By Henry Curtis
The increased use of intermittent renewable energy resources such as wind, solar, waves and tidal are adding to the complexity of grid management, regulatory oversight and watchdog review.
Traditionally, well over 90% of all energy storage has been hydroelectric.
That is changing and evolving into a vast new complexity.
There are many very diverse ways of storing energy for future use.
They include wind-up clocks, hydroelectric dams, frozen ice blocks used for future air cooling, stored food for human consumption and ancient energy beds (long dead organisms converted over eons to fossil fuel).
Energy can be stored in its kinetic form (momentum) or its potential form (chemical, gravitational, electrical energy, temperature differential, latent heat).
Batteries are but one type of energy storage devices. A battery is a container consisting of one or more (usually two or more) cells, in which chemical energy can be converted into electricity.
Batteries that are used one and then tossed away are called primary, while those that can be re-used are called secondary. Wikipedia lists 39 types of primary (non-rechargeable) batteries and 38 types of secondary (rechargeable) batteries.
Primary Batteries represent about a quarter of the $50 billion world market. Their market share is trending downwards.
Batteries are very diverse in terms of the chemicals that are used in their make-up and in their construction.
The three dominant types of batteries are lead-acid, lithium and alkaline. These are broad categories which contain multiple subcategories.
Lead-acid batteries are primarily used to power motors. Their secondary main use is providing Uninterruptible Power Supply (UPS). Lithium batteries are used in consumer goods.
Lead Acid and Lithium batteries are the two dominant batteries used to support centralized and distributed electrical generation; they are used at the utility, commercial and residential scale.
First Wind installed a lead acid battery system at their Kahuku wind facility. That battery facility burnt down.
The Hawaii Natural Energy Institute (HNEI) is installing three lithium (Altair Li-ion titanate) batteries. The first site is Upolu Point at the interface between the HELCO grid and the Hawi wind farm. The second site is at a substation on O`ahu. The third and largest battery will be interfaced to the Moloka’i grid.
Adding a battery to a grid changes the way the grid is managed. It can change the economic dispatch of generators. The differential footprint is what matters. That is, what is the footprint of a grid operating in real time with and without batteries?
The batteries could be connected directly to the grid, at a generator feeding the grid, at a building which is net-metered into the grid, or a building which then severs its connection to the grid. Under each of the four conditions the grid would need to be re-optimized for efficient operation.
Another complexity is that we are in the middle of a battery revolution. New processes and approaches are being tested. They are often proprietary.
Then there are several economic, social, cultural and environmental impacts which must be evaluated in any battery analysis.
The environmental impacts include but not limited to resource depletion, global warming potential, acidification potential, eutrophication potential, ozone depletion potential, photochemical oxidation potential, ecological toxicity potential, human toxicity potential, occupation cancer hazard, occupational non-cancer hazard.
Finally there is the growing problem of disposing batteries. Landfills are leaking hazardous waste.
In the complex battery field there are no easy answers. Intermittent renewable energy resources are exponentially increasing. Batteries are coming.
The environmental and social footprints are significant and unknown.
Legislators, Regulators and Watchdogs are playing catch-up.
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