Ball State University

Transcription

1 Ball State University Journey From Stokers to C F B to Geothermal International District Energy Association June 2010

2 Ball State University Opened students; 900 faculty; 2300 staff 47 major buildings 5.8 million square feet 660 acres Urban area has built up around the entire campus 2

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4 Heat Plant and Chiller Plant 4

5 Central Heat Plant Annually produces about M pounds of steam (85% from coal) Winter peak: 170,000 lbs/hr 4 stoker units: 1941, 1941, 1955 and 1958 Stokers limited by air permit to 100,000 lbs/hr 3 gas/oil units: 1956, 1961, 1971 Steam generated at 150 psig 75% distributed at 150 psi 25% distributed at 30 psi 85% condensate is returned 5

6 Chillers Five Centrifugal, producing 42 F Installed: Early 1990 s Capacity (in tons): Connected Name plate 9200 Peak production 6500 to

7 Background Fosdick & Hilmer study (2001) concluded that old coal boilers were obsolete: perhaps another 10 years Impending EPA Boiler MACT pollution requirements We have only cyclone particulate treatment Stanley engaged to develop alternatives and estimated CFB-based project cost Legislature (2005) authorized $48 M to bond for CFB 7

8 First solution: CFB Sebesta Blomberg designed new 100,000 lbs/hr CFB RFP November 2007 Problem #1: No bidders responded to RFP Proceeded under sole source statute (Babcock & Wilcox) Problem #2: CFB vessel price doubled from original estimate total project costs jump to $65 M 8

9 Start over Reviewed carbon based solutions Add significant pollution controls to stokers Go 100% gas Long phase out decommission one stoker every few years; cannibalize parts Trust fund for future gas purchases No reasonable set of assumptions using our appropriation bought us even 20 years 9

10 Earliest geothermal research Sen. Lugar s visit to learn about green buildings (8/2007) Internet research: International Ground Source Heat Pump Assoc (IGSHPA) GeoExchange: case studies about dozens of projects National Ground Water Association (NGWA)--drilling Found some huge- Ft. Polk (4003 units in 1290 buildings) Galt House --Louisville (1.5 M square feet) Stockton College (NJ) (400 wells under parking lots) AUL/One America (two blocks from here) 1 M square feet in 36 story tower Second most efficient building in US ( ) 10

11 Jim Lowe s M-APPA list serve List serve inquiry to Midwest APPA (5/16/2008) Has any institution conducted a feasibility study for campus geothermal systems? A few dozen replies Most were single buildings Until Lake Land College (Illinois) 6 buildings; 350,000 sq ft Loop around perimeter First loop solution that we found 11

12 Research II Senator Lugar arranged a NREL conference call (12/8/2008) List of key heat pump designers and researchers Dr. Steve Kavanaugh and Kevin Rafferty Jointly wrote the book on heat pumps Disfavor district system; focus is on unitary systems New Oak Ridge study (Dec 2008) Patrick Hughes Latest DOE efficiency info re: geothermal Barriers to implementation- first costs; public understanding Our Problem: 7000 boreholes where would they fit??? 12

13 First contacts with designers Phone calls with Kirk Mescher, CM Engineering, ASHRAE Geothermal Standards Chair Jeff Urlaub, MEP first visited campus 12/9/2008 Separating the wells from the buildings Other discussions with designers of K12 systems; webinars with large design firms Time constraints: approvals; Stimulus 13

14 More meetings with designers First test borehole produced good conductivity results; other gross production and building and data collected Mescher and Urlaub came for another multi-day visit Started plugging data into a couple programs while in our conference room Eureka Moments (smaller system would work): Very positive results for second and third conductivity tests Higher diversity factor (1200 tons) increases system COP Hybrid concept (shave off the peaks to save capital costs) 14

15 Data gathered/estimated Most precise estimates of single building HVAC loads Campus is slightly heating dominant Length of cooling and heating runs Ground Loop designed using Thermal Dynamics software Input parameters: fluids (pure water no anti-freeze necessary) soil (1.56 thermal conductivity; 1.12 diffusivity) piping (1 ; double U-Tube; 6 borehole; 0.84 grout) 15

16 Go or No Go A point came where we needed to decide whether we thought this idea had merit We kept getting green lights Next step: contract for a Proof of Concept for Board of Trustees and Legislature Designers brought a roomful of engineers to more carefully calculate: building loads, hydraulics kw consumption, HW pipe diameter location of borehole fields 16

17 Financial estimates Difficult aspects of getting decent price estimates: Number and depth of boreholes Availability and cost of sufficient drillers Size and path of new hot water pipe More straightforward: Heat Pump Chillers (150 F) Building change outs (we have a lot of experience here) 17

18 Geothermal Phase I: $50 M capital Reduce coal use by $1.6 M $500,000 new electricity cost $1.1 M per year net savings Phase II: $35 M capital Cut coal by another $1.6 M $500,000 new elect/yr $2.2 M per year net savings 18

19 Proof of Concept Issued 1/28/2009 Described loads Mescher estimated electrical consumption Rough description of system 3 energy centers Flow diagram 170 degree hot water; 44 F chilled water 3750 estimated boreholes; 400 ft deep; 15 feet on center 19

20 Borehole design, continued Modeled long term soil temperatures (120 months) Cooling Heating Design day loads: heat gains and losses based on time of day; days per week operations; Annual equivalent of Full-load hrs Hybrid boiler/cooling tower option 20

21 Approvals Board of Trustees (February 2008) Legislative reallocation of bond proceeds (March 2008) Design, design, design 150 F water; two energy centers; Two HW Pipe Solution ; Phase I vs. Phase II; $5 Million from Stimulus Construction documents issued on first 1800 boreholes issued March

22 Geothermal Conversion Project 1. Eliminates 36,000 tons of coal ($3.2 Mil/year) 2. Reduces Energy Costs $2.2 Million/year 3. Dramatic improvement in COP 4. Mitigates Fuel Cost Volatility 5. Eliminates Air Pollutants 85,000 T of CO2; NOx, SOx, CO, Particulate matter 6. Awarded $5 M DOE Demonstration Grant 7. Potential for Cap and Trade Carbon Credits 8. Uses only American Made Components 9. Creates 2,000 Jobs 22

23 Geothermal Groundbreaking Ceremony, May 9,

24 Ball State University Journey From Stokers to C F B to Geothermal International District Energy Association June 2010