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Energy Trust New Buildings Solar Design Training March 16th, 2015
Solar ready incentives • xxx Incentives and technical guidance to reduce costs:
• Solar assessment • Solar ready design • Solar ready construction
Templates and tools to simplify the design process
Solar in New Construction and Major Renovations…
• Make the case for solar installation
• Ensure that building design maximizes solar potential
Today’s Training Goals • Expose design professionals to solar design
tools, resources and principles
• Build connections between design and solar professionals
Today’s Agenda • 1:00pm – ETO Introduction • 1:10pm – Solar Design Principles • 3:30pm – Solar Trade Ally Perspective • 4:00pm – Networking
• Review ETO Solar Ready requirements • Discuss design principles to make the
solar ready roof workable • Present methods for calculating total
solar resource fraction • Show current technology for inclusion in
PV systems • Evaluate current and future Codes
Solar Ready Program Goals and Objectives
• Purpose is to include PV in the building design for easier implementation of PV later
Solar Ready Program
• Solar Ready Commercial Design and Construction Requirements
• Program Guide for Solar Electric Allies • Solar Electric Installation Requirements
Solar Ready Program Key ETO Documents
• 10kW minimum • Total Solar Resource Fraction (TSRF)
minimum 75% • 20 year roof • Roof designed for additional weight -
3.5psf minimum • Chase or conduit installed • Point of interconnect identified and
labeled
Solar Ready Program Select Requirements
• Best case ~9W/ft2 for low slope roof • Pathways and RTUs ~6W/ft2
Solar Ready Program Roof Area Required
• Definition and estimation of Total Solar Resource Fraction (TSRF) – TSRF = TOF% x Unshaded%
• TOF is Tilt and Orientation Factor • Unshaded % is the amount of time the array is
shade free
Solar Ready Program TSRF
• Tilt and orientation factor (TOF)
Solar Ready Program TSRF
• Unshaded Percentage
Solar Ready Program TSRF
• Unshaded Percentage
Solar Ready Program TSRF
• Estimating TSRF • RTUs and array shading • Estimating external shading components • Using software tools to help estimate TSRF
Solar Ready Program TSRF
• Software that can be used to help the design/TSRF process – Solmetric online tools – SketchUp/Google Earth – AutoDesk Vasari – HelioScope – Pictometry/Eagle View
Key Design Considerations
– SketchUp/Google Earth screen shots
Key Design Considerations Google
– SketchUp/Google Earth screen shots
Key Design Considerations Google
– HelioScope screen shot
Key Design Considerations HelioScope
– HelioScope screen shot
Key Design Considerations HelioScope
Key Design Considerations HelioScope
– Pictometry/Eagle View screen shot
Key Design Considerations Pictometry
• Hardware that can be used to help the design process – Solmetric SunEye
Key Design Considerations
• Typical PV design strategies and industry trends
Key Design Considerations
• Commercially available components – PV Modules ~300W
• 3’W x 6.5’T, 50 lbs – Inverters
• Commercial trend moving to transformerless 1,000 Vdc
• 3 phase string 16-60kW – 23kW 26”W x 27”T, 135 lbs
• 3 phase central >85kW – 100kW: 78”W x 80”T,1,200lbs
Key Design Considerations
Key Design Considerations
• The battery back-up question
Key Design Considerations
• Module layout and orientation including tilt angle – Roof layout DWG
Rooftop Layout
• Inter-row spacing and free area from RTUs and parapets
Rooftop Layout
• Inter-row spacing and free area from RTUs and parapets
Rooftop Layout
• Attached racking: ~2.5 lbs/ft2
Structural Considerations Roof Loading and Racking
• Ballast racking: 3.75 lbs/ft2 min – >5.5 lbs/ft2
Structural Considerations Roof Loading and Racking
Hybrid ballast: ~3 lbs/ft2
Structural Considerations Roof Loading and Racking
• Metal Roofs: ~2 lbs/ft2
Structural Considerations Roof Loading and Racking
• Metal Roofs
Structural Considerations Roof Loading and Racking
• Structural attachments and rail systems – UL 2703 listing
Structural Considerations
• Structural attachments and rail systems – UL 1703 listing and fire classifications
matching roof classifications
Structural Considerations
• OR Structural Specialty Code • International Fire Code
Structural Considerations
• Roof to electrical room wiring – OESC/NEC requirements
Electrical Considerations
• Utility interconnection and disconnect – Supply Side – Load Side
Electrical Considerations
• National Electrical Code/OESC - current and future – 690.12 Rapid shutdown – 690.11 DC Arc Fault
Electrical Considerations
• Utility interconnection – NEC 705.12 – Supply side (“line side tap”) treated nearly
the same as a new service – Load side to meet 705.12(D)(2)
Electrical Considerations
Electrical Considerations Equipment locations
Electrical Considerations Equipment locations
Electrical Considerations Equipment locations
Electrical Considerations Equipment locations
Electrical Considerations Equipment locations
• Major building renovation • PV system size driven by energy yield • Owner requested infrastructure for
future system expansion via carport
Case Study
• SketchUp used to model array locations, tilt angles and row spacing
Case Study
Case Study Energy Analysis
• Racking system designed and configured with engineers and racking manufacturer
Case Study
• SLD created for system integration and utility interconnection
Case Study
• Energy Trust: energytrust.org • SolarPro magazine:
solarprofessional.com • Solar ABCs: solaracbs.org
Resources
By Luis Robles with
Solar Ready Assessment 101
Agenda What is Solar Ready Site Assessment Process Solar Trade Ally Solar Install Costs Involving Solar Trade Ally Conclusion
What is Solar Ready A building designed and constructed to make it easy to
incorporate solar energy
What is Solar Ready Solar assessment—Technical support and up to $2,000 to determine the solar potential of your building. Solar ready design—Technical guidance and up to $5,000 to prepare solar plans and specifications for use during the bidding process. Solar ready construction—Technical assistance and up to $15,000 to help you build to solar ready standards.
What is Solar Ready Building Orientation Shading Roof Type Roof Structure Obstructions Electrical Conduit Run Electrical Equipment Location
What is Solar Ready Grid Tied to Pacific Power or Portland Gas Electric 10kW to 1 MW Must meet Energy Trust of Oregon requirements
Site Assessment Process Client Consultation Ladder Up Or Plan Review (if Project is Ground-up Construction)
Measure Usable Space Graph Obstructions Measure TSRF Snap Photos Measure Rafter Sizes and Spans Find Mechanical/Electrical Room Make Design Recommendations
Site Assessment Process Top Down Approach
Site Assessment Process Building Orientation
Site Assessment Process
South View Shading West View Confirmation
Site Assessment Process TSRF = Total Solar Resource Fraction
TSRF = TOF x Shading Factor
TOF = Tilt and orientation factor
Shading = Solmetric
Site Assessment Process Shading Fail
Site Assessment Process Shading Fail
Site Assessment Process Roof Type
-PVC
-TPO
-Mod Bit
-Tar and Gravel
-Comp Shingle
-Metal
Site Assessment Process Roof Structure
-AHJ – Authority Having Jurisdiction
-OSISC - Oregon Solar Installation Specialty Code
Site Assessment Process Obstructions
Site Assessment Process Electrical Conduit Run
Site Assessment Process Equipment Location
Solar Trade Ally Licensed Insured Experienced Recognized by Energy Trust Required to acquire incentives
Solar Trade Ally What does experience mean? Installation Practices
TSRF
Solar Trade Ally - Panel Manufacturers - Inverter Manufacturers - Racking Manufacturers
Solar Trade Ally
Solar Trade Ally
Costs
Incentives
Solar Install Costs
Involving a Solar Trade Ally Why?
Conclusions and Next Steps To conclude if this building is Solar Ready or not through an
in depth assessment
To inform customer of their eligibility for solar
Define potential actions
Proceed to design and construction ready steps
