Proposed Low Power Factor (LPF) charge A price signal for energy efficient consumption. Consultation presentation July 2010

Transcription

1 A price signal for energy efficient consumption Consultation presentation July 2010

2 Power Factor (PF) An indicator of efficient electricity consumption The proposed Low Power Factor (LPF) charge intended to strengthen the price signal for the efficient use of energy through an increase in the customers power factor (PF) levels. The targeted supplies are those on the Large Power User tariffs (LPU) i.e. Megaflex, Ruraflex, Miniflex, Nightsave and Transflex tariffs. The proposed charge would replace the existing reactive energy charge for Megaflex, Miniflex and Ruraflex. Customers can avoid the proposed monthly charge if they achieve consumption power factors of >0.96PF. Power Factor (PF) is the ratio of the kilowatt (kw) and apparent power / kilovolt-ampere (kva) i.e. PF = kw/kva. The highest power factor is 100% or 1PF i.e. kw = kva. In the electrical current flow when the voltage and current are in-phase and the ratio of kva and kw is closer to 1PF in this situation there is optimal demand for the same level of kwh. The implementation of this charge is planned for 1 July 2011 and is subject to a NERSA public consultation and decision. It is planned that from early 2010, until the implementation date, customers bills will reflect the average power factor and potential Low Power Factor (LPF) charge due. 2

3 Power Factor (PF) An indicator of efficient electricity consumption The motivation to propose the Low Power Factor (LPF) is create a power factor price signal to encourage higher power factor levels of Eskom supply points at all times throughout the year. This is so as to optimise demand (kva) i.e. demand reduction at the same level of kilowatt-hours. The proposed LPF charge is intended to: Complement the existing demand price signals in network and energy demand charges with a power factor price signal. Support increased mitigation of negative impacts from low power factors. Access customers with electricity cost-savings and operational benefits from higher power factors. 3

4 Power Factor (PF) An indicator of efficient electricity consumption Analyses of the average power factors amongst the large power user tariffs demonstrate an opportunity for customers to manage their PF levels upwards: Notably, there is a conservatively estimated 481MW savings due to average power factors below 0.96PF. There is 1% potential additional annual electricity sales based on 481MW savings. There is an increase in higher power factors during winter / high-demand period. 67% of the total points of supply are on the Rural tariffs and 29% have <0.85PF. Although there is a low contribution total electricity sales by supplies with <0.85PF, they contribute to the majority of the excess reactive energy. 4

5 Large power user (LPU) tariffs power factors Megaflex, Miniflex, Ruraflex, Nightsave and Transflex tariffs Most potential savings from Megaflex Highest kvarh impact from <0.85PF supplies 5

6 Large power user (LPU) tariffs power factors Megaflex, Miniflex, Ruraflex, Nightsave and Transflex tariffs High-demand season (Winter) 6

7 Large power user (LPU) tariffs power factors Megaflex, Miniflex, Ruraflex, Nightsave and Transflex tariffs % of total points of supply by average power factor Highest number of supplies with <0.85PF are rural 7

8 Large power user (LPU) tariffs power factors Megaflex, Miniflex, Ruraflex, Nightsave and Transflex tariffs Most of the reactive energy from >2MVA customers with >0.85PF and <0.96PF 8

9 Large power user (LPU) tariffs power factors Megaflex, Miniflex, Ruraflex, Nightsave and Transflex tariffs Municipalities: % of total points of supply by average power factor Most of the supplies with low PF are on NS rural 9

10 Large power user (LPU) tariffs power factors Megaflex, Miniflex, Ruraflex, Nightsave and Transflex tariffs Municipalities: % of total points of supply by average power factor Most of the supplies with low PF are on NS rural 10

11 Large power user (LPU) tariffs power factors Megaflex, Miniflex, Ruraflex, Nightsave and Transflex tariffs Municipalities: % reactive energy (kvarh) per customer size category 91% of total reactive energy by >2MVA supplies 11

12 Power Factor (PF) The proposed charge The targeted supplies are those on the Large Power User tariffs (LPU) i.e. Megaflex, Ruraflex, Miniflex, Nightsave and Transflex tariffs. The proposed charge would replace the existing reactive energy charge for Megaflex, Miniflex and Ruraflex. Customers can avoid the proposed monthly charge if they consume at a power factor of >0.96PF: 30-minute integrated measure of PF (coincident kva and KW used) to calculate excess kvarh Billing month total kwh and kvarh used to determine the average PF that indicates the rate to be applied. Customers with a PF of >0.96PF throughout the month do not get billed for the LPF charge. 12

13 Structure of the LPF charge Applicable to all LPU tariffs and is a per pod c/kvarh charge. Charged throughout the year and at all time-of-use periods (peak, standard and off-peak). Differentiation of the rates per customer size (notified maximum demand). A different rate level depending on the average power factor in a given month. Higher charge level for smaller supplies to create a stronger signal where incidence of <0.85PF is highest. 13

14 The LPF dynamic The dynamic of the LPF charge is one where: The lower the average power factor for a given month per point of supply, the higher the LPF rate. This is to cater for the higher contribution of lower power factors to the total excess reactive energy. The larger the size of supply, the lower rate. This is to cater for the incremental costs from the charge so that the overall increase in electricity costs is equitable across supply sizes. Highest due to lowest PF Lowest due to Highest PF Customer A is a 2MVA supply Cutomer B is a <500V supply Differences in impact due to changes in monthly average power factors. 14

15 Customers electricity cost increase from the LPF charge Most customers will see a <=5% increase 15

16 Customers electricity cost increase from the LPF charge High Most increases customers on will the see rural a <=5% tariffs increase 16

17 Customers electricity cost increase from the LPF charge Most The customers <=5% increase will see is a <5% across all customer increasesizes 17

18 Investment in compensation versus paying the LPF charge Most compensation per supply is not more than 1 year 18

19 Power factors in the standard conditions of supply (1) EXCERPT APPLICABLE TO STANDARD CONDITIONS OF SUPPLY FOR LARGE SUPPLIES AND DISTRIBUTORS (REV 21 Nov. 07) 4. LOADING REQUIREMENTS The power factor at each point of supply shall under all loading conditions not be leading, unless otherwise agreed to by ESKOM. The power factor of the load at each point of supply shall not be less than 0,9 (naught comma nine) lagging. Should the power factor be less than 0,9(naught comma nine) the CUSTOMER shall be required to install at his/its own expense suitable apparatus to ensure that this requirement is complied with. For purposes hereof 'power factor' is defined as the kwh divided by the kvah (where the kvah equals the square root of the sum of the kwh squared and the kvarh squared) measured over the same demand integrating period

20 Power factors in the standard conditions of supply (2) STANDARD CONDITIONS OF SUPPLY S FOR SMALL SUPPLIES WITH CONVENTIONAL METERING (Rev. 18 Aug. 08) 17 POWER FACTOR, PHASE BALANCE AND INTERFERENCE WITH OTHER SUPPLIES 17.1 The power factor of the supply consumed by the CUSTOMER for small power purposes shall at all times be to the approval of ESKOM Where the CUSTOMER is provided with a three-phase supply, it shall balance the requirements of its load between the phases to the reasonable approval of ESKOM The CUSTOMER shall so use the supply as not to interfere with an efficient and economical supply to other customers, and shall at all times ensure that any voltage distortions caused by the CUSTOMER's load shall not exceed the values specified by ESKOM from time to time. When supplied from an 11 or 22kV network, the CUSTOMER shall ensure before connecting to its electrical installation any motor that may be started direct-on-line or with a star-delta starter, that such motor does not exceed such maximum permissible size as laid down by ESKOM in respect of the network in question. 20