What Are the Major Innovations in Solar PV Cell Technology | 3 Major Innovations

Perovskite tandem conversion efficiency breaks 33%, N-type HJT mass production efficiency exceeds 26%, bifacial modules utilize reflection extra lift 15% electricity quantity.

Suggest purchasing N-type bifacial modules, and lay a bottom reflective film in order to maximize revenue.

TOPCon/HJT

Chat chat thickness

TOPCon cells internal needs to lay one layer thickness strictly controlled at 1.5 to 2.0 nanometers range inside silicon oxide tunnel layer. Closely sticking to this tunnel layer above the polysilicon coating thickness usually maintains inside 15 to 20 nanometers standard specification. HJT cells use intrinsic amorphous silicon thin film on the front and back two sides P region and N region separate open, this layer thin film physical size is limited to 5 to 10 nanometers in an extremely narrow range.

Adopting HJT process silicon wafer thickness has already declined from previous few years, 160 micrometers, to current 130 micrometers, several head laboratories are currently testing a 90 micrometers limit slicing thickness. Silicon wafer thickness every decreases 10 micrometers, single piece module silicon material manufacturing cost can just reduce about $0.015. One line production capacity reaches 1 gigawatt production line, every year consumes silicon wafers quantity as high as about 12 million pieces huge base number.

Calculate calculate temperature

Producing TOPCon modules factory needs to high temperature diffusion furnace internal temperature raise to 800 to 850 degrees Celsius. Up to 120 minutes high temperature baking cycle will consume away whole assembly line about 30% of the total electricity quantity budget. Turn to HJT process route after, production line on highest processing temperature is forcibly suppressed at 250 degrees Celsius warning line below. Lower than 250 degrees Celsius processing environment greatly reduced silicon wafer physical warpage probability, put mass production link fragmentation rate controlled at 0.5% ratio range inside.

l HJT cells at outdoor running time temperature coefficient performance is excellent, numerical value reaches -0.24%/degree Celsius, deviated from conventional cells -0.35%/degree Celsius average number.

l When the summer photovoltaic panels surface temperature reaches 65 degrees Celsius peak value time, HJT modules actual output power compared to other modules extra out 4% to 5% ratio.

l This kind of low temperature process put the whole set production working procedures streamlined to merely 4 steps, single piece cell average production stay time shortened by about 40%.

Silver consumption quantity

Manufacturing one piece standard size TOPCon cell, front and back two sides printing circuit needs to consume about 110 to 130 milligrams of silver paste. Industry inside through large area adopting 0MBB busbarless process, already put single piece cell pure silver material fee pushed down to $0.04. HJT cells because of the need for low temperature solidification, single piece needs to consume 120 milligrams of low temperature silver paste. This kind of chemical material unit price compared to high temperature silver paste expensive about 20%. In order to lower this part's total bill of materials, 15% proportion high budget, global factories generally introduced contains 30% to 50% copper module silver-coated copper material do 1 to 1 ratio replacement.

l Put silver paste printing line width from 35 micrometers compressed to 20 micrometers below, every year can for one line 5 gigawatts production capacity factory save down exceeding 2 million dollars money budget.

l Through put secondary grid lines quantity increased to 16 lines even 20 lines above, electrons transmission distance shortened about 15 micrometers.

l Transmission distance shortening put internal series resistance lowered 10%, along with it brought 0.1% photoelectric conversion efficiency lift.

Look bifacial ratio

Deployed in light reflectance exceeding 30% sandy land environment inside, bifacial modules absorb ground scattered light can increase 8% overall power generation revenue. TOPCon cells back side photoelectric conversion efficiency and front side efficiency ratio, that is bifacial ratio parameter, all year round stable at 80% to 85% range inside. Symmetrical structure HJT cells bifacial ratio factory test parameters generally exceed 90%, part extreme value samples even reached 95% upper limit.

Installed at leaving ground 1.5 meters high fixed bracket on time, 90% bifacial ratio HJT array compared to 80% bifacial ratio array extra outputs about 2.5% annual average power generation quantity. If the total weight is 25 kilograms, modules equipped with every day rotate 120 degrees angle single-axis tracking bracket, this kind of high bifacial ratio brought power generation quantity amplitude will magnify 1.5 times. In up to 8760 hours full year running cycle inside, extra increased 2.5% electricity quantity can let a 100 megawatts power station overall recovery cycle shortened by about 6 months.

Calculate calculate account book

Establish one line brand new TOPCon production line, per gigawatt hardware equipment purchasing budget roughly is at 15 million to 18 million dollars. Newly built HJT production line initial fixed asset investment leans high, per gigawatt funds fee at 25 million to 30 million dollars range inside fluctuates. Photoelectric conversion efficiency as high as 25.8% mass production HJT modules, at global terminal market single sales price per watt can get $0.015 premium.

In 30 years, the product's full life cycle inside, HJT cells first year light-induced degradation rate controlled at 1% within, subsequent 29 years inside average every year appears 0.25% power decline rate. Comprehensively comparing production cost and life cycle total power generation quantity after, TOPCon project internal rate of return maintains at 8.5% median value, HJT project approached 8.2% revenue ratio. As long as HJT production equipment penetration rate crosses 80%, its per watt comprehensive manufacturing cost will decline 15 percentage points.

Tandem/Multi-Junction Solar Cells

Look wide narrow

Single piece crystalline silicon cell physical absorption upper limit is stuck at 29.4% fixed numerical value. Towards silicon wafer above stacking one layer thickness at 400 to 600 nanometers range inside perovskite thin film, photoelectric conversion efficiency theoretical ceiling is pushed high to 43%. The top perovskite layer bandgap width is usually allocated at 1.67 to 1.75 electron volts, and is specially responsible for swallowing wavelengths at 300 to 600 nanometers inside the high energy shortwave blue-green light.

Bottom silicon wafer bandgap maintains at 1.12 electron volts physical constant, used to absorb wavelengths between 600 and 1000 nanometers infrared light and near infrared light. At two layers, the middle insert one layer thickness merely is 15 to 25 nanometers composite conductive layer, light transmittance parameter needs to be strictly maintained at 98% above extremely high level. Two layers cells superimposing after absorbing solar spectrum in about 85% visible light energy, makes overall short circuit current density maintain at per square centimeter 20 milliamperes level.

Calculate calculate voltage

Single junction TOPCon cells open circuit voltage usually can only reach 0.72 volts, the average number. Single junction perovskite cells open circuit voltage can easily run onto the 1.20 volt high position range. Adopting two terminals series structure tandem cells in a laboratory environment inside open circuit voltage test samples broke through 1.92 volts extreme value. Voltage multiplying amplifier put single piece module at standard light intensity under output power lifted about 35% ratio.

Whole piece tandem panel fill factor parameter in the past three years time inside from 72% climbed to current 82% baseline. Series structure requires top cell and bottom cell output current must achieve 1 to 1 absolute matching, any 5% above current deviation will trigger wooden barrel effect. If the top layer perovskite because of thickness uneven causes current less output 0.5 amperes, the whole piece tandem cell total current will also synchronously decline 0.5 amperes numerical value. Series internal resistance loss is finely controlled at 0.1 ohms per square centimeter low micro range inside, significantly lowered charge transmission process inside energy dissipation.

Fear water, fear heat

Perovskite materials towards working environment humidity and temperature have extremely harsh physical limits. At 85 degrees Celsius high temperature and 85% relative humidity, dual pressure under continuous baking 1,000 hours, module power degradation rate must be controlled at 5% allowable range inside. Encapsulation used polyolefin elastomer film thickness needs to increase to 450 micrometers, water vapor transmission rate index must be lower than every day per square meter 0.0001 grams, extremely low order of magnitude.

When the outdoor temperature crosses the 60-degree Celsius threshold, material internal halides will happen 20% to 30% ratio phase separation phenomenon. Test data shows, experiencing continuous 10,000 hours solar simulator irradiation after, adopting newest encapsulation material tandem samples still maintained initial efficiency 95% absolute value. The life cycle is rigidly stipulated at 25 years, with the initial degradation rate upper limit set at 2%, thereafter 24 years annual average degradation rate not exceeds 0.45%. In order to resist minus 40 degrees Celsius to above zero 85 degrees Celsius high frequency thermal expansion cold contraction cycle test, bifacial glass thickness specification uniformly maintains at 2.0 millimeters standard line on.

Construction price pattern

Want to silicon wafer surface evenly coat perovskite solution, slot die coating equipment running speed currently is set at per minute 2 to 5 meters range. Adopting atomic layer deposition technology manufactured tin oxide electron transport layer, processing one furnace 500 pieces cells needs to consume about 45 minutes waiting cycle. Silver paste purchasing fee at BOM bill of materials inside proportion is significantly compressed, per watt silver consumption quantity is abruptly squeezed to not enough 5 milligrams limit range. Once tandem production line comprehensive yield rate crosses 90% watershed, per watt comprehensive manufacturing cost can just be with current single junction crystalline silicon route tie flat.

Occupy land return

One piece 2 square meters standard size conventional module, rated output power usually calibrated at 600 watts parameter level. Exchanged onto a 30% conversion efficiency tandem module after, completely same volume and area panel, output power reached astonishing 750 watts. The area receives a strict limit of 30 square meters on the roof, and the total installed capacity from 10 kilowatts jumped to 12.5 kilowatts.

At daily average 4 hours effective light illumination, statistical distribution under, whole set system every day can extra output 10 kilowatt-hours electricity pure revenue. Every year, extra 3650 kilowatt-hours of electricity can put the whole power station funds recovery cycle shortened by about 1.5 years. Large ground power stations because of power density lifting, bracket purchasing, cable laying and land leasing average apportioned fees declined about 18% ratio. Investors project internal rate of return from 9.5% median value towards up floated to 12.2% extremely high range. Every invested 1 million dollars to construct a tandem photovoltaic matrix, full life cycle inside electricity fee total revenue expectation will reach 2.8 million dollars rich return.

Bifacial Solar Panels

Two sides both generate power

Conventional single-sided modules backplane usually uses opaque white polyvinyl fluoride backplane, light rays penetrate silicon wafer after will be converted into waste heat, leading to module working temperature climb to 55 degrees Celsius above, triggering -0.35%/degree Celsius negative power temperature coefficient penalty. Bifacial modules at the back side exchanged onto light transmittance reaching 97.5% 2.0 millimeters semi-tempered glass, allowing wavelength at 300 to 1,100 nanometers range inside photons secondary penetrate, enter silicon wafer back side PN junction conduct secondary photoelectric conversion.

At standard test conditions (1000 watts/square meter irradiance, 25 degrees Celsius test temperature), the back side light-receiving surface is able to provide 5% to 30% short circuit current increment, putting one piece nominal power at 580 watts module, abruptly pushed to the highest 750 watts comprehensive output extreme value. N-type TOPCon cells factory bifacial ratio parameters are locked at 80% to 85% statistical range inside, and HJT heterojunction cells relying on symmetrical physical structure, its bifacial ratio median value all year round maintains at 92% above, part laboratory samples highest test values approached 98% theoretical extreme value.

Look reflectance

Bifacial modules extra power generation revenue depends on installation ground surface albedo parameter, different materials ground surface will towards spectrum produce huge scattering variance. Paved full fresh snow high latitude areas surface albedo as high as 80% to 90%, painted high reflective white paint cement roof albedo distributed at 60% to 70% range, dry light color sandy terrain maintained at 40% average number, and grew full green vegetation grass land and black asphalt road surface then respectively plummeted to 15% and 7% extremely low ratio.

When one beam intensity is per square meter, 800 watts of vertical incident light hits the module front side. If the ground albedo reaches 50%, the back side can receive about 120 watts/square meter diffuse reflection radiation flux. This kind of front-back two-sides simultaneously being excited physical state, let module internal electrons and holes pair concentration present exponential level growth, overall output working current from single side receiving light time 13 amperes sharply increased to 15.5 amperes above. In order to bear this kind of big current continuous high load impact, the combiner box internal fuse rated current specification must be forcibly adjusted from the traditional 15 amperes to the 30 amperes safety threshold.

According to the North America area 100 megawatts level power station continuous 36 months dispersion statistical samples, at an average albedo of 65% white paint roof on deploy bifacial modules, full year 8,760 hours cumulative power generation quantity compared to single-sided modules extra out 18.5% absolute revenue percentage, abruptly put system levelized cost of energy towards down pushed low $0.006/kilowatt-hour, overall investment rate of return presented extremely high positive correlation.

Calculate calculate bracket

Modules installation tilt angle and leaving ground clearance height are affecting back side entering light quantity two biggest variable parameters. If the fixed bracket leaves the ground height from 0.5 meters to 1.5 meters high position, the back side captured photon quantity will present a 12% to 15% non-linear growth rate. Matched with single-axis tracking bracket periodic running inside, tracker main axis will one day middle from negative 60 degrees angle uniform speed flip to positive 60 degrees angle, constantly maintain with solar rays vertical intersection angle. This kind of dynamic tracking can put front side vertical light absorption rate lift 25%.

Because of the tracking system, the bottom usually has one root diameter that reaches 100 millimeters, this root thick and strong steel tube will at every day noon 12 o'clock around the module back side project out about 50 millimeters wide shadow band. Blocking will lead to back-side local short circuit current suddenly drop about 4%, at system design time, must put inverter direct current turn alternating current capacity ratio parameter from 1.2 downward adjust to 1.15, used to buffer noon time period as high as 15% peak power fluctuation.

Installation height breaks through 1.5 meters critical value after, back side irradiance marginal revenue diminishing curve becomes extremely steep, every towards up lift high 0.1 meters only can exchange come less than 0.5% power generation increment, but with it corresponding is per megawatt system needs extra consume about 4500 kilograms galvanized steel material, overall hardware purchasing budget wants upward float about 6,000 dollars money fee.

Compete light transmittance

Bifacial dual-glass modules encapsulation structure by two layers thickness each is 2.0 millimeters glass sandwiching middle silicon wafer composed, total volume and weight are significantly pushed high. One piece length 2,384 millimeters, width 1303 millimeters 72-cell layout dual-glass module, its physical absolute weight reached 34.5 kilograms, compared to the same size single-glass module, it is heavy full 6 kilograms. Per square meter, 11 kilograms of mass load requires photovoltaic bracket compressive strength must satisfy front side 5400 pascals static snow load test, as well as back side 2400 pascals dynamic wind load cycle.

Polyolefin elastomer at laminator inside experiencing 150 degrees Celsius high temperature cross-linking reaction after, volume shrinkage rate less than 2%, perfectly filled cell pieces and glass with 250 micrometers physical gap. This kind of encapsulation process puts glass inside an iron element concentration lowered to 120 parts per million below, ensuring penetrating two layers of glass after effective photon retention rate maintains at 95% ultra high baseline.

Traditional EVA film on both sides receiving light brought continuous ultraviolet ray bombardment, extremely easy to produce acetic acid byproducts, leading to light transmittance every year decline 0.2% rate. In order to suppress this kind of chemical degradation, factories put encapsulation materials completely replaced by polyolefin elastomer. This kind of polymer has a water vapor transmission rate rigidly suppressed at every day per square meter 1.0 grams below extremely low order of magnitude.

Life big test

Adopting dual-glass symmetrical encapsulation modules at resisting micro cracks and resisting potential induced degradation physical confrontation inside occupied advantage. Because of glass water permeability rate is zero, the back side no longer like organic backplane that way exists water vapor penetration probability, usage lifespan age upper limit is forcibly delayed to 30 years even 35 years time span inside. In up to 30 years' time, long river inside, manufacturers give linear power warranty clauses very harsh: running first year light-induced degradation rate forcibly limited to 1% narrow range inside, subsequent 29 years annual average power decrease rate fixed at 0.4%.

Walk 30th year, modules retained output power bottom line still as high as initial nominal value of 87.4%. Towards a 50 million dollar budget 100 megawatts level ground power station, life cycle is pulled long 5 years, extra plus back side contributed 10% average power generation amplitude, at discount rate set as 6% financial model under, whole project internal rate of return will from 8.5% median value pull lift to 10.8% high position range, extra create out about 12 million dollars net present value currency return.

According to a third party laboratory issued continuous 3,000 hours damp heat cycle test report, bifacial dual-glass modules at 85 degrees Celsius and 85% relative humidity extreme environment under, overall power biggest degradation variance extremely rarely breaks through 2.5% warning line, test error and deviation values far far lower than single-glass modules 5% allowable accuracy upper limit.