Batteries are everywhere. It seems we cannot live without them.
It also seems they cost really little, and are really economical.
So, is the cost of battery storage come down such that such storage is inexpensive and affordable?
The answer is: Not really.
Sure, battery costs are coming down, be they for lead acid or for Li-ion, but they have not come down to the extent that they can be used for large scale storage.
When thinking about battery costs, remember this: It is not just the cost of batteries alone that matter.
What finally matters to battery users is the cost per unit of electricity while using batteries. So, what also matters is the energy wastage that fact happen while using batteries: as an example, about 25-30% of electricity is wasted during charging and discharging of batteries.
In addition, batteries need to be replaced every 4-5 years, depending on the type of battery and how well it was maintained.
So, taking into account both the upfront costs for batteries, their replacement costs and the energy wastage that happens, let us look at how batteries fare, in the crucial metric of cost/unit of electricity delivered (cost/kWh).
This is a fairly intricate topic where you will find discussions becoming quite technical, so I will provide an easy-to-understand illustration – if using solar panels without batteries costs you 10 US cents/unit of power, using a battery that provides a reasonable amount of backup power could double the cost to about 20 US cents/unit, all stuff considered.
Essentially, use of batteries in a typical solar power plant set up could double the cost of power.
Now, something that doubles the cost cannot be really called inexpensive, can it?
Many of us do not feel the pinch of the high battery costs because we mostly use them in small power capacity equipments such as smartphones and watches, where the energy consumption itself is so small that doubling the cost of that energy hardly makes a difference. Not so when you try to use the same batteries for a much larger scale power system.