Title: Electric Service Options for Kirkwood
1Electric Service Options for Kirkwood
- Review Power Engineers Cost Estimate
- Update Assessment of Power Supply Options
KMPUD, 18 September 2009
2BackgroundMuch work has been done, much is
underway.
- Diesel-fired internal combustion (IC)
generation was installed in the Kirkwood valley
during 1972. - Sierra Pacific Power Company 1997 evaluated
several transmission line routes. - Henwood 1999 assessed various power supply
options, including interconnection. - BCo 2006 evaluated various power supply, also
including interconnection. - Discussions with PGE regarding interconnection
began during 2007 and continue, but slowly. - KMPUD efforts thru mid 2009
- Acquisition of MU is substantially negotiated.
Closing planned during 2010. - Resource Concepts, Inc. has field biology
assessments of a transmission line route
underway. - Power Engineers completed a design and capital
cost estimate. - PGE is considering interconnection, overbuild,
and route options. - USFS and CalTrans are informed and involved in
environmental and routing issues. - REAC is working as a vehicle for community
involvement.
31.0 Review Power Engineers estimate.
- Power Engineers (PE and PEs report is dated 1
September 2009) prepared a design and cost
estimate for a transmission line from Salt Spring
to Kirkwood. - 115/230 to 35 kV Salt Spring Substation, 27.3
mile transmission line, 35 to 12 kV Kirkwood
substation. - 13.5 miles direct buried, 5.5 miles under Highway
88, 5.2 miles under other roads, and 3.1 miles
overhead. - 35 kV, 10 MW, 500 kcmil aluminum XLPE cable in
single conduit. 2.5 to 3.0 loss. - Substations account for approximately 25 of
total cost. - 24.1 million (MM) including 15 contingency.
- In sum
- BCo reviewed PEs work item by item and from a
total cost perspective. - Subject to several issues discussed below, both
PEs design and cost estimate appear reasonable. - PEs estimate does exclude some of the total
costs that consumers will ultimately pay. - Caution, cost estimates change with design, local
(labor rates, contractor mark ups, ), and global
(cable, concrete, ) market conditions.
41.1 Item by item, PEs estimate appears
reasonable.
- BCo reviewed PEs design and costs, and then
BCo discussed several items with PE. - Design assumes a 5 MW peak transfer. 5 growth
for 20 years means that peak could approach 10
MW. - BCo understands from PE that they will evaluate
a 10 MW case on request. - Extra voltage regulators and possibly larger
cable could be necessary. Peak losses could be
higher. - Geotechnical assumptions concerning no-rock and
rock amounts and costs appear reasonable and are
supported by data from Henkels McCoy. - Traffic control and safety costs appear ample at
150 days. - Overhead line is a replacement of and overbuild
of an existing 12 kV line. - PGE charges are a ball park estimate and may
be low. PEs budget of 345 K could double to
700 K. - BCos findings are that
- Concept-level estimate of incremental 5 MW cost
could be approximately 1 MM. - PEs cost assumptions reflect current economic
conditions. A rough industry rule of thumb is
that costs are now down approximately 15 from
summer 2008.
51.2 Compared to others, PEs estimate appears
reasonable.
- Total cost compared to other transmission line
projects - Mix of overbuild, overhead, underground, and
terrain features make comparisons difficult. - 15.6 MM plus 15 contingency is approximately
660/mile. - Subject to the qualification above, PEs total
cost per mile is within the range of costs
experienced by SPP, Kauai Coop, and Puget Sound
Energy. - Previous estimates have been concept level
without the benefit of detailed route analysis
and engineering. - BCo 6/06 Conceptual design, 35.4 MM total
project including 23 contingency. Note that a
15 saving off this estimate is 30.1 MM, very
close to the comparable PE figure. - PGE 2/08 Conceptual design, 53.0 MM including
unspecified contingency and 100 new back up. - BCo/PGE 5/08 Trim of PGE estimate by BCo,
44 MM including 21 contingency. - KMPUD 3/16/09 Total costs of 35, 45, and 55
MM used in sensitivity analysis. No break down.
61.3 PEs estimate does exclude some costs.
72.0 Update Assessment of Power Supply Options
- KMPUD requested a comparison of three broad power
supply options. - Modern ICs
- Micro Turbines
- Interconnection to PGE, including PEs design
and cost results. - In addition, BCo added a concept-level analysis
of renewable supplements to key firm supplies. - In sum, this update confirms previous results.
- Previous evaluations include Henwood 1999 and
BCo 2006. - Micro Turbines are more costly than Modern ICs.
- Modern ICs are more costly than Interconnection
assuming either of moderate load growth or
increases in diesel fuel costs. Load growth and
diesel costs are materially uncertain, and
Interconnection provides other potential benefits.
82.1 Background on power supply and cost
- For various reasons, Mountain Utilities rates
have been high and volatile. Recent retail rates
have been between approximately 0.35/kWh and
over 0.60/kWh. - Electric power requirements
- Installed Capacity, gross 6.47 MW 5.34 (MU
2009) 1.13 (KMPUD 2009). - Peak Load, gross 3.55 MW 3.30 (BCo 2006,
update on request) 0.25 (KMPUD 2009). - Annual Energy, gross 8,656 MWh 7,957 (MU/CPUC
avg 05-08) 710 (KMPUD avg 05-08) - Future load depends on uncertain weather, growth,
conservation, resort operations, and costs. - Energy costs have been volatile
- Diesel 1.41/gal to 3.57/gal during last year
and current cost is approx 2.25/gal (KMPUD
2009). - Propane 1.50/gal to 2.25/gal during last year
and current cost is approx 1.60/gal (KMPUD
2009). - PGE system power cost 0.06/kWh to 0.08/kWh (PE
2009 0.060/kWh, PGE 2008 0.077/kWh). - KMPUD expects to finance capital costs by issuing
tax-exempt, long-term bonds.
92.2.1 Install modern internal combustion
generation.
- Install a set of modern diesel-fired IC engines,
add capacity to match growth as needed. - Performance, costs and schedule
- 0.075 gal/kWh in service (Caterpillar 830, BCo
2006). - Capital cost approx 725/kW (CHP Assn 2009, CEC
2007, BCo 2006). - Non-fuel operating cost approx 25/kWyr plus
15/MWh (CHP Assn 2009, CEC 2007, BCo 2006). - Diesel costs are volatile.
- Schedule would involve few permitting,
procurement and construction risks. - Environmental considerations
- Particulate, CO2, CO, NOx, and SOx emissions.
- Noise during normal operations.
- No access to out-of-valley renewable energy.
- Diesel-based energy for recharge of plug-in
electric vehicles.
102.2.2 Install micro turbine generation.
- Install a set of micro turbines, add capacity to
match growth as needed. - Performance, costs and schedule
- 11,800 Btu/kWh LHV (Capstone C65 spec). HHV and
7,800 de-rate to approx 18,000 Btu/kWh. - Capital cost approx 1,500/kW (CHP Assn 2009, CEC
2007, BCo 2006). - Non-fuel operating cost approx 30/kWyr plus
10/MWh (CHP Assn 2009, CEC 2007, BCo 2006). - Both diesel and propane costs are volatile.
- Schedule would involve few permitting,
procurement and construction risks. - Environmental considerations
- CO2, CO, NOx, and SOx emissions.
- Noise during normal operations.
- No access to out-of-valley renewable energy.
- In-valley, fossil-based energy for recharge of
plug-in electric vehicles.
112.2.3 Connect to PGE at Salt Spring.
- Salt Springs PGE substation, 27 mile 34 kV
mostly underground line, Kirkwood substation. - Performance, costs and schedule
- Capital cost approx 30.1 MM (PE 2009 plus
concept-level other costs). - Transmission line operating cost approx 260 K/yr
(BCo 2006). - PGE system power cost is less volatile than
diesel and propane costs. - Schedule would involve material permitting but
few procurement and construction risks. - In-valley back up from several potential sources
including KMPUDs own capacity. - Environmental considerations
- No in-valley emissions except, if any, during
occasional back-up testing and service. - No noise except for occasional back-up testing
and service. - Access to out-of-valley wind, hydro, solar, and
biomass renewable energy. - Grid-based energy for recharge of plug-in
electric vehicles.
122.2.4 Develop in-valley renewable generation.
- Supplement gird power or in-valley, fossil-based
generation with renewable energy. - Renewable sources have been assessed by Henwood,
BCo, and others. REAC asserts that renewable
potential is 5 to 20 of Kirkwoods 8,000 MWh
energy needs (REAC 9/09, pages 2, 3 w/o
supporting analysis). - Wind costs over 2,000/kW, typical capacity
factor is lt 30. KMR-Synergy wind project 20
turbines, 6 MWh, cost and schedule unknown. No
wind studies completed. - Solar photo voltaic costs over 6,000/kW, typical
capacity factor is lt 15. No insolation studies
completed. - Hydroelectric, typical cost over 3,000/kW,
typical capacity factor is lt 50. Caples Lake
potential is unknown, no biological or
hydrological studies completed. - Schedules would involve material permitting but
few procurement and construction risks. - Non-firm energy requires firm back up, it
displaces back up energy costs but not capital. - Environmental considerations
- No incremental in-valley emissions.
- Conflict Hydro (land use, aquatic), wind (land
use, noise, visual, power quality) and solar
(land use, visual, power quality). - Very awkward for recharge of plug-in electric
vehicles.
132.3 Micro Turbines are more costly than Modern
ICs.
- BCo 2006 found micro turbines uneconomic due
primarily to their high capital cost and altitude
de-rate (BCo 2006, pg 22). - Simple comparison at right shows calculation of
the present value of total power costs and a 2010
c/kWh cost of gross generation. - This update shows that micro turbines remain
uneconomic. In particular, they have higher
capital and fuel costs than modern ICs.
142.4 Modern ICs are more costly than
Interconnection assuming either moderate load
growth or higher diesel costs.
- Interconnection Appears to be least expensive
alternative in the long run (Henwood 1999, pg
3). - While Option 3 (interconnection) depends on
substantial load growth and involves the high
capital costs and challenges associated with
connecting to either PGE or Sierra Pacific
Power, if a new transmission line can be built,
it appears to result in the lowest rates over the
long term (BCo 2006, pg 3). - Simple comparison at right is consistent with
previous results. - More detailed analysis on following pages.
152.4.1 More detailed Excel model confirms simple
results.
- BCo prepared an Excel cost model, provided to
KMPUD, for Modern IC and Interconnection power. - 30 year time horizon. Performance and cost
assumptions enumerated on previous pages. - Structured to evaluate uncertainty surrounding
load growth, energy costs, and cost of capital. - Load Growth
- Henwood 1999 forecasted increase from actual
8,400 MWh in 1999 to over 24,000 MWh at build out
(pg 22). - BCo 2006 Likins Forecast of doubling from
8,870 MWh to over 17,700 MWh at build out (pgs
8, 31, 33). - 1 (to 10,562 MWh) and 5 (to 22,968 MWh) for 20
years are evaluated in this update. - Energy Costs
- BCo 2006 considered a broad range of future
diesel costs. - Current and recent high /gal diesel costs are
evaluated in this update. Both the PE and PGE
assumptions concerning system power costs are
also considered. - KMPUD Cost of Capital
- Muni bond rates are unusually low as of 9/09,
approximately 3.5 (BA Merrill). - 5, 6, and 7 are evaluated and reflect both
higher benchmark rates and a KMPUD spread.
162.4.2 Pro forma model results show lower costs.
- Summary of Excel model results at right. Cost
shown is the 2010 c/kWh cost of power at the
power house (Modern IC) or Kirkwood Substation
(Regional Grid). - Retail rates will be higher and reflect
power-source independent distribution losses and
overhead costs. - IC rate will increase with inflation and diesel
costs, Interconnection rate will increase with
inflation.
172.4.3 There is more to consider.
- Modern IC
- Higher diesel costs of 1.00/gal mean rates are
higher by 8 to 9 c/kWh. - BCo has employed middle-of-range cost estimates.
If and once detailed design is completed, costs
are more likely to be higher than lower. - GHG compliance requirements, if any, will
increase costs. - Financial model results already include the
benefit of building out only if and as demand
increases. - Interconnection
- A capital cost overrun of 5 MM means rates are
higher by 2 to 3 c/kWh. - Sales to communities along the route will lower
the cost to Kirkwood. - Risk of high long-term inflation favors
interconnection. Diesel and incremental capacity
costs will soar. - Transfer of the line and retail service to PGE
may be a long-term option. - Lowest emissions, lowest noise, highest access to
large-scale renewable energy, and best potential
power supply for plug-in electric vehicles.