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HomeMy WebLinkAboutSaint Point Wind to Heat Feasibility Study Report - Nov 2016 - REF Grant 7081163P�7-vr v r r TDX Power: • Part of a diversified Alaska Village Corporation committed to identifying and implementing renewable energy solutions in Alaska that reduce fossil fuel dependence and improve rural community sustainability and economics. • TDX presently owns & operates 5 regulated Utilities in Alaska • Two are Wind / Diesel Utility Systems N SG FY20 # mart2016 $265 J 63] )632¥Ems, a� % . � $10,0$9,365 5s, $m 7 !47' 65% 13% •Eodw- Sale■ ■C Pw Sam ■ Q*d« SaR„ ■ D@A m Adak FY 2016 SP O FY 18 67412 , 22314., -. �w 4c� $65 31 3 �7f622 ", .46& 65% ■ E �:Sales @GOPA.Saes ■ Eec 2:Sales GOOPAS-aes JOE SMITH Bill Batch # Bill pate 17ue Dale M FN 104 5112/2011 6/12/2011 PO Box 5555 SAND PDINT,AK 99661 Account Number SeNce Address — Prwous Balance __T Paymentsicredts 011111111 RENTAL S44.55 44.55 Class taster MtlfiVier I Pregous Curren I from To Residential 1111111 1 9D695 90932 CKSA 1 0430111 Charge KVVH Consumption Amount BalanceForward 4EMEE $apa Energy Charge Actual 237. 0 x 0.2399000 S56.86 Customer Charge Rates per $7.48 Cost of Paim Add stmen 237.0000 x 0.19C70W S45.20 Power Cast Equei4adon 237.0000 x 0.2501000 (S59.27) Regulatory Cast Charge 237.0000 x 0,0005520 $0.13 City Sales Tax $3.29 Current Charges; S53.69 REMIT TO: SAND POINT GENERATING PLEASE INCLUDE ALL PAYMENT STUBS Total Due: S53.69 Discussion Point: Wind power cost per KWH is about half of fuel cost for diesel generated KWH. These savings are reflected in the CODA rate and passed directly to customers. Since PCE eligible customers receive credit to keep their first 500KWH at a rate equivalent to sail belt, they do not see benefit from lower COPA in the bill. 35cents generated Wind approximate electricity 15cents — approximate Heat? Cost for power n tanntlq.— company Performance Sand point Power Generation ati°/��ti° \�tiati°' �,�oti° o�.° tioti° �,�ti° � ti° tioy° 1°' �{�a�* o�h tip, �tih / ° 5 / �[� 1 a�� yo�R ��.� spa' ,av�'' ry�° ��\ 2014 — Feb 2015 power TEK powercompany Sand Point Wind Project 70C ,M 500 400 3 300 A 200 100 TYPICAL DATA 0 500 1000 1500 2000 2500 3000 3500 Time (s) since start of file SandpointData2012040819,csv Red line represents power being dumped to keep the diesel genset at minimum load. At least some of this power could be dispatched to remote boilers. 0 I1 — WT total LB BUS Gen total KW 000 t)0() 400 3CX) 200 Gray line = combined power output from both wind turbines Sand Point 01/10/2016 It Blue line = total City load, holding constant at about AAAvLAI 100 i- Drange line = Diesel Genset Yellow line = combined power Output used by power plant boiler and air cooled dump load ­4 CT) r� Ln rn r-t cr, rti Ln r -� V-+ Ln v7 " k.0 o a) 1711� Lr) rf) r-I 4. oo rl Ln rn m r-- C V) M o d oo " �0 cr) ro r - .--I Ln Oo � �r1 4:OOAM *`I r-I rl " N MI M M d` —k b Ln u i IIi7 I'D 1�0 r`- r-- r�- M Ob Q1 cr) CT) 0 CD SECONDS `-4 r-4 4:17AM �City Load cef) -Total Wired Total Dump This is the same graph as in the previous page, but represents a period where more power is available to be dispatched to remote boilers Wind turbines need to be connected to a grid to operate. (We do have a system at St Paul that can run with diesels off, but that is an extremely rare system) The wind diesel system installed at Sand Point requires a diesel generator to run continuously to maintain system voltage and frequency. The power plant has a dump load controller to make sure the online diesel engine runs at least 30% loaded. The power plant system controller simply reads the power output of the genset, and switches resistive elements on and off to keep the genset loaded to minimum load level. The wind turbines (unless they are down for repair) are always enabled and start automatically whenever there is enough wind. Their power output goes up and down with the wind, until they reach their maximum power output setting. At that point, the blades automatically change their pitch angle (spill wind) to not exceed their power limit setting. The maximum power output setting allowed for each turbine is 500KW. The power plant operators change these settings routinely based on wind, load and equipment conditions. For example, if one turbine is down for repair, the power limit forthe operating turbine should be turned up to 500KW. In the example graph (see preceding page), the city load (blue line partially covered by the gray line) is about 400KW. We can see that the gray line (gray line is the sum of wind turbine output power) is also about 400KW. Since the total wind output is holding a constant average of 400KW, we can assume that the power limits on both machines is set to 200KW. We can assume that there is plenty of wind to maintain 200KW, and we can assume the wind turbine pitch controllers are actively increasing and decreasing the blade pitch angle as wind goes up and down, such that the turbines do not exceed their power limit setting. In this example, there is plenty of wind to power the City load. No diesel power is needed, but a diesel must be continuously running to keep the system operating. In this case, the Power Plant's smallest genset is running. In this case, since the wind power happens to match the city load, the load controller needs to dump 100% of the diesel genset power to keep the genset at its minimum load level (about 180 to 200KW). Regarding proportioning the power that is dumped. Presently, the power plant has both an electric boiler and an air cooled dump load. In the preceding example graph above, the total power dumped consists of about 50% electric boiler and 50% air cooled dump load. The air cooled dump load is very fast acting and has smaller KW step sizes for more precise regulation. The electric boiler is slower and has larger KW step sizes. The controller works to assign a "baseload" power level to the electric boiler, but it needs to dissipate some power in the air cooled dump load, which is switched rapidly and often to react to wind power variation. With a boiler installed at the School and Clinic, the controller will do exactly as it does today, to assign as much power dump as possible to the remote boilers. The heating loop water temperatures at the remote boilers will be transmitted to the power plant controls. If the heating water is cold, then 100% of that boiler rating is available as a dump load. As water temperature in those buildings increase, then those boilers will begin to have reduced capacity as a dump load. On a hot day with no heat demand, the power will need to be dumped at the power plant, as it is done presently. The existing boilers have a simple on/off control. If the return water supplying the boiler is 150F (approximately) the boiler turns on. If the temperature reaches 170F (approximately) the boiler turns off. The existing boiler controls will have no interconnection with the new electric boilers. The new electric boilers have multiple steps so the power consumed is variable. If the water is cold, the power plant controller will command them to dump as much as there is excess wind available. If there remains plenty of wind, eventually the return water supplying the boiler will reach 180F (approximately) and will be held at that temperature. The fuel boilers will not turn on again as long as their water supply reaches them at 150F or greater. Projected Savings Wier size selected for the school is 300kw and 75kw for the clinic. -he school is projected to burn 35,270 gallons of diesel (without wind to seat) and would save 45.6% or 16,083 gallons of diesel with wind to heat 7stalled. -he clinic is projected to bum 11,778 gallons of diesel (without wind to heat) ind would save 46.8% or 5,512 gallons of diesel kssuming the school pays $3.75 per gallon, the value of the fuel saved at he school would be 16,083 x $3.75 = $60,311. Q an excess wind rate of $0.06 per kWh. To replace the 16,083 gallons of Biel with electricity, the savings would be $23,999_ ($8225 for Clinic) TIC power a IYne dg..Ix c pan, We learned the school is heating with diesel fuel at a current price of $2.75 gal updated the projections in the preceding slide with $2.75 gal diesel fuel for the school. Also in the slide neglected to include boiler inefficiency, so I adjusted for that with some boiler efficiency assumptions as well: Low Sulfur Diesel LHV = 128,488 Btu/gal and 1KWH = 3412.142BTU 16000 gal of fuel contains 2055808000BTU and assume new boiler is 90% efficient (condensing) gives 1850227200 BTU and costs $44000 @2.75 $/gal 1850227200BTU = 542248 KWH and costs $32535@ 0.6 $/KWH School savings protection = $11465 year We assume the Clinic burns Stove Oil. We are not sure what EAT pays for oil, but our estimate for current price would be around $4.10/gal. Assume boilers are 85% efficient. If so the clinic savings projection would be: 5500 gal of fuel contains 706684000 BTU and assume boiler is 85% efficient gives 600681400 BTU and costs $22550 @4.10$/gal 600681400 BTU = 176042 KWH and costs $10562@ 0.6 5/KWH Clinic savings projection = $11988 year l r i EMI--D Ee.,i a ea IV een Baler 3 1 New equipment is cut into the existing building return loop. A circulation pump circulates water through the electric heating elements in the electric boiler, and raise the temperature of the water returning to feed the boilers. Sand Nnl Excess Wind Ullizalien Sand Pcint School P&ID ELM* DoGar adek on DAL 11, lix1r. � " Nrs ems© ■© 1111111111161 power M1 c ecaE�usVx comps ny mx}a 615 E N2,2nd pre, SuIe:UU x2 Ardmpe, AK 92519 07) P2.8V0 1 of t r Kv"ir Qom � 1 I C_� :jMr w . "Fammv It r M l SCHOOL ELECTRIC ROOM POSSIBLE ANTENNA LOCATION An antenna mounted where this abandoned antenna mast would provide line of sight to power plant. Proposed would be to run the antenna cable under the eaves, back to the boiler/ electric room Sand Point clinic boiler Current situation Sand Point Clinic Proposed electric boile Contractor )est location ocation I", 'location 4" These are some additional notes covering questions about how the excess wind is proportioned between the School and Clinic: The size selection of 30OKW for the school and 75KW for the Clinic is based on trying to match the heat demands of the respective buildings. Given that 375KW total is required to heat both buildings, the ratio of 75KW over 375KW indicates the clinic needs 20% of the heat delivered to keep it heated the same as the school. For example, if there is, say, only 20OKW of power to be dumped, then 20% (40KW) of that would be assigned to the clinic and 80% (160KW) would be assigned to the school. This won't be precise, but the intent is that customers are paying the same rate for the excess wind and to try to give equal access to it based on their heating needs. The new excess wind boiler controls at the clinic and school will tell the power plant controller how much power the remote electric boiler can receive (based on the building heating water return temperature) The power plant controller knows how much power it needs to dump, and allocates to dump as much power as possible to the clinic and school (as much as they are able to receive based on the heating needs) If it is very cold, the clinic and school boilers should be able to run full on. If they can't keep up, either because it is too cold, or because there is not enough wind power available, then the electric boiler water output (which is the fuel boiler water input) will fall below 150F and the fuel boiler will kick on. Catherine Bliss From: Timothy J. Sandstrom Sent: Wednesday, November 30, 2016 7:07 AM To: AEAPayables Subject: FW: Sand Point Wind to Heat Progress Report Attachments: Sand Point Excess Wind Utilization Project Update Nov 28 2016.pdf From: Jan Tierson[mailto:jtierson@sandpointgenerating.com] Sent: Wednesday, November 30, 2016 6:05 AM To: TimothyJ. Sandstrom <TSandstrom@aidea.org> Cc: Travis Hammond <thammond@tdxpower.com> Subject: Sand Point Wind to Heat Progress Report Tim, please find attached report covering period from 10/14 to 11/14. Please let me know if there any questions and always happy to discuss the project in more detail. The meeting on November 8tn went well, and my feeling is that momentum of all parties is favorable. I was hopeful you could attend, but understand you were out during that period. Thanks, Jan Jan Tierson TDX Corporation — Sand Point Generating LLC General Manager/Engineering Manager Office/Cell: 907 350 7532 TDX Corporate Headquarters: 615 E 82nd Avenue Suite 200 Anchorage, AK 99518 TDX Power VT Engineering Office: 5197 Main Street, Suite 4 Waitsfield, VT 05673 Sand Point Generating, a TDX Company, is a seasoned utility operator and energy services contractor with expertise in remote location logistics and renewable energies in critical operating environments. SPG has developed strategic alliances and partnerships, and expanded our capabilities to offer a multitude of energy sector services to meet your mission requirements.