Overview of
Supplier Volume Allocation
David Osborne
Introduction
• Supplier Volume Allocation (SVA)
– Purpose
– History
– Supplier Hub and other participants
– Interface with Central Services
Generation, Transmission,
Distribution and Supply
Generation
Generation
Transmission
Network (the ‘Grid’)
Grid
Supply
Points
400/275 kV
Distribution Network
132 kV
Supplier’s
customer
factory >100 kW
Supply
Supplier’s
customer domestic
GSP Group
SVA History
• 14 Regional Electricity Boards
• 1990 – competition in Supply > 1MW
• 1994 – extended to > 100 kW
• 1998 – full competition
• 2000+ – competition in agency services
• 2001 – NETA Arrangements
• 2005 – BETTA Arrangements
Distribution Companies / Grid Supplier Point
Groups
Liberalised market
Metering Systems
29 million Metering
Systems
314,000,000 MWh
demand per year
(45% Half Hourly Metered)
Profiling
• Over 29 million NHH meters
• Settlement operates on HH basis
• Consumption is profiled to allocate
annualised consumption to Half Hours
8 Profile Classes
1
Domestic
24 * 7
2
Domestic
2 –rate with night-time electrical
storage and immersion heating
3
Non-domestic
24 * 7
4
Non-domestic
2 –rate with night-time electrical
storage heating
5-8
Non-domestic
Maximum Demand with load factor
of < 20%, 20-30%, 30-40% and
>40%
Roles and Responsibilities – Suppliers
and SMRAs
•
Supplier Meter Registration Agent (SMRA)
– 1 per GSP Group
– SMRA service - LDSO licence requirement
– Provides a registration service
– LDSO Party to the BSC
•
Supplier
– Discharges many obligations through Supplier Agents (MO, DC and DA)
– Registers “Supplier Hubs” in each GSP Group
– Supplier Hub = combination of Supplier, Meter Operator, Data Collector and
Data Aggregator in each GSP Group
– Multiple combinations of “Supplier Hubs” operate within each GSP Group
– Supplier is a Party to the BSC
Roles and Responsibilities – Supplier
Agents
• Supplier Agents (NHH and HH)
– Meter Operator - asset provider and maintainer
– Data Collector - data retrieval and processing
• For NHH - determines EAC/AA data based on Daily Profile
Coefficients received from the SVAA
– Data Aggregator - provides aggregated meter data
by Supplier, GSP Group, Profile Class to the
Supplier Volume Allocation Agent
– Supplier Agents are not BSC Parties
Roles and Responsibilities – BSC
Agents
• Appointed by ELEXON to perform certain activities
• ELEXON cannot be a BSC Agent
• Supplier Volume Allocation Agent (SVAA)
– Calculate Supplier volumes
– Produces Daily Profiles for use by NHH Data Collectors
– Manages market data
– Contracts for Sunset Data and Temperature Data
– Applies GSP Group Correction
Roles and Responsibilities - BSC
Agents
• Profile Administrator
– Programme of load research in order to collect
demand data from customers
– Derives Regression Coefficients
• Teleswitch Agent
– Provides switching times for certain groups of
customers
BSC Systems and Processes
• Processes undertaken by Suppliers/Supplier
Agents are highly prescribed in the BSC and
procedures
• Some systems provided centrally and operated
under licence
– EAC/AA software
– NHHDA software
SVA Process Overview
Industry Processes
Supplier
DC/DA
appointments
Central Systems Processes
SMRS
Data
Collector
Regression
Data
Aggregated
consumption
Data
Appointment and
Settlement Data
Meter
Operator
Profile
Administrator
Data
Aggregator
NHH Daily
Profile
Coefficients
Central Data
Collection
Agent
GSP Group
Take
SVAA
Allocated
Supplier
Volumes
Settlement
Administration
Agent
Teleswitch,
sunset and
temp data
Other Data
Providers
Timing of Settlement Runs
Final
Settlement Settlement
Run
Day
Time
+39WD
+5WD
+16WD
Interim
Information
Settlement
Run
Reading
Targets
n/a
Final
Reconciliation
2nd
Reconciliation
+154WD
+84WD
1st
Reconciliation
30%
+30
Months
+292WD
3rd
Reconciliation
60%
80%
Post-Final
Settlement
Run
97%
Supplier
Charges
Costs
• Supplier Volume Allocation
Year to March 2008
£m
– SVA Operations
1.59
– Data Transfer Service (DTS)
0.58
– Profiling
0.74
– Software Support
0.87
– Entry Process/Qualification
0.41
– Other
0.14
– SVA Total Cost
4.33
Electricity Metering & Settlement
Jon Spence, ELEXON
8 November 2008
The Ice Cream Test
• If 50% of annual ice cream sales occur
in August
• And 50,000 ice creams are sold in
August
• What are the annual sales? ______
• If 5% of annual ice-cream sales
occur on 5th August
• How many are sold
on 5th August? ______
That’s how electricity settlement
works!
• What do profiles look
like?
• How are they used to
annualise customer
demand?
• How are they used to
estimate Suppliers’
demand in a given half
hour?
Yearly Profile – domestic unrestricted
Average Domestic, Unrestricted Customer - Yearly Profile
April to March
16
14
12
kWh
10
8
6
4
2
0
1
12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188 199 210 221 232 243 254 265 276 287 298 309 320 331 342 353 364
Settlement Day
Daily Profile – domestic unrestricted
Average Domestic, Unrestricted Customer - Daily Profile
0.9
0.8
0.7
0.6
kW
0.5
0.4
0.3
0.2
0.1
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
Settlement Period
Winter Weekday – single-rate and
dual-rate
Domestic Profile Classes
2
1.8
1.6
1.4
kW
1.2
1
0.8
0.6
0.4
0.2
0
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
Settlement Period
Profile Class 1 - Domestic Unrestricted Customers
Profile Class 2 - Domestic Economy 7 Customers
43
45
47
Non-Domestic Load Profiles
Non-Domestic Customers
6
5
kW
4
3
2
1
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
Settlement Period
Profile Class 3 - Non-Domestic Unrestricted Customers
Profile Class 4 - Non-Domestic Economy 7 Customers
Non Domestic Maximum Demand
Non-Domestic Maximum Demand Customers
35
30
25
kW
20
15
10
5
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
Settlement Period
Profile Class 5 - Non-Domestic MD 0-20% LF
Profile Class 7 - Non-Domestic MD & 30-40% LF
Profile Class 6 - Non-Domestic MD & 20-30% LF
Profile Class 8 - Non-domestic MD and over 40% LF
Profiling Cycle
Year one – data logged at sample 2,500 customers
(split 50-50 between domestic & non-domestic) – confidential
process
Year two – data analysed
Year three – profiles used in Settlement process
Profiling process
Temperatures
and sunset times
Sample data
switching times
SVAA
Load
Research
Regression
Analysis
Daily Profile
Production
Profile
Administrator
Data
Collector
Annualise
Meter
Advances
SVAA
Deemed Take
calculation
Yearly
Supplier Reports
Daily
Data Collector
An estimate of annual consumption is extrapolated from
meter advance using profile
1,150 kWh in 90 days
Average Domestic, Unrestricted Customer - Yearly Profile
16
14
12
kWh
10
4,250 kWh per year (AA)
8
6
4
2
0
1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188 199 210 221 232 243 254 265 276 287 298 309 320 331 342 353 364
Settlement Day
EACs/AAs
• Annualised Advance
– the rate of consumption for a Settlement Register
over the period between two meter readings.
• Estimated Annual Consumption
– an estimated rate of consumption used in
Settlement until an AA is calculated
– similar to an Annual Quantity (AQ) in Gas?
EAC / AA cycle
timeline
INITIAL EAC
AA 1
EAC 1
AA 1
AA 2
AA 1
AA 2
EAC 2
AA 3
EAC 3
“carried forward” EAC is calculated using latest AA
and “brought forward” EAC (weighted using the
profile over the meter advance period)
AA Example
1/1/07
MR1
7,000
31/3/07
MA = 2,000
MAP∑DPCs
= 0.4
Previous EAC = 3000
AA = Meter Advance / MAP∑DPCs
= 2,000 / 0.4
=5,000
MR2
9,000
EAC Example
1/1/04
MR1
7,000
31/3/04
MR2
9,000
MA = 2,000
MAP∑DPCs
EACnew
= 0.4
Previous EAC = 3000
AA = 5,000
EACnew = AA * (MAP∑DPCs * SP) + EACold * (1-MAP∑DPCs * SP)
EACnew =
EACnew =
5,000 * (0.4 * 2)
4,000
+
+
3,000 * (1 – (0.4 * 2))
600
= 4,600
Data Aggregation
Estimated yearly demand values are added up for customers
with same Supplier, Profile Class, meter configuration by a
Data Aggregator to give the
estimated yearly demand for Settlement Class or
a “super customer”
NHH Data Aggregation
• NHH Data Aggregator aggregates
annualised consumption for each
distribution area, Settlement Date and Run
Type
• an AA is used in preference to an EAC
• a default value is used where there is no
AA or EAC
The NHH Settlement Cycle
Average Domestic, Unrestricted Customer - Yearly Profile
16
AA / EAC
(Meter)
14
12
kWh
10
8
6
4
2
0
1
12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188 199 210 221 232 243 254 265 276 287 298 309 320 331 342 353 364
Settlement Day
Meter Advance
Daily Profiles
Average Domestic, Unrestricted Customer - Daily Profile
0.9
0.8
0.7
0.5
kW
HH
profiled
demand
(Supplier)
0.6
0.4
0.3
0.2
0.1
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48
Settlement Period
Half Hourly Profiles
Aggregated
AA / EAC
(Supplier/
Profile Class)
Supplier Volume Allocation Agent
• applies half hourly profile to aggregated
AA/EACs to calculate profiled HH demand
per Supplier
• estimates line losses based on factors from
Distribution businesses
• applies ‘GSP Group Correction’
GSP Group Correction
Electricity is metered twice – at customer’s meter and at Grid Supply
Point (i.e. entry/exit points to distribution networks)
NHH
NHH
HH
GSP
GROUP
TAKE
HH
GSP Group Correction
•
NHH demand (import less export plus estimated line losses) are
“corrected” so that total NHH and HH volumes for the Settlement
Period equal the GSP Group Take
•
volumes attributable to each Supplier are scaled up or down in
each HH/GSP Group via CF
•
since GSP Group correction is effectively distributing “settlement
error” amongst Suppliers, it makes sense to correct those
categories of consumption that are more prone to error than
others
•
NHH is obvious candidate as Settlement Period values are
estimated (using profiles) rather than metered.
The Ice Cream Test
• If 50% of annual ice cream sales occur
PrA
in August
• And 50,000 ice creams are sold in
August
NHH Data
Collector
• What are the annual sales? ______
• If 5% of annual ice-cream sales
PrA
occur on 5th August
• How many are sold
on 5th August? ______
SVAA
Questions
?