Find out what problems they have had with their machines' performance, utility cooperation and so on. Ask how responsive the dealer has been to service calls since the installation. As you narrow your choices to just a few machines, compare wind turbine warranties and note differences between those provided by the manufacturer and those offered by the dealer. Inquire whether the dealer's warranty is transferable or assumable by the manufacturer should the dealer go out of business. Compare the maintenance requirements of machines.
Higher maintenance means higher annual costs.
You should compare the terms and prices of service contracts offered by different dealers. If you plan to interconnect the wind system with the utility's power lines, you must first contact the local utility office. The utility in turn should provide you with a written description of its costs and conditions involved with interconnection, such as double-metering. Determine the need for safety and power conditioning devices, additional monthly service and demand charges, buy-back rates and electrical inspection of the installation. This is the time to evaluate the financial consequences of your pending decision.