UPS SYSTEMS
Critical Power Investment
Lithium-ion Technology
By: Robin Koffler, Thamesgate Group Director & Co-founder of EcoPowerSupplies
Introduction
Robin Koffler explains
how Lithium-ion UPS
could benefit energy
storage
When uninterruptible power supplies
(UPS) were developed for the oil and
emerging computer industries in the
1950s their primary purpose was to
provide both ‘uninterruptible power’
and condition the power, which could
be mains derived or supplied by a local
generating set. Early computer power
supplies were less reliable than they
are today, with smaller input voltage
and frequency ranges, and were very
susceptible to power pollution: sags,
surges, brownouts, spikes, transients and
electrical noise. The power supplies in
today’s modern servers are far more
robust. While server power supplies
undoubtedly benefit from a UPS
conditioned supply (reduced ‘wear and
tear’), the purpose of a UPS in most
modern data centres and comms rooms
is to provide uninterruptible power.
Short Term Reserve
Today’s UPS system can be thought of
more as an energy storage device for the
site it’s protecting. With advancements
in distributed energy storage
management, UPS could provide a way
for the National Grid to gain access
to distributed energy storage in much
the same way as their Short Term
Operating Reserve (STOR) programme
couples on-site generators to the grid.
The STOR programme pays owners of
generating sets to be connected to the
grid via aggregating companies. When
the National Grid needs more power
generation capacity, the aggregators
contact their clients to see if they can
run their on-site generators and take the
power into the grid. Everyone benefits
through a Feed-In-Tariff (FIT) like
programme.
There are thousands of UPS systems
installed across the UK ranging from
small systems to some fairly large
installations above 1MW or more.
What’s to stop larger UPS owners
from also signing up to a STOR-type
programme? Quite simply, the standard
battery technology used. Driven by the
data centre world, UPS manufacturers
have focused on energy efficiency,
compactness and modularity. Little
development has gone into the primary
‘energy storage’ component within UPS
systems; namely the battery set.
Today’s dominant technology is
the VRLA – valve regulated leadacid – battery. Normally sealed and
maintenance-free, UPS battery
technology is not far removed from
that of a standard car battery. Leadacid technology is ideal for periodic
cyclic charge/discharge cycles i.e.
non-continuous use. Of course, a UPS
battery will provide a runtime (from
several minutes to hours), but the point
is that the discharges (to cover mains
power cuts) are fairly infrequent.
While Nickel-Cadmium batteries
fell foul of environmental changes (and
rightly so), they did offer some benefits
in terms of capacity and their charge/
discharge cycle capabilities, albeit with
their infamous ability to remember their
last point of recharge.
Lithium-ion Technology
Lithium-ion battery technology has
emerged rapidly as the only viable
alternative for applications requiring
rapid recharges and frequent discharge
rates. These are the batteries most
commonly found in smart mobile
phones, tablets and laptops and for those
pioneering few, their electric vehicles.
IT infrastructure
from smallest
to largest.
ENCLOSURES
44 NETCOMMS europe Volume V Issue 6 2015
POWER DISTRIBUTION
CLIMATE CONTROL
www.netcommseurope.com