Modern Building: Green LibraryEric StrafeldaTyler MitchellJordan 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. 220.12 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 6 150 hp motors for AHU’s

Service Sizing Calculations Combining Motor/Mechanical Loads

According to NEC section 440.7 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=2,786.14 Using NEC section 240.6 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 AnalysisSolar Cash Flow ProjectionNDSU Modern BuildingProject Cash Flow

Assumptions Incentive Assumptions Financial Performance

Installed Capacity DC kW 342 Fair Market Value $/watt 4.00 Unlevered IRR 3.61%

DC/AC Derate % 83% Tax Rate 35.00% Payback Period 13.32

Installed Capacity AC kW 283.86 Federal/State ITC 45%System Capacity Factor % 16.8206% Depreciation basis 85%

Annual Generation kWh 418,264 Cost basis

1,368,000

Annual System Derate % 0.50% Bonus Depreciation 50%

Solar PPA Rate $/kWh 0.067 Depreciable Basis 1,162,800

Utility Escalation Rate % 2.50% Bonus Depreciation 581,400

Utility Incentive $/kWh 0 Ongoing Depreciation 581,400

System Cost $/watt 4.00

Annual O&M $/kW 20.00  

MACRS Schedule 20.00% 32.00% 19.20% 11.52% 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 13.32 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

BudgetItem Qty. Cost Total Purchase Price

2011 NEC Code 3 $90 $270 3 @ $75 = 225

AutoCAD MEP 1 $200 $200

Plotting $125 $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?