Wesleyan University. Electrical Power Study

Transcription

1 1 Wesleyan University Business Continuity Planning Electrical Power Study

2 2 October 2011 snow storm 80% of Connecticut lost power including Wesleyan Wesleyan buildings were without power 3-6 days Without power Wesleyan can not establish a shelter for faculty, staff, students Without power ongoing experiments in the science buildings can be destroyed along with important material stored in freezers Without power food is lost in Usdan and Summerfields

3 3 The existing cogeneration system was used to power parts of campus once it was clear that the outage would be longer than a day. The consequences of the outage were studied. It became clear that emergency power reliability is an important part of business continuity and campus safety. Soon after the storm a study of campus power reliability was undertaken. In response the State of Connecticut Department of Energy and Environmental Protection (DEEP) created incentive programs for cogeneration systems and microgrids (where facilities are connected to localized power generation sources)

4 4 The following options were evaluated for their ability to provide emergency power, their ability to provide a return on investment and their impact on the environment: Fuel Cells set up as Combined Heat and Power Solar Wind Standby Emergency Generators Cogeneration Micro-Turbines Cogeneration Gas Engines

5 5

6 6

7 7 Cogeneration Fuel Cells Combined Heat and Power (CHP) The technology uses natural gas to make hydrogen and hydrogen is used to make electricity Visited an installation at CCSU Pros No NOx emissions Comparable CO2 emissions to a combustion cycle Cons Very expensive, up to 7 times the cost of an engine generator Difficult to synchronize the electronic sine wave of a fuel cell with a mechanically produced sine wave in cogen island mode Poor service records Efficiency degrades overtime Costly stack replacement at 5 year increments, or sooner No Return on Investment, tax incentives are used to drive the market, typically developer installed with a power purchase agreement Removed from service at U.S.C.G. Cape Cod after 5 years, Bridgewater State College after 5 years, Mohegan Sun after 10 years

8 8 Solar Materials that exhibit the photoelectric effect are arranged so that when exposed to the sun an electron flow occurs Wesleyan has 3 installations on campus Pros No emissions Minimal maintenance Cons Very expensive, up to 15 times the cost of an engine generator Difficult to synchronize the electronic sine wave of a PV array with a mechanically produced sine wave in cogen island mode Requires large land areas to achieve substantial output Can not be used as emergency power, no power at night, clouds or snow Return on investment exceeding 30 years Requires substantial infrastructure to route power Battery storage scaled to a campus size is not feasible

9 9 Wind Blades turn a copper winding in a magnet using the force of the wind Pros No emissions Low maintenance Cons Very expensive, up to 15 times the cost of an engine generator Requires large land areas to achieve substantial output Permitting a scaled wind farm is impossible in urban areas Can not be used as emergency power Minimal return on investment Requires substantial infrastructure to route output power Middletown doesn t have the wind profiles to support wind power

10 10 Standby Generators Gas and Diesel Purchase and place stand alone generators at important buildings Pros Cons Instant power Generally very reliable Expensive to provide full back up at several locations No return on investment Require monthly testing and periodic maintenance Produces high uncontrolled emissions as compared with CHP engine packages Could impact Wesleyan s existing air emissions permit

11 11 Cogeneration Micro-Turbines Place a gas powered turbine pack near a building to recover electricity and waste heat Pros Cons Used in a cogeneration system they can be efficient and also provide emergency power when required Relatively low maintenance Poor field service record Relatively expensive Electrically unstable with a variable load Units produce low grade waste heat that cause system efficiencies to be very low

12 12 Cogeneration Gas Engine -Combined Heat and Power(CHP) Place a gas powered reciprocating engine in or near a building to provide electricity and waste heat A large number of colleges, universities and secondary schools are installing gas engine cogeneration systems such as - Clark, Wellesley, Amherst, Smith, UConn, Yale, Harvard, Fairfield, MIT, Williams, UMass, Trinity, Loomis, Avon Old Farms, SUNY Syracuse Environmental Science, CCSU, Duke, SUNY Westbury, Plymouth State Pros Cons Used in a cogeneration system they can be efficient and also provide emergency power when required Relatively low maintenance Best return on investment of any option Good emissions ratings, lower emissions than utility generators Higher system efficiency than utility generators because the heat from the engine is used Replaces gas used for production of an equivalent quantity of steam and hot water Replaces gas used for production of an equivalent quantity of electricity with reduced emissions

13 13

14 14 Emissions Analysis for Natural Gas Reciprocating Cogeneration Unit at Freeman as Compared to Emissions from Purchased Utility (From EPA Worksheet)

15 15

16 16 Conclusion: Several technologies investigated including Fuel Cells, Solar, Wind, Stand Alone Generators and Cogeneration with Gas Engines. The final selection was CHP using a reciprocating natural gas engine. Multiple engines modeled. Final selection based on optimal ROI is rated for 676 kw Suitable location identified as Freeman Athletic Center mechanical space Engine would provide steam to the campus loop and hot water to serve pool heating, domestic hot water and heating loads of the facility New unit would be connected to Vine Street substation via new feeder Current electrical load on Vine St and Freeman is ~ 8,126 mwh annually. The new engine will produce 4,635 mwh annually

17 17 New cogen would operate in parallel with existing cogen to produce >87.5% of existing campus electrical load at Vine Street Total current boiler plant gas costs plus Vine St. & Freeman electrical costs ~ $2.39M

18 18 Expected total installation cost - $3,454,000 Expected savings net of service agreement & Renewable Energy Credits Fossil Fuel & CL&P Savings - $304,177 Expected Maintenance Agreement Cost - ($120,785) Expected Renewable Energy Credit Revenue - $46, Net Annual Savings - $229,742 CEFIA rebate (applied for on 9/28/12)- $300,000 Simple Payback 15 Years (13 Years with rebate, 14 years without SCR)

19 19 Anticipated start up approximately 16 months from project approval Installation at Freeman Athletic Center, mechanical room serving the pool Installation includes Oxidation Catalyst to reduce CO emissions by 90% and Selective Catalytic Reduction to reduce NOx by 85% CoGen and Microgrid installations are a Connecticut Department of Energy and Environmental Protection priority

20 20

21 21

22 22

23

24

25

26

27

28

29

30

31

32

33

34

35