What Are the Benefits of Solar Tracking Systems | Energy Gain, Sun Alignment Efficiency

Single-axis tracking can lift power generation about 15%–25%, dual-axis reaches 30%–40%; real-time tracking sun angle (error < 2°). Suggest combining irradiance data to optimize control algorithm and regularly calibrate drive system.

Energy Gain

Curve pull flat

Conventional fixed tilt angle bracket's power generation power curve presents a steep parabola shape, normally only can at morning 11:30 to afternoon 1:30 this period 2 hours inside reach 85% above's rated power output. Flat single-axis tracking system through every interval 3 to 5 minutes turning 0.5 to 1 degree, makes photovoltaic modules at morning 8 o'clock and afternoon 4 o'clock's power generation power compared to fixed bracket respectively lifted 40% and 45%.

A unit rated capacity being 100 megawatts' solar power station, on a clear summer day, single day full load running's time from original's 4.5 hours extended to 7.2 hours. Broad flat's power generation curve lets the inverter operate at 60% to 90% high efficiency load interval inside every day extra run 180 minutes, inverter's AC-DC conversion efficiency therefore stabilizes at 98.5% highest threshold. Statistics latitude at 25 degrees to 45 degrees between's 50 pieces commercial power station sample data show, single-axis system's whole year overall power generation amount increment distributes at 14.6% to 21.3%'s interval inside.

Match double face

· Single-axis tracker and power attenuation rate only being every year 0.4%'s double-face double-glass module combined using time, system overall's equivalent full load utilization hours number increased from 250 hours to 320 hours.

· Reflectivity being 30% light color sandy soil ground environment inside, bracket rotation axis distance ground 1.5 meters to 2 meters' design, lets module back face received's scattered radiation amount reached per square meter 150 watts to 200 watts.

· Back face's extra power generation amount is able to bring 7% to 12% power generation gain, making the whole direct current side's input power peak value at noon time period exceeded module front face nominal power's 5% to 8%.

· In order to handle overflowed electric energy, design personnel normally put the system's capacity allocation ratio from conventional's 1.15 to 1.25, allowing the inverter to appear 3% to 4% of the time in a limit power running state.

· The environment temperature reaches 35 degrees Celsius's high temperature time period, the leeward face's airflow flow speed with per second 1.2 meters' speed takes away heat, makes the module backplane's actual running temperature lowered 2.5 degrees Celsius to 3 degrees Celsius, according to the negative 0.35%/℃'s temperature coefficient, nearly 1% power loss is successfully exchanged back.

Overcast day power generation

Cloud layer coverage rate exceeding 60% cloudy or overcast rainy weather under, sky inside's direct radiation amount will sharply drop to per square meter 200 watts below. Tracking system's controller will cut off standard's astronomical aligning sun trajectory algorithm, in 2 minutes, inside puts photovoltaic panel's tilt angle adjusted to 0 degrees' completely horizontal state. Horizontally placed modules are able to maximize area-ly capture coming from the whole sky dome's diffuse reflection light, system at low irradiance conditions under's current output raised 4.5% to 6.2%.

Meteorological station point's historical irradiance probability model shows, at annual average rain falling days reaching 120 days' climate zone, anti-shadow and weak light capturing strategy can exchange back every year total power generation amount 2.8% to 3.5%'s loss. Once the illuminometer detects direct light intensity at continuous 5 minutes inside, returns rising to per square meter 300 watts above, push rod motor immediately with per minute 1.5 degrees' rate rotates, not reaching 10 minutes inside re-aligns sun's real-time azimuth angle.

Calculate tilt angle

High latitude region's sun elevation angle at winter's lowest will drop to 15 degrees to 20 degrees, fixed type bracket produced's shadow length will compared to summer increase 2.5 times to 3 times. Adopting reverse backtracking algorithm's controller, at sun elevation angle lower than 25 degrees' morning and evening time period, will actively put module's tilt angle toward back retreat 5 degrees to 12 degrees.

Reverse rotation deviates from theoretical optimal incidence angle, makes single piece module received's radiation amount reduced 1.5% to 2%, but thoroughly avoids front row module toward back row bottom end 1/3 region caused's shadow blocking.

Bypass diode at blocking time will cut off the whole string cell's current passing, avoiding 10% area's blocking actually exchanged back one whole string photovoltaic module's 100% power dropping. Calculating different row spacing's array discovers, array front back spacing set as 7.5 meters time, this algorithm at every year 11th month to next year 2nd month's low sunshine cycle inside, puts whole square array's daily average effective power generation amount pulled rising 8% to 11%.

Dual axis gain

· Dual-axis tracking system through two units' independent rated power being 45 watts' servo motors, simultaneously at horizontal 360 degrees azimuth angle and vertical 0 to 90 degrees elevation angle two dimensions on runs.

· Module surface's normal line and sun ray's included angle all weather maintains at 0.5 degrees within's absolute deviation range inside.

· North latitude 45 degrees above's region, dual-axis system every year can extra generate 12% to 15% electric quantity.

· Installed capacity being 50 kilowatts' small size dual-axis commercial power station, at 15 years' running cycle inside, total calculated generated out's electric quantity reached 1.45 million degrees, compared to fixed tilt angle system extra 450 thousand degrees.

· Dual-axis system's mechanical structure weight reached single axis's 2 times, footprint area needed increased 35%, at levelized cost of energy's financial calculation model inside, normally needs per degree electricity 0.15 US dollars above's selling electricity price only then can at 8th year reach internal return rate 10%'s standard.

Sun Alignment Efficiency

Calculate orbit

Longitude latitude coordinate's input accurate to decimal point after six digits, altitude height parameter's error controlled at 5 meters within, time synchronization protocol every interval 24 hours through satellite signal calibrates one time, puts system time and Coordinated Universal Time's deviation shrinks to 5 milliseconds within. Microprocessor per second conducts over ten thousand times floating point operations, output's sun zenith angle and azimuth angle's theoretical calculation numerical value error is smaller than 0.0003 degrees.

A unit installed at north latitude 35 degrees, west longitude 110 degrees' single-axis tracking bracket, on the day of the summer solstice, that day's running stroke will be from morning 5:45's negative 60 degrees starting angle, with per minute 0.125 degrees' average angular velocity, continuously smooth rotating to afternoon 6:15's positive 60 degrees terminating angle.

The motor does not will one moment not stop-ly run, set's program lets system accumulate to 1.5 degrees to 2 degrees' angle difference value time only then issues one time starting instruction, every day full stroke's starting stopping times number is strictly limited at 60 times to 80 times interval inside. Lower's running frequency lowered mechanical structure's fatigue stress concentration phenomenon, guaranteed reducer at experiencing 25 years' life cycle inside as high as 500 thousand times' starting stopping cycle after, outer shell crack happening probability is lower than 0.01%.

Measure light intensity

Part regions all year round receive oceanic climate influence, whole year has 150 days above's morning situates in thin fog or cloudy state, purely relying on astronomical algorithm will let photovoltaic panel align at being cloud layer blocked's sun physical position, instead misses sky inside brightness higher's scattered light region.

Carrying dual-side photosensitive diode's closed-loop control system is installed at the bracket's most top end, the photosensitive probe surface's light-transmitting glass possesses 98% ultraviolet ray transmittance rate, can per second read surrounding 160 degrees field of view range inside's photon flux density. Two groups of probes read to's voltage signal difference value exceeds 50 millivolts time, the analog-digital converter will put the analog signal change into a 12-bit digital signal, command push rod motor toward voltage higher's one side finely tune 0.5 degrees to 1 degree's elevation angle.

When the external environment meteorological station recorded the total irradiance at 10 minutes inside per square meter 800 watts drops to per square meter 200 watts below time, the light sensing program will cover the astronomical program, motor in 45 seconds inside puts photovoltaic panel pushed flat to 0 degrees' horizontal posture. Horizontal panel toward full sky dome's field of view opening angle reached biggest's 180 degrees, is able to capture free-floating in air inside's diffuse reflection photons, whole array at low illuminance period's short-circuit current data rose 3.5% to 4.8%.

Gear biting

Physical level's transmission accuracy extremely greatly receives slewing drive device processing craft's restriction, worm gear worm structure at assembling leaving factory time's standard backlash error normally is set at 0.1 degrees to 0.15 degrees between. One row as long as 90 meters, loaded with 120 pieces of photovoltaic modules' linked bracket, total weight exceeds 3500 kilograms, and during the running process, it will produce as high as 12000 newton meters' torque load.

The wind speed reaches per second 12 meters, and the wind pressure acting at a tilt angle of 40 degrees on the module surface will let the main shaft produce 0.4 degrees to 0.6 degrees' elastic torsion deformation, installed at the main shaft terminal end's module actual facing angle and main motor end's angle appeared 0.5 degrees above' deviation.

Bearing internal's lubricating oil at local air temperature drops to zero below 15 degrees Celsius, kinematic viscosity will from normal time's 150 square millimeters per second soar to 800 square millimeters per second, leading to motor starting instant's resistance torque enlarged 3 times.

In order to overcome low temperature and mechanical friction coefficient rising brought's influence, motor's rated output power normally reserved 40% redundancy amount, and at controller mainboard set overload current protection threshold as 5 amperes. Experiencing 10 years' wind sand erosion and ultraviolet ray sun exposure after, worm gear metal surface's wearing will lead to the original's backlash gap expanding 0.05 millimeters, whole mechanical transmission chain's return stroke error following it increases, system's absolute aligning accuracy will from initial's 99.5% drop to 98.8%.

Consume how much electricity

A unit standard's 24-volt brushless direct current motor at normal load under's running current is 2.5 amperes to 3.5 amperes, single time running 15 seconds consumed's electric energy is about 0.00025 degrees. According to every day turning 70 times, sunset after with the highest rotation speed spending 3 minutes time from positive 60 degrees returning position to morning's negative 60 degrees standby position calculating, single piece tracking bracket whole day's mechanical energy consumption total amount only has 0.018 degrees electricity around. Main control box internal's low power consumption microcontroller and wireless gateway module's standby power normally is lower than 2 watts, whole year 8,760 hours uninterrupted standby's electricity consumption amount is 17.5 degrees electricity.

One row rated direct current side power being 60 kilowatts' photovoltaic tracking array, at annual equivalent full load power generation time being 1600 hours' region, the whole year's total power generation amount reaches 96,000 degrees electricity. Putting whole year mechanical rotation consumed's 6.5 degrees electricity and electronic equipment standby consumed's 17.5 degrees electricity, mutually added, system whole year's total own power consumption is 24 degrees electricity, own power consumption occupying total power generation amount's ratio is merely ten thousandths two point five.

Extremely low's parasitic energy consumption proportion proved spending thousands of US dollars procuring motor and control system's financial budget completely within a reasonable range inside, obtained's 15% above's power generation amount increment far far covered equipment running own's energy expenditure.