Use of English

Storing Green Power

Renewable energy sources such as wind and solar are essential (0) FOR reducing carbon emissions, but storing the electricity they produce remains a major challenge. One reason is that energy generation does not always coincide (1) .......... periods of high demand. Solar panels, for instance, produce nothing at night, while wind farms may generate power when it is least needed. As a result, engineers are searching (2) .......... efficient ways to store surplus electricity and release it later. Batteries are currently the best-known option, but they are expensive and depend (3) .......... materials that are not always easy to obtain. In addition, large-scale battery systems lose some energy in the process of storing it and converting it back (4) .......... usable power. Another difficulty lies in the fact that no single storage method is suitable (5) .......... every situation. Pumped hydro works well in mountainous regions, but it cannot be built just anywhere. Hydrogen is often presented as a promising alternative; however, it requires a great deal of energy to produce and is difficult to transport safely. Until storage technology improves, renewable systems will continue to rely, at least partly, (6) .......... backup sources or highly flexible grids. What experts agree (7) .......... is that investment in storage is just as important as investment in generation itself. Without it, the transition to clean energy will be far more difficult (8) .......... many people assume.