Alaska Rural Energy Conference April 30, Brent Petrie, Retired Alaska Village Electric Cooperative

Transcription

1 Alaska Rural Energy Conference April 30, 2013 Brent Petrie, Retired Alaska Village Electric Cooperative

2 In 2013 most of Alaska s rural village power plants use diesel-power engine-generator sets to create the electricity for local supply for a single village. Some sites are supplemented by hydro or wind.

3 In 2011, of the 183 rural communities participating in the PCE program, only about 27 are electrically connected to another village. However, many of those interconnected villages are supplied by hydro and wind that offset diesel generation. Selawik - new integrated wind-diesel power plant.

4 Alaska Village Electric Cooperative Alaska Power and Telephone Iliamna Newhalen Nondalton Electric Cooperative Bethel Utilities Inside Passage Electric Cooperative Naknek Electric Association

5 Hub communities like Bethel, Kodiak, and Kotzebue may have had central power from the 1940s. Central village power grew out of school power generation plants with efforts in the 1960s. Central station power was still being installed in some villages for the first time as late as the 1990s (1994 in Brevig Mission). Stringing power lines in Kasigluk in 1971.

6 Some of the central station facilities may have been in a central part of the village In some cases, the old school power plant was provided as the starter building of the new village power plant Village populations grew Schools were added (new Alakanuk school is $26 million and nearby Emmonak renovation is $33 million)

7 Water and sewer projects provide cleaner water and healthier conditions than in the 1970s A new piped water system tends to increase village electricity demand by about 20% Pumping and circulation Home-based washer and dryers replace washeterias Heat trace is needed to keep some pipes from freezing

8 This leads to a need to expand fuel storage to meet fuel needed to produce electricity Power plant expansion is also necessary to meet increasing loads This often leads to space availability problems to provide expansion of existing facilities and meet code requirements for setbacks from property lines In some villages the plants may abut or cross into public rights-of-way because of the constricted sites The Stebbins power plant and tank farm must be removed from the airport site.

9 Further, lenders or granters of funds require certain standards Plants and tanks are preferred to be away from hazards such as floods or eroding shorelines or river banks The plant transformers at Emmonak were put on raised pedestals due to flooding. Powerlines are more replaceable than an engine that weighs several tons or a fuel tank that may have fuel in it and need an engineered foundation. The Stebbins tank farm and power plant are at sea s edge.

10 Spring breakup of the rivers can cause massive flooding. The high water and strong currents can topple heavy tanks. Heavy chunks of ice can damage facilities. The Emmonak plant operator paddled a canoe to get to work.

11 Started with a handful of villages in 1968 Now serves 55 member villages Population of 23,417 Would be the 4th largest city in Alaska after Anchorage, Fairbanks and Juneau 44% of Village Alaska s population Anvik (smallest) 79 Hooper Bay (largest) 1,137 Average population 433 Anchorage 298,842

12 80 Anchorage-based Employees 7,954 services 48 prime power plants 4 standby plants diesel generators 95 Village technicians fuel tanks Over 5 million gallons fuel burned 10 wind systems serving 14 villages 34 turbines total Gambell Cousins

13 160 fuel deliveries in 2012 Over 40 SPCC, FR Plans and O&M Manuals Thousands of feet of fuel pipeline Reduced regulatory requirements for fuel with intertied villages M/V Cavek and barge AVEC-208 in Quinhagak.

14 Average Average Average Average Average Average Average Average Average Average Average Increase $ %

15 Reduce diesel use 25% in 10 Years 1,250,000 gallons 77% of our fuel is used in Wind Class 4+ villages Reduce power plants by 50% in 10 Years Interconnect another 24 villages Reduce non-fuel costs by 10% Plant costs, depreciation, interest Rate reduction of 2 cents/kwh as of 1/1/2010

16 Installing wind generation 10 systems serving 14 villages 34 turbine fleet is the largest in the state (3.26 MW) Capturing recovered heat where feasible More than 40 AVEC locations Building Interties Toksook Bay to Tununak (2005) Toksook Bay to Nightmute (2006) Emmonak to Alakanuk (2011) Stebbins to St. Michael (2014 est.) New Stuyahok to Ekwok (2014 est.) Developing HVDC concept Welcoming new villages Nightmute (1998), Teller (2005), Kotlik (2007), Ekwok (2011), Kobuk (2012)

17 New Brevig Mission plant is 35% more efficient than the nearby Teller plant Solution is to intertie Teller to Brevig Mission

18 Reduce the number of power plants Larger loads make renewables like wind or hydro feasible Interties access wind or hydro sites that can serve several locations Consolidation of loads can aid the economics of connecting to other efficient generation sources such as the Railbelt or North Slope natural gas generation Toksook Bay Tununak intertie.

19 Kasigluk Nunapitchuk St. Mary s Andreafsky Upper Kalskag Lower Kalskag St. Mary s Pitka s Point Emmonak-Alakanuk intertie. Shungnak Kobuk Toksook Bay Tununak Toksook Bay Nightmute Emmonak - Alakanuk Local hires on the Emmonak-Alakanuk intertie.

20 Stebbins to St. Michael New Stuyahok to Ekwok St. Mary s to Pilot Station St. Mary s to Mt. Village Retensioning the Toksook Tununak intertie Potential Village Interties for Study Ambler Shungnak Kobuk Kiana Noorvik Selawik Kivalina Red Dog Port Noatak Red Dog Port

21 An interconnection that permits the passage of electricity between two or more load centers Alaska has relatively small village loads that can be interconnected with standard distribution voltages of 12.47, 25 and 34.5 KV. This can be done using overhead conductors on poles or underground and underwater cable. Interconnected groups of villages can be interconnected by higher transmission voltages of 69, 115, 138, 230, 345 kv (most transmission voltages in Alaska at present are 69,115 or 138 kv) Brevig-Teller underwater cable.

22 Other than certain types of switches, interties have no moving parts (like engines do) that operate continuously An overhead line may consist of 25 wood poles per mile with three overhead conductors Other components may be a transformer bank at a power plant and manually or remotely operated switches that can isolate sections of line for trouble-shooting or maintenance. Brevig Mission overhead section of the tieline.

23 AVEC s consolidated power plant, wind turbines and tank farm at Toksook Bay. This is a good example of efficiencies we are trying to achieve. The project serves Tununak and Nightmute via 23 miles of intertie. Eliminated two power plants and their associated tank farms 12 tanks replaced 35 tanks 3 prime power engines replaced 9 engines Load consolidation made wind power at Toksook Bay more feasible. Four 100-Kw wind turbines were installed.

24

25

26 Size Cost (millions) Diesel power plant 1.5 MW $3.5 - $5.0 (including warehouse and substation) Bulk fuel 250,000 gal $3.0 - $5.0 Total: $6.5 - $10.0 Subtotal for two villages $ $20.0

27 Consolidated diesel plant 2.0 MW $4.0 - $6.0 Bulk fuel at one site 500,000 gal $5.0 - $10.0 Sub total: $9.0 - $ mile $250K to $450K/mile $2.5 - $4.5 Subtotal for two intertied villages $ $20.5 Operating costs offset = $140,000 per year

28 Reduce the number of operational facilities (power plants and tank farms) Reduce the amount of running hours on equipment (this reduces consumables and overhauls) Reduce exposure of plants and tank farms to floods and erosion Open access to more efficient sources of supply Renewables (hydro, wind) Natural gas generated electricity More efficient diesel plants

29 Any questions? Brent Petrie Rural Energy Conference April 30, 2013