22
Analyzing Risk & Economic Impact of Two Solar Tracker Architectures November 2017

Analyzing Risk & Economic Impact of Two Solar Tracker ... · Analyzing Risk & Economic Impact of Two Solar Tracker Architectures ... The report analyzes the economics and risks of

Embed Size (px)

Citation preview

Analyzing Risk & Economic Impact of Two Solar Tracker ArchitecturesNovember 2017

ARRAY HAS INSTALLED +13,000 MILES OF TRACKERS

“Array has the most extensive track record of any PV tracker vendor.”

– Greentech Media Research, Global Tracker Landscape Report 2017

Munich,Germany

Hawaii,USA

Vast experience provides timeless reliability

16,000+ MW Years of Operation

TÜV Rheinland

• Founded in 1872, TÜV Rheinland is a global leader in independent engineering services, ensuring quality and safety for people, the environment, and technology in nearly all aspects of life. • Due to TÜV’s extensive experience with solar power plants,

they support their clients in all project phases and ensure plant safety and reliability.

Risk & Economic Analysis

The report analyzes the economics and risks of two solar tracker architectures.1. The first architecture is a centralized system

driven by a single motor, linked by a rotating driveline to multiple tracker rows.

2. The second architecture is a decentralized system where each row operates as a self-contained unit with a dedicated photovoltaic (PV) panel, battery, motor, and other components.

Download the report here: http://www.arraytechinc.com/tuv-report-findings/

TÜV’s in-depth process

Summary of Architecture 1

& 2

Summary of Failure Modes

and High Ricks

Components

Comparative Failure Modes

and Effects Analysis

(FMEA) and Cost Priority

Number (CPN) Analysis

Cost of Failure Analysis

NPV and LCOE Calculations

Comparative failure mode effects analysis (FMEA)

FMEA is an important factor in determining LCOE/NPV often discounted or given cursory attention, this factor can make or break a project

Example of components studied: • Motor Drive• Tracker control• Communications• Sensors

Key component selection

(less than 30 year life)

Architecture 1 Architecture 2

Tracker Control 30.5 units, 15 years 3400 units, 15 years

Site Control 1 unit, 15 years 8 units, 15 years

Battery - 3400 units, 7 years

Communication & Sensors 1 unit, 15 years 3400 units, 15 years

Motor Drive 122 units, 30 years 3400 units, 15 years

Transmission Worm Gear: 3400 units, 30 years

Slew Drive: 3400 units, 30 years

Torque Tube 27200 units, 30 years 34000 units, 30 years

Mechanical End Stop 34000 units, 30 years 34000 units, 30 years

Bearings Included in End Stop 34000 units, 30 years

Vibration Dampeners 6800 units, 30 years 6800 units, 30 years

Steel Structure 3400 units, 30 years 3400 units, 30 years

FMEA: Number of parts vs life expectancy

Total Number of Parts

Architecture 1 74954Architecture 2 129208

0

20000

40000

60000

80000

100000

120000

140000

Less components. Fewer failures. More reliable.

ArrayDuraTrackHZv3 DecentralizedRow

TrackerElectricalandElectromechanicalComponents UnitsPer100MW UnitsPer100MW

Activestowcomponents(anemometers) 0 20Motors 122 3400Inclinometers 0 3400Controlelectronics 31 3400Ancillarysolarmodules 0 3400Wirelessradios 0 3400BatteryChargecontrollers 0 3400Batteries 0 3400TOTALCOMPONENTSper100MW 149 25,220

153TOTAL

COMPONENTS

23,820 TOTAL

COMPONENTS

Cyber Attack

A system is only as strong as its weakest link

Anemometer

With an electrical stow design, any failure of ANY link in the chain leaves the system vulnerable to catastrophic failure during wind and snow events

Battery for Central Controller

Coaxial Controller Panel Supply

Central Controller Electronics

Radio

Radio

Row Controller Electronics

Row Controller Power Supply

Row Controller Motor

Row Controller Battery

Unscheduled maintenance costs

• Costs were calculated using a Cost of Failure (CoF) methodology, which estimates the expected market cost of a failure.• Cost of failure

calculations are unique to each architecture as they are a function of cost of the part being replaced, labor, and production losses.

Unscheduled O&M Leads to Significant Cost*

With Centralized Trackers: 1 repair/year for 100 MW site, and far fewer truck rolls†

With Decentralized Trackers:794 repairs/year (2 per day) for 100 MW site, and far more truck rolls†

433 × fewer number of service hours†

†Verified by 3rd party data from TÜV

*Verified by 3rd party data from TÜV

LCOE & NPV findings

TÜV Spreadsheet: 30 year warranty

TÜV Spreadsheet: = Sched. Maintenance

TÜV Spreadsheet: 30% discount

TÜV Spreadsheet: Can it pencil?

TÜV Spreadsheet: But wait a second…

7% Lower LCOE*

CAPEX

Highest uptime in the industry delivers

maximum energy production

Production

OPEX

Streamlined installation and commissioning reduces time onsite

and saves upfront cost

The lowest scheduled and unscheduled O&M achieves the highest savings

7% Lower LCOE†

†Verified by 3rd party data from TÜV

*Verified by 3rd party data from TÜV

Is your site destined for catastrophic failure?

Wind calculations, what can go wrong? • Use of existing code pressure

coefficients & methods• Mono-slope roof coefficients

developed for 4-leg table• Improper dynamic analysis

(1 Hz is not safe!)

• Too low or misapplied wind tunnel coefficients• Small area concentrations,

directionality, tracker angles, GCR not considered

• Effects on misaligned rows

• Ignore specific effects of wind • Torsion, dynamic behavior

• Stow methodology too heavily relied upon

• Forces may be magnified by 3-4X in some cases!

Post Hurricane Maria damage in Puerto Rico

Proper wind calculations• Determine tracker e requirements for

wind/snow/seismic/etc. considering• Stow strategy• Local studies and code development• Wind tunnel analysis

• Develop dynamic model of the system• Structural natural frequencies• Damping mechanisms• Wind forcing functions

• Design for max load combinations according to code requirements (generally wind+snow)• Will stow mechanism see same loads as structure?• Choose max load conditions at each tracker position• Incorporate dynamic response into static load

combinations as appropriate• Local and edge forces amplified compared to system-

level

• Analyze worst case events on structural and mechanical components• Fatigue• Max load

Questions?• There may be more components in some systems but those components

are far less expensive. How does that affect O&M costs?• What components should I pay particular attention to? Are there

components which are more prone to failure?• Of the various tracker system architectures which has proven to be the

most reliable?• You raise the question of catastrophic failure. Is this a common

occurrence? If so why haven’t we heard more about it?

22