Small wind energy systems can be connected to the electricity distribution system and are called “grid-connected” systems. A grid-connected wind turbine can reduce your consumption of utility-supplied electricity. If the turbine cannot deliver the amount of energy you need, the utility makes up the difference. When the wind system produces more electricity than the household requires, the excess is sent or sold to the utility. Federal regulations require utilities to connect with and purchase power from small wind energy systems.

The concept of net metering is to allow the electric meters of customers with generating facilities to turn backwards when their generators are producing more energy than the customers’ demand. Net metering allows customers to use their generation to offset their consumption over the entire billing period, not just instantaneously. This enables customers with generating facilities to receive retail prices for the electricity they generate.

The Virginia Electric Restructuring Act authorizes eligible customer-generators to engage in net metering. Under the Restructuring Act and amendments adopted in 2004, eligible customers include residential customers with small wind systems with a capacity of no greater than 10 kilowatts (kW) and non-residential customer-generators with systems with a capacity that does not exceed 500kW. A customer-generator must own and operate the small wind system on their own premises and use the wind system “primarily to offset all or part of their own electricity requirements.”

Most utilities and other electricity providers require you to enter into a formal agreement with them before you interconnect your wind turbine with the utility grid. Usually the utility or the electricity provider writes these agreements. In the case of private (investor-owned) utilities, the terms and conditions in these agreements must be reviewed and approved by the Virginia State Corporation Commission.

The Virginia net metering regulations govern the amount of liability insurance required for small wind generators as well as for other customer-generators of renewable energy. The rules require that the generators of small wind systems with a capacity of less than 10kW must maintain homeowners, commercial, or other insurance coverage in the amount of at least $100,000 for liability of the insured against loss arising from the use of the small wind system. As of October 2004, the rules required liability insurance coverage of at least $300,000 for small wind systems with a capacity exceeding 10 kW. Utilities may not require customers to purchase liability insurance in excess of limits specified in the law. It is worth noting that in the more than 20 years since utilities have been required to allow small wind systems to interconnect with the grid, there has never been a liability claim relating to electrical safety.

An indemnity is an agreement between two parties where one agrees to secure the other against loss or damage arising from some act or some assumed responsibility. In the context of customer-owned small wind systems facilities, utilities often want customers to indemnify them for any potential liability arising from the operation of the customer’s generating facility. Although the basic principle is sound—utilities should not be held responsible for property damage or personal injury attributable to someone else—indemnity provisions should not favor the utility but should be fair to both parties. Look for language that says, "each party shall indemnify the other . . ." rather than "the customer shall indemnify the utility . . ."

Customer charges can take a variety of forms, including interconnection charges, metering charges, and standby charges, among others. You should not hesitate to question any charges that seem inappropriate to you. Federal law prohibits utilities from assessing discriminatory charges to customers who have their own generation facilities. In addition, the Virginia net metering law limits the ability of utilities to impose excessive charges on owners of small wind generators. The regulations require that the utility charges the same amount for customers generating their own power under the net metering law as those customers that are purchasing all power from the grid (20 VAC 5-315-50).

Whether or not your wind turbine is connected to the utility grid, the installation and operation of the wind turbine is generally required to meet state and local electrical codes. In Virginia, most local governments require compliance with the National Electrical Code. The government’s principal concern is with the safety of the facility, so these code requirements emphasize proper wiring and installation and the use of certified components.

If your wind turbine is connected to the local utility grid, then your utility also may have concerns about safety and power quality. The utility’s principal concern is that your wind turbine will automatically stop delivering electricity to the grid during a power outage. Otherwise, line workers and the public, thinking that the line is "dead," may not take necessary precautions to avoid injury. Another concern among utilities is that the power from your facility synchronizes properly with the utility grid, and that it matches the utility’s own power in terms of voltage, frequency, and power quality.

To address these utility concerns, the Virginia net metering rules have imposed certain technical conditions for interconnection. In addition, the Institute of Electrical and Electronic Engineers (IEEE) has adopted a consensus technical standard (IEEE-1547) for interconnection of small renewable energy generating facilities including wind turbines.