Stanford University scientists have worked out that from an energy point of view it doesn’t make sense to store wind power in batteries. The energy cost of building the batteries is more than the value of the power that would be lost through curtailment.
The researchers compared the finding to the cost of storing cash in a safe, noting that it would not be worth paying USD$100 to store a $10 watch. Since wind power is so cheap, buying batteries to store the excess energy it produces is not worth the effort. This is not the case with photovoltaic energy, which costs more to produce in the first place.
Nor does it apply to other forms of energy storage: storing excess wind power in pumped hydro reserves, for example, is still energetically economical. The authors note that the value of batteries for excess wind energy storage could be improved by increasing their cycle life.
To be worth the investment for wind energy storage, batteries would have to last between 10,000 and 18,000 cycles, they say.