The European Renewable Energy Directive adopted in 2009 focuses on achieving a 20% share of renewable energy in the EU overall energy mix by 2020. A major part of renewable energy production is related to climate, which we will call in this report “climate related energy” (CRE), and we focus mainly on wind- solar- and hydropower. The CRE production systems are characterized by a large degree of intermittency and variability on both short and long time scales due to the natural variability of climate variables. The main strategies to handle the variability of CRE production include energystorage, -transport, -diversity and -information (smart grids). The three first strategies aim to smooth the intermittency and variability of CRE production in time and space whereas the last strategy aims to provide a more optimal interaction between energy production and demand, i.e. to smooth the residual load (the difference between demand and production). The working hypothesis of this report is that in order to increase the CREs share in the electricity system, it is essential to understand the space-time co-variability between the weather variables and CRE production under both current and future climates. Based on this working hypothesis we find that the different reviewed studies generally tackle sub-problems. The majority of studies deals with either a single CRE source or with the combination of two CREs, mostly wind and solar, probably because the most advanced countries in term of wind equipment have very little hydropower potential (Denmark, Ireland or UK for instance). Hydropower is characterized by both a large storage capacity and flexibility in electricity production, and has therefore a large potential for both balancing and storing energy from wind- and solar-power. Several studies look at how to connect regions with large share of hydropower (e.g. Scandinavia and the Alps) better to regions with high shares of wind- and solar-power (green battery North-Sea net). Various studies consider wind and solar and their cofluctuation at small time scale. The multi-scales nature of the variability is less studied, i.e. potential adverse or favorable co-fluctuation at intermediate time scales involving water scarcity/ abundance. It could be especially interesting to study how the pronounced large-scale fluctuations in inflow to hydropower (intra-annual) and smaller scale fluctuations in wind- and solar-power (daily) interact in an energy system. There is a need to better represent the profound difference between wind-, sun- and hydro-energy sources. On the one hand, they are all directly linked to the 2-D horizontal dynamics of meteorology. On the other hand, the branching structure of hydrological systems transforms this variability and governs the complex combination of natural inflows and reservoir storage. The CRE production is, in addition to weather, also influenced by the energy system and market, i.e. the energy transport and demand across scales as well as changes of market regulation. The CRE production system lies in this nexus between climate, energy system and market regulations.