Technology Status - NET Nowak Energie & Technologie AG

152
Generation Costs
Generating capacity is primarily determined by the rotor-swept area and the
local wind speed (regime), not by installed power. The installed power
should be matched to the wind speed and rotor-swept area in order to
achieve optimum energy output and the best economy. Machines with the
lowest cost per unit of installed power are not necessarily the most economic
ones for a particular site. As a rule of thumb, the annual energy output, of
modern and properly matched wind turbines is about e = 3.2 x V 3
x AV (where
V is the annual average wind speed (m/s) at hub height and A is the rotorswept
area in m2 ). Doubling the wind speed means roughly an eight-fold
higher energy output due to the cubic relation between wind speed and wind
power. O&M costs for modern turbines can be up to half a USD cent per kWh.
For wind turbines located on difficult terrain, such as offshore or in
mountainous regions, this cost is likely to be higher. Availability, defined as
the capability to operate when the wind speed is higher than the wind
turbine’s cut-in wind speed and lower than its cut-out speed, is typically
higher than 98% for modern machines.
Based on system investment needed and electrical output yielded annually,
generation costs can be given for a range of applications (see Figure 55). Very
low generation costs (slightly above 3.5 USD cents per kWh) occur with
installations characterised by low investment costs (around USD 800) and
high energy output (over 2,000 kWh per kW per year). These installations
are found onshore, with excellent accessibility and wind regime. The
economics are generally less favourable for inland installations with lower
average wind speed and for offshore installations with higher investment
costs. As general economic indicators, power generation costs are USD cents
4 to 7 per kWh on land and USD cents 7 to 12 per kWh offshore. In the best
locations, wind power can cost less than USD cents 3 per kWh.
The best cost-competitiveness is in areas with strong wind regimes and
where development and installation costs are low. Generation costs are
below USD cents 4 per kWh in many coastal and some inland areas with
intense but regular wind regimes and good accessibility for plant
construction and grid connection.
● Industry
The commercial development of grid-connected wind generators started after
the oil crisis in the mid-1970s in countries like Denmark, the Netherlands and the
US. In the early 1980s, most commercial wind turbines were assembled using a
number of standard components such as gearboxes, generators, hydraulic
WIND POWER X7