Commercial PV Projects with AEE Solar Glenn Hall AEE Applications - - PowerPoint PPT Presentation

Commercial PV Projects with AEE Solar

Glenn Hall AEE Applications Engineer 1/26/2019

Seminar Discussion Topics

• Considering 60-cell vs 72-cell modules for Commercial PV Projects
• Trends and developments for Commercial PV Systems
• Sizing arrays with regards to Inverter capacity
• Optimal tilt of arrays on Commercial Projects
• NEC 2014/2017 Rapid Shutdown for Commercial Projects

‒ NEC2017 Module Level Requirements – Jan. 1, 2019!

• Trends and developments for Commercial PV in 2019

‒ Inverter Advances

• Ballasted and Metal Roof Racking Systems
• Example of maximizing output of a ballasted commercial PV system
• New Aerocompact Metal Roof offerings

‒ New! SnapNrack Ultrarail for Commercial Roof Projects

• Benefits of Commercial PV Monitoring
• Commercial Ground Racking Solutions
• Aerocompact Ballasted Ground Mounts
• New! PLP Power Peak Ground Mount System
• Benefits of Commercial PV System Monitoring
• Tax Credits – ITC and MACRS Depreciation

60-Cell vs. 72-Cell Modules

• Polycrystalline – 270-300 Watts
• Monocrystalline – 300 to 335+ Watts
• High Efficiency Mono – 350+ Watts
• Polycrystalline – 335 to 350 Watts
• Monocrystalline – 350 to 380 Watts
• High Efficiency Mono – Not Typical

60-Cell Modules (typical) 72-Cell Modules (typical)

Considerations with using 72-Cell modules for Commercial Projects

• Spike in demand for 72-cell modules! Tight supply, due to drop in ITC at end of 2019.
• Last year, projects with long timelines benefited from easier sourcing of 60-cell panels
• 60-Cell modules often are not much higher cost per watt than equivalent 72-Cell modules
• Minimum order quantities often apply for 72-cell panels – full pallets or containers
• Module power densities are typically higher using 60-Cell modules
• PERC and Split-Cell options increased power densities for both 60 and 72-cell modules
• 72-Cell panels may be restricted in areas with heavy snow load, or need Alpine Brackets
• Two people often required to handle 72-Cell modules, 60-cell panels are one person
• More aesthetic options available for 60-cell modules, if this is a customer requirement

Commercial PV Design Trends

Higher DC to AC inverter load ratio

‒ <120% DC:AC in the past was regarded as the PV industry standard ‒ 130% to 135% is becoming much more common ‒ Inverters such as SMA Core1, Fronius Symo, and SolarEdge inverters, can utilize high DC to AC Ratios PV in designs that can be up to 150%!

• A 50kW inverter could be used for up to a 75kW DC Solar Array

‒ Inverters can reach peak output earlier in the day, and minimal clipping during high irradiance is allowed. Inverters are not damaged by the PV Array. ‒ Fewer inverters needed for given site. Results in lower cost to purchase and deliver, and install. Also lower cost to maintain, service, and warranty. ‒ More kWh can be generated at the site with lower overall costs, considering materials, install labor, BOS, and maintenance. ‒ This results in lower cost per generated kWh for the PV system.

High tilt angles on commercial projects are not always ideal

‒ Higher tilts angles results in larger inter-row spacing to prevent shading ‒ High percentage of net-metered solar production occurs during summer months ‒ Therefore, lower tilt angles allow larger PV arrays and more net energy production ‒ East/West racking solutions eliminate inter-row shading. ‒ Lower tilts and E/W maximizes module density; lower install cost and ballast weight ‒ Some considering West facing arrays to avoid higher TOU utility rates

Rapid Shutdown Considerations

• NEC2014 690.12(B)(1), the PV Array Boundary for limiting voltage for

controlled conductors is 10’

• Applies to all energized DC conductors on or inside of a building
• Conductors outside this boundary must be under 30 volts in 30 seconds
• This allows first responders to de-energize the high voltage conductors quickly
• Roof Mounted Commercial inverters within the PC Array Boundary met

NEC2014, but now do NOT meet NEC2017 code.

• Free Standing SMA Core1 commercial inverters easily located next to a PV Array
• Other commercial inverters placed on ballast racks
• Some 3rd party String Level RSD devices available
• Examples: Midnite Solar LSOB, Birdhouse with Shut Off Boxes, Innovative Solutions
• NEC2017 code reduces the PV Array Boundary to 1’, and limits maximum

voltage allowed within the PV Array to 80 VDC.

• NEC2017 shrinks the boundary for controlled conductors to a 1’ perimeter
• Conductors outside this boundary must be under 30 volts in 30 seconds.
• Jan.1, 2019 – NEC 2017 690.12(B)(2) becomes effective
• Voltage within the array boundary must be under 80 volts in 30 seconds
• In essence, this requires Rapid Shutdown at the module level
• Two module/one input optimizer solutions may be over this voltage, coldest day!

NEC2017 Compliant Module Level RSD Options

• Meeting NEC2017 Module Level RSD requirements after Jan.1, 2019
• Tigo TS4-F MLPE – Shutoff under each module, with Sunspec inverters
• SMA Residential inverters with -41
• SMA Commercial Core-1 inverters with -41
• Fronius Symo Advanced Commercial inverters as examples
• No signaling Gateway or additional wiring needed, powerline communications
• Solar modules with Maxim optimized junction boxes
• Rapid Shutdown Functionality built into module junction box
• Used with inverter manufacturers with SunSpec powerline communications
• Tigo TS4-S or TS4-O optimizers, with Cloud Connect and Gateway
• Enhanced range of rooftop Gateway makes deployment easier
• Monitoring (TS4-S/TS4-O) and Optimization (TS4-O) added functionality
• IMO FireRaptor RSD
• Two panels served with each MLPE Device
• Separate Emergency Switch, AC Powered
• Midnite Little Shut Off Box (LSOB)
• Transmitter placed around inverter output conductor
• One LSOB receiver under each module for NEC2017
• Only one LSOB receiver needed for states still on earlier code cycles
• Separate Bleed Down Unit also available for inverters that do not dissipate

voltage

• SolarEdge single panel optimizers (P320/P370/P400/P505) or commercial
• ptimizers that have two inputs (P800P/P860)
• Enphase IQ/IQ+/IQx microinverters
• Traditional string inverters may become limited to being used on carports and

for ground mount PV Arrays

• NEC2014/NEC2017 Rapid Shutdown requirements are only required for roof

mounted solar arrays

NEC Adoption Map – 1/1/2019

NEC Adoption Map – 1/1/2019

SMA Tripower Core1 – 50kW Inverter

SolarEdge – Commercial Inverters

Enphase IQ for Commercial Projects

• Enphase IQ microinverters
• Enphase Energy’s 7th generation microinverter
• IQ7 for 235-350W 60-cell modules
• IQ7+ for 300-440W 60 and 72-cell modules
• IQ7X for 96-cell modules, (SunPower and

Panasonic)

• Two wire IQ Trunk Cable system, reduced

components, resulting in lower costs

• 25-year warranty product in US
• Roof top Aggregator – Acts as easy plug and play

roof top combiner

• Envoy IQ for both 1P-120/240VAC and

3P-208VAC or 3P-240VAC projects

• High CEC Efficiency rating of 97.5%
• Next Gen - IQ8 to be released later this year!
• Commercial Applications
• Module level optimization, with high DC to AC ratios
• UL1741-SA Compliant for new utility requirements,

and Smart Grid Ready

• Built in module level NEC2017

Rapid Shutdown compliance

• Ideal for smaller commercial projects, as well as

larger ones with broken up arrays that may be difficult to meet Rapid Shutdown compliance.

• Applicable to 3P-208-WYE or 3P-240-DELTA grids!

Commercial Rooftop Racking

• Flat-roof arrays using ballasted racking solutions
• Quick to design & install
• Fewer materials needed than rail-based systems
• Minimizes or eliminates roof penetrations
• Avoids re-sealing
• Easier servicing of roof
• Less roof warranty issues
• Limitations of ballasted systems
• Seismic-related building codes may mandate some penetrations
• Not suitable for roofs with greater than 5° slope
• Not suitable for roofs over 50’ high
• Wind exposure drives ballast and module tilt limitations
• Be sure that designer and/or supplier uses correct wind loads,

exposure categories, and risk factors!

Penetrating vs. Ballasted

• Roof penetrations into roof

structure anchors PV array

• Roof penetrations must be

properly sealed for array life

• Higher tilt angles are possible

to increase module efficiency

• Can be installed on pitched or

flat roof surfaces

• Lower array weight than

ballasted, less roof dead load

• Roof maintenance requires

removal of array racking and re-installation of penetrations

• Easier Wire management and

MLPE Attachment Options

• Weight of array plus additional

ballast anchors PV array

• Few to no roof penetrations

required to anchor array

• Tilt angles typically <10° to

minimize wind effects

• Pitch of roof limited depending
• n racking solution
• Higher roof loading due to

ballast weight, higher dead load

• Array can be more easily

removed and reinstalled for roof maintenance

• Special consideration to wire

management and MLPEs

Penetrating Racking Ballasted Racking

Hybrid Ballasted Systems

• Minimally attached ballasted rack can offer best of both worlds
• Majority of array quickly installed
• Roof anchor and penetration points made in key areas of array
• Fewer penetrations to install and flash, array still removable
• Lower ballasting requirements can allow systems to be installed where

roof loading is a concern

• If penetrations are located correctly, they prevent sliding of array, and

can use static friction values, further reducing ballasting requirements

• Optimize tradeoff between penetrations and ballast
• Less penetrations require more ballasting and vice versa
• Combination of penetrations and ballast can be best way to

meet wind and seismic load requirements

• California and some other seismic jurisdictions will always require some

penetrations

Aerocompact Ballasted Racking

Aerocompact CompactFlat Ballast Racking

‒ Landscape Format – connects directly to module frames – no rails

• South Facing 5°/10°/15° tilt
• East/West 10° tilt - maximizes module

density and lowers ballasting requirements

‒ 25 year warranty ‒ Wind Tunnel tested to 150 mph ‒ UL2703 grounding and fire code compliant ‒ Aerotool Design Software

• Full layout, ballasting plan, material list, and

engineering reports

• Wet-stamp support for all 50 states
• Final engineering with detailed BOM

‒ Pre-attached EPDM rubber pads on supports to protect roof surface; ballast trays if required ‒ Fast installation with single tool ‒ Support for penetrations to lower ballasting

• r for Seismic requirements.

‒ Microinverters/optimizer/MLPE Frame Mounts ‒ Over 300MW of installed projects: last 3 years

Aerocompact Anchor Examples

(For Seismic, or to reduced roof loading and ballasting)

Example – More solar per roof possible with lower tilt arrays

Examples using Aerocompact South and East/West Ballast Rack

15° South Tilt Ballasted Racking

• 1,244 modules, 373.5kW DC Array
• Using 8x SE33.3kW inverters and P730 or P800P optimizers
• Array would produce estimated 608 MWh of power in year 1
• 3.22 psf roof dead load, needing 3,270 ballast blocks

5° South Tilt Ballasted Racking

• 1,430 modules, 400.4kW DC Array
• Using 9x SE33.3kW inverters and P730 or P800P optimizers
• Array would produce estimated 663 MWh of power yr1 (+9%)
• 2.80 psf roof dead load, needing 2,389 ballast blocks

10° Tilt East-West Ballasted Racking

• 1,586 modules, 444.6kW DC Array
• Using 10x SE33.3kW inverters and P730 or P800P optimizers
• Array would produce estimated 720 MWh of power yr1 (+18%)
• 2.35 psf roof dead load, needing only 910 ballast blocks
• Racking cost per watt can be up to half that of 15 degree racking,

as it uses less materials, and does not require wind screens.

SnapNrack Ultra Rail

SnapNrack Ultra Rail

• Lightweight rail solution that results in lower

installed cost solar racking, ideal for commercial applications

• Optimized for states for light to moderate snow

and wind loads, with largest span capabilities of any light rail solution

• UR60 (Avail. Q3) – Allowance for longer rail

spans and higher allowed snow/wind loads

• Low profile rail maintains open channel with

room for wire management

• Rails snap into mounts, with roof attachments

for composite shingle, tile, metal standing seam, and metal roofing systems

• Compatibility with all existing module clamps

maintains the same intuitive install experience installers know and love.

• Unparalleled wire management solutions with

accessories such as Junction Boxes, Universal Wire Clamps, MLPE Frame Attachment Kits, Smart Wire Clips, and Conduit Clamps

Commercial Ground Mount Arrays

• Small to Medium sized systems can be completed with a

conventional ground mount racking

• SnapNrack Series 200 Ground Mount can be competitively

employed for arrays up to about 150 kW DC.

• Example: 30kW racks of 100 300-watt, 60-cell modules with 25 rows
• f 4 high in landscape would result in a 30.0kW DC array, and using

3x Fronius Symo 24kW or 2x SMA Core1-50kW inverters

• In most environmental conditions, ten 3’ deep front piers and ten

4’ deep back piers are sufficient

• 4 racks → 112 kW DC array field
• This array could fit in a 100’ x 150’ space
• Cost roughly $0.15-0.17/watt, plus cost of support pipe and concrete
• Pile driven systems may require special engineering studies

and specialized equipment rentals that can quickly add too much cost and delays for small to medium sized PV projects

Commercial Ground Mount Arrays

SnapNrack Series 200UL

• Optimal solution for small to medium sized ground mount arrays
• Four Module High Landscape orientation, optimal deployment
• High module/power density
• UL2703 Listed – Only one grounding point per subarray required
• On-line configuration tool to determine BOM and engineering requirements
• Specialized equipment and soil study not required for installation
• Locally sourced Schedule 40 1-1/2” galvanized pipe lowers shipping costs
• Residential installers can easily utilize a known solution for larger projects

Commercial Ground Mount Arrays

Aerocompact CompactGround G and G+ Ballasted Racking

• Commercial and utility scale ground mount installations
• Quick install times, without the need for piles, concrete or large machinery.
• Install as Completely ballasted, or with optional screw soil anchors.
• Up to 1 MW of racking can ship to a jobsite in a single truck load.
• Ideal for areas that have soil issues like landfills or brownfields, areas that

cannot support deep piles or excavation due to rocks, or for areas of sensitive ecological nature where excavation is discouraged.

• Fleece mesh can be supplied to prevent vegetation growth around the

module field.

• This ground mount system can be designed with either a South

15°-20°-25° tilt, or with a 10° tilt East/West Configuration

Ballasted Ground Mount Arrays

Commercial Ground Mount Arrays

PLP Power Peak Commercial Ground Mount Racking

• Large Commercial or Utility Projects
• Can accommodate uneven terrain
• Two high portrait design typical to maximize number of panels per post
• Posts are typically pile driven; cement piers and ground screws available
• Designed for exceptional value for cost driven projects
• Soil sampling is required as part of the project planning process
• Aluminum extrusions, integrated grounding components, and component pre-assembly

allow this commercial racking system to be quickly installed

• Integrated grounding to UL2703 for lower install time and component count

Considerations for locating PV Inverters on Ground Mount Arrays

• Inverters for Ground Mount Arrays can be located behind the

panels on the ground racks to save space and simplify installation

‒ NEMA 4 enclosures of typical inverters allow outdoor mounting ‒ Locating decentralized inverters at panels simplifies array wiring and installation

• AC vs. DC voltage drop considerations

‒ Most 480VAC-3P inverters allow for 1,000 VDC max wiring ‒ Locating inverters close to point of connection will allow typical 600-800 VDC operation for array to inverter wiring

• 277 VAC Line-to-Neutral is 2-3 times more voltage drop and system

losses vs. 600-800 VDC wiring for equivalent wiring

• Mounting inverters under array may avoid extra DC disconnects
• Monitoring may be easier if inverters are centralized

Commercial System Monitoring

• Value of Commercial Monitoring
• Early detection of problems
• Identify problems before your customers do!
• Avoid Loss of generated Solar PV Production
• Avoid loss of SREC credits
• Commercial PPA agreements
• Reduce Energy Usage
• TOU/Demand charge avoidance
• Plan for Storage, if it makes sense
• Customer Assurance of Plant Performance
• Real Time Data
• Kiosk View for Facility
• Inverter Direct Monitoring through Inverter

Monitoring Platform

• Often included or easy upgrade from standard

inverters

• Fronius-Solar.Web, SMA-Sunny Portal, SolarEdge
• Inverter data (MPPT or Optimizer Level)
• Optional Upgrades
• Revenue Grade Meter for overall Plant Production
• Cellular Router and Data Plan
• Weather Station Data

Commercial System Monitoring

• SolarLOG Dataloggers and Monitoring Service
• One platform, central monitoring for all PV Systems
• Subscription service to WEB Enerest XL
• Automatic SREC Data Reporting
• Feed-In Management to Grid/Self Consumption
• Integration with most inverters
• Inverter level data, down to MPPT level
• Optional Active monitoring of PV Plants
• 24/7 Active Professional Monitoring – WEB-4U
• Options
• Cellular Router and Data Plan
• Solar RGM kit
• Facility Consumption Metering
• Weather Station Data if needed
• Customizable Kiosk View available
• eGauge Commercial Dataloggers
• Easy to deploy Datalogger, with CTs to capture data
• Customizable – Place CTs where needed
• Around PV Plant Output, or on each inverter output
• PV Production and Consumption Monitoring
• Real Time Data Stream
• Direct Reporting of SREC data
• Options
• Powered NEMA 4x Enclosures
• Cellular, WiFi, Powerline, or Wired Connections
• Customizable Kiosk Views available

Federal ITC and MACRS Depreciation Tax Credits

• Federal Investment Tax Credit (ITC)
• 30% tax credit through 2019
• Drops to 26% in 2020
• 22% in 2021
• 10% from 2022 on (no expiration for commercial ITC)
• Modified Accelerated Cost Recovery System (MACRS)
• 5-year accelerated depreciation for solar assets
• Represents additional tax savings of up to 10% of system cost
• The ‘Protecting Americans from Tax Hikes Act of 2015’ included an

extension for bonus depreciation in YR1

• Companies could elect to have an initial depreciation bonus up front, while

remainder is depreciated under the normal MACRS recovery period.

• 2015-2017-50%, 2018-40%, 2019-30%, 2020-0%
• NOTE: See that your end-customer reviews these options with their

accountant and/or tax attorney

MACRS Depreciation Example

MACRS Depreciation Example

• Consult your tax professional about IRS Form 4562 in calculating the

allowed MACRS depreciation for the 6 year period.

‒ 85% of the net PV install costs are eligible for depreciation ‒ Depreciation Schedule for year 1 to year 6

• 20% / 32% / 19.2% / 11.52% / 11.52% / 5.76%
• Determines the ‘deduction’. Actual value depends on Corporate Tax Rate
• Example: 40kW PV array, $100,000 total system cost, and 30%

corporate tax rate

‒ Year one ITC Federal Tax Credit - $30,000 tax credit ‒ Tax savings resulting from calculating MACRS Depreciation

• Year 1 - $5100
• Year 2 - $8160
• Year 3 - $4896
• Year 4 - $2938
• Year 5 - $2938
• Year 6 - $1468
• Net PV system install cost over 6 year period after ITC & MACRS

‒ $100,000 - $30,000 - $25,500 = $44,500 net system install price ‒ System costs drop to $1.11/watt, ~50% of project offset by tax credits ‒ This is independent of the value of the energy provided!

Questions and Answers Questions?

Aerocompact 5° South Racking

Aerocompact 5° South Racking

Aerocompact 10° South Racking

Aerocompact+ 10° East-West

Aerocompact+ 10° East-West

Aerocompact 5° Racking