Hanscom Air Force Base & Boston Logan Airport

CHALLENGE:

The purpose of this study was to assess the economic feasibility of installing a microgrid at Hanscom Field, comprised of open-rack PV systems and stationary storage systems. The motivation for considering a microgrid at Hanscom Field was to maintain power resilience during grid outages while minimizing energy costs and emissions.

Extreme weather events such as “Super” Storm Sandy had triggered outages lasting multiple days, and sites reliant on fuel-fired generators to ride out islanding events were dependent upon fuel resupply.

Fuel delivery supply chains are vulnerable to the same conditions that cause long electricity outages.

SOLUTION:

Evaluating the economic feasibility of either supplementing or replacing the fuel-fired generators with PV and storage is a relevant solution option. A renewable microgrid had the potential to reduce energy costs, emissions, and reliance on fuel resupply over long outages. 

To test a reasonable risk scenario, a three-day outage duration was assessed. For the assessment both photovoltaic systems (PV) and electric stationary storage (ESS) sizing was optimized to reduce Hanscom Field’s energy costs, as well as provide resilience services alongside existing fuel-fired generators.

Additionally, this study identified the PV and ESS capacities required to provide renewable-based resilience through the same outage, without any fuel-fired power sources. 

Current tariff agreements (including potential sale of excess PV-generated electricity) and available incentive programs were considered in the analysis. Annual energy cost savings were also evaluated. Sensitivity analysis was done on key variables and Carbon impact was also assessed to improve project economics.

RESULTS:

In summary, during the project we were able to quantify the following: savings from peak reduction and energy arbitrage including reduced price volatility, benefits from enhanced reliability, Carbon emissions reduction, analysis of any relevant incentives or tax credits as well as revenue from the sale of excess electricity. 

As part of this effort, Xendee also worked with Rocky Mountain Institute (RMI) to develop a microgrid implementation toolkit for airports. The Toolkit provided guidance and implementation strategies to improve airport energy resilience and to develop microgrid projects with a focus on helping an airport in early stage Microgrid planning. The following aspects were covered in depth in the toolkit:

• Modules related to energy resilience data requirements, critical load identification, cost-benefit analysis, and microgrid technology selection 
• How to determine the size of the microgrid, which assets to backup, and evaluations of renewable energy resources 
• Help airports explore a range of technologies, including energy storage 
• Assess tradeoffs between clean power and fossil power — including fuel cells and hydrogen 
• Understand the costs, installation, and other utility related and stakeholder management issues 

The toolkit was tested and validated by airport personnel and emergency preparedness personnel from across the country.