This document analyzes power line efficiency for Shenandoah Valley Electric Cooperative (SVEC). It finds that nearly 8 GWh were lost in 2010 from transmission and distribution lines in Virginia alone. The purpose is to determine power loss across SVEC's system and identify technologies to improve efficiency and reduce loss. The analysis finds that upgrading to more efficient conductors like Linnet ACSR and NEMA Premium transformers would significantly reduce losses and save SVEC and customers money, with payback periods of less than two years for some upgrades. A multi-stage strategy is proposed that focuses first on replacing outdated equipment and later integrating smart grid technologies system-wide.

1. POWER LINE EFFICIENCY ANALYSIS
Presented by Wade Reynolds
James Madison University – ISAT 493 Senior Capstone
Sponsored by Shenandoah Valley Electric Cooperative

2. INTRODUCTION
 In 2010, nearly 8 GWh were lost from
transmission and distribution in Virginia alone
 Equivalent to enough energy to power 1.3
million homes

3. ELECTRICITY SUPPLY CHAIN
eex.gov.au

4. IMPORTANT EQUATIONS
 Power = Current x Voltage
 Power Loss = Current2 x Resistance

5. PURPOSE
 Determine power loss across system and
find technological solutions that can be
implemented to improve efficiency and
reduce loss

6. BACKGROUND
 The Rural Electrification Act of 1936 provided
federal assistance for rural electrification
 RECs are private, non-profit utilities owned
by the customers they serve
 Two types of RECs: Generation and
Distribution
 SVEC is a Distribution cooperative that
serves nearly 90,000 customers across
western Virginia

7. RESEARCH QUESTIONS
 What are the sources of loss in the system?
 Are technologies currently available to
replace SVEC’s current technology and
improve efficiency?
 Are these technologies cost-effective?
 What will improved efficiency mean to SVEC
and its customers?

8. METHODOLOGY
 SCADA software was used to find the current
and voltage at five strategic points across the
system
 Focus is on losses due to inefficiency in
conductors and transformers
 All formulas and methods used are
consistent with industry standards and
relative to the desired level of accuracy we
wish to achieve

9. CLOVER HILL SYSTEM
 Clover Hill Line extends 10.6 miles from the
Dayton Substation
 Conductor type = 1/0 Raven ACSR
 A single substation transformer and 1,415
distribution transformers located along the
line
 Substation transformer rated at 100 MVA
capacity
 Each distribution transformer rated at ~10 kVA
capacity

10. CONDUCTOR EFFICIENCY
 Calculating Impedance
 Resistance
 Reactance
 Calculating Loss
 Total Impedance per unit length
 Power Loss = Current2 x Resistance
 Calculating Efficiency
 Power Loss/Power Supplied

11. FORMULAS
 Conductor Impedance:
 Ra = Resistance
 Xa = Reactance
 Xd = Construction Reactance Factor
 Construction Reactance Factor:
 Xf = Inductive Reactance Spacing Factor
 ƒ = Frequency
 GMD = Geometric Mean Distance

12. CONDUCTOR ANALYSIS
Conductor Type Raven ACSR Quail ACSR Linnet ACSR Azusa AAAC
Size 1/O 2/O 336.4 123.3
Resistance @25°C 0.1633 0.1301 0.0517 0.166
Reactance @25°C 0.104 0.1017 0.0854 0.102
Total Impedance (Ω) 12.7 11.2 7.8 12.8
Power Loss (kW) 115.5 101.7 70.8 115.9
Efficiency % 96.59 96.99 97.91 96.57
Inefficiency Cost Per Year $ 87,736.46 $ 77,265.83 $ 53,804.58 $ 88,052.18
Conductor Cost $ 20,737.26 $ 23,685.10 $ 67,833.78 $ 20,333.17

13. INEFFICIENCY COST VS. CONDUCTOR COST
$0
$10,000
$20,000
$30,000
$40,000
$50,000
$60,000
$70,000
$80,000
$90,000
Raven ACSR Quail ACSR Linnet ACSR Azusa AAAC
Inefficiency Cost Conductor Cost

14. TRANSFORMER EFFICIENCY
 Transformers incur two types of losses
 No-Load
 Load

15. TRANSFORMER ANALYSIS
Type Standard NEMA Premium
Capacity (kVA) 10 15
Efficiency 96% 98%
Average Yearly Load (kWh) 6,000 6,000
Loss Incurred (kWh) 234 96
# of Transformers 1,415 1,415
Total Loss (kWh) 331,110 135,840
Inefficiency Cost Per Year $ 28,707 $ 11,777

16. RESULTS AND FINDINGS
 Linnet conductor will have a payback period
of less than 2 years
 NEMA Premium transformers will save nearly
$17,000 annually in power losses

17. TECHNOLOGY SOLUTIONS
 High-Efficiency Conductors
 ACCC cut line loss by 30-40% under equal load
 NEMA Premium Efficient Transformers
 Meet or exceed DOEs efficiency requirements
 Smart-Grid Devices
 Two-way communication provides real-time
information to ensure system is operating at
optimal levels

18. BENEFITS
 Lower customer electricity bills
 Improved reliability
 Greater response to power outages
 Lower maintenance costs
 Reduced need for generating capacity
 Lower greenhouse gas emissions

19. BARRIERS
 Inventory Replacement Costs
 Construction Costs
 Customer Resistance
 Cash on-hand

20. STRATEGY
 Short-term (2 to 10 years)
 Replace blown-out transformers with high-
efficiency transformers
 Mid-range (11 to 20 years)
 Replace old conductors with either high-
efficiency conductors or larger ACSR conductors
 Long-range (beyond 20 years)
 Install smart-grid devices across distribution
system

21. QUESTIONS?