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(with connection costs however on the shoulders
of TSO’s/clients) (Transmission System Operator).
Considering the variable nature of wind and sun
with the relevant impact [1] on the overall power
system performance and costs (need for additional
reserve capacity and flexibility, balancing costs, po-
wer storage costs etc.) the real challenge for their
development, once they reach an important frac-
tion of total generated power, is a holistic long-term
approach in system redesign and planning with
sophisticated regulatory / technical and economic
evaluations and the introduction of cheap storage
systems.
Fig. 3 - Electricity production in OECD and non-OECD countries (CIGRE 2014) An important trend in the last decades has been
the increasing share of non-OECD countries in to-
tal world electricity production as well as for pri-
It is quite clear from figure 2 how from 2004 to mary energy consumption, as shown in figure 3.
2016 the global RES capacity has increased 2.5 From the year 2000 to 2015 the average annual
times, with an average annual growth of 8%, com- growth in OECD countries was a little less than 1%
pared to the growth of conventional thermal and compared to around 6% in non-OECD countries.
nuclear capacity of 4%. This growth of RES was After 2010 the electricity production in non-OECD
mainly driven by more than 700 GW of new wind countries has significantly outpaced that of OECD
and solar capacity, with an average annual growth countries, but with significant differences, as clearly
rate of 21% and 47% respectively. The much lo- shown in figure 4:
wer share of wind and solar generated power with • in both sectors the role of oil as the primary
respect to their installed capacity is explained by a energy source has been reduced;
much lower utilization rate (around 2000 and 1200 • the share of coal has collapsed in OECD
hours per year, respectively) compared to the other countries after 1985, but it has increased in
sources. non-OECD ones, reaching an overall share
It is worth noticing that increased volumes of RES close to 50%;
installations combined with technology deve- • the usage of gas has increased greatly sin-
lopments have led to substantial reduction in the ce around 1985 in OECD countries, while its
capital expenditures of wind and solar plants; this share has been rather constant in non-OECD
has produced, in areas with high wind and solar ra- ones.
diation and with low local costs, results of auctions
for large plants at around 18 US$/MWh for pho- Hydro has halved its percentage share in OECD
tovoltaic (PV) in Mexico and Saudi Arabia and 28 countries (where the potential for large plants is
US$/MWh for wind in Morocco. But also in Europe, practically fully exploited) but has kept a constant
we have seen recently very interesting results from share in non-OECD markets. For wind and solar, the
auctions: wind power in Spain at 47.8 US$/MWh OECD countries have been frontrunners (especially
and PV in Denmark at around 60 US$/MWh. An the European Union) with a larger increase in its ap-
investor has offered for one off shore wind project plications with respect to non-OECD countries; but
in Germany to sell the energy at the pool price now they have lost their leadership in this area, both

Fig. 4 - Past trends in gross electricity production by source in OECD (left diagram) and non-OECD countries (right diagram) (IEA [2])

26 Impiantistica Italiana - Gennaio- Febbraio 2018