RES Scenario in the European Union - The Sustainability of Renewable Energy in Europe - page 33

between 1.5 and 3 MW. Today, the wind farm built on land in Europe typically has
a total power of tens of mega watt.
Offshore installations 1 , as well as terrestrial ones in countries with wider avail-
ability of space, can be up to several 100 MW each.
Installations of wind power generation in use today can be divided into two cat-
egories:
• the wind farm power significantly related to the medium-voltage networks and
especially the high voltage;
• the mini wind turbines, that is low power plant (not more than 100-200 kW)
used for feeding of users not served by the network with the help of accumula-
tion systems or for connection to low-voltage networks.
The key component of both types of system is the machine that converts wind en-
ergy into electricity, i.e., the wind turbine. In wind farms, a certain number of wind
turbines are installed in patterns appropriate in an area with adequate wind condi-
tions. The power of each unit today is tend to exceeding 1 MW. The mini wind
turbines instead often include a single wind turbine whose power is 1 kW (or less)
up to 100-200 kW.
The division of the cost of a wind farm in a typical land site is on average 70-
80 % of the purchase and installation of the wind turbines and 20-30 % for the
remainder, including the foundations of the wind turbines, the streets of access,
internal roads, electricity infrastructure, installation work, the line connecting to
the network, and the planning and authorization procedures. The incidence of these
costs is naturally higher in hilly or mountainous areas.
Generally, the typical costs of plant lie in the range between 1300 and 2000 €/kW,
with the highest values for relatively small plants in remote areas in complex ter-
rain.
The offshore farms have a much higher installation cost compared to terrestrial
ones, both for the higher prices of wind turbines designed for offshore use and for
the higher costs of foundations underwater, installation in the sea, and electrical
infrastructure connection to the mainland. For the most recent projects, estimates
range from 2800 to almost 4000 €/kW; the ma higher costs of offshore should be
offset by higher annual energy production.
In order to calculate the average cost of a wind power plant project, it is neces-
sary to evaluate its annual net real manufacturability and it is appropriate to make
assumptions regarding the useful life of the machines, usually 20 years, and the
discount rate. For instance, for an average Italian wind farm of 20 MW with spe-
cific cost 1740 €/kW for a life of 20 years and a discount rate of 5 %, it is estimated
an average cost of between 110 and 160 €/MWh. Of course, in other countries
with easier terrain, open spaces, and strong and regular wind regimes (e.g., in the
1 The offshore wind is the wind made in the sea. Thanks to the favorable conditions of wind at
sea, offshore wind (with the same installed power) produces on average 30 % more energy than
usual onshore.