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Energy: European scale

Hydropower and thermoelectric power potential on a global scale

Worldwide, 81% of total electricity generation is currently produced by thermoelectric (nuclear, biomass- and fossil-fuelled) power plants, and 17% by hydropower plants (46). It is therefore of utmost importance for the electricity sector to have sufficient fresh water resources of low temperature to generate power and cool thermoelectric power plants. How will global warming change the world’s available surface water resources, in terms of stream flow and water temperature, and how will these changes affect the potential for hydropower and thermoelectric power generation?

This has been assessed on a global scale by calculating both gross hydropower potential and cooling water discharge capacity (45). Gross hydropower potential is defined as “the annual energy potentially available when all natural runoff in a country is harnessed down to sea level (or to the border line of the country) without any energy losses” (47). In other words, “the capacity of hydropower generation possible if all natural water flows contained as many 100% efficient turbines as possible” (48).  Cooling water discharge capacity is defined as the potential of surface water systems to dilute a certain amount of waste heat without exceeding environmental legislations (i.e. maximum permitted water temperatures and water temperature increases). Thus, gross hydropower potential and cooling water discharge capacity are upper limits that indicate the potential of future growth of thermoelectric and hydropower electricity generation. Actually, only a few percent of these upper limits is being used today (45)!

Gross hydropower potential and cooling water discharge capacity have been calculated for both a low- and high-end scenario of climate change (the so-called RCP2.6 and RCP8.5 scenarios), by using a combination of different models for climate change and river discharge (45).

Currently, both gross hydropower potential and mean cooling water discharge capacity are highest in Asia, followed by South America, Africa, North America, Europe, and Australia & Oceania. The assessment shows that global gross hydropower potential may increase between +2.4% and +6.3% for the 2080s compared to 1971 - 2000. Regions with considerable (>20%) increases in gross hydropower potential are mainly central Africa, India, central Asia and the northern high-latitude region. Regions with considerable (>20%) declines in hydropower potential are southern Europe, northern Africa, southern United States and parts of South America, southern Africa and southern Australia (45).

Global mean cooling water discharge capacity is projected to decrease by 4.5 - 15% (2080s). The largest reductions are found for the United States, Europe, eastern Asia, and southern parts of South America, Africa and Australia, where strong water temperature increases are projected combined with reductions in mean annual stream flow. Cooling water discharge capacity is expected to increase considerably (>20%) in India, central Africa, some northern parts of Australia and for the most northern high-latitude regions (45).

So on a global scale gross hydropower potential will increase by 2.4% - 6.3%, and mean cooling water discharge capacity will decrease by 4.5% - 15%, between now and the end of this century. These numbers may be misleading when looking at the possibilities to expand actual hydropower and thermoelectric power. Both hydropower and thermoelectric power may increase up to a few hundred percent in the course of this century (45). These percentages are completely different from the relative changes of the upper limits due to the fact that currently only 5% and 0.3% of these upper limits of gross hydropower potential and mean cooling water discharge capacity are actually being used for hydropower and thermoelectric power, respectively (45)! Thus, there seems to be a lot of potential to further increase hydropower and thermoelectric power. This is especially interesting since most current hydropower plants are situated in regions with expected declines in mean annual stream flow (49), whereas a large part of the world’s land surface will experience increases in stream flow and thus in gross hydropower potential (45). 

Opportunities in Europe

Wind energy

While the wind power share in the world’s electricity mix is currently 3%, wind power already provides 15 to 30% of national electricity in a few countries (e.g. Ireland, Spain, Portugal, Denmark) and is targeted to provide 18 % of global electricity by 2050 (35). In Europe, wind power installed capacity represents almost 40 % of the installed capacity globally in 2013 (36). It is expected to double within the next 10 years and might quadruple by the middle of the century (37). By 2020, the European Commission aims to produce 15.7% of the EU’s electricity from wind (43). In 2014, offshore and land-based wind farms generated about 7.3 % of Europe’s total electricity consumption in an average year (50). 

Future changes in the potential for wind power generation over the whole Europe and in the effective wind power production from national wind farms operating at the end of 2012 and planned by 2020 have been assessed (32). This assessment is based on several (regional and global) climate models under a scenario of moderate climate change (the SRES A1B emission scenario). Future changes are computed as the difference between the mean values obtained for the 1971–2000 present period and the 2031–2060 and 2071–2100 future periods.

According to this assessment, future changes in wind power potential are weak or non-significant over a large part of Europe: changes in wind power potential will remain within ±15% and ±20% by mid and late century respectively. Changes in multi-year power production will not exceed 5% and 15% in magnitude at the European and national scale respectively for both wind farms in operation at the end of 2012 and planned by 2020. The sign of changes differs from one model to another. Therefore, climate change should neither undermine nor favor wind energy development in Europe (32). From another study based on an intermediate and high scenario of climate change (the so-called RCP4.5 and RCP8.5 scenarios) and a large number of global climate models (GCMs) it was concluded that it is more likely than not that wind energy potential will increase over Northern and Central Europe on an annual basis (42).

Within Europe there are regional differences: a tendency toward a decrease of the wind power potential over Mediterranean areas and an increase over Northern Europe (32,42,44). A robust decrease in wind power is found over the Mediterranean region, with the exception of the Aegean Sea area which exhibits a robust increase (see also (33)). A robust increase is also highlighted over the Baltic Sea (see also (34)).

The assessment results above agree with the results summarized by the IPCC (2014) and many more (44). For most of Europe (except for the Mediterranean area), wind energy potential is projected to increase for the winter and decrease for the summer. As a result, intra-annual variability of wind energy potential may strongly increase for most of Europe. In general, signals are stronger for the second half of this century compared to the first half and for scenarios of strong (such as the RCP8.5 scenario) compared to intermediate (RCP4.5) global warming. A higher variability can potentially lead to a lower reliability of wind energy as an alternative energy source in future decades (42). No significant changes are expected before 2050, at least in Northern Europe (23). After 2050, the wind energy potential in Northern, Continental and most of Atlantic Europe may increase during winter and decrease in summer (24). For Southern Europe, a decrease in both seasons is expected (42), except for the Aegean Sea and Adriatic coast where a significant increase during summer is possible (25).

The differences in future projections of different models are large, however. Uncertainty about the magnitude of future changes is especially high for large parts of Germany, Scandinavia, and Eastern Europe. Uncertainties are much lower for Southwestern Europe (42).


For hydropower, electricity production in Scandinavia is expected to increase by 5-14% during 2071-2100 compared to historic or present levels (22, see also 41); for 2021-2050, increases by 1-20% were estimated (26). In Continental, and part of Alpine Europe, reductions in electricity production by 6-36% were estimated (27). For Southern Europe, production is expected to decrease by 5-15% in 2050 compared to 2005 (28). For 2070-2099 compared with 1971-2000, declines in hydropower potential >15% are projected for south-eastern Europe (Balkan countries like Greece, Bulgaria, Romania, Serbia, Macedonia) (41).

Solar energy

The energy output from photovoltaic panels and especially from concentrated solar power plants in most of Europe is projected to increase (under the A1B climate change scenario) (29).

Thermal power

A 6-19% decrease of the summer average usable capacity of power plants has been projected by 2031–2060 compared to 1971-2000 (30), while smaller decreases have been also estimated (31).

Marine biomass 

The production of marine biomass like microalgae for bioenergy and/or biofuel has emerged as a promising renewable energy source. Results suggest that use of marine biomass if commercially realised could potentially be as large and comparable to existing land-based forestry and agricultural energy crops (51). 


Power supply disruptions

Currently, nuclear power has a share of about 28 % in the electricity supply in the EU while the respective share of hydropower is about 12 % (2). Therefore, disruptions in the use of both nuclear power and hydropower plants may have significant impacts on the electricity supply system.  Autonomous adaptation in the energy sector takes place via international electricity markets by balancing demand and supply when climate change causes local or regional supply disruptions. Temporary autonomous adaptation in response to extreme weather patterns (heat waves and droughts) has been considered for different climate change scenarios. It has been found that strong declines in electricity generation due to climate change may occur, e.g. in Austria, France and Switzerland. By modifications of European power generation patterns as well as by changes in import and export balances, local electricity shortages can be overcome. Yet, then electricity prices tend to rise significantly in some European countries (e.g. Switzerland and France) (1).

The possibe impacts of climate change on thermal power plants have been inventoried from the literature (9):

  • Gradual climate change. Research has shown that a rise in ambient air temperatures of about 1 °C would reduce the thermal efficiency of a thermal power plant by 0.1–0.5 %. The total capacity loss accounts for 1.0–2.0 % per 1 °C higher air temperatures, including decreasing efficiency of cooling processes and shutdowns (7). The effects and the relevance of gradual climate change on the probability of power outages and blackouts are difficult to quantify. It has been stated that by 2040 capacity reductions of 13–19 % are possible due to increasing water temperatures and decreasing runoff in Europe. For the US reductions of 12–16 % in capacity have been estimated by 2040 (8).
  • Heat waves. Extreme heat leads to a shortfall in water supply or high river temperatures, influences the cooling of the building itself, and may lead to spontaneous combustion and self-ignition of coal stockpiles (9).
  • Wind-related impacts. Wind load pressure can cause the uplifting of tiles and roofs, damage to overhead lines and to storage tanks, and it can lead to damage to insulation and cooling towers (10).
  • Thunderstorms. When a lightning strike hits the tank, off-tank fluids may be ignited. Additionally, direct hits or creeping currents can damage electricity distribution and the control equipment necessary for power plant operation (9).
  • Water temperature. Rising water temperatures lead to a higher withdrawal of water in order that legal and environmental thresholds for the temperature of discharged water can be met without the need for large reductions in efficiency. If the higher amount of cooling water is still not sufficient, the power plant efficiency decreases further and the energy conversion consequently needs to be reduced in order to meet environmental thresholds (11,21). There are numerous examples, from the United States in 2002, Switzerland (12), Germany (13) and France in 2003 and France, Spain and Germany in 2006 where high ambient water temperatures have resulted in reduced power output at several thermal power plants; some of them even had to be shut down (14). Warmer cooling water was computed to lower thermal power plant efficiency and thus electricity production by 1.5-3% in European countries by the 2080s under emissions scenario A1b (22).
  • Floods. Most of the impacts of a site flooding occur to the connected infrastructure, such as uprooting and displacement of storage tanks, rupture of pipes and cable connections, underground breaching of tanks due to collision with debris, disruption of water purification and sewage disposal systems, short-circuiting and power outages resulting in malfunctioning of cooling systems, pumps, and safety systems (15).

Heat wave impacts

Extreme heat waves have an impact on western European electricity supply due to the increased electricity demand for cooling (39) and the power limitation of thermoelectric plants due to regulation constraints concerning downstream water temperature (40). At least the two most severe heat waves during 1979–2008 (those of 2003 and 2006) had a negative impact on western European electricity supply, with shut downs of thermoelectric plants (40).

Therefore, changes of western European heat wave characteristics have been studied for the end of the twenty first century (2070–2099), compared with 1979–2008 (38). Heat waves were defined as periods of at least 3 consecutive days of extremely high daily maximum temperature affecting at least 30 % of Western Europe. For the high temperature threshold the 98th percentile of the daily maximum temperature during March-October was chosen; for western Europe, this more or less agrees with a threshold of 30°C, commonly used to define a “hot day”.

The study is based on 19 climate change models and three scenarios of future greenhouse gasses concentrations (the so-called RCP2.6, RCP4.5 and RCP8.5 scenarios) that cover a range of moderate to high-end climate change projections. The results indicate a strong increase of the number of heat waves. Besides, the average future heat wave lasts longer, is more extended and more intense. Heat waves with similar or higher severity than observed for the 2003 heat wave remain rather rare, except for the most extreme scenario of climate change (RCP8.5) (38).

For the more moderate scenarios of climate change (RCP2.6 and RCP4.5), the median values of highest simulated severities for all model results are comparable to the 2003 heat wave; for the high-end scenario (RCP8.5), heat waves (median of all model results) with 5 times higher severity than the 2003 heat wave are simulated. For this scenario, planners would need to adapt to yet unprecedented heat wave severities. The spread in results between different models is large for all heat wave characteristics, however. Far more extreme values for heat wave characteristics have been calculated than the median values of all model results: the variability in results due to different models is larger than the variability due to different climate change scenarios (38). 

Oil and gas sector

Climate change and extreme weather events represent a real physical threat to the oil and gas sector, particularly in low-lying coastal areas and areas exposed to extreme weather events. The sector needs to take climate change seriously, assess its own vulnerability, and take appropriate measures to prevent or mitigate any potentially negative effects (3).

The oil and gas sector has been affected by climate-related events in the past, which in many cases have led to oil spills and releases of hazardous materials, thus providing lessons on better preparing for extreme weather events in the future. The impacts of a changing climate will vary depending on location. However, most studies show that oil and gas facilities and infrastructure in low-lying coastal areas and areas subject to severe weather will be most vulnerable (3). 

The economic, social, and environmental impacts caused by the disruption of and damage to the oil and gas sector could be huge, with global repercussions. In 2005, hurricanes Katrina and Rita demonstrated that both the offshore and onshore oil and gas industry remain vulnerable to the impacts of hurricanes. In total, they destroyed 113 offshore platforms and severely damaged at least 163 others (4). These hurricanes also revealed a weak delivery and distribution system. Following the storms there were hardly any options available to deliver the products to the markets because of the onshore devastation (5) that led to a shortage of fuel at pumping stations in several states. In Europe, a severe storm set adrift a drilling rig in the North Sea off the coast of Norway in 2006 (6).

Adaptation strategies

Power supply disruptions

In addition to autonomous adaptation to climate change, strategic public policy intervention may be needed, for instance because the short-term, temporary reallocation of power generation might cause an undesired redistribution of wealth. Such strategic public policy intervention could either target the affected power sector itself or it may (also) address the upstream water supply sector. In the latter case, an improvement of the management of water supply is an option. Improvements in the power sector itself could be attained, e.g., by raising legal standards for power plants’ cooling systems. Also, those rents which decision makers consider to be unfairly usurped by the suppliers at the expense of consumers could be (partly) taxed away (1).

Another option to prevent power supply disruptions is the diversification of the sources of supply. The augmentation of the use of such power plants that do not require cooling systems (e.g., photovoltaic installations) could contribute to the mitigation of the adverse effects of climate change on the electricity supply system (1).

Three kinds of adaptation categories have been identified with respect to thermal power plants (9):

  • Adaptation of the cooling options: the use of so-called non-traditional waters (waters that are not withdrawn from a river, lake, the groundwater, or the ocean, but are otherwise obtained from the environment, for instance, recirculation of water from oil and gas fields or coal mines); the reuse of process water; dry cooling towers that emit surplus heat only by convection without causing water loss through evaporation; regenerative cooling where the compressed steam cools down because it is allowed to expand; heat pipe exchangers that allow the conveyed steam to release heat to the environment without direct contact (the cooled/condensed steam can be recirculated).
  • Adaptation of the (infra-)structures: adjust standards for construction and protection of power plants and connected infrastructure (16); installation of underground cables instead of overhead wires, as the former are less vulnerable to storm, wind throw, and freezing/ice loads on wire (17).
  • Adaptation of the sites: installation of dams, dikes, flood control reservoirs, polders, ponds, and the improvement of channel capacity (18); drainage improvement and rerouting of service water pipes as well as improved pipe isolation (19); zoning, improved building codes and flood insurance (20).

Oil and gas sector

Adaptation options in some cases will require possibly large investments to upgrade facilities, build redundancy and robustness into the systems, and protect critical infrastructure to ensure that it remains operational following an extreme weather event. Adequate contingency planning plus emergency-response and recovery planning and preparedness will also be essential to ensure the safety of people, property, and the environment, as well as business continuity (3).


The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Europe.

  1. Rübbelke and Vögele (2013)
  2. EUROSTAT (2010), in: Rübbelke and Vögele (2013)
  3. Cruz and Krausmann (2013)
  4. MMS (2006); Energo Engineering (2007), both in: Cruz and Krausmann (2013)
  5. Fletcher (2006), in: Cruz and Krausmann (2013)
  6. Paskal (2009), in: Cruz and Krausmann (2013)
  7. ADAM (2009), in: Sieber (2013)
  8. Van Vliet et al. (2012), in: Sieber (2013)
  9. Sieber (2013)
  10. O’Connell and Hargreaves (2004); Center for Health and Global Environment et al. (2005); Chang and Lin (2006); Heymann (2007); Bailey and Levitan (2008), all in: Sieber (2013)
  11. Kirkinen et al. (2005); Krysanova and Hattermann (2007); Mills (2007); EPRI (2009), all in: Sieber (2013)
  12. BUWAL et al. (2004), in: Sieber (2013)
  13. Federal Institute of Hydrology (2006), in: Sieber (2013)
  14. DOE/NETL (2007), in: Sieber (2013)
  15. Steininger et al. (2003); Young et al. (2004); Krausmann and Mushtaq (2008), all in: Sieber (2013)
  16. Auld et al. (2007), in: Sieber (2013)
  17. Ott and Richter (2008), in: Sieber (2013)
  18. UNFCCC (2006), in: Sieber (2013)
  19. Vaurio (1998), in: Sieber (2013)
  20. Kundzewicz and Kaczmarek (2000), in: Sieber (2013)
  21. IPCC (2014)
  22. Golombek et al. (2012), in: IPCC (2014)
  23. Pryor and Schoof (2010); Pryor and Barthelmie (2010); Seljom et al. (2011); Barstad et al. (2012); Hueging et al. (2013), all in: IPCC (2014)
  24. Harrison et al. (2008); Hueging et al. (2013); Nolan et al. (2012); Rockel and Woth (2007), all in: IPCC (2014)
  25. Bloom et al. (2008); Hueging et al. (2013); Najac et al. (2011); Pašičko et al. (2012), all in: IPCC (2014)
  26. Haddeland et al. (2011); Hamududu and Killingtveit (2012); Seljom et al. (2011), all in: IPCC (2014)
  27. Schaefli et al. (2007); Paiva et al. (2011); Pašičko et al. (2012); Hendrickx and Sauquet (2013); Stanzel and Nachtnebel (2010), all in: IPCC (2014)
  28. Bangash et al. (2013); Hamududu and Killingtveit (2012), both in: IPCC (2014)
  29. Crook et al. (2011), in: IPCC (2014)
  30. Van Vliet et al. (2012), in: IPCC (2014)
  31. Linnerud et al. (2011); Förster and Lilliestam (2010), both in: IPCC (2014)
  32. Tobin et al. (2015)
  33. Bloom et al. (2008); Hueging et al. (2013), both in: Tobin et al. (2015)
  34. Hueging et al. (2013); Barstad et al. (2012); Pryor et al. (2005, 2012), all in: Tobin et al. (2015)
  35. IEA (2013), in: Tobin et al. (2015)
  36., in: Tobin et al. (2015)
  37. Capros et al. (2014), in: Tobin et al. (2015)
  38. Schoetter et al. (2015)
  39. Savić et al. (2014), in: Schoetter et al. (2015)
  40. Van Vliet et al. (2012), in: Schoetter et al. (2015)
  41. Van Vliet et al. (2015)
  42. Reyers et al. (2016)
  43. Moccia et al. (2011), in: Reyers et al. (2016)
  44. Barstad et al. (2012); Cradden et al. (2012); Nolan et al. (2012, 2014); Pryor et al. (2012); Hueging et al. (2013); Tobin et al. (2015), all in: Reyers et al. (2016)
  45. Van Vliet et al. (2016)
  46. EIA (accessed 2015), in: Van Vliet et al. (2016)
  47. Eurelectric (1997), in: Van Vliet et al. (2016)
  48. WEC (2010), in: Van Vliet et al. (2016)
  49. Van Vliet et al. (2016), in: Van Vliet et al. (2016)
  50. EWEA (2014), in: Halsnæs et al. (2016)
  51. Roberts and Uphamb (2012); Jard et al. (2013), both in: Halsnæs et al. (2016)

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