The true cost of energy storage depends on the so-called LCOE = Round-trip efficiency + maintenance costs + useful life of the energy system
By Anna W. Aamone
“With regard to [battery] energy storage systems, many people erroneously think that the only cost they should consider is the initial – that is, the cost of generating electricity per kilowatt-hour. However, they are not aware of another very important factor.
This is the so-called LCOE, levelized cost of energy(also known as cost of electricity by source), which helps calculate the price of the electricity generated by a specific source. The LCOE also includes other costs associated with producing or storing that energy, such as maintenance and operating costs, residual value, the useful life of the system and the round-trip efficiency. […]
Batteries and round-trip efficiency
[…] due to poor maintenance, inefficiencies or heat, part of the energy captured in the battery is released … or rather, lost. The idea of round-trip efficiency is to determine the overall efficiency of a system (in that case, batteries) from the moment it is charged to the moment the energy is discharged. In other words, it helps to calculate the amount of energy that gets lost between charging and discharging (a “round trip”).
[…] So, as it turns out, using batteries is not free either. And it has to be added to the final cost of the energy storage system.
[…] An energy storage system requires regular check-ups so that it operates properly in the years to come. Note that keeping such a system running smoothly can be quite pricey. Some batteries need to be maintained more often than others. Therefore when considering buying an energy storage system, you need to take into account this factor. […]
Useful life of the energy system
Another important factor in determining the true cost of energy storage is a system’s useful life. Most of the time, this is characterized by the number of years a system is likely to be running. However, when it comes to batteries, there is another factor to take into account: use. […]
More often than not, the life of a battery depends on the number of charge and discharge cycles it goes through. Imagine a battery has about 10,000 charge-discharge cycles. When they are complete, the battery will wear out, no matter if it has been used for two or for five years.
[…] [However] flow batteries can be charged and discharged a million times without wearing out. Hence, cycling is not an issue with this type of battery, and you should keep this in mind before selecting an energy storage system. Think twice about whether you want to use batteries that wear out too quickly because their useful life depends on the number of times they are charged and discharged. Or would you rather use flow batteries, the LCOE of which is much lower than that of standard batteries?
So, what do we have so far?
LCOE = Round-trip efficiency + maintenance costs + useful life of the energy system.
These are three of the most important factors that determine the LCOE. Make sure you consider all the factors that determine the true cost of energy storage systems before you buy one.
Image credit: Flickr/INL”