HomeMy WebLinkAboutMountain Village to Saint Mary's Intertie Project Final Closeout Summary Report - Jul 2020 - REF Grant 7091224Alaska Energy Authority - Award 7091224
to Mountain Village Wind Intertie Construction
Final Closeout Summary Report July, 2020
Submitted by Alaska Village Electric Cooperative, Inc.
Page 1 of 4
This Closeout Summary Report is filed with the State of Alaska grantor agency Alaska Energy Authority
; award number 7091224) by grantee AVEC
was the grantee of the AEA award. This project is being closed because the project is complete and the
funding has expired. This report represents the project status as of June 30, 2020. AVEC is the sole project
participant, is the owner and operator of the new facilities provided by this grant, and is responsible for
future maintenance thereof. There are no unexpended state or federal funds remaining on any grant award.
Background AVEC is a member-owned, non-profit electric utility serving members in 58 communities
throughout
are generally accessible year-round only by aircraft and seasonally by ship. Consumers in rural Alaska pay
some of the highest electric power rates, gasoline prices, and home heating costs in the U.S. As is true in
most of rural Alaska, AVEC procures diesel fuel in the summer and stores it for use throughout the year to
generate most of its power; wind turbines supply the rest.
St. Mary's, Alaska (pop. 683) is an AVEC member community located on the north bank of the Andreafsky
River, 5 miles from its confluence with the Yukon River. It lies 450 air miles WNW of Anchorage, 100 air
miles NW of Bethel, and 180 air miles SSE of Nome (Bethel and Nome are the nearest communities with
populations exceeding 1,000). The climate is continental with a significant maritime influence.
Temperatures range between -44 and 83 °F. Annual precipitation averages 16 inches, with 60 inches of
snowfall. The Yukon and Andreafsky are ice-free from June through October, permitting boat traffic
including barge shipment of bulky cargo during that period.
commercial fishing and subsistence lifestyle 7 under Alaska
state law as a first class city.
Activities - The scope for this project involved the final design and construction of an 18-mile-long, 12.47
kV electric power transmission line between the nearby community of Mountain Village
(pop. 860), another AVEC member community The route
of the intertie closely parallels a summer road that connects the two communities; this road is owned and
maintained by the State of Alaska, Department of Transportation and Public Facilities (ADOT). The intertie
was built within the -of-way which is relatively accessible, generally on dry ground,
and encounters no river crossings; consequently this routing resulted in lower-cost construction, and also
promises lower long-term repairs and maintenance costs.
Year ended 12/31/2019
Diesel Wind Total Peak Average
St. Mary's (incl. Pitka's Point)1,891,432 1,342,374 3,233,806 702 370
Mountain Village 2,644,906 2,644,906 522 302
Total 4,536,338 1,342,374 5,878,712
Generation (kWh) by source Load (kW)
Alaska Energy Authority - Award 7091224
to Mountain Village Wind Intertie Construction
Final Closeout Summary Report July, 2020
Submitted by Alaska Village Electric Cooperative, Inc.
Page 2 of 4
AVEC has long maintained prioritized rankings of its facilities, with the goal of first upgrading those with
the highest environmental risk exposure; and/or those presenting the greatest opportunity for increases in
fuel efficiency (defined as kilowatt-hours produced per gallon of fuel, or kWh/gallon), such as through
consolidation and interconnection of communities, or replacement of older, less efficient generators and
control systems, or incorporation of
Mountain Village Intertie accomplishes several of these goals; most notably, it consolidates the two
it enables or will enable:
- installation of fewer but higher-capacity diesel generators into one new planned prime power
ew plant will replace the two older and smaller plants in the separate
older) generators could;
- the planned elimination of one power plant, which will reduce total overall long term operations
and maintenance costs, in comparison to the two plants that are to be decommissioned; and
- larger wind turbines to be selected and installed at a substantially lower cost-per-kW-installed
as compared to smaller turbine(s) for each community, and the power now being produced
from the wind turbine will be more effectively dispatched and utilized by the combined loads
than would be the c
This intertie was developed and built as part of an amalgamated program of energy projects fo
and Mountain Village; other projects in this program include:
-
is int, an AVEC member community 5 miles NW
s power plant; this new
wind turbine is expected to provide approximately 25
Point Mountain Village electric demand. Major funding was provided by AEA.
- A new 414,000-gallon capacity bulk fuel storage tank farm for AVEC is now under
construction in St. .
- A new 3.25 MW prime power plant of sufficient capacity to power all three communities has
been designed and competitively bid, and a contract awarded for its construction in 2021
2022. The new power plant will feature modern, remotely-accessible switchgear and is
designed to meet the N-1 criteria, and to fully integrate and achieve maximum efficiency when
deployed together with the newly-installed wind turbine, the new intertie, and a planned backup
power facility in Mountain Village.
Alaska Energy Authority - Award 7091224
to Mountain Village Wind Intertie Construction
Final Closeout Summary Report July, 2020
Submitted by Alaska Village Electric Cooperative, Inc.
Page 3 of 4
Two prior efforts, both funded by the Denali Commission (DC), accomplished much of the preconstruction
work required for this final design and construction project. First, the potential for the intertie between St.
nd Mountain Village was initially evaluated in the comprehensive feasibility study of a number of
potential AVEC interties funded by earlier DC award 356-07 (DC project 73A); that initial overview study
concluded that the intertie was feasible, i.e., it bore a positive benefit-cost ratio.
Mountain
Village intertie itself as well as for: anticipated distribution grid upgrades; consideration and planning for
the integration of a standby-only power plant in Mountain Village, and for the integration of future potential
renewable energy sources; preliminary coordination with ADOT regarding site control, including submittal
of the draft permit application for installation of the intertie in the road right-of-way; and submittal of the
application to the Federal Aviation Administration for hazard determination of power poles near both the
(Note: the scope of DC 356-07 and DC 1347 also
, another AVEC
intertie to Pilot Station.)
Final design and permitting were completed under the subject project by consulting engineers CRW
Engineering Group, LLC (CRW); final design in particular was provided by Errico Electrical Engineering
LLC (EEE), under contract to CRW. CRW also prepared and advertised the bid documents and cost
estimates, and provided engineering assistance during construction. The field construction portion of the
project was put out to bid in March 2018; three qualified contractors responded, and the contract was
awarded to low bidder Alaska Line Builders LLC (ALB) in May 2018. To avoid damaging fragile tundra,
wetlands and permafrost soils in the construction zone, the contract required the preponderance of the field
work be executed during winter, and only once local soils had frozen to an adequate depth.
The construction contract specified AVEC was to supply the poles and stage them along the intertie route;
poles were procured in spring 2018, shipped by oceangoing barge
in August 2018. The contract specified ALB was to provide all other materials and construction services;
ALB shipped major materials and major construction equipment by oceangoing barge prior to freeze up of
the Bering Sea coast and Yukon River in fall 2018, then mobilized personnel in January 2019. STG
Incorporated (STG) staged the poles along the intertie route for AVEC, and drilled all holes for installation
of poles (and foundation piles where required) for ALB. Construction was accomplished in 2019Q1 Q2,
to include installation of all 452 direct-set poles (including guy poles), cross arm assemblies, conductor,
and other components.
EEE performed a substantial completion inspection in mid-July 2019; ALB then completed all punch list
tasks, and EEE conducted a final inspection in early August 2019. AVEC then accepted the intertie and
began making connections to tie it into the power plants and electric grids;
this work was not included in the construction contract with ALB.
Alaska Energy Authority - Award 7091224
to Mountain Village Wind Intertie Construction
Final Closeout Summary Report July, 2020
Submitted by Alaska Village Electric Cooperative, Inc.
Page 4 of 4
Funding and Costs - Funding to date has been provided by grants from Alaska Energy Authority (State
of Alaska) and U.S. Department of Agriculture Rural Utilities Service, as shown in the following table
(all figures are as of June 30, 2020):
Note: Actual grant-eligible project expenditures ($5,236,890) exceeded formal, official funding provided by grantors
($5,042,431); AVEC paid these excess project expenditures.
Problems Encountered/Lessons Learned Constructing several major infrastructure facilities in one
group of communities over an approximately five-year timeframe resulted in better long term designs,
reduced construction costs, and reduced expected life cycle costs. The measurable success of all of these
projects, including this intertie, is due in part to the cooperation and support of these projects by community
stakeholder entities and individuals. The contractor performed as expected and the end product is of high
quality.
After drilling, standing water was present in some pole and anchor holes. To ensure strong and secure
installation, ALB pump-extracted the water, then used pole foam to set those poles and anchors. Upon
inspection, in a very few cases the pole foam did not perform as hoped, and the holes were again pumped
dry and promptly backfilled with select fill then compacted.
Conclusions - The completed project meets all current regulations and codes governing electrical
transmission facilities of this size.
Bibliography:
CRW Engineering Group LLC: Prepared for
Alaska Village Electric Cooperative; May 2014.
Errico Electrical Engineering LLD: ns Issued For Construction;Prepared
for CRW Engineering Group and Alaska Village Electric Cooperative; June 23, 2017.
AEA Award 7091224: St. Mary's -
Mountain Village Intertie
State of Alaska
(AEA 7091224)
Federal portion
(RUS AK27R84)
AVEC portion
(See Note)
Total Funding
and Outlays
Design and Construction: Funding 2,042,431$ 3,000,000$ -$ 5,042,431$
Design and Construction: Expenditures 2,042,431$ 3,000,000$ 194,459$ 5,236,890$
Balance of Funding not expended -$ -$ (194,459)$ (194,459)$