings. Buildings use the energy for air conditioning, space heating, and water heating. A microgrid is a self-contained electric grid with distributed energy resources. The microgrid can either connect to the main power grid or operate in "island" mode. Combined heat and power (CHP) systems generate both electricity and steam. Trigeneration goes one step further. It provides electricity, heating, and cooling. Many combo systems and trigeneration systems use fossil fuels, but they can also use waste heat or biomass.

The project team is studying different gas policy options. Natural gas generates half of our electricity. It's also used to provide heat and power to many of Boston’s buildings. But natural gas combustion emits greenhouse gases.

Policy decisions can dictate the role that natural gas plays in our future energy sector. They also affect how utilities plan their investments. Today's gas policies will affect Boston’s long-term emissions. These are some of the gas policy options the team will be looking at:

Renewable gas supply (hydrogen, biogas)

Refining biogas recovered from landfills or wastewater treatment creates "renewable" natural gas. This renewable natural gas may take the place of conventional natural gas. Renewable natural gas is carbon neutral. But, it emits air pollutants like carbon monoxide. As a result, renewable natural gas may pose a threat to public health.

Natural gas leak mitigation policy

Boston has some of the oldest natural gas infrastructure in the country. Emissions from leaks contribute less than 1% of community-wide greenhouse gas emissions. But, natural gas leaks also present a public health hazard and can kill local vegetation. A July 2017 ordinance is working to end natural gas leaks.

The team is studying policy options to boost renewable energy generation. If we grow Boston's renewable capacity, we can reduce our demand for electricity from the grid. This could help speed up the transition to carbon neutrality. The policy ideas under consideration include:

Mandate and/or incentivize solar panels on roofs

Many incentives for solar panels are already available to Boston residents. As well as a 30% federal tax credit, Massachusetts solar owners can deduct 15% of the solar system cost from state taxes.  Solar homeowners in Massachusetts also enjoy sales tax and property tax break incentives. The Mass Solar Loan Program offers low-cost solar financing solutions to help with the upfront cost. After installation, solar homeowners can sell excess solar electricity to the grid. They can also sell their Solar Renewable Energy Credits to their local utility. The Massachusetts Department of Energy Resources is developing a new solar incentive program. The Massachusetts Renewable Target (SMART) program will promote cost-effective long-term solar development.

Ensure that solar panel owners can interconnect to the grid

Massachusetts has adopted a net metering policy. Net metering pays solar array owners for the electricity they add to the grid at full market value. Our net metering policy caps the total solar capacity that a utility can connect. This cap seeks to ensure utilities have enough revenue to maintain and improve the main power grid. But when reached, the cap threatens the development of large solar farms. (The cap does not affect most individual homes installing small arrays.) The feed-in tariff (FiT) offers a different model to connect solar owners and support solar deployment. Under a FiT, a second meter is installed to track generation and consumption separately. Utilities compensate solar producers at a depreciating rate under a long-term contract. This encourages solar owners to install arrays that meet their own electricity needs. Strengthening grid interconnection policies is important to support solar energy deployment.

Install distributed renewable energy generation (e.g., solar) on municipal facilities

The City has deployed pilot solar arrays on some buildings, like the Boston Archives Center in West Roxbury. The City has installed approximately 340 kilowatts of solar capacity to date. With over 300 municipal buildings, the City can lead solar energy deployment in Boston. The City is planning new solar installations under the Renew Boston Trust project.

The team is evaluating many renewable energy credit and purchase policy options. Not everyone can generate their own renewable energy. The electric grid will also not be carbon-free in 2050. Boston will need to compensate for its remaining emissions. Here are some of the different policy options the team will be modeling:

Increase locally-produced and community-owned renewable power

In community renewable energy projects, members pool their financial resources. Together, they fund a renewable energy installation. The new system can be inside or outside the city boundary. The benefits are distributed to community members, like an investment dividend. Members can count their earnings toward lower utility bills. This “crowdfunding” model allows members to access renewable energy without breaking the bank.

Buy more Renewable Energy Certificates (RECs)

Some electricity users cannot create or buy their own renewable electricity. For example, a historic property may not be well suited for a solar panel installation. They may instead buy tradable credits that prove electricity comes from renewable energy. These are called Renewable Energy Certificates, or RECs for short. Each megawatt-hour (MWh) generated from renewable energy sources creates 1 REC. Purchasers can count RECs toward their clean energy goals. And REC sales can help developers finance renewable energy projects. The project team is studying best practices for REC purchases.

Buy renewable energy through power purchase agreements (PPAs) and other mechanisms

Cities can negotiate with electricity providers to buy renewable energy. The two parties can enter into a power purchase agreement, which is often a 20-year contract. Under the agreement, the consumer pays a fixed price over the whole contract. A provider installs a new system to supply renewable energy to a consumer. The new installation can either be on- or off-site. The consumer doesn't need to spend any money upfront.

These agreements protect consumers from volatile energy prices. Another mechanism is the “net metering credit purchase agreement”. Under this type of agreement, electricity is generated off-site. The price of electricity also changes with the market. The team is studying how buying renewable electricity will affect Boston’s emissions.

Buy carbon offsets

A carbon offset equals one metric ton of greenhouse gas emissions avoided or reduced. Cities can buy carbon offsets, which are often generated by projects outside city boundaries. These offsets can compensate for local emissions. Cities can use offsets to lower their emissions even when local reductions are not possible. Carbon offsets can also help compensate for any residual emissions.

Buying offsets supports investment in projects that reduce greenhouse gas emissions. To be effective, this policy would need clear transparency rules. This framework would state how to choose offsets and disclose carbon offset purchases.

Provide clean power purchasing options to consumers

Community Choice Energy (CCE) allows local governments to bulk-buy electricity for their communities. Many communities have entered into such agreements to buy more renewable energy. Once a city enters into an agreement, residents can buy clean energy at wholesale prices. Residents may also choose to opt out of the program. The City Council recently authorized the City of Boston to enter into an agreement. The City put out a Request For Information, and has released the responses it received.

Provide financial incentives for on-site and off-site renewable generation

Boston residents have access to many renewable energy tax credits and loan programs. Other financial incentives could include:

  • a lower property tax for buildings with renewable energy systems
  • a lower sales tax for renewable energy purchase or installation, and
  • loan guarantees or mortgage-related loan programs.

Building sector policy options

Building policy options

New building policies would strengthen sustainability requirements for new construction. These policies could impose higher energy efficiency and renewable energy use rules. Such policies could prevent future growth in energy demand from the building sector. Here are some of the policies the team is looking at:

Put in place new energy efficient zoning, building and energy conservation codes

Since January 2017, Boston builders have been applying the Massachusetts building energy “stretch” code. This new part of the building code imposes higher energy efficiency requirements. The new "stretch" code applies to new builds and big remodels. The stretch code is roughly 20% more energy efficient than the base code in Massachusetts. But an even stricter code could make buildings even more efficient. These codes could adopt a carbon neutral or zero net energy approach.

These strategies seek to increase energy efficiency and renewable energy use. For example, a “zero net energy” building uses energy efficient design and systems. This reduces its energy needs. Such buildings then use onsite renewable energy to meet their remaining energy needs. A building may even become “net positive energy.” This means it produces more energy than it uses. It can then sell any excess electricity back to the grid.

Put in place a Passive House requirement

The Passive House is a global standard for energy efficient construction. First, a passive house makes efficient use of the sun's warmth to heat the house. Passive houses may then call for more building insulation to reduce heat loss. Finally, efficient ventilation, heating, and cooling systems reduce the home's energy needs. This standard results in comfortable, energy efficient buildings.

Expand Boston Zoning Code Article 37, Green Buildings

Article 37 requires that all major building projects be LEED-certified. LEED stands for Leadership in Environmental and Energy Design. LEED is the U.S. Green Building Council’s rating system. Pursuing LEED certification helps create healthy, efficient, and cost-saving green buildings.

Today, Article 37 covers buildings complying with Zoning Article 80B, Large Project Review. Article 37 only requires that these buildings achieve the “certifiable” level. Article 37 could cover more buildings, or mandate a higher level of certification.

The bulk of Boston’s building stock was built before 1950 and the first modern building code. These policies would work to improve the energy efficiency of existing construction. Policy options for existing buildings include:

Require deep retrofits of buildings at designated intervention points

All buildings, including green buildings, can be retrofitted to save energy. A deep energy retrofit studies all of a building’s systems and their interactions. That includes:

  • the building envelope
  • heating and cooling
  • hot water, and
  • lighting and appliances.

This analysis can find opportunities to replace or upgrade systems and save energy. Deep retrofits can cut a building’s total energy usage by half or more. These improvements save money in the long run while reducing greenhouse gas emissions. Retrofits could be undertaken at different times. They could be carried out at the point of sale, or during a major renovation.

Carry out deep retrofits of City buildings

The City of Boston is also an important property owner. The City can retrofit its buildings to save energy and reduce emissions. In doing so, the City can lead by example as we work toward our carbon neutral goals.

Develop funding mechanism to finance energy retrofits

Mass Save currently offers energy retrofit incentives for both residential and commercial buildings. Building on existing mechanisms could encourage more retrofits. For example, a new mechanism could target rental housing. By reaching more buildings, we can save more energy and further reduce our emissions.

Ease setback requirements to allow more envelope insulation

Boston's zoning code prevents buildings from building right up to the property line. Adding envelope insulation to an existing building would violate this rule. Relaxing setback requirements would allow building owners to add more insulation. Building owners would be able to take an easy step to improve their building’s energy efficiency.

This includes policy options for both new construction and existing buildings. Here are some of the policy ideas the team is looking at:

Require energy storage and electric vehicle charging requirements for new and retrofitted buildings

The City requires that 5% of parking spots be equipped with electric vehicle chargers. Another 10% of parking spots should be EV-ready in:

  • South Boston and Downtown, and
  • in all remodels and new buildings across Boston.

That means that parking zones need to be able to support charging stations in the future if EV demand goes up. The City does not currently have energy storage requirements. Boosting electric vehicle capacity is important to support the transition to carbon neutrality.

Establish minimum energy efficiency standards for rental housing

Two-thirds of Boston residents rent their homes. Boosting energy efficiency in rental units could help tenants use less energy. This would cut greenhouse gas emissions and utility bills while boosting property values. The City could pass an ordinance to require rental properties to meet minimum energy efficiency standards. Programs like MassSave can perform energy audits. This would help owners improve the energy efficiency of their property.

Expand the Building Energy Reporting and Disclosure Ordinance (BERDO)

BERDO requires large buildings (35,000 square feet and up) to report their energy use to the City each year. Buildings must also complete an energy audit or energy saving actions every five years. Expanding BERDO could involve asking buildings under 35,000 square feet to start reporting. The City could also strengthen the energy action and assessment requirement.

District energy systems produce energy in a central location. They then distribute that energy to a local building network. Low-carbon district energy systems can reduce building sector emissions. Thinking sustainability at the neighborhood level can also boost resiliency. These are some of the options the building team is considering:

Develop and expand low- to no-carbon district heating and cooling systems

District energy systems can generate heat, steam, hot water, or chilled water in a central location. The utility distributes that energy through underground pipes to buildings. The energy is then used for:

  • air conditioning
  • space heating, and
  • water heating.

District heating systems can use a wide range of low- to no-carbon energy sources. These include:

  • combined heat and power
  • geothermal heat
  • solar heat, or
  • waste heat.

District heating and cooling provides an energy efficient alternative to individual heating systems. With many consumers located in a small area, district systems are well-suited to urban environments like Boston.

Establish zoning code requirements for ‘district energy ready’ buildings

Today, many buildings are not designed to receive district energy. For example, a building’s basement might not be big enough to fit a substation to connect to the district network. The zoning code could establish new district energy requirements. These changes could help make buildings district energy ready. This allows for the future provision of low-carbon district energy.

Transportation sector policy options

Transit policy options

Options include both electric vehicles and vehicles that use alternative fuels, like ethanol. Policy options might support clean vehicle purchases, or discourage the use of fossil fuel vehicles. Here are some of the options the team is looking at:

Incentivize adoption of electric and alternative fuel vehicles

A suite of policies can encourage the use of electric and alternative fuel vehicles. For example:

  • allowing electric and alternative fuel vehicles to use public transit lanes
  • granting them free or preferential parking, and
  • exempting them from taxation, or granting them rebates.

Establish taxes or fees on fossil fuel vehicles

A “feebate” program would levy fees on fossil fuel vehicles. The City would levy a tax or fee at the time of a vehicle purchase.

Ban fossil fuel cars

This policy option would ban gas- and diesel-fueled vehicles. A ban could apply to designated zones or the entire City. This policy option can reduce smog and air pollution, as well as greenhouse gas emissions.

These options seek to reduce the total number of trips made using fossil fuel vehicles. This can help reduce emissions from the transportation sector. Reducing transportation emissions supports Boston’s goal of carbon neutrality. These are some of options the team will study:

Establish congestion or climate taxes on fossil-fuel vehicles in designated areas

Congestion pricing charges drivers traveling during rush hour or within a certain zone. A climate tax charges drivers based on how much carbon they emit as their car burns fuel to run. The City could work with the state to set a congestion charge on fossil fuel vehicles, or tax carbon emissions in certain zones. This would discourage the use of inefficient fuel-burning vehicles within designated areas. This policy might also boost public transit use.

Set taxes on gasoline or petroleum purchases

Gasoline and diesel are exempt from states sales tax. But, they are subject to both state and federal fuel taxes. The state fuel tax pays for:

  • highway maintenance
  • safety services, and
  • regional transit.

Fuel taxes can reduce fossil fuel consumption and cut greenhouse gas emissions.

Establish regional congestion pricing

Regional congestion pricing charges drivers for road use, using one of several models. Variably priced lanes charge different tolls for different separated highway lanes. For example, the pricing system could charge a lower toll in an HOV lane.

Variable tolls on entire roadways would apply one toll to roads and bridges, and another rush hour toll to other facilities. A cordon area charge would charge road users that drive into a congested area in the City. Area-wide charges would charge road users on a per-mile basis. That fee could vary by level of congestion. Learn more about congestion pricing on the U.S. Federal Highway Administration’s website.

Institute new parking pricing models

Innovative parking pricing models can help reduce travel demand and emissions. Smart meters could adjust the price of on-street parking based on supply and demand. Unbundling parking costs from the rent or sale price of a home can improve affordability. Both of these policies provide an incentive to go car-free.

Parking pricing policies can also affect off-street parking. Taxing off-street parking could encourage redeveloping parking lots toward other uses, like housing.

Promote carpooling, ride-sharing, car-sharing, and High Occupancy Vehicle (HOV) lanes

Carpooling and ridesharing programs help people share cars and commute together. Ridesharing programs can cut traffic congestion and greenhouse gas emissions.

A common incentive for ridesharing is access to High Occupancy Vehicle (HOV) lanes. HOV lanes are restricted for vehicles with a driver and one or more passengers. Their goal is to increase the average number of people traveling per car. HOV lanes should reduce the total number of cars on the road.

The goal of such policies would be to encourage more residents and commuters to walk, bike, and take public transit. Here are some of the options the team is studying:

Improve bicycle infrastructure

The City can improve bicycle infrastructure to encourage more residents to start biking. “Complete streets” is a design approach that focuses on safe access for all road users. This includes both pedestrians and bicyclists. Complete streets offer separate bicycle lanes on roads and bicycle racks on sidewalks.

The City can also instruct developers to include bike infrastructure in their site designs. Installing secure storage facilities at transit hubs can encourage car-free commuting. Tourists and residents who don’t own a bike can use Blue Bikes, the Boston metro area bikeshare program. The City is also considering opening Boston to e-bikes, or dockless bike-sharing. With appropriate regulation, e-bikes might complement Blue Bikes and boost ridership.

Improve bus infrastructure

Bus infrastructure improvements can help to reduce traffic congestion and transit delay. They can also encourage more residents to use public transit. Reserving lanes for exclusive use by buses can help speed up public transportation. Transit signal priority (TSP), or “queue jump,” allows buses or trains to bypass traffic.

Improve pedestrian infrastructure

The City can encourage residents to adopt active transportation modes. "Complete streets" is a design approach that focuses on safe access for all road users. This includes pedestrians of all ages and abilities. Safety measures include:

  • curb extensions
  • raised crosswalks
  • refuge islands, and
  • high-visibility signage.

The pedestrian must also be accessible and comfortable for all to use. Adequate lighting, landscaping, and wheelchair accessibility are vital for safe and agreeable streets.

Invest in public transit

Public transit allows users to go car-free and lowers transportation emissions. A public transit system should provide diverse and affordable travel options. Fast, reliable, accessible, and convenient public transit relies on sustained investment.

Expanding public transit boosts its capacity to serve more travelers. The transit system might grow to include new modes, like street cars or urban light rail. Clean technologies, like electric buses, can cut emissions and save money. Last-mile programs might help passengers reach their final destination without a car. These might include:

  • transit shuttles, or
  • an expansion into low-service zones.

Tackling transit delay improves reliability and satisfaction thanks to reduced waiting times. For example, bus lanes allow buses to bypass traffic and get to their destination on time. Way-finding and transit information applications further boost accessibility and convenience. Reduced transit fares also ensure that all residents can access public transit.

School buses and the MBTA represent about 10% of Boston’s transportation emissions. Fleet policies can help reduce the public sector’s contribution to these emissions. Here are some of the options the team is looking at:

Convert public transit, government, commercial, and taxi fleets to no- to low-carbon energy

Electric and alternative fuel vehicles have low- to no-tailpipe emissions. For example, the MBTA Silver Line uses diesel-electric hybrid buses. Diesel hybrid buses use 44% less fuel, saving money and cutting emissions. This policy would convert public fleets to lower carbon energy sources. Low-carbon vehicles can be electric or hybrid, or use natural gas or hydrogen.

The team is looking into various policies to improve freight efficiency. Urban deliveries depend on freight transport, particularly trucks than run on fossil fuels. Freight policies seek to improve efficiency. This can help reduce emissions from bringing goods into the city. The team will be looking at policy options to improve freight efficiency:

Electrify Class 5-7 trucks

These would have a gross vehicle weight ranging from 16,001 to 33,000 pounds.

Permitting policies

We could put in place:

  • designated loading and parking zones
  • truck routes and hours of operation
  • anti-idling policies, and
  • truck permitting policies.

Permitting policies could encourage the use of fuel-efficient and electric trucks.

Freight distribution centers

Improve energy efficiency at freight distribution centers.

Carry out outreach programs to educate fleet owners

We could provide owners information about best practices and low-emissions freight technologies.

Travel demand management means managing vehicle demand on the transportation network. These programs seek to provide travelers with non-motor vehicle travel options. They can also help to shift the demand away from peak hours and heavily-traveled routes. This helps reduce traffic congestion and emissions. Here are some of the policies the team will be looking at:

Reduce transit fares or pass subsidies for workers

Workers already have access to various incentives to take public transit or alternative transportation to work. For example, many employers offer employees the opportunity to purchase pre-tax commuter passes. Providing discounted passes could encourage more workers to use public transit.

Travel demand management or reduction requirements for either new commercial development or for all workplaces with more than 50 employees

Private companies can contribute in diverse ways. For example, employers might subsidize public transit passes. They can also provide bike parking, lockers and showers to encourage non-motorized commuting. Work-at-home programs or adjusted work hours could also help employees avoid peak traffic or skip the commute altogether. Large job sites can also offer shuttle services to nearby transit hubs or to certain neighborhoods. Parking cash out programs could also allow employees to take the cash value of their designated parking space in lieu of the space itself. And workplaces can also give electric vehicles, car-shares and vanpools preferred parking.

Establish travel demand management requirements for new residential construction (more than 10 units)

Like employers, residential buildings can also encourage residents to go car-free. For example, they can create an attractive streetscape to encourage walking and provide bicycle parking and amenities. They can also provide on-site childcare services and other family-friendly amenities, like cargo bikes. Unbundling parking costs from apartment rental costs can also encourage renters to use alternative transportation modes. Residential buildings can also give electric vehicles, car-shares and vanpools preferred parking.

Waste sector policy options

We are studying policy options for the waste sector through the Zero Waste Boston planning process.

As a leading sustainable city, the City of Boston is committed to reducing waste by increasing recycling and reuse, and diverting organics. By keeping these valuables out of Boston's waste stream, we can:

  • save money
  • create local jobs, and
  • improve the environment.
Zero waste in Boston

Zero Waste Boston is our initiative to transition the City towards zero waste. The City will do this through:

  • infrastructure and policy development
  • community engagement, and
  • putting in place projects as part of the city’s Climate Action Plan.
Learn more

Carbon Free Boston is coordinating with Zero Waste Boston. We want to understand how different policy and technology options can reduce greenhouse gas emissions from waste.

You can learn more about our ongoing Zero Waste Boston initiative. You can read all of the team's meeting notes online, including the policy options currently under consideration.