Aggregation is a banding together of customers to purchase goods and services. Energy Aggregation offers individuals the ability to enhance their buying power with competitive energy suppliers by grouping their energy usage into a larger buying group.

Since the deregulation of Maine's electricity utility industry, effective March 1, 2000, electricity consumers statewide have been able to choose an electric generation provider from the open market. While many consumers opt for the "Standard Offer Service" or default price, others choose to seek pricing in the competitive market and enhance their attractiveness to competitive energy providers by joining other organizations in their purchase of electricity.

Aggregations can generally be classified into two primary models or types, Endorsement and Committed-Participation. An Endorsement occurs when a supplier is chosen as a "provider of choice" for a particular group with no real commitment from the members. A Committed-Participation Aggregation, members commit to purchasing energy from the awarded supplier prior to knowing the details of the supply offer. Maine PowerOptions is a combination of the endorsement and committed participation models, offering the services of the committed-participation model without the pre-commitment. The load data or energy usage information is compiled, the RFP issued, and a master agreement is reached with a supplier outlining the supplier's responsibility to those members choosing to participate. It then becomes the option of each member of the aggregation to enter into a supply agreement with the winning supplier. While the supplier-community generally values an up-front commitment, they are still receiving the other benefits present in the committed-participation model and will rarely pass up the opportunity to bid on a large group of energy users.