Determining Value in Energy Storage
Written by Brent Perry, CEO, Sterling PBES
Introduction
In the 10 years since I started the first company dedicated to producing specialist lithium ion batteries for the marine industry, there has been a huge uptake from the market. In the very early days, I would tell people that their vessels would be able to run on battery power and they would look at me with disbelief; at that point in time, land based electric propulsion was rare and – in many cases – people’s experiences of it painted a picture of inconsistency and unreliability.
Fast forward and the electric cars are here to stay. With few exceptions, western countries are committing to exclusively use electric or hybrid electric vehicles in the medium term. Lithium battery power taken hold in other industries in a similar way, especially commercial shipping. Commercial mariners the world over have fully embraced the use of the technology. They are cheaper and cleaner to run and, most importantly, they outperform conventional vessels with very short-term payback.
Today, most vessels being built either use energy storage in some way or have the provision for it. They are being built to future proof their investment.
The Apples to Apples comparison
At the beginning of the age of megawatt scale lithium energy systems, it was determined that cost per kilowatt hour (kWh) was a good way to measure the value that lithium could be evaluated. In the years since, there have been many articles, white papers, and countless conference speeches about the goal of reducing the cost of lithium batteries to below $100 USD/kWh. This may be an arbitrary number largely driven by the stationary grid and automotive suppliers, but suppliers were trying to use this measure to identify when lithium would be cheap enough for these industries to be successful.
The problem with using an arbitrary metric like cost/kWh is that it assumes that all lithium batteries are equal. In the commercial marine space, that assumption is simply not true. The concept of cost/kWh is further complicated by the engineering requirements of marine systems, driven by the flag authorities and classification societies. Things like safety, reliability and risk a far greater real-world influence on the cost of building batteries for the marine industry and all of the associated systems involved. But, how do we create an “apples for apples” comparison that supports rational commercial decision making?
The Challenge:
Power systems on large vessels are highly complex and it is not easy. At Sterling PBES, we have taken the decision to measure the cost of an installation and its payback by including all of the elements necessary to offer a complete installed system. Batteries (priced per kWh) are a part of this – but certainly not all of it. For customers to make a sound decision and understand the overall financial impact, everything needs to be considered.
How do available batteries differ?
There are several versions of battery chemistry available to the battery manufacturers; the dominant chemistries are NMC, Titanate, and LPO or Iron phosphate. Each of these chemistries have different energy densities (energy density is the amount of energy stored for the volume of the cell. Systems with lower energy density tend to be heavier as well as larger while higher energy density systems are usually lighter). Different battery systems have different lifecycle characteristics, age in different ways, and charge/discharge characteristics. The marine industry has gravitated towards NMC as a dominant chemistry but even in one chemistry type there are variations in performance existing from one cell manufacturer to the other, principally focussed on whether the cell is a power cell (instant power) or an energy cell (a larger gas tank). Even the form factor of the cells has a lot to do with the managed risk and performance of a battery.
Balance of System
Then there is the balance of systems required to make a battery system qualify for Type Approval. These are items from simple things like power cables, communication cables, plumbing systems, racking, emergency ventilation, HVAC, chillers, approved battery rooms, vibration and impact supports, fire detection, fire management, gas detection, and gas management. While not typically supplied by the battery manufacturer, the impact to each required sub-system to overall system cost can add up: building a complete battery system in this way leads to hidden incremental costs.
System Integration
A battery that is not fully integrated is not practical . We need to ensure that batteries are optimized to their performance characteristics to deliver the best overall return on investment and optimization of risk management. This is typically associated with the systems needed to make the batteries work – switch panels, cooling systems, heat extraction systems, large scale power electronics including inverters, converters, transformers, frequency regulation equipment, integrated power management systems and the sophisticated software that brings it all together to make the whole system work as designed.
Obviously, integration is a real challenge, but it is imperative that the customers are able to navigate through the many options to actually compare the solutions available and understand the impact to their vessels and their profitability.
gCaptain
