Green tag system adapts renewable energy to marketplace

Green certificate marketing is an informal system which supports the production of renewable energy in a still-evolving market.

To generate commercial levels of electricity economically, most forms of renewable technology require specific conditions—high winds, sunny climates, strong water flow or proximity to agriculture. The sites with the best conditions, however, may not be located in an area where there is demand for clean but higher priced energy.

Power buyers—generation and transmission companies and investor- owned-utilities—may have the customer base for green power, but little renewable development in their service area. Buyers may contract with green power producers in other parts of the country to pay a negotiable fee per kWh and pass that fee on to their customers. Contracts are arranged one-on-one between buyers and sellers, and the tags are usually sold in bulk lots of thousands of kWhs.