In recent years, the cost of solar and wind energy has fallen sharply, which has accelerated the growth of these renewable energy technologies. The energy suppliers are increasingly planning a future network that will be dominated by sun and wind. This requires changes in network management and transmission upgrade, as well as the addition of storage to smooth the supply of variable generators.
Grid storage is pretty early on, but we're already seeing huge cost reductions as the industry matures. The US Energy Information Administration (EIA) recently highlighted this, showing that the cost of grid-scale battery projects in the US has dropped 70 percent in just a few years.
Between 2015 and 2018, the average project cost decreased from $ 2,152 per kilowatt hour of storage to $ 625. Costs need to drop much further in order for grid batteries to scale. However, this is a huge improvement in a short period of time.
Enlarge /. The average costs (per kilowatt hour of capacity) fell by around 70 percent from 2015 to 2018.
By the end of 2018, the USA had a battery capacity of 869 megawatts and an energy capacity of 1,236 megawatt hours. (Power is the rate at which the batteries can deliver electricity, while energy is the total amount they can deliver as they switch from full charge to empty charge.) EIA also has installation dates for 2019, at which an additional 150 megawatts / 450 megawatts were added – hours In the first seven months of 2020, another 300 megawatts of power were installed.
EIA does not see any slowdown. It is expected that the installed battery storage will increase by 6,900 megawatts “in the next few years” – a number that is not clear enough to enable a rapid increase in the number of planned projects.
While you might think one battery is more or less the same as another, there are regional differences that are hidden in the average cost of recent projects. For example, in the Midwest to Mid Atlantic region of the PJM-managed grid, the average cost between 2013 and 2018 was $ 1,946 per kilowatt hour. The projects in Hawaii averaged just $ 947 per kilowatt hour.
Enlarge /. Average cost for different grid regions, where the circle size represents capacity. Batteries can be designed in such a way that power (rate) or energy (total storage) are prioritized.
Much of this difference can be explained by the fact that batteries serve many different purposes. For example, in the PJM region, if you calculate this cost per kilowatt instead of per kilowatt hour, this cost drops to $ 1,004. And by that metric, the average Hawaiian cost rises to $ 1,498.