Battery storage for electricity generation is not always cost-effective

Ars Technica : The ability of wind turbines and solar power plants to generate energy depends on local conditions, and they sometimes are unable to produce enough electricity to meet demand. They are often paired with batteries or other systems, such as pumped-storage hydroelectricity and compressed air, to store energy produced during low-demand periods. A new study by Charles Barnhart of Stanford University and his colleagues suggests that using batteries to store extra electricity produced by cheaper energy sources, such as wind turbines, may not be worthwhile. Energy return on investment (EROI) is a way of determining whether the energy generation ability of a technology is efficient compared with the cost of creating the technology. Barnhart’s team found that even the most efficient lithium batteries scored two orders of magnitude lower in EROI than pumped hydro and compressed air storage. This means that for cheap-to-produce wind turbines, it is often more efficient to just build extra turbines or more transmission lines than to add battery storage. For solar devices, which are more expensive to manufacture, battery storage can make the difference in cost-effectiveness. The study notes that many other factors can play into the overall viability of battery storage, such as a need to strengthen the electrical grid or emergency electricity services and a lack of availability of other storage options.