The 2004 Alternative Energy Portfolio Standards Act

Tom Coyle
May 27, 2018

Submitted as coursework for PH240, Stanford University, Fall 2017


Fig. 1: Solar Panels in Myerstown, PA. (Source: Wikimedia Commons)

On November 30, 2004, Governor Ed Rendell instituted the Alternative Energy Portfolio Standards Act (AEPS) in the state of Pennsylvania. The act requires that Pennsylvania's electric distribution companies and electric generation suppliers must use certain percent of alternative energy sources for energy generation and distribution by 2021. Later, in 2008, Governor Rendell signed Act 129, which expanded the different eligible energy sources that count towards "alternative" energy.

Defining the Alternative Energy Sources

In order to be compliant with AEPS by 2021, EDCs and EGSs must supply 8 percent of their electricity from Tier I energy sources and 10 percent from Tier II energy sources. According to the 2004 Act, Tier I energy sources include solar PV, solar thermal, wind, geothermal, biologically derived methane gas, coal-mine methane and fuel cell resources. Tier II resources include new and existing waste coal, distributed generation (DG), demand-side management, large-scale hydro, municipal solid waste, wood pulping and manufacturing byproducts, and integrated gasification combined cycle (IGCC) coal facilities. [1] In 2008, Act 129 expanded Tier 1 resources to include categories of low impact hydropower and biomass energy. [2] While solar photovaltaic technologies is included in the Tier I resource, there are also milestones for each year for the percentage of solar PV technologies sold in relation to all electricity. By 2020, 0.50% of all electricity sold in Pennsylvania must originate from solar photovoltaic technologies. In order to track the distribution and generation of power through alternative energy sources, EDCS and EGSs must track the number of megawatt hours generated at each site and report that number monthly. Each megawatt hour, defined as an Alternative Energy Credit (AEC), are tracked by the PJM Generation Attribute Tracking System (GATS), a third party service. [1]

According to the 2017 Annual Report, 14.2% of electricity generation in Pennsylvania was through an alternative energy resource. Several other states are participating in the PJM GATS service. At the end of 2017, 48.4% of AECs were generated within the state of Pennsylvania. One help is from the Solar requirement, which has impacted the generation of energy. In 2017, 85.3% of solar installations have come from the residential sector, such as the solar panels in Myerstown in Fig. 1. As of May 31, 2017, there are 13,524 AEPS-registered generators in Pennsylvania that generate a capacity of 7,146 MW. This accounts for 0.2933% of the total energy sold in the state, nearing its goal. The Tier I goal of 8% is nearing close with 5.71% and the Tier II goal of 10% is closing in with 8.2%. [3]


The Alternative Energy Portfolio Standards Act was signed in November of 2004. The act aimed to increase the generation of power from alternative energy sources such as solar, wind, geothermal and waste coal. The target of 18% of total energy sold is coming close. As of May 31st, 2017, 14.2% of all energy sold in Pennsylvania comes from an alternative energy source.

© Tom Colye. The author warrants that the work is the author's own and that Stanford University provided no input other than typesetting and referencing guidelines. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.


[1] "Alternative Energy and Economic Development in Pennsyvalnia," Pennsylvania Public Utility Commission, July 2017.

[2] "Alternative Energy Portfolio Standards Act," Pennsylvania General Assembly, July 2007.

[3] "2017 Annual Report: Alternative Energy Portfolio Standards Act of 2004," Pennsylvania Public Utility Commission, 2017.