Transcript Simple Energy Management through Utility Bills

17th November 2015
Simple Energy Management
through Utility Bills
How to help improve energy management without a dedicated energy manager
Welcome!
• What does your
energy bill tell you?
• How do you know it
is right?
• How can bills be
used to target &
monitor change?
A programme delivered by Zero Waste Scotland
“What does my bill tell me?”
What does you bill tell you?
How much money your energy consumption is
costing you:
• Energy consumption
• Tariff structure
• Energy rates
• Other charges
Electricity invoice
New charges – 1 May to 31 May
Charges
All nights
Summer day
All weekend
Site charge
Agreed supply capacity charge 100.00 at £2.15 for 31
days
Agreed supply capacity excess 34.0 at £2.15 for 31 days
Other charges
Reactive charge for April 2011 @ 20%
Climate change levy
VAT at 20%
Total including VAT
Sample
kWh Used
Pence
Total charge (£)
per
kWh
9,590.10
10.5
1,006.96
26,027.80
13.5
3,513.75
13,086.10
15.5
2,028.35
224.47
215.00
73.10
48,704.00
0.485
0.32
236.22
1,459.63
8,757.80
Terms on your electricity bill (A)
Kilowatt-hour (kWh). Unit of electric energy equal to 1 kW of power supplied
from an electric circuit for one hour
Unit rate (p/kWh). Higher rates for on-peak (day and weekend) and lower rates
for off-peak times (night)
HH metered supply. Meter electricity consumption data every half hour (HH)
Charges
• Tariff structure – agreed variable and fixed charges
• Variable charges – energy use, peak capacity, use of system, taxes
• Fixed charges – connection
Terms on your electricity bill (B)
Transmission Use of System (TUoS)
• Charge for the cost of using the National Electricity Transmission System
(NETS) that delivers electricity from power stations to regional transmission
networks
• Calculated based on site demand during peak periods called triads
Distributed Use of System (DUoS)
• Charge for using the regional transmission network between NETS and your
building
• Calculated based on volume of electricity consumed on site during times of
peak demand, mid demand, and off-peak demand
Terms on your electricity bill (C)
DUoS charges include:
• Unit rates (p/kWh). 3 time periods: Red (peak), Amber (mid peak), and Green
(off-peak)
• Supply capacity charge. Based on “peak” energy use during a specific period.
Charge is paid to the grid operator to have the capacity available to meet your
peak demand, regardless of when it occurs
• Supply capacity excess charge. If the agreed supply capacity is exceeded, a
higher capacity charge is paid than the regular rate
• Site charge. Fixed or standing charge due per day and per meter whether or
not electricity is used on premises
Terms on your electricity bill (D)
Reactive charge. Electrical systems use power to perform business or
manufacturing processes
• Some equipment has reactive power requirements
• Inductive devices – motors, welding sets, induction heaters, fluorescent lights
• Reactive power charges normally indicate poor Power Factor (PF)
Power factor
• PF proportion of current in an AC circuit used for its task
• PF 0.8 means 80% of current is used effectively by equipment
Settlement Charges
• Fee for half hourly data service; HH data charges can also apply
Terms on your electricity bill (D)
Climate change levy (CCL). Tax on the supply of energy products (electricity, gas,
coal), set up to encourage energy efficiency improvements; currently set at 0.554
p/kWh for electricity and 0.193 p/kWh for gas – goes up in April each year
Gas invoice
Bill period from 4 May to 1 June
Reading date Reading Reading
this time last time
01/06/2011
149262 C
Sample
Units
Used
138475 C 10987.00
Correction
factor
Adjusted Calorific KWh
units
value
(m3)
1.022640 11235.74
39.4 122968.93
Business
unrestricted
Unrestricted units
£p
122968.93 kWh at 2.687p
Monthly charge
3,304.17
439.76
CCL
122968.93 kWh at 0.1690p
207.81
VAT
20% on charges of 3,3951.74
790.34
Total this invoice
4,742.08
Terms on your gas bill (A)
Kilowatt-hour (kWh). Unit of energy equal to 1 kW of energy supplied from gas
mains network for one hour
Reading this time, 149262 C. C is for meter reading supplied by customer, E is for
estimate
Correction factor. Factor to convert gas units into kilowatt hours (kWh). Standard
across all suppliers (1.02264)
Calorific value (CV). Amount of energy contained in gas, or heat generated when
a known volume of gas is combusted (~39.4 MJ/m3)
Terms on your gas bill (B)
Unrestricted units. Where there is an ‘unrestricted’ meter, there will be one
single reading.
Monthly charge. Fixed or standing charge due per day and per meter whether or
not electricity or gas is used on premises
Climate change levy (CCL). Tax on the supply of energy products (electricity, gas,
coal), set up to encourage energy efficiency improvements
“How do I know it is right?”
How do you know it is right?
Actual or Estimated meter readings? Estimated meter readings are often higher
than actual energy use. Every month, read your meters (electricity, gas, other
energy, as well as water) and provide this information to your suppliers
Check supply capacity excess. If your organisation exceeds the agreed peak capacity,
the additional capacity will be charged at a higher rate. Update agreed capacity to
peak capacity
Check tariff. Check that your organisation is on the right tariff (electricity, gas) by
checking online information from your supplier (or telephoning); compare rates with
other buildings or suppliers to check costs are reasonable – base on all in rate
How do you know it is right?
Check Climate change levy (CCL). Excluded or exempt from CCL?
Exclusions: electricity & gas for domestic use or charities for non-business purposes
Exemptions: supplies to good quality CHP schemes
Check reactive power. Some distribution companies base their charge for reactive
power on an assumed Power Factor. Find out if you can exchange your meter for one
that measures reactive power if this is the case.
How is the bill calculated?
1. Billed units are calculated in kWh for the period of use for onpeak and off-peak times (day, night, weekend)
2. Multiply billed units by respective prices (i.e. £/kWh for period
of use). Time periods and prices are stated in contract
3. Total consumption is sum of all billed units in the period of use
4. Multiply agreed peak capacity by agreed capacity rate (£/kVA)
5. Multiply excess peak capacity multiplied excess capacity rate
(£/kVA)
6. Multiply reactive billed units by price (£/kvar)
7. Multiply billed number of units (kWh) by the CCL rate (£/kWh)
8. Add VAT at 20% unless exemptions apply
9. Sum to find total
How is the bill calculated?
Energy used last month (kWh)
Charge (£ per kWh)
Energy charge (£)
Capacity charge (kVA)
Charge (£ for 31 days)
Energy used last month (kWh)
CCL
Standing charge (£/month)
Reactive charge
x
x
x
Night
9590.10
0.105
1006.96
Day
26027.80
x
0.135
3513.75
Agreed
100.00
2.150
215.00
Excess
34.00
x
2.150
73.10
48704.00
0.005
236.21
224.47
0.32
Example
Weekend
13086.10
x
0.155
2028.35
How is the bill calculated?
Example
Night charge
1006.96
Day charge
3513.75
Weekend charge
2028.35
Agreed capacity charge
215.00
Excess capacity charge
73.10
CCL
236.21
Standing charge
224.47
Reactive charge
+
Subtotal
VAT at 20%
Total
0.320
7298.16
+
1459.63
8757.80
Sample analysis of bill data – change of supplier and rates
Electricity
Bill Dates
From
Use (kWh)
To
Total
Cost
p/kWh
Total
MD
(kVA)
PF
Supply Capacity
Tonnes of capacit charge
CO2
y kVA £/kVA
Day
30-Jun
31-Jul
253,140
9.061
£22,936.76
135.9
Night
30-Jun
31-Jul
65,803
6.832
£4,495.53
35.3
Day
31-Jul
31-Aug
258,699
9.061
£23,440.46
138.9
Night
31-Jul
31-Aug
78,562
6.832
£5,367.20
42.2
Day
31-Aug
30-Sep
232,143
9.061
£21,034.25
124.7
Night
31-Aug
30-Sep
67,547
6.832
£ 4,614.68
36.3
Day
30-Sep
31-Oct
229,152
8.573
£19,644.28
Night
30-Sep
31-Oct
73,354
8.573
£6,288.35
Day
31-Oct
30-Nov
229,813
8.573
£19,700.95
Night
31-Oct
30-Nov
64,002
8.573
£ 5,486.64
Day
30-Nov
31-Dec
218,985
8.573
£18,772.71
Night
30-Nov
31-Dec
67,366
8.573
£5,775.02
Total
3,652,226
£ 0.090
£655,921
Annual
6,275,656
£ 563,092
0.98
728
123.1
850
696
123.4
850
728
852
117.6
850
£27.07
£42.75
£1.37
£42.75
0
£
£59.96
0
£
£0.05
£12,932
0
£61.54
£0.05
1,985
-
£
£0.05
£1,194
0
£27.07
£1,155
850
-
£
£1,194
850
0
£27.07
£1,165
850
p/kWh
total
CCL
£
£1.37
36.2
24
£42.75
£1,165
34.4
0.98
£1.37
£ 1,165
39.4
0.98
Settlement Standing
charges
charges
£61.54
0
£
-
-
-
Total
kWh
£
28,667
318,943
Total
kWh
£
30,042
337,261
Total
kWh
£
26,883
299,690
Total
kWh
£
27,188
302,506
Total
kWh
£
26,403
293,815
Total
kWh
£
25,803
£
327,701
£
563,092
286,351
8.99
8.91
8.97
8.99
8.99
9.01
Alternative tariffs
•
•
•
•
•
Single rate
Block rate
Off-peak
Time of use (part of DUoS structure)
Feed-in tariff
Reduce your costs by selecting appropriate tariff
• Under some tariffs, Use of System (UoS) rates
change depending on time of day
• UoS rates are generally lower between midnight
and 7am
Red
Rate
Monday to Friday
High
16:30 - 19:30
Weekends
Amber Medium 08:00 - 16:30 and
19:30 - 22:30
16:00 - 20:00
Green
00:00 - 16:00
and 20:00 24:00
Low
00:00 - 08:00 and
22:30 to 24:00
Electricity bills & the Future
Electricity Market Reform (EMR)
• Electricity price increases are expected as a result of the EMR
• Carbon Price Floor. Electricity generators are expected to have to pay more
to meet the carbon price floor for emissions (perhaps paying £16/tCO2 ),
and they are expected to pass this price on to consumers
• Capacity Market. Electricity generators are expected to participate in a
Capacity Market where they will receive a guaranteed price for electricity in
exchange for guaranteeing a certain electricity capacity to the electricity
grid. This may lead to higher costs for electricity customers
“How can I use my bills to target &
monitor change?”
How can I use my bills to target and
monitor change?
Understand your energy use – end-use breakdown
Identify where targeted improvements can be made across the estate
• Benchmarking. Compare buildings using a league table to identify poorly
performing buildings
• Activity-based targeting. Calculate expected consumption with reference to things
you can measure that make consumption vary. Sub-meter to measure energy
consumption by end use
Monitor and measure impacts of changes in the future
• Meter readings. Quantify impacts of changes
• Share success. Share monitoring results of energy savings
Understand your energy use
Energy consumption
end-use breakdown
Image source: Carbon Trust. Schools, Learning to improve energy efficiency. CTV019
Benchmarking
Compare similar buildings
Image source: Better Metering Toolkit. Better Building Partnership. London 2011
Estate league table
Use benchmarking within the estate identify poorly performing buildings
that can be improved, and also to identify buildings that are performing well
that can be emulated
Targets can be set and over – consumption league tables to prioritise
investigations
Building
ID
Name
Floor
area
(m2)
Annual
heat
(kWh/m2)
Peak
Heat
(kW)
Annual
electricity
(kWh/m2)
Annual Emissions
(kgCO2/m2)
Water
consumption
(m3/person)
Opportunities for energy and cost
saving
• Switching off. Turn off energy consuming equipment when not in use.
Can be switched off by building users, or timer switches, or building
control systems
• Maintenance. Routine maintenance procedures can improve energy
efficiency
• Identify simple changes to tariffs. Alternative tariffs
• Power factor correction. Reduce reactive power used by equipment
• Demand-side response. Run equipment at night for lower off-peak
electricity rate
• Refurbishment. Including energy saving measures in major
refurbishments can be cost effective
Targeted improvements
Activity-based targeting. Calculate expected consumption with reference to
things you can measure that make consumption vary
Energy use
Possible driving factor
Space heating
Outside temperature
Air conditioning
Outside temperature, possibly also humidification levels
Steam raising
Quantity of steam produced
Production process
Production quantity
Exterior lighting
Hours of darkness
Drying
Quantity of water removed from product
Table source: Monitoring and Targeting, Techniques to help organisations control and manage
their energy use. Carbon Trust
Walk around checklist
Identify energy saving opportunities in a
walk-around
Image source: Energy audit checklist. Resource Efficient Scotland
http://www.resourceefficientscotland.com/resource/energy-audit-checklist
Monitor and measure
Automatic meter readings
Image source: Better Metering Toolkit. Better Building Partnership. London 2011
Monitor &
measure
24-hour profile
Image source: Monitoring and Targeting, Techniques to help organisations control and
manage their energy use. Carbon Trust
Monitor &
measure
Week profile
• Sub-metering to
show end-use
Image source: Better Metering Toolkit. Better Building Partnership. London 2011
Monitor &
measure
False-contour plot
• Each horizontal column is
one day (x-axis)
• Each vertical column is one
hour (y-axis)
• Cells colour-coded for
power level
Image source: Monitoring and Targeting, Techniques to help organisations control and
manage their energy use. Carbon Trust
Share
success
Energy
consumption
• Before and
after energy
saving
measures
Image source: CMU energy savings over a year
Share
success
Energy dashboard
• Energy consumption by end
use in buildings (e.g. plug
loads)
Image source: CMU energy savings over a year
For more information on our tools, guides and available support,
please visit our website:
www.resourceefficientscotland.com
Alternatively, contact us by email:
[email protected]
Alternative tariffs
Single rate
• Standard rates
Alternative tariffs
Block rate
Charges are based on a series of
different kilowatt-hour rates
applying to successive kilowatthour blocks of a given size during
the period
Alternative tariffs
Off-peak (E7, Economy 7)
• Electricity is charged at two
rates
• The day rate is higher
• The night rate is less expensive
• Often installed in properties
that use electricity for heating
and hot water
Alternative tariffs
Time of Use (ToU)
Rate Monday to Friday
• Part of DUoS structure
• Different times of day
incur different rates
Red
High
16:30 - 19:30
• Red – Peak
• Amber – Mid-peak
• Green – Off peak Amber Medium 08:00 - 16:30 and
19:30 - 22:30
Green
DUoS = Distributed Use of System
Low
Weekends
16:00 - 20:00
00:00 - 08:00 and 00:00 - 16:00 and
22:30 to 24:00
20:00 - 24:00
Alternative tariffs
Feed-in tariff
• Payment made to organisation
generating own electricity using
renewables (e.g. PV)
Control
Consumption driven by
weather
• Relationship between fuel
consumption and heating
degree days
Source: Monitoring and Targeting, Techniques to help organisations control and manage their
energy use. Carbon Trust
Power factor correction
Power factor. Ratio of useful power to total
power drawn from AC supply
Inductive devices use reactive power.
Motors, welding sets, induction heaters,
fluorescent lights.
Image source: Power factor correction, An introduction to
technology and techniques. Carbon Trust
Power Factor Correction (PFC)
• Uses capacitors
• Reduces power consumption
• Leads to increased supply capacity
• Increases life expectance of electrical
equipment
Image source: http://electrical-engineering-portal.com/beer-mugand-power-factor
Voltage
Voltage. Average supply voltage in UK is 242V
• May not match building equipment needs, causing electricity losses
Transformer tap settings
• Check building equipment voltage requirements
• Adjust voltage to match building requirements to reduce losses
• Use settings on your existing transformer for voltage regulation
• Distribution transformers have off-circuit selectors (“tap changers”) to allow
for manual ratio adjustment of site Low Voltage (LV)
Demand-side response
• Load shifting. Use off-peak electricity rates where possible by operating
some equipment at night – e.g. charge electric vehicles at night
• Thermal energy storage
• Cooling. Building chillers operated at night to generate cold brine, or
ice, which is stored in a central tank. During on-peak hours, chilled
water circulated from storage system to supply building air conditioning
system or supplement chilled water from a smaller chiller
• Heating. Electric storage heaters (where gas heating is not available)
• Distributed generation. Generate low-carbon electricity at the site – e.g. PV
panels