Environmental Engineering Reference
In-Depth Information
side is appropriated by producers of PV modules and system installers and added to
their pro
ts as a result of the market interplay between supply and demand. Lastly,
in spite of the high tradeability of PV modules, which ensures internationally
homogeneous prices, the variability in PV system prices and costs is likely to
continue, since there are many other factors that in
uence PV system installation
costs and the LCOE.
Summarising, because of their many advantageous properties and the continued
support that they enjoy in many parts of the world, substantial price and cost
reductions can be expected in the near future for all kinds of PV system, and
signi
ciency within two to 5 years. Thus, PV systems of
all types will soon be achieving grid-parity in many parts of the world. It should be
noted in this respect that reality has systematically outperformed cost reduction
forecasts in the recent past (see e.g. [
31
]). This can be con
cant up-grades in their ef
rmed by comparing
the data presented in Tables
1
and
2
, offered in 2011
2012 by several research
think-tanks, to casual observations of the market at the time of writing this chapter,
i.e. the end of 2013.
-
3.3 Wind Power
The most common wind power technology is onshore turbine towers, set up in
farms with good wind resources, i.e. high speed, the maximum feasible consistency
and high capacity factors. The power generated is directly proportional to the cube
of the wind speed and the square of the blade diameter. Wind speeds are faster at
higher altitudes, which explains why turbine heights have increased over time.
Moreover, at lower heights turbulence caused by terrain irregularities is more
marked, making the generation of power less ef
cient. Turbines generally work at
between 15 and 45 kph: faster wind speeds can damage them, so they have to be
stopped if such speeds occur. The rotating shaft can be perpendicular or parallel to
the tower, though the latter case is less frequent and is better suited for smaller,
lower-power turbines (mini-wind power technology). Lately, more attention is
being paid to offshore technology, i.e. wind farms deployed at sea, on relatively
shallow shelves. This is because the wind at sea is usually more regular and
frequent, and blows at higher speeds. But the scope of this development is more
limited, since it requires shallow shelves far enough from shore and not too harsh
sea weather. The sites in northern Europe
—
Scotland, Denmark, north of Germany,
etc.
are among the best in the world.
The basic technology has been known since the beginnings of the electrical era,
and started to be deployed signi
—
cantly in the 1970s and 1980s at experimental
levels. Since then, it has experienced substantial growth, mainly in European
countries, with Denmark pioneering it and Germany and Spain following closely.
Today it is still growing, but at a slower pace, partly because of the general decrease
in support for renewables in Europe and, remarkably, due to the competing growth
of solar technologies, mainly PV. Nevertheless, continued support is coming from
Search WWH ::
Custom Search