The Experimental Renewable Energy Exchange (EX-REX), previously called the Michigan Renewable Energy Exchange (MI-REX), is a pilot project operated by the Energy Office to provide a means for owners of small solar and wind electric systems to sell Renewable Energy Certificates (RECs).  The Energy Office can certify RECs and use this web site to notify potential buyers that the RECs are available for purchase.  The Energy Office is not involved in the actual purchase transaction.  The Energy Office provides this service at no charge, but only for solar or wind energy systems 1-100 kW in size located in Michigan. Systems under 1 kW or over 100 kW are not eligible.

The EX-REX RECs only represent the "green attributes" of the renewable energy and are separate from the electrons or electricity generated by the facility.  A particular quantity of renewable energy includes a variety of avoided emissions and other environmental attributes and these differ by type of renewable energy. An EX-REX REC includes all environmental attributes intact and together.

Verification and Measurement

An EX-REX REC represents one or more MWH (megawatt hour), e.g. 1.6 EX-REX.  The minimum REC is one MWH or 1 EX-REX. EX-REXs are determined using meter readings or, in the case of photovoltaic systems 1-10 kW, you can use the PVWATTS software from the National Renewable Energy Laboratory ( http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version2/#directions ). 

Interested owners of solar or wind electric systems can apply to the Energy Office (see below) at the time of system installation or any time after installation.  The application includes a copy of the utility interconnection agreement or local building permit to verify installation.  The Energy Office will conduct inspections on a random basis to verify installation and operation.

All EX-REXs are for the previous year and are for MWHs AC.  Actual meter readings or PVWATTS documentation has to be provided to the Energy Office by March 31 of the following year. After certification has been completed by the Energy Office on a previous year's MWHs, an EX-REX certificate will be provided to the owner of the solar or wind electric system.  EX-REXs will be identified as either "solar" or "wind," e.g. 2.4 Solar EX-REX.  

Trading, Sales, and Deliveries

This web site records all EX-REXs available for sale.  Owners of the EX-REXs offer their RECs for a fixed price and this price offer can be changed by them at any time.  In addition to available EX-REXs and contact information on sellers, statistics on EX-REX prices and quantities of EX-REXs sold will be displayed on this web site.

The Energy Office will not be directly involved in the exchange of dollars and EX-REX certificates.  After identifying available EX-REXs on this web site, a buyer should directly contact an EX-REX owner and arrange the purchase. Upon receipt of the EX-REX certificate, the buyer will send a check or money order to the seller.  Upon receipt of the check or money order, the seller will notify the Energy Office and the EX-REXs will be retired.

The sale of the EX-REX will transfer the right to use the REC in any other program or to meet any mandate or requirement.  Transfer will not transfer eligibility for any tax benefits or incentives.  The buyer will have to purchase 100% of the EX-REX value indicated on the certificate.  

All data and information maintained by the Energy Office will be public information.  EX-REX is a pilot project that may be ended at any time.

EX-REX Membership Application

2008 Certification Application

Certificates Available for Purchase   

Statistics