As triad avoidance becomes more popular and the market dynamics more complicated, the value of suppliers warninghs reduces. This can be addressed with active management using automated demand side reduction.

1. Triad Warnings vs Triad Management – Know the difference.
Triad or Transmission Network Use of System Charge (TNUoS) is an element of many businesses
utility cost that has become more broadly recognised over recent years. This is because it is a
significant annual cost that for many companies who have Half Hourly metered sites it is ultimately
avoidable.
The “triad” system is the means by which industrial and commercial electricity consumers pay for
the electricity transmission network in Great Britain. The triad system doubles up as a peak load
management mechanism. Triad charges are part of Transmission Network Use of System (TNUoS)
charges, which National Grid recovers every year from Licensed Generators (23%) and Licensed
Electricity Suppliers (77%). The TNUoS charges which Electricity Suppliers pay for the consumption of
their half-hourly (HH) customers are in the form of triad charges. The cost of owning and operating
the transmission network is driven by the peak demand which the network must satisfy, and is
higher where demand is high and generation is insufficient. The triad charging system has been
designed to penalise consumption during peaks, especially in highly stressed parts of the network.
Triad mechanism
The “triad season” runs from the beginning of November to the end of February every year. Once
the triad season is over and half-hourly meters have been read, the three half-hour periods of
maximum demand are identified. These are the triads for that season, and must be separated by at
least ten clear days.
For each Electricity Supplier, its customers’ average consumption, in each network zone, over the
three triad periods, is calculated. This is multiplied by the triad charge for that zone to create the
total amount which the Supplier must pay to National Grid.
Author ; Gary Swandells Flexitricity Limited

2. Commercial opportunity
Because the cost of owning and operating the GB transmission network for a year is recovered in the
three triad periods, consumers and small generators can save and earn money from the triad
system.
Consumers who avoid consuming during those periods, whether by turning down or by running
generators, save money for their Electricity Suppliers. Small generators who export electricity from
their sites during the triad periods also save money for the Electricity Supplier who purchases their
generation. A consumer or generator wishing to exploit this opportunity requires:
1. Flexibility in consumption or generation – Flexitricity can identify, connect and manage flexible
loads and small generators to maximise triad benefit;
2. The right tariff – For consumers, the triad charges must be explicit, not hidden in the unit rates.
For generators exporting electricity, a share of the triad benefit must be negotiated with the
Supplier.
Cost of TNUoS
The value of triad avoidance depends on the network zone. Triad charges for 2010/11 and draft
charges for 2011/12 are in the table below
These are the charges which can be saved by avoiding consumption during triads. Generators
exporting electricity can usually negotiate a 90-95% share of triad benefits from their Supplier.
Generators must also consider the cost of fuel. Most generators will have traditionally run for
around 25-40 hours in each triad season in response to triad warnings. The savings are therefore
the net figure between the avoided cost + any generated electricity value less the cost of any
avoidance strategy. For most commercial sites this will be the cost of the fuel used to generate
locally or any lost commercial opportunity resulting from deferring consumption.
Author ; Gary Swandells Flexitricity Limited

3. Where do triad WARNINGS come from ?
Most electricity suppliers can offer triad warnings to their clients which range in timing and
frequency from weekly through to daily, typically being issued either day ahead or in the morning for
that day. There is also a small number of specialist energy management consultants who can offer a
daily service based on either a success fee or annual subscription charge. These will typically be of
greater accuracy as they will base their analysis on consideration of several supplier alerts as well as
their own internal working.
How reliable are Warnings ?
Reliability of warnings services for each source can partially be assessed by looking at their historical
attainment for hitting all three triads, but also critically it is necessary to consider the number of
warnings that they issued in order to achieve their performance record.
This however is only part of the picture as due to changes in the way the overall energy market
operates and responds to triad alerts can and will affect the reliability of warnings. There are three
main factors that affect this and both are related to activity that takes place at the distributed level
of the network.
1. With an increasing volume of participation in triad avoidance, the warnings offered by the
large suppliers has a direct impact on the likelihood of a triad being realised. Using the same
principal that the combined impact of many consumers reducing their consumption will
flatten many of the peaks resulting in increased numbers of calls requiring to be issued.
2. As the winter period experiences a flattening of many of the peaks, it is also increasingly
likely that the failure of any of the big suppliers failing to issue a warning will as has
historically been demonstrated, create enough of a peak to make that day one of the three
triads. This will then result in the consumers that subscribe to that suppliers warnings failing
to hit all three.
3. Increasing levels of distributed generation is connecting to the system at a Distribution level
and therefore not subject to TNUoS calculation. The most significant element of this is the
rapid growth in renewables, and wind in particular. If the wind output is either lower or
higher than predicted this will have a direct impact on either increasing or reducing the
volumes that are supplied through the transmission network. It is widely recognised that
wind prediction notoriously difficult and assessment of how much may be delivered around
a suspected triad peak either several hours or days in advance is a significant variable to
consider amongst the other influences currently considered.
Author ; Gary Swandells Flexitricity Limited

4. Historical triads
Peak demand is driven by the co-incidence of lighting-up time with the end of the working day. For
this reason, triads have historically occurred between 16:30 and 18:00 on Mondays, Tuesdays,
Wednesdays and Thursdays. The only exceptions since 1972/73 were Sunday 7th January 1973
(17:00-17:30) and 15th February 1973 (18:00-18:30).
Around the winter solstice, triads tend to occur earlier in the day. Triads are strongly correlated with
temperature, so a cold snap late in the winter can cause a triad to fall later in the day.
What is Triad Management?
Triad management is currently provided exclusively by Flexitricity by virtue of the technical
infrastructure that we have developed in order to be recognised as the most advanced Smartgrid
service provider in the UK. This unique system is employed for a range of services that are detailed
at www.flexitricity.com but includes STOR aggregation, Frequency Control and geographic constraint
assistance.
In order to provide this broad range of services Flexitricity are able to communicate directly on a
machine to machine basis with the assets on partner’s sites to either start / increase generation or
reduce demand. This creates a distinct advantage of not having to make a decision until far closer to
the time when a triad may or may not occur. During this time it Flexitricity will have had the benefit
Author ; Gary Swandells Flexitricity Limited

5. of having received and assessed the impact of all the large supplier triad warnings in addition to
those of some subscriber services. Flexitricity also have access to and monitor the National system
demand profiles that show consumption levels and generation outputs updated on a 30 minute by
30 minute basis.
Armed with this more accurate information and the ability to remotely start / stop generation and
demand reduction Flexitricity can more prudently respond to ensure that all triads are avoided but
with a risk profile that will avoid excessive number of calls and shorter runs, and thus reduce the
costs associated with the operation. Not only can
This is reflected in the charging methodology that is employed for the service. In keeping with the
founding principal of partnership, Flexitricity employ a success fee that is based upon the NET
savings after the deduction of the avoidance costs from the gross benefit that is achieved.
Author ; Gary Swandells Flexitricity Limited