Peak demand at Center Parcs
February 1st 2008 Often operating in excess of 95% occupancy,Center Parks wanted to increase efficiency by peak lopping or eliminating overnight wastage. Brian Jones, managing director of Sinergy describes how electricity monitoring can save energy
s part of Center Parks'
ongoing efficiency drive, the
energy team needed to
survey current, voltage and
power demand for the whole estate
during the four weeks that
constitute the peak of its tourist
season. Sinergy was chosen to carry
out this survey because as
manufacturers, it could install
enough portable energy loggers to
complete a parallel monitoring
exercise on the 40+ distribution
transformers.
With visitors around there was no
way that the technical services
departments could tolerate
any power down periods however
short. Fortunately the Sinergy e-
Tracker energy monitor was
designed to cope, its battery would
keep it going for over 16 days, a 3
phase voltage measurement
reference could be accurately
derived via its EV-TRAC synthesiser.
The EV-TRAC simply plugs into a
single phase socket and has an
electrostatic phase identity feature,
essential in this style of
measurement.The easiest means of
measuring the load current on
Center Parcs' distribution
transformers was on the
outgoing cables where safe access
was available. It was common for
these phase cables to be run in
parallel pairs or sets of three or four.
However the span of the
phase cables did not cause any
installation problems because e-
Tracker's flexible CT's were long
enough to go round the parallel
conductors.The e-Tracker units
were magnetically clamped to
the transformer casings.
Deltrax software was used to
produce the demand profile graphs
for the survey report with daily and
weekly graphs of multi and single
parameter graphics. A kW demand
profile of a swimming arena is
shown (left) the graph indicates a
peak demand of over 500kW (level
A).The results were dramatic with
very heavy daytime consumption
(level B) but why has the midnight
to 8am usage not fallen to say 15-
20% (level C) as might have been
expected? Perhaps more puzzling
are the frequent but short lived dips
from level C to level D, what has
switched off to cause them? Can
these switch offs be extended over
the whole night period? It was
estimated that if overnight demand
fell for 8 hours to the 120kW level of
theses short lived dips, there would
be a saving in consumption of some
7000 kWhs per week.Tight demand
control of this nature overnight for
just the summer season would lead
to the saving of around £3000-
£4000 in kWh unit charges in this
bathing arena alone.
The peak demand of 500kW will
have a significant effect on
the site monthly maximum demand
charge and annual capacity charge.
These two elements can represent
up to 25% of the electricity bill.The
question is whether the peak
demands at the other distribution
transformers coincide to push the
500kW level two or three times
higher.The Excel uplink within e-
Tracker's Deltrax software package
enables cumulative additions and
comparisons with similar sites in the
other villages to be made. Deltrax
should display an improvement, its
tariff section will work out the
appropriate cost saving.
Both fixed sub-metering systems
with automatic data
collection and portable profile
recorders take their place in
the forefront of the continuing
battle to save energy costs.
The latter with its non-invasive
operational characteristics is often
the starting point in the cost
reduction strategy. More articles from Sinergy Limited: | 
