Under this approach, consumers receive a bill credit or rebate to the extent they reduce their usage below individual baseline levels during certain peak pricing events (Attachment J). The baselines of individual consumers are administratively determined, often based on usage in a recent past time period. Of note, baselines are based on an administratively determined formula set out in the utility's tariff or operating procedures. Under such a design, there is the potential to create significant variation in how baseline usage values are determined. Different utility rate designs could calculate baseline usage based upon differing time periods, selected by day type, date proximity, demand levels, weather conditions, or other factors. Additional adjustments could be made to the baseline to address conditions deemed unrepresentative or other concerns.

For supporting detail, see:
http://www.oasis-open.org/committees/download.php/40642/Centolella-%20Comments%20on%20EMIX%20Product%20Specification%20Standard%20complete%20FINAL.zip