The power system supply is affected by climate change and variability, moreover when future renewables-based power systems are considered. This issue has been thoroughly studied in the literature.
Literature reviews on the impacts of climate change on power systems supply, such as those of Solaun and Cerdá [28] and Cronin et al. [57], highlight the discrepancies on regional coverage (with Europe as the most studied region) and the predominance of studies on wind and hydro resources.
The impact of future climate on solar electricity potential has been studied for several locations. According to Jerez et al. [29], Ravestein et al. [34] and Müller et al. [58], climate change is not expected to significantly affect the solar electricity potential in Europe, especially in the Iberian Peninsula, as efficiency losses are outweighed by the increase on the solar resource. For Africa, Soares et al. [59] studied the potential of both photovoltaics and concentrated solar power (CSP) and found that PV potential would be unequally affected by climate showing pronounced increases in southern Africa, including Angola and Mozambique, but decreasing potential in parts of northern Africa. Wild et al. [30] expects a general increase in CSP potential across the globe in 2050. To address such impacts on the solar potential, the studies usually apply mathematical models that use irradiance and air temperature or use directly specific tools to calculate PV generation [9].
Extensive literature on the future wind power potential can be found for Europe. Ravestein et al. [34] explore the effect of climate change and climate variability on wind and photovoltaics in 2050 in Europe. They found that the impact of climate change in wind power is weaker than that of climate variability (triggered by changes in large-scale atmospheric circulation), which is responsible for a variation of up to 20-30% in renewable generation (enhanced by the changes in wind power). Karnauskas et al. [60] explore the potential changes in wind power across the globe up to 2100, showing a great spatial discrepancy of results. While at the north of the Equator, the study projects decreasing wind generation potential in the middle latitudes, at the Southern tropics it is expected to increase. As for offshore wind, Soares et al. [61] expect a small decrease in offshore wind generation for Iberia, except in summer. The methods applied to assess
wind power potential are mainly based on global climate models for future projections, often converting wind speed to wind generation using wind turbine models on the chosen turbine height [9], [60], [61].
The main impact of climate change on hydropower is precisely its increased variability [37], [38], [62]. Climate change impacts on hydropower resources are extremely site-dependent. Due to its critical role in power systems, future hydropower generation has also been the focus of several pieces of research. Studies focusing on the consequences of hydropower alterations for the power system performance found that increased dispatchable capacity is required to cope with the higher variability and uncertainty on hydropower generation. Such is concluded by Carvajal et al. [38], who explore the impact of different hydropower policies for the 2050 power system in Ecuador, and by Tarroja et al. [37] that studies the impact of hydropower changes on the power system from California, USA, in 2050. According to Teotónio et al. [63], exploring the consequences of future water availability in the Portuguese power system, hydropower generation will be impaired due to a more pronounced variability of precipitation caused by higher extremes of weather conditions (more accentuated droughts and stronger precipitation periods). Focusing on revenues from hydropower plants, Mendes et al. [64] study the impact of climate change in the Amazon, concluding that changes in river flows will result in fewer revenues in 2050, continuing to decline until 2100. Hydropower potential is commonly addressed through simulation models of hydropower plant operation or hydrological models [9], [37], [38].
As highlighted in Chapter 1, thermal power generation may suffer decreases in efficiency and shut-downs (for safety), due to water scarcity and increased water temperatures. This is supported by two studies for the mid-century in the USA addressing the thermal power plants' response to climate changes: the work of Miara et al. [65] and Liu et al. [66]. It is noteworthy to mention that this applies to all thermal power plants; those based on the combustion of fossil-based but also those based on other resources, such as nuclear or biomass. The operation of thermal power plants under climate change is assessed using specific thermal generation models and often considering water use models and hydrological models [9].
To assess the impacts of climate change on the supply side of the power system, several works are presented in Table 2.2, which differ on multiple dimensions. Time-horizon and regions are some of the most important factors that differ among the studies. Different
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levels of complexity can be found across the literature, namely on the use of climate data [9]: whereas some authors base their work directly on the climate data, others feed these data to other models (e.g. economic, emission or energy planning simulation models) to explore the impacts on different background areas. Resource projects are generally addressed using Global Climate Models (GCMs) or Regional Climate Models (RCMs). Most of the studies use the representative concentration pathways defined by the IPCC.
Table 2.2. Literature on the impacts of climate change and variability on the supply
Summary of characteristics of reviewed literature on the impact of climate change and variability on the supply side of the power system (ordered by resource and alphabetic order).
Literature Resource Geographic
scope Model type (generation) Climate (IPCC scenarios) Parameter analyzed Results 2050-2060 2070-2100
Carvajal et al. [38] Hydro Ecuador
hydrological model energy system simulation
model
RCP4.5 Energy
generation -44 to +21%
Tarroja et al. [37] Hydro USA hydrological model
grid dispatch model RCP8.5
Energy
generation -20 to +15%
Teotónio et al. [63] Hydro Portugal
hydrological model energy system simulation
model SRES A2c SRES B2a RCP4.5 RCP8.5 Energy generation -17 to -41%
Liu et al. [66] Thermal USA hydrological-thermoelectric
generation model
RCP4.5 RCP8.5
Available
capacity -12 to -2%
Miara et al. [65] Thermal USA hydrological-thermoelectric
generation model RCP2.6 RCP8.5 Available capacity (RCP8.5) -31 to +6%
Jerez et al. [29] Solar (PV) Europe mathematical model RCP4.5
RCP8.5
Energy
generation -12% to -3%
Energy potential -14% to +2%
Müller et al. [58] Solar (PV) Europe mathematical model RCP4.5
RCP8.5
Energy
generation -6 to +3%
Soares et al. [59] Solar (CSP and
PV) Africa empirical model
RCP4.5 RCP8.5
CSP generation -5 to +5%
PV generation -3 to -2%
Wild et al. [30] Solar (CSP) Global empirical model RCP8.5 CSP generation -24 to +14%
Karnauskas et al. [60] Wind Global turbine power curve RCP4.5
RCP8.5
Energy
generation -25 to +40% -40 to +40%
Soares et al. [61] Wind offshore Iberia turbine power curve RCP4.5