Batteries

Introduction to Batteries

Table of Contents

Batteries are electrochemical devices that store electrical energy for later use. Batteries can either be used once and discarded such as the common dry cell alkaline batteries, or recharged for multiple employment. We use Batteries for many applications everyday including power supply for cell phones, laptops, and for starting automotive engines. These applications typically require relatively small amounts of electrical power, either because the devices are small and not energy intensive, or because the power is used for a very short period of time. The cost of energy in the form of AAA batteries is about $165 per kWh, more than a thousand times higher than the cost of the same electrical energy from a grid connected utility. Batteries are also used for various grid applications.

The amount of energy stored in typical batteries is much smaller than the amount of energy used in residential and commercial buildings, which means that many batteries need to be connected in a bank to provide appropriate capacity. This is a familiar problem for the many Alaskans that live off the grid and rely on generators and battery banks to provide power.

Most conventional batteries have high maintenance costs and a limited lifetime — a typical lead-acid battery will last five to six years in most remote power applications if properly maintained. This means that the cost of storage, (calculated by dividing the cost of the battery by the total number of kilowatt-hours (kWh) of storage possible) is generally much higher than the cost of generating electricity directly from fuel, which means that batteries are generally not appropriate for long-term energy storage.

A battery system is an uninterruptible power supply.

Systems

Batteries are currently used in small scale Alaska village applications to provide short-term energy storage to allow transition between a variable renewable energy source, like wind or hydro power and a dispatchable generator. Since batteries operate on direct current (DC), a power inverter is also required to allow them to supply and be charged by alternating current (AC). There are many types of batteries with different operating characteristics.

Increased market focus on high-quality, lightweight, inexpensive, and high-power density batteries for the electric and hybrid car markets will hopefully result in new battery types that hold promise for remote applications in the coming years.

Several battery types can be considered for rural applications, however many of these systems are still currently precommercial.

Lead-Acid Batteries