Currently, a noticeable research effort is being fostered to improve the quality of sub-seasonal to seasonal (S2S) weather predictions, a field still with a high capacity of improvement. European energy companies have a strong interest in such climate information to improve energy efficiency and predictability. Improving the forecast quality is essential to reduce (i) the need for balancing energy, (ii) to reduce adverse fluctuations in power generation and (iii) to increase business profitability. Benefiting from the state of science and technology and receiving valuable weather information in a due timeframe is a challenge for energy companies and key to success in an ever-growing competitive market. Energy commodity trading at the various European markets (power, gas, coal, CO2) is considerably affected by long-term weather predictions and the resilience as regard to this type of information is steadily growing. Several cases affecting activities at the power utility EnBW AG (Germany) will be discussed and the need for seasonal climate information will be demonstrated. In particular, the water situation at the Rhine river during the first half of 2017 and the resulting economic consequences for power production and transport logistic will be detailed. Also, different trading periods will be shown to illustrate the impact of S2S-information on the related energy markets. The description and use of other energy/climate H2020-projects (IMPREX, S2S4E) will complement this discussion.