Impact of black silicon on the total yield of a system-Malcolm Abbott

www.pvlighthouse.com.au Premium PV software Slide 1 Impact of black silicon on the total yield of a system CSPV 2018 Malcolm Abbott1,3, Keith McIntosh1, Ben Sudbury1, Jenya Meydbrey2, Tsun Fung3, Muhammad Umair Khan3, Yu Zhang3, Bram Hoex3, David Payne3,4 www.pvlighthouse.com.au Premium PV software Slide 2 Project overview Creating algorithms/models Implementing in SunSolve™ Running simulations Building test systems for validation Making design decisions for utility scale Fundamental research Characterisation of texture Many other partners involved www.pvlighthouse.com.au Premium PV software Slide 3 • Improve the accuracy of total yield simulations – The true output of solar technology is the amount of energy it delivers when deployed in a real situation. – Used to design and finance large installations. • Understand/optimise the performance of black silicon – What is the impact of different black silicon technology on the total energy yield of a bifacial tracking system? – Can black silicon replace upright random pyramids on mono- crystalline silicon? • Develop modelling techniques for black silicon – Must be fast to solve. – Must include angular and specular dependence. Motivation www.pvlighthouse.com.au Premium PV software Slide 4 • Determine the annual energy output for a module installed in a system. • How does technology interact with variable conditions? Total energy yield simulations Optical Solver Temperature Solver Electrical Solver Environmental Conditions Energy (kWhr) www.pvlighthouse.com.au Premium PV software Slide 5 Systems investigated • Bifacial • 1D tracking, NS axis • One-high Image from https://www.nextracker.com www.pvlighthouse.com.au Premium PV software Slide 6 Detailed solving example θsun = 90˚ φsun = 91˚ θinc = 90˚ θmod = 0˚ Example system Bifacial 1D tracking with axis oriented north-south. Located in Golden Colorado www.pvlighthouse.com.au Premium PV software Slide 7 Detailed solving example 4 3 2 1 South θsun = 90˚ φsun = 91˚ θinc = 90˚ θmod = 0˚ Cell generation map 72 cells in each module. Each cell ray traced to the micron level. Ray tracing includes frames and white space. www.pvlighthouse.com.au Premium PV software Slide 8 Detailed solving example 4 3 2 1 South θsun = 90˚ φsun = 91˚ θinc = 90˚ θmod = 0˚ Power versus time Direct and diffuse light (including spectra). Output power of modules. www.pvlighthouse.com.au Premium PV software Slide 9 Detailed solving example 4 3 2 1 South θsun = 90˚ φsun = 91˚ θinc = 90˚ θmod = 0˚ Relative power of each module Solved for each cell at 300K and at elevated temperature. Module solver includes bypass diodes, ribbon etc. Modules assumed ‘disconnected’. www.pvlighthouse.com.au Premium PV software Slide 10 Detailed solving example 4 3 2 1 South θsun = 90˚ φsun = 91˚ θinc = 90˚ θmod = 0˚ Mismatch loss Caused by non-uniform illumination. Further mismatch possible with additional cell-to-cell variance. www.pvlighthouse.com.au Premium PV software Slide 11 Detailed solving example 4 3 2 1 South θsun = 90˚ φsun = 91˚ θinc = 90˚ θmod = 0˚ www.pvlighthouse.com.au Premium PV software Slide 12 Detailed solving example 4 3 2 1 South θsun = 84.3˚ φsun = 102˚ θinc = 60.4˚ θmod = 24.5˚ www.pvlighthouse.com.au Premium PV software Slide 13 Detailed solving example 4 3 2 1 South θsun = 73.3˚ φsun = 112˚ θinc = 24.3˚ θmod = 60.0˚ www.pvlighthouse.com.au Premium PV software Slide 14 Detailed solving example 4 3 2 1 South θsun = 63.2˚ φsun = 124˚ θinc = 30.0˚ θmod = 58.6˚ www.pvlighthouse.com.au Premium PV software Slide 15 Detailed solving example 4 3 2 1 South θsun = 54.5˚ φsun = 138˚ θinc = 37.4˚ θmod = 43.0˚ www.pvlighthouse.com.au Premium PV software Slide 16 Detailed solving example 4 3 2 1 South θsun = 48.2˚ φsun = 156˚ θinc = 42.7˚ θmod = 24.7˚ www.pvlighthouse.com.au Premium PV software Slide 17 Detailed solving example 4 3 2 1 South θsun = 45.3˚ φsun = 176˚ θinc = 45.1˚ θmod = 4.2˚ www.pvlighthouse.com.au Premium PV software Slide 18 Detailed solving example 4 3 2 1 South θsun = 46.5˚ φsun = 197˚ θinc = 44.1˚ θmod = 16.8˚ www.pvlighthouse.com.au Premium PV software Slide 19 Detailed solving example 4 3 2 1 South θsun = 51.6˚ φsun = 215˚ θinc = 39.8˚ θmod = 36.1˚ www.pvlighthouse.com.au Premium PV software Slide 20 Detailed solving example 4 3 2 1 South θsun = 59.4˚ φsun = 231˚ θinc = 33.0˚ θmod = 52.7˚ www.pvlighthouse.com.au Premium PV software Slide 21 Detailed solving example 4 3 2 1 South θsun = 69.1˚ φsun = 243˚ θinc = 25.6˚ θmod = 60.0˚ www.pvlighthouse.com.au Premium PV software Slide 22 Detailed solving example 4 3 2 1 South θsun = 79.8˚ φsun = 254˚ θinc = 28.5˚ θmod = 55.2˚ www.pvlighthouse.com.au Premium PV software Slide 23 Detailed solving example 4 3 2 1 South θsun = 90˚ φsun = 268˚ θinc = 90˚ θmod = 0˚ www.pvlighthouse.com.au Premium PV software Slide 24 • We solve this for everyday of the year, the chart below is an example output from this type of simulation. • It is a prediction of the amount of energy to be generated every hour of every day of the year (~4300 solutions). Solving annual yield The true output of solar technology www.pvlighthouse.com.au Premium PV software Slide 25 • Inputs are material properties and geometries. • Optics solved by ray tracing: – cloud-based (≤ 1000 parallel cores) – optimized physics solver – extremely fast. • Widely used by – tier 1 module manufacturers – materials companies – leading research institutes. • Expanded for PV systems – Ground, torque-tube, system configuration, backtracking – SPICE to solve module circuit – Temperature model SunSolve™ www.pvlighthouse.com.au Premium PV software Slide 26 • For black silicon we are mostly concerned with the optical solver. • We have assumed no change in temperature or recombination (future work?). Total yield of black silicon Optical Solver Temperature Solver Electrical Solver Environmental Conditions Energy (kWhr) www.pvlighthouse.com.au Premium PV software Slide 27 3 μm Technology investigated 3 μm 3 μm Typical MCCE Advanced MCCE Upright Random Pyramids Isotexture www.pvlighthouse.com.au Premium PV software Slide 28 Texture reflectance (no ARC) 0 10 20 30 40 50 60 300 400 500 600 700 800 900 1000 1100 1200 Re flect ance (%) Wavelength (nm) Isotexture Typical MCCE Advanced MCCE Random Pyramids These textures cover a very typical range of performance for industrial style texturing. www.pvlighthouse.com.au Premium PV software Slide 29 How do we model black silicon? That depends on (1) the size and (2) the shape. K. Tang, R.A. Dimenna, R.O. Buckius, Regions of validity of the geometric optics approximation for angular scattering from very rough surfaces, Int. J. Heat Mass Transf. 1 (1996) 49–59. 0.01 0.1 1 10 0.01 0.1 1 10 σ/ τ σcos(ϴ0)/λ Geometric optics approximation region Specular approximation region Electromagnetic theory region www.pvlighthouse.com.au Premium PV software Slide 30 We can measure the size (mostly). 0E+00 2E+06 4E+06 6E+06 8E+06 1E+07 1E+07 0 100 200 300 400 500 ρ (µ m- 1 ) Surface height (nm) 4 min 6 min 8 min 16 min 14 kW 16 kW 18 kW 22 kW 0.0 0.2 0.4 0.6 0.8 1.0 0 100 200 300 Nor mali zed De ns ity Surface Height (nm) σrms • Size distribution measured and statistics extracted using AFM or other more advanced techniques. • More about this in the next talk.