The Alternative Energy Portfolio Standard (APS) was developed in 2008 to require a certain percentage of the Massachusetts electricity supply to be sourced from specific alternative energy sources. In October of 2017, the Massachusetts Department of Energy (DOER) drafted regulations, pursuant to Chapter 251 of the Acts of 2014 and Chapter 188 of the Acts of 2016, that added renewable thermal, fuel cells, and waste-to-energy thermal to the APS.
Alternative Energy Credits (AECs) are issued as an incentive to the owners of eligible renewable thermal energy facilities per every megawatt-hour equivalent (MWhe) of thermal energy generated. Retail electricity suppliers may purchase these credits to meet APS compliance standards. The APS expands the current renewable mandates to a broader spectrum of participants, as the state continues to expand its portfolio of alternative energy sources.
States Eligible for AECs
The following renewable thermal energy sources are eligible to produce AECs:
Any facility that generates useful thermal energy using sunlight, biomass, biogas, liquid biofuel, or naturally occurring temperature differences in air or water.
|Energy Year||% Minimum Standard||ACP|
A registered system has 10 years of AEC production eligibility. For all solar thermal, heat pump, biomass, or biogas systems, the unit must have been put into operation after January 1st, 2015 to be eligible for the program.
A facility’s eligibility to produce AECs can begin with the system’s operation start date, so long as the SQA application is submitted prior to that quarter’s application deadline. Otherwise, the eligibility start date will be based on the application date and its corresponding quarter.
AECs have a useful life of 1 year. AECs must be sold by the end of each trading year (June 15th).
There are three different schedules by which the state mints AECs:
Pre-Minting - All AECs for the 10 year lifespan are issued upfront at the end of the first calendar quarter. Only small systems are eligible for pre-minting.
Forward Minting - A predetermined number of AECs are issued on a quarterly basis. Only small systems are eligible for forward minting.
Quarterly Minting - AECs are issued on a quarterly schedule based upon production metering. Intermediate and large systems will quarterly mint their AECs.
Meter readings vary by system size and type. There are 3 different buckets for system size: small, intermediate, and large.
|AEC calculation basis||Calculated net renewable thermal output||Calculated net renewable thermal based on indirect metering||Calculated net renewable thermal output based on direct metering of fuel input||Metered net renewable thermal output|
|Solar thermal: evacuated tube and flat plate solar hot water||Collector surface area less than or equal to 660 sq ft||Collector surface area between 660 and 4,000 sq ft||-||Collector surface area greater than or equal to 4,000 sq ft|
|Solar thermal: solar hot air||-||Collector surface area less than or equal to 10,000 sq ft||-||Collector surface area greater than 10,000 sq ft|
|Eligible Biomass Fuel||-||-||Capacity less than or equal to 1,000,000 Btu per hour||Capacity greater than 1,000,000 Btu per hour|
|Air source heat pump: electric motor or engine driven||Output capacity less than or equal to 134,000 Btu per hour||-||Output capacity between 134,000 and 1,000,000 Btu per hour||Output capacity greater than or equal to 1,000,000 Btu per hour|
|Ground source heat pump||Output capacity less than or equal to 134,000 Btu per hour||-||Output capacity between 134,000 and 1,000,000 Btu per hour||Output capacity greater than or equal to 1,000,000 Btu per hour|
Small renewable thermal systems do not require meter readings, as pre-minted AECs are issued based upon predetermined formulas that estimate future production.
Intermediate renewable thermal systems’ production is calculated by indirect metering, which is based upon the electric draw of the pump and the Coefficient of Performance. Intermediate biomass systems must comply with direct metering that is based upon equations that account for fuel input.*
All large APS systems must comply with extensive metering requirements that measure useful thermal energy output.*