Princeton University Microgrid

Transcription

1 Princeton University Microgrid IDEA evolvingenergy Conference Toronto, Canada 28th 30th October 2014 Edward Ted Borer, PE

2 Overview Campus Energy Demands Energy Plant Equipment Combined Heat and Power Production Plant Economic Dispatch Historic & Projected Emissions Solar PV Microgrid issues Water Sources & Use Continuing Opportunities

3 Energy Demands at Princeton > 180 Buildings Academic Research Administrative Residential Athletic

4 Energy Equipment & Peak Demands Electricity Rating Peak Demand (1) Gas Turbine Generator 15 MW 27 MW Solar Photovoltaic System 5 MW Steam Generation (1) Heat Recovery Boiler 180,000 #/hr (2) Auxiliary 150 ea. 300,000 #/hr 240,000 #/hr Chilled Water Production (3) Steam-Driven Chillers 10,100 Tons (5) Electric Chillers 10,700 Tons 13,800 Tons (1) Thermal Storage Tank *peak discharge 40,000 Ton-hours 10,000 tons (peak)

5 Plant Energy Balance PSEG Electricity Solar PV Electricity Electricity Natural Gas Gas Turbine & HRSG Backpressure Turbines #2 Diesel Fuel Oil Biodiesel Fuel Oil Duct Burner & HRSG Auxiliary Boilers Chilled Water & Thermal Storage Systems Steam Chilled Water Campus Energy Users

6 HRSG & Auxiliary Boilers

7 HRSG & Auxiliary Boilers

8 Campus District Energy Systems

9 Centrifugal Electric Chiller

10 Chilled Water Thermal Storage Warm vapor Warm water from HTX or tank ~ 56 F Warm water from Campus ~ 58 F Cooling Tower Hot Chiller Thermal Storage Tank Cold water To Campus ~ 34 F Cool Cold water To HTX or tank ~ 32 F Plate & Frame Heat Exchanger

11 TES Tank Stratification

12 Total Chilled Water Flow Outdoor Temperature Princeton Chilled Water Use Campus Chilled Water Production, June , , , , , , , , , ,000 2,000 Total Flow, gpm Outdoor Temp Jun 11-Jun 12-Jun 13-Jun

13 Princeton Summer Steam Use Steam Flow, M#/hr 20 Outdoor Temperature, F 0 22-Jun 23-Jun 24-Jun 25-Jun 26-Jun 27-Jun

14 Combined Heat & Power, Cogeneration Air Fuel & Water Gas Turbine Power Turbine Gearbox Electric Generator AC Electricity Hot exhaust Gas CO Catalyst Feed Water Heat Recovery Boiler Exhaust Gas Steam

15 How Much More Efficient is Combined Heat & Power?

16 The GE LM-1600 Gas Turbine

17 Megawatts. Princeton Power Demand With Cogen Dispatch To Minimize Cost Generation Campus Demand Power Purchase Jul Jul Jul Jul Jul Jul Jul 05

18 Princeton Economic Dispatch System PJM Electric Price NYMEX gas, diesel, biodiesel prices Biodiesel REC value & CO 2 value Current Campus Loads Weather Prediction Production Equipment Efficiency & Availability Business Rules Historical Data ICETEC Operating Display Historical Trends Generate/Buy/Mix Preferred Chiller & Boiler Selections Preferred Fuel Selections GT Inlet Cooling Mode Live feedback to Icetec ICAP & Transmission Warnings Operator Action

19 TES Economic Dispatch Screen

20 PSEG Generation Stack

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22 Campus CO 2 Emissions by Source

23 Previous Energy Saving Projects Cogeneration Plant Lighting Retrofits VFDs Premium Efficiency Motors Central EMS Vending Misers Monitor Sleep Mode Condensate Recovery Energy Guidelines Backpressure Turbines Reverse Osmosis Cooling Tower Chemistry High Efficiency Chillers Hybrid Vehicle LCD Monitors Building Heat Recovery Thermal Energy Storage Retro-commissioning

24 Backpressure Turbine - Generators

25 Backpressure Turbines Heating steam is produced and distributed at 200 PSIG on campus. The pressure must be reduced to less than 15 PSIG when it enters a building. Pressure reduction is normally done by using control valves. Backpressure turbines reduce pressure and use that energy to turn small steam-turbine-generators. Princeton installed two backpressure turbines in Dillon Gym. They make 540 kilowatts at full power i.e., power for several buildings. $243,000 Smart Start grant for the use of new technology. Estimate $188,000 annual savings, < 4 year payback. Avoids 1270 metric tons of CO2 per year. Compact footprint of 3 feet x 11 feet.

26 Data Center Absorption Chiller 600 tons of cooling using only waste exhaust heat from a 1.9 megawatt gasfired reciprocating engine. It is the most efficient of it s type in the world. Princeton s will be the first gas-engine & absorption chiller combination used at a data center. Footprint: 11 feet x 20 feet

27 CO 2 Reduction Goals

28 Annual Chilled Water Use (Ton-Hours) Campus Floor Area (Sq.Ft.) Millions Millions Reduced Chilled Water Use 40 Princeton University Chilled Water Load Growth Chilled Water Bldg Sq.Ft Year

29 Campus Floor Area (sq.ft.) Millions Reduced Annual Steam Energy Princeton University Annual Steam Use Annual Steam Use (lbs) Millions 1, Steam Use Floor Area Fiscal Year

30 Princeton Solar PV 5.3 MW DC 27 Acres Lease equipment Own all power and Solar Renewable Energy Credits from day one Sell SRECs until system is paid for Eventually stop selling SRECs and claim all avoided CO2

31 Technical Scope 5.3 Megawatts, 8.4 Million KWH/year Avoid 3091 Metric Tons CO2 per year 9.4% of CO2 reduction goal Retire Solar Renewable Energy Credits (SRECs) and claim avoided CO2 from year 9 on. 27 Acres of Overgrown Fields & Lake Dredgings Connect to Existing Substation under lake and canal via underground cable

32 Solar Overview

33 Megawatts 20 Main Campus Power, Generated & Purchased During PV System Testing August 30, Charlton St Import MW Elm Drive Import MW CoGen Output MW West Windsor PV Output MW :00 AM 1:00 AM 2:00 AM 3:00 AM 4:00 AM 5:00 AM 6:00 AM 7:00 AM 8:00 AM 9:00 AM 10:00 AM 11:00 AM 12:00 PM 1:00 PM 2:00 PM 3:00 PM 4:00 PM 5:00 PM 6:00 PM 7:00 PM 8:00 PM 9:00 PM 10:00 PM 11:00 PM

34 Total Campus Imported Power, Megawatts PSEG Locational Marginal Price & Delivery, $/MWH Purchased Power and Power Price During Solar PV Testing August 30, Total Campus Import, MW PSEG LMP + Delivery, $/MWH :00 AM 2:00 AM 4:00 AM 6:00 AM 8:00 AM 10:00 AM 12:00 PM 2:00 PM 4:00 PM 6:00 PM 8:00 PM 10:00 PM 12:00 AM

35 Campus Microgrid

36 Simple Microgrid Concept KWH Local Generator Utility Meter Synchronizing Isolation Breaker Local Power Demands Central Utility Power Station KWH Utility Meter Isolation Breaker Local Power Demands

37 Microgrids Add Reliability KWH Local Generator Utility Meter Synchronizing Isolation Breaker KWH Local Generator Utility Meter Synchronizing Isolation Breaker Central Utility Power Station KWH Utility Meter Isolation Breaker KWH Local Generator Utility Meter Synchronizing Isolation Breaker

38 Microgrid Options GT, Diesel, Micro-turbine Economic Dispatch KWH Utility Meter Synchronizing Isolation Breaker Battery or flywheel reciprocating gas engine, solar PV, wind, micro-hydro Central Utility Power Station

39 Utility Company Power Feeds To Princeton Campus

40 Campus One-Line

41 A Few Princeton Campus Power Distribution Components

42 Emergency/Life Safety Generators

43 Campus Power During Hurricane Sandy

44 Must Do For Microgrid Reliability Distributed base-load generator(s) Ability to run isochronous Ability to isolate generator-load combinations Skilled, manual, in-person effort, not automatic Underground utility distribution Black start capability Gross load-shed capability

45 Should Do For Microgrid Reliability Fully commission complete systems Re-test periodically Test using realistic conditions Building-level load-shed capability Multiple fuel options Use emergency response teams periodically Plan for human needs

46 Less Than You d Expect In An Emergency 5 MW Solar PV Uncontrollable, volatile output Off at night and extreme weather Utility-interactive inverters can t run in isolation ½ MW Backpressure Steam Turbines Not significant scale Not controlled power output No black start Induction generators can t run in isolation 5 6 MW Emergency generators Serve emergency circuits only Usually carry much less than design load Most can t be synchronized

47 Water Use and Recovery

48 Princeton University Water Use 282 million GPY NJAW 91% Well 9% = 775 thousand gallons per day 34% is used in energy plant

49 Energy Plant Water Use 97 million gallons per year consumption 2011 Energy Plant Water Uses And Sources Largest users are cooling towers, then boilers, then NOx 2011 Energy Plant Water Uses By Month Strong summer peak; over 600k gpd.

50 Water Price Breakdown Average ~ 7%/year cost increase. Water and Sewer Prices by Year Supply = $3.36/kgal Discharge was $7.82/kgal New sewer rate of $10.24/ccf following Township-Borough merger in 2013, i.e., $13.90/1000 gallons

51 Initial Concept for Sanitary Water Recovery System Capacity Capacity: 400,000 gallons per day 146 million gallons annual Anticipated annual recovery 71 million gallons per year 95% of Energy Plant Water Supply 49% system utilization factor Arts Neighborhood rainwater recovery Primarily for storm water mitigation 1.2 million gallons per year Compatible with, not mutually exclusive of Sanitary Water Recovery

52 Existing & Proposed Concept 71 mgy recovered sanitary water for use in the energy plant Reduced water demand and sanitary discharge Water Flows 181 MGY Reduced water & sanitary expenses 110 MGY

53 Ongoing Opportunities Retro-commissioning, continuous commissioning Ground Source Heat Pumps Variable Frequency Drives Chilled Water Controls Optimization Real-time emissions calculation Energy Star & Smart Start grants as applicable Use Condensate to pre-heat Domestic Hot Water CHW-HTW Heat Pumps Biodiesel Deep Well Geothermal Fuel Cells Trash-to-energy

54 Thank you