Solar Energy Perspectives - IEA

Solar Energy Perspectives: Solar electricity
Morocco is not unique; other countries, mostly developing ones, such as India, show evening
peaks. More often there is a relatively good match between the solar resource generation and
peak demand, despite peak and mid-peak demand extending into the late afternoon and
evening (Figure 3.9).
Photo 3.1 The Gemasolar power tower near Sevilla (Spain)
Source: Torresol Energy.
Key point
Molten-salts solar towers can generate electricity round the clock.
Seen by many as competitors, PV and STE should thus be viewed rather as complementary.
PV is variable, STE can be made firm through thermal storage and fossil-fuel back-up.
STE technologies without storage may face tough competition from either concentrating PV
(CPV) technologies or thin films, both of which are less sensitive than standard silicon
modules to high ambient temperatures, in areas where the peak closely matches the sunshine.
More often, STE with thermal storage should be compared with PV plus electricity storage.
Such a comparison puts STE in a better competitive situation.
Hybridisation of solar fields on existing fossil-fuelled plants offers options – but only to STE –
for introducing solar in the electricity mix at a lower cost than “full-fledged” STE plants, as the
cost of non-solar specific parts of the plants (turbines, balance of plants, interconnection)
would be shared with another technology, or be already paid for in existing plants. In the latter
case, only the cost of the solar field and possible thermal storage would have to be considered
(see Chapter 8), roughly halving the investment costs required to generate STE electricity.
Currently, STE is available only as concentrating solar power (CSP), which make economic
sense only in areas with high DNI (see Chapters 2 and 8). The best examples of such areas
are in Australia, Chile, Mexico, the Middle East, North Africa, South Africa, and the
southwestern United States, but many other places are suitable, notably in China, India,
Latin-America and south Europe.
Consistent with the BLUE Hi-Ren Scenario of ETP 2010, the IEA Technology Roadmap:
Concentrating Solar Power foresees, by 2050, CSP contributing up to 40% of electricity
generation in regions with very favourable conditions (IEA, 2010d); 15% or 20% for large
consuming areas close to very favourable regions, and lower levels for other areas (Table 3.1).
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