Institutional - Wind Energy: Renewable Energy and the Environment - page 225

high-voltage line while moving a rebar cage for a wind turbine foundation, and the worker, Patrick
Acker, holding the cage was electrocuted; that fatality is in the database.
Another source reports a mortality rate of 0.4 deaths/TWh for the mid-1990s, which dropped
to 0.15 deaths/TWh by the end of 2000 [6]. Of course, some of the deaths are associated with the
transport of wind turbines. A database is available. Those numbers for the mortality rate for the
wind industry need to be compared to those of other energy industries, such as coal.

11.2.2 P OWER Q UALITY
Power quality refers to harmonics, power factor, and voltage and frequency control. A number
of wind turbines on the end of a feeder line could require extra equipment to maintain quality of
power. Utility companies have to supply reactive power for induction generators, and in general,
capacitors on the wind turbine or at the wind farm substation are required to maintain the power
factor.

11.2. 3 C ONNECTION TO THE U TILITY
The utility should be informed at the earliest possible stage of the intention to connect a wind tur-
bine to its system. Information for the utility should include:

r Specifications of the wind turbine

r Schematic (block diagram) of the electrical system

r Description of machine controls when there is loss of load (utility power)

Even though there may be net energy billing, the utility may require a meter that measures energy
flow in both directions.
Liability for damage is another concern of utilities. The utilities would like to be insured against
all damage due to the wind turbine operation. Of course, the small power producer would like to be
insured against damage to the wind turbine as a result of utility operation; however, that is impos-
sible to obtain. Insurance should be available as part of your homeowner policy or as part of your
business policy. Some electric cooperatives were requiring proof of a $500,000 liability policy for
connection of a wind turbine to their system.
For wind farms, an interconnection study from the utility will cost from $30,000 to $100,000.
This study determines the effect of the wind farm on the transmission lines and existing generators.
Guides for utility-scale wind turbines are available [7].
An example of onerous regulation for small wind turbines comes from the State of Washington,
where the Department of Labor and Industries refuses to sign off on small wind systems without
an Underwriters Laboratory (UL) listing on every component. Washington will now require a few
specially registered electrical engineering firms to certify even existing wind systems that are not
UL listed (all) at a cost of around $2,000. This action on the part of Labor and Industries inspectors
has brought small wind sales to a halt in Washington.

11.2.4 A NCILLARY C OSTS
Wind farms, especially as they become a larger percentage of the generation capacity on the grid,
pose other costs for the utility. The variability of wind can increase operating costs, such as commit-
ting unneeded generation, scheduling unneeded generation, allocating extra load-following capa-
bility, violating system performance criteria, and increasing cycling operation on other generators.
Estimates of these costs are $0.001-0.005/kWh [8] or even up to 0.0185/kWh. The wind integration
impact becomes more significant at higher wind penetration into the grid.