Influence of winter North-Atlantic Oscillation on Climate-Related-Energy penetration in Europe
Introduction
The UNFCCC (United Nations Framework Convention on Climate Change) Paris Agreement promotes the transition to low carbon economy by replacing conventional energies by Climate-Related Energies (hereafter called CRE) such as wind-power, solar-power and hydro-power. Several European countries such as Norway, Sweden, Spain and Austria have already achieved an important step forward to the transition with already a high rate of renewable generation [25]. The European Climate foundation now typically dates for 2050 optimistic scenarios with close to 100% renewable energy in Europe [4].
Following the driving weather variables (i.e. solar radiation wind speed, precipitation, and temperature), CRE power generation fluctuates in time and space and can synchronize or desynchronize with the load [6]. With increasing rate of CRE equipment, balancing the energy network requires solution of challenging backup generation and energy storage issues due to the intermittent nature of wind, solar and to a lesser extent, hydro-power [6]. Backup needs must cover the wide range of time scales within which CRE driving weather variables are fluctuating. The high frequency time variability (i.e. from second to hour) is well known and quite well documented. For instance, wind and solar power generation may experience large and rapid variations, usually called ‘ramps’, linked with wind variability and cloud evolution and movement [5], [13]. This range of time variability may be handled by using fast ramping energy storage technologies or backup generation (see for instance [12] for wind power balancing). The intermediate variability range (i.e. from hourly to seasonal) results from astronomic drivers (i.e. diurnal and seasonal cycles) and mesoscale atmospheric circulations (e.g. storms, fronts). Most of the published studies related to this time range are based on relatively short time periods, usually shorter than ten years. These studies highlighted for instance different degrees of complementarity among CREs at different time scales (e.g. Ref. [28] for solar and wind complementarity and Ref. [7] for solar and small hydro complementarity). They also discussed methods for optimizing these complementarities (e.g. Ref. [18] for optimizing solar and small hydro power complementarity), the role of the energy grid (e.g. [19], [30], [35]); and the role of the energy storage (e.g. [29], [35]).
Interestingly, low frequency time variability (from annual to decades) is less studied, although it plays a major role from the point of view of the equilibrium between energy generation and load. Assuming that CRE would be massively used to meet electricity consumption, what is the risk of ending up in a situation in which the level of production of one or more CRE is exceptionally low or exceptionally high for a long period of time and/or over a large area? What would be the risk for an investor if the return on investment has been calculated on a high energy production period? What would be the carbon emissions associated with the mobilization of conventional means of production to compensate for CRE in production resulting from a low-production period? Even though it might be partially explained by astronomic factors (e.g. solar activity cycle [26]); and geological events (e.g. volcanism; [31]), low frequency time variability results mainly from different large-scale teleconnection patterns impacting the climate at global scale (e.g. El Niño – Southern Oscillation (ENSO) in the tropics and in North America; the North Atlantic Oscillation (hereafter, NAO) in North America and Europe).
The NAO positive phase (noted as NAO+) corresponds to a positive anomaly of sea level pressure over the Azores and a negative anomaly over Iceland; NAO negative phase (noted as NAO−) corresponds to the opposite pattern. Its influence on the European climate and especially during winter season (i.e. December, January, February and March, denoted as DJFM, Fig. 1) was widely established during the last two decades (e.g. Refs. [14], [15]). Strong NAO+ phases are associated with negative temperature anomalies across southern Europe and positive temperature anomalies across Northern Europe. During NAO+ phases, precipitation is also affected with positive anomalies across Northern Europe and Scandinavia, especially in winter, and negative anomalies across Southern and Central Europe. The opposite pattern is observed during strong NAO− phases. NAO teleconnection pattern also affects other weather variables than temperature and precipitation [3]. show that inter-annual variability of solar radiation is linked with cloud cover variability induced by the NAO. In winter, several studies show that NAO index is positively correlated with the solar radiation in Northern Europe, and negatively correlated with the solar radiation in Southern Europe (e.g. Ref. [20], [21]). mapped the wind speed-NAO correlation during winter in Europe and found high and significant positive correlation in Northern Europe and negative correlation in the Mediterranean basin.
Few studies show that low frequency variability of weather variables, induced by NAO pattern, influences CRE power generation. For illustration, Ref. [17] shows for the Iberian Peninsula significant differences in hydro, solar and wind power generation during positive and negative NAO phases. To our best knowledge, influence of low frequency time variability on integrated indicators of the resource-demand balance, either at regional or national levels, does not appear in the literature, but the study by Ref. [32] who show a sharp energy price increase in Scandinavia during years with low NAO index (i.e. cold and dry years in this area). Such a result motivated this study.
This study investigates the effects of the NAO on the penetration rate of wind, solar and run-of-the river (hereafter noted as RoR) power over a 33 year period and for a benchmark set of 12 regions covering a large range of climates in Europe. It especially focuses on winter season, the season most influenced by the NAO teleconnection pattern. Neither energy storage nor energy transport among regions is considered.
The paper is organized as follows: The different regions and the data bases are presented in Section 2. The analysis framework is detailed in Section 3. This framework extends the one described by Ref. [8] to the analysis of low frequency variability due to NAO. Section 4 presents the results and Section 5 concludes and gives perspectives for future research.
Section snippets
Study areas and dataset used
The different areas selected are mapped in Fig. 2. Although the areas do not match country borders, they will be referred for convenience with country or region names. Surface area of each domain roughly equals 40,000 km2 (Table 1). It is then assumed that all areas are climatologically homogeneous, both in terms of average and time variability. Their location was chosen for representing a range of climates in Europe along two climatic gradients: the north-south gradient explores changes from
Study framework
The study framework used in this study extends the one established by Ref. [8] to the analysis of low frequency variability related to the NAO pattern. Each region is considered as autonomous in a sense that the regional demand can be only satisfied (or not) with the production obtained within the region from these three energy sources: there is no energy import/export with neighboring regions. Furthermore, each region is considered as being a ‘copper plate’ grid, meaning that the energy can
Results
This section focuses on the relation between NAO and penetration rates. All the results are for the DJFM season. We first focus on the 100% generation scenario (i.e. considering an average CRE generation factor γ equal to 1).
Conclusion
Several studies looked at regional or national CRE abundancy and at potential benefits of combining different CRE for supplying the load from regional to continental scales. The literature shows that studies were mainly based on short records which results in disregarding low frequency variability of weather variables driving power generation.
This study focuses on the inter-annual variability in winter season due to the NAO teleconnection pattern and its impact on CRE penetration rates. A set
Acknowledgements
This work is part of the FP7 project COMPLEX (Knowledge based climate mitigation systems for a low carbon economy; Project FP7-ENV-2012 number: 308601; http://www.complex.ac.uk/). This paper also benefited from comments and suggestions from two anonymous reviewers.
References (35)
- et al.
Complementarity between solar and hydro power: sensitivity study to climate characteristics in Northern-Italy
Renew. Energy
(2016) - et al.
Increasing climate-related-energy penetration by integrating run-of-the river hydropower to wind/solar mix
Renew. Energy
(2016) - et al.
Quantifying PV power output variability
Sol. Energy
(2010) - et al.
Integration of Renewable Energy Sources in future power systems: the role of storage
Renew. Energy
(2015) Use of paleo-records in determining variability within the volcanism–climate system
Quat. Sci. Rev.
(2000)- et al.
Grid vs. storage in a 100% renewable Europe
Renew. Energy
(2013) - et al.
Classification, seasonality and persistence of low-frequency atmospheric circulation patterns
Mon. Weather Rev.
(1987) - et al.
Evaporation, Evapotranspiration and Climatic Data
(1994) - et al.
Influence of NAO and clouds on long-term seasonal variations of surface solar radiation in Europe
J. Geophys. Res.
(2010) Roadmap 2050: a practical guide to a prosperous, low-carbon Europe
Eur. Clim. Found.
(2010)
Predicting sudden changes in wind power generation
North Am. Wind
Integrating hydropower and intermittent climate-related renewable energies: a call for hydrology
Hydrol. Process
Long-term uncertainty of hydropower revenue due to climate change and electricity prices
Water Resour. Manag.
PV Potential and Potential PV Rent in European Regions
A European daily high-resolution gridded data set of surface temperature and precipitation for 1950–2006
J. Geophys. Res.
Compensating for wind variability using co-located natural gas generation and energy storage
Energy Syst.
Decadal variations in climate associated with the North Atlantic Oscillation
Clim. Change
Cited by (25)
Complementarity of wind and solar power in North Africa: Potential for alleviating energy droughts and impacts of the North Atlantic Oscillation
2024, Renewable and Sustainable Energy ReviewsThe increasing risk of energy droughts for hydropower in the Yangtze River basin
2023, Journal of HydrologyStatistical analysis of electricity supply deficits from renewable energy sources across an Alpine transect
2022, Renewable EnergyCitation Excerpt :On the demand side, the growing capacity of private solar behind the meter system increases both the variability and the uncertainty of the demand to the utilities [15,40,41]. On the supply side, the effect of weather on renewable generation vary across a large range of temporal and spatial scales [8,23], which complicates their integration to the network. Electricity storage [42] and transport [21] infrastructure is paramount for smoothing out the variability of the renewables, although the associated investment and operational costs are important [1].
A copula-based assessment of renewable energy droughts across Europe
2022, Renewable EnergyCitation Excerpt :In particular, wind and solar power installed capacities have rapidly grown over the past years [5] and they are expected to be important contributors to the European renewable power system. However, their fluctuating nature represents a challenge for renewable energy production as both sources are directly dependent on weather conditions with a high spatio-temporal variability [6–8]. As a result of the dependency of renewable energy sources (RES) on meteorological variables that are strongly time-variable, balancing the RES generation and energy consumption is a key concern, since electricity demand must be continuously matched by electricity supply to avoid blackouts [6].
Assessing low frequency variations in solar and wind power and their climatic teleconnections
2022, Renewable EnergyCitation Excerpt :Nowadays, climate-dependent renewables (mainly wind and solar) are reaching significant shares in the electricity generation mixes in several countries [9], which imposes significant challenges in the operation and planning of electricity grids [10,11]. Wind speeds and solar radiation vary on multiple timescales: From seconds to minutes (associated with turbulent eddies and the passage of clouds), the diurnal cycle, synoptic scale variations associated to weather systems, an annual cycle, and interannual variations which are associated to long term trends and/or low frequency variations [12–14]. The impacts of these variations on power systems are different according to the timescale considered [15].