Can We Overcome The Last Few Hurdles For Renewable Energy?
Forbes Oct. 2019
Storing renewable energy at a large scale is one of the most pressing tasks for the renewable energy industry.
While recent advances in battery capacity and longevity (as well as battery chemistry itself) are encouraging, the cost is always the most significant factor that limits the adoption of new technology.
When choosing the right chemistry, there are 2 major factors affecting the effective cost of the Lithium-ion battery system
1/ Cost per Capacity ($ per Wh)
Capacity, with a factor of time, determines how long the energy storage system will last to support the power requirement of the facility.
For example, a premise of equipment with total 10MW can be supported by an energy storage system with 10MWh capacity for one hour.
There several popular chemistries:
- Lithium Nickel Cobalt Aluminum Oxide (LiNiCoAlO2) — NCA
- high energy density
- ~$350/KWH, 500 Cycle life BatteryUniversity
- Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) — NMC
- NCM, CMN, CNM, MNC, MCN with different metal combinations
- high energy density
- ~$420/KWH, 1000-2000 Cycle life, BatteryUniversity
- Lithium Iron Phosphate(LiFePO4) — LFP
- ~$580/KWH, 2000 Cycle life, BatteryUniversity
- Lithium Iron Yttrium Phosphate (LiFePO4) — WP-LYP
- ~$580/KWH, 5000 Cycle life
NCA and NCM/NMC have higher energy density than LFP types, but it does not affect the cost per capacity ($ /Ah) very much.
2/ Cost Per Battery life ($ per year)
NCA,NCM
These high energy density cells can have 1000-2000 cycles at 80% D.O.D.
LFP
The specification of CALB LFP with 2,000 cycle life at 80% D.O.D
WB-LYP
The specification of Winston WB-LYP with 5,000 cycle life at 80% D.O.D.
The cycle life improvement is stemmed from the fact that Yttrium (rare earth) is added to the new series of Winston WB-LYP comparing the old series LFP.
Other than cost, the safety of the Energy Storage System is also a major concern
Why the Korean Energy Storage System (ESS) burned themselves? detail blog.
In energy storage systems, a lot of battery cells are closely packed. The heat generated by high continuous discharge current is very difficult to dissipate.
It brings out the problem that high energy density cells like NCA/NMC/NCM are not capable of dissipating heat comparing to Iron Phosphate cells like LFP/WB-LYP.
Conclusion
Megawatt or Gigawatt Solar energy storage facilities are our hope for our future renewable energy and they are expected to be used for a very long period of time.
The real cost of the system is highly dependent on the battery life.
However, the safety of the battery system is the primary concern.
The author has 30 years of experience in the Lithium-ion battery industry from the laptop application, electric vehicle, to large energy storage.
To learn more about Lithium-ion batteries, please visit everspring.net