AOC 15 - Manual (Page 94)

10.0 System Monitoring
NOTICE: Use of the material contained in this document is subject to the warning on page Iv and the disclaimer
on page v of this document.
DOC012R02 AOC 15/50 User Manual Nov 2001
86
The following sections discuss the various monitoring systems of the AOC 15/50.
10.1 Kilowatt-Hour Meter Applications
Some utilities may require the use of detented, unidirectional kilowatt-hour (kWh) meters: one
to read the energy supplied by the utility and another to read the energy absorbed by it. This
enables the utility to pay the avoided cost rate for the energy it buys and to charge the standard
rate for the energy it consumes. A detented kWh meter can be used to monitor power
production. The most useful information for evaluating system performance is obtained by
comparing the kilowatt-hours generated with the average wind speed over the same period. The
relevant parameters can be measured using a dedicated kWh meter (energy production) and an
anemometer (wind speed).
Net billing refers to the installations where a single kWh meter is allowed to run forwards or
backwards depending upon whether the system is consuming or producing energy. The kWh
meter indicates the net energy flow and energy is valued at the same rate for consumption and
production.
10.2 Anemometers
The AOC 15/50 has two anemometers which are boom-mounted across two tower legs,
approximately 10 m (32 feet) below the tower top casting. The PLC samples the wind speed
measured by each anemometer every second and calculates 8 second and 128 second averages
from the sampled data.
10.3 Output Analysis
One of the best methods for evaluating a wind system's performance is to monitor energy
production. Unless there is an obvious mechanical or electrical fault, wind speed and kilowatt-
hour production should be recorded for at least one month after the wind turbine has started
running and ideally afterwards also, either continuously or at regular intervals, so that any
drastic changes in performance can be noted and investigated. Note that a number of factors can
affect output, including wind velocity, wind turbine maintenance, temperature, humidity, etc.
Recording these parameters will help evaluate system performance, as well as understand
system operation.
10.4 Output Analysis Worksheet
The system monitoring checklist (see Appendix G) will assist in evaluating system performance,
by providing the information necessary to reach an informed conclusion. It can be used for
routine system monitoring, as well as to observe and understand normal system function. Energy