Product category:
Batteries, chargers and circuit protection
News Release from: Saft Industrial Batteries | Subject: Sunica batteries
Edited by the Engineeringtalk Editorial
Team on 23 July 2002
Batteries cover hybrid photovoltaic
applications
Saft Sunica batteries enable a Cummins' Hybrid Energy System to power microwave transmission equipment on an Australian mountain-top.
Saft Sunica batteries enable a hybrid photovoltaic and diesel generator energy system developed by Cummins Power Generation to provide a reliable source of DC power for microwave transmission equipment installed by Spencer Gulf Telecasters on Mt Edwards, near Yunta, South Australia The energy storage efficiency of the Sunica batteries, which are designed specifically for photovoltaic applications, means that even in the winter months the diesel genset only has to be started around once a week
Cummins designed the hybrid energy system to combine the advantages of both photovoltaic and conventional diesel generation for this remote application where there is no electricity grid.
It is housed in a standard 20ft transport container with a roof mounted photovoltaic generator, with a battery bank and automatic control system inside.
A small diesel genset (10kVA/240V) is also integrated into the system for backup purposes.
The solar generator covers the major portion of the mean energy demand from the microwave transmission system while at the same time charging the Sunica batteries.
At night or at peak times when power consumption exceeds the available solar power the balance is drawn from the batteries, and should the battery capacity decrease to a pre-set level the diesel genset is started automatically to provide back-up power.
The initial project for Spencer Gulf Telecasters, who are a regional television company, comprised a 3kW solar array supported by two 18 cell parallel strings of SUN 84-1 Sunica cells, each with a nominal capacity of 860Ah.
This was installed in 2000 and Saft Australia also supplied two Harmer and Simmons SMF 2800 24V/100A switched mode rectifiers and one Plasmatronics SPS24D200 24V/200A regulator and two-step battery stands.
In 2001 the capacity of the system was increased to support additional loads and a further 3kW solar array was installed together with another string of 18 SUN84-1 Sunica cells.
Photovoltaic systems require efficient batteries with a long cycle life and a potential for both shallow and deep cycling.
The Saft Sunica nickel-cadmium batteries which Cummins specified for the hybrid energy system are designed specifically to offer a number of key advantages in this type of application, namely: constant charging efficiency over time; continuous operation at any state of charge; minimal self-discharge rates; a high available performance even at very low states of charge; sustained efficiency even at high or low temperatures; and long cycle life even when the charge/discharge cycle involves 100% depth of discharge.
Sunica batteries feature pocket plates, shock-resistant polypropylene casing material and a special spill-proof vent.
An extra electrolyte reserve ensures almost supervision-free service and a long interval between topping up.
They also benefit from the long service life of nickel-cadmium technology, with no risk of the 'sudden-death' failure found in lead-acid batteries, and are expected to have a lifetime of up to 20 years. Request a free brochure from Saft Industrial Batteries ...
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