Modern Building: Green Library Eric Strafelda Tyler Mitchell Jordan Timmersman

NDSU Modern Building  300,000 sqft (3x the size of the current library)  Site location: East of Memorial Union  6 floors  Two roof areas that allow for solar panel  Allows for sunlight to be utilized fully

Requirements  Electrical Engineering Design – Blue Prints  Electrical Engineering Specifications  Electrical Engineering Studies  Solar Roof Study

Meeting with Architect  We met with the architect and got the AutoCAD drawings form him.  He wanted the building to be as green as possible  Wanted us to design for the following:  Efficiency  Cost  Light Quality

Meeting with NDSU Facilities  We talked with Brent Dekrey about seeing what the current library has in it.  Library is provided heat from steam plant  Has a 1200A service  Needed to have chillers and air handling units in our calculation for new library.  Roughly 100,000 sqft  Has a 100 kW backup generator

Service Sizing Calculations  Receptacle Loading: All loading is unknown for our building so we assumed a 1 VA per square foot  1VA*1VA*300,000sqft = 300,000VA  General Lighting: All lighting is unknown for our building so we assumed a 3.5 VA per square foot  3.5 VA was found in code book Sec  3.5VA*300,000sqft = 1,050,000VA

Service Sizing Calculations  Lighting Demand Factor: Most of your lighting loads are considered to be a continuous load  25%*General Lighting Load = 262,500 VA

Service Sizing Calculations  Motor/Mechanical Loads  1 CFM per sq ft and 340 sq ft per ton of coolant  With 300,000 sq ft over 6 floors that is 50,00 sq ft per floor. With 1000 ton chiller.  1000 ton chiller = 3500 kW  (6) 50,000 Air Handling Units (AHU)  2 motors rated at 75 hp motors  hp motors for AHU’s

Service Sizing Calculations  Combining Motor/Mechanical Loads  According to NEC section you use 125% of your highest rated motor and then face value for all other loads.  150 hp X 746 W/hp X125%=140,000 W  5 X 150 hp X 746 W/hp=560,000 W  3500 kW for the chiller  Total Motor Load of 700 kW

Service Sizing Calculations  Combing all the numbers previously found.  Total VA=2,312,500  VA=V*I*1.73  V=480V  A=2,  Using NEC section We selected a service size of 3000 Amps

PV Economic Study  One of our major objectives in this project was to be able to work with an outside client such as an architect.  Our client asked us to provide an economic study to see if installing a photovoltaic array would be a wise investment.

PV Payback Analysis Solar Cash Flow Projection NDSU Modern Building Project Cash Flow AssumptionsIncentive AssumptionsFinancial Performance Installed Capacity DCkW342Fair Market Value$/watt 4.00Unlevered IRR3.61% DC/AC Derate%83%Tax Rate35.00%Payback Period Installed Capacity ACkW283.86Federal/State ITC45% System Capacity Factor% %Depreciation basis85% Annual GenerationkWh 418,264Cost basis 1,368,000 Annual System Derate%0.50%Bonus Depreciation50% Solar PPA Rate$/kWh0.067Depreciable Basis 1,162,800 Utility Escalation Rate%2.50%Bonus Depreciation 581,400 Utility Incentive$/kWh0Ongoing Depreciation 581,400 System Cost$/watt 4.00 Annual O&M$/kW MACRS Schedule20.00%32.00%19.20%11.52% 5.76%

PV Fringe Benefits  Some Fringe Benefits that are not related to direct energy cost analysis include:  Educational  Thermal  Demand Savings  Power Quality  Utility Buyback  Environmental  Public Perception

PV Analysis Conclusion  Given the warranty/useful life a PV array is 20 years. The payback period is very favorable  Including the 3.61 return on investment along with all fringe benefits.  We would recommend the inclusion of a PV array atop our modern building

Project Status  We have successfully completed the deliverables for the first semester.  We had to do a little rearranging of our schedule and an updated timeline is on the following slide.

Timeline

Budget ItemQty.CostTotalPurchase Price 2011 NEC $75 = 225 AutoCAD MEP1$200 Plotting$125 TOTAL$595$225.00$370

Summary  Using the NEC code book and information gathered from campus administrators we were able to select a service size of 3000A  Using engineering economic analysis we were able to accurately predict the cost of a PV Array installation and recommend its inclusion.  We are still on track to deliver our completed project next semester.

Questions?