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Evaluating the Net-Zero Claims for the Hanscom Jet Hangar Project

April 10, 2024

The developer has boldly claimed the hangar project is Net-Zero. This paper examines those claims and finds them to be false, and a gross misrepresentation of the greenhouse gas effects.

There are two sources of GHG emissions associated with the project. First, the GHG from flights enabled by the project, and second the emissions from the building infrastructure. To counter these emissions, the developer has incorporated features into the buildings intended to reduce emissions and has described a solar array intended to provide carbon-free power with the effect of offsetting GHG emissions. These will be discussed in turn.

Aircraft-related GHG Emissions

The developer takes three approaches to discussing flight-related GHG emissions, all of which grossly understate the project’s emissions.

First, they argue that only GHG emitted in the immediate vicinity of the airport should be considered. They base this approach on the concept that only the immediate local effect of pollutants on people near the airport should be evaluated. While this might make sense for certain types of pollutants where the impact on the local community is the largest concern, it does not make any sense for GHG emissions which have no specific local effect but affect the planet and everyone everywhere equally. By excluding GHG outside of the vicinity of the airport, they claim that almost all GHG by aircraft enabled by this project are excluded from consideration.

The second argument they make is that aircraft emissions do not matter because future flight growth is not affected by hangars: "These flights are projected to arrive and depart Hanscom regardless of whether the Project is constructed." This argument defies common sense since it says that doubling the jet hangar capacity will have no effect on the number of flights! They take the position that flight growth is essentially “an act of God” that is not affected by infrastructure. Their position on this issue is incompatible with FAA guidance stating that hangar capacity directly impacts flight growth projections. 1

In the third argument, the developer goes beyond this claim of decoupling hangar capacity from jet flights and makes the remarkable further claim that the additional infrastructure will reduce flights. In this argument, the developer claims there are over 3,500 “ferry flights” that will be eliminated by the project. The theory is that there exist today 3,500 unnecessary flights, called ferry flights, which result from aircraft that would like to base at Hanscom, but cannot due to lack of capacity. These hypothetical aircraft are based at a different nearby airport and fly empty to Hanscom to pick up passengers, later dropping off passengers at Hanscom and returning empty to their base. If the new hangar capacity were used to accommodate these aircraft, 3,500 flights and their associated GHG would be eliminated.

This third argument can be verified by examining the detailed flight records of all aircraft that used Hanscom Field in the past year. The developer claimed they were not able to do that analysis, so citizen groups engaged a research firm to perform the study.2 The findings were remarkable. It was found that the project would result in the elimination of 75 flights, and not 3,500 flights. The detailed flight data that shows this result was available to the developers, but they chose not to examine it. The study found only three aircraft exhibiting ferry flights, which would take up only three spaces in the new hangar complex. The vast majority of the hangar space would accommodate new aircraft, enabling up to 6,500 additional flights, generating 134,000 to 161,000 tons per year.3

When the total GHG emissions from the new aircraft were considered, the report found the project is responsible for nearly 160,000 tons per year. The developer has gone to great lengths to obscure the GHG effects of this project, in order to avoid both public scrutiny and possible further environmental filings.

Building related GHG emissions

The developer noted many design details to reduce the GHG emissions of the hangar buildings. Nevertheless, the developer determined that the buildings would generate 2,200 Tons of GHG per year. While considerable, this is 72 times smaller than the 160,000 tons generated by the aircraft.

Solar offsetting GHG emissions

To support its claim of Net-Zero, the developer discusses adding a solar PV array whose carbon-free electricity offsets GHGs. The developer describes a plan for solar arrays covering the entire 522,380 sq ft of roof area of the hangars. An estimated of 7,500 kw of solar array is described, which the developer estimates would offset 2,800 Tons of CO2, which is a high but reasonable estimate if the project were to include a 7.5 MW solar array.

To put this solar project in perspective, it would certainly be by far the largest solar project in Bedford. It is 15 times larger than the only other large solar project known, the 500kw system by Fuji film, and would be among the largest systems in the region. An interconnect of such a large system would be disruptive to the local electrical grid and would require extensive review and possible expensive system upgrades. There can be no assurance that such an installation is possible.

If built, the enormous solar installation could save 2,800 Tons of CO2, more than compensating for the 2,200 Tons produced by the buildings. If only the buildings are considered, this project could be described as Net Zero (if the solar array were built). However, when the whole project, including the aircraft, is considered, the 2,800 Tons saved by the solar panels would be dwarfed by the aircraft emissions, only saving 1.7% of the total emissions of 160,000 Tons. Therefore, the Net Zero claim is untrue and deceptive.

The solar panels only offset a tiny fraction of this project's GHGs. Yet even that savings is not within the project's scope. Although the developer makes detailed claims about the GHG savings of solar in the DEIR, and analyzes the effects of the project by including the solar array, the project does not actually include any solar. The DEIR is careful to say that the buildings “may be appropriate for PV systems” and will be made “solar ready.”4 It also examines how the developer would evaluate any potential future investment in the solar array. There is no commitment to any amount of solar: “The final sizes of the solar arrays are subject to change as the design progresses.” With respect to the 19 buildings that would be ready for solar arrays, they say only they will commit to “a solar array.” If built as described in the DEIR, this project could end up with little or no solar PV. The DEIR should not have estimated the project impacts by relying on a solar array in the analysis that is only a future option and not actually a committed part of the project.

Conclusion

Net zero claims about this project are false and deceptive. The developer grossly understates the GHG resulting from the project. The developer states they intend to reach net zero using a enormous solar installation. Yet, that installation is only put forward as a possible future option and, even if implemented in its entirety, would cancel out only 1.7% of the project’s GHG emissions.

In the submission to the state titled “Climate Resilience Design Standards Tool Project Report,” the developer falsely writes that this project “promotes decarbonization” and answers “maybe” to the question of “Improves air quality” and “prevents pollution”.5


1. "Airport Master Plans" FAA Jan 27, 2015, section titled "Steps in the Forecast Process"
2. Analysis of the Greenhouse Gas Emissions Impact of Proposed Expansion of Hangar Capacity at Hanscom Field. Industrial Economics, Inc. April 4, 2024
3. Using the numbers from the IEC report. Other estimates, based on different assumptions, find up to 400,000 tons, over twice this amount.
4. DEIR p 9-23
5. DEIR Appendix F, p 38

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