How Do You Install Solar PV in Remote Locations | Transport, Mounting, Maintenance

Remote region adopt flexible module can lower 60% transport fee.

Install time directly drive in 1.5 meters spiral pile to replace cement foundation, and match 4G module to carry out remote monitoring, then can realize free manual patrol inspect's long effect operation maintenance.

Transport

Find out road conditions

Take photovoltaic equipment transport into distance paved highway 100 kilometers above's no power grid region, often need to face gravel roads and dirt roads. Road surface width once smaller than 2.8 meters, standard 40-foot container truck then unable to pass through. Mountain slope dirt road's inclinometer reading exceeds 18 degrees, ordinary two-wheel drive truck will lose grip force, must change to carry low-speed four-wheel drive mode's off-road truck, through transfer case take engine torque magnify 2.7 times. Winding mountain roads' hairpin bends inner diameter often insufficient 6 meters, this then limits transport vehicles' wheelbase, which absolutely cannot exceed 4.5 meters.

Along the route, encounter wooden bridges or cement culverts, bear weight upper limit usually at 3 tons to 5 tons. One vehicle single row seat light type truck self weight 1.8 tons, if load 20 pieces 550 watts' photovoltaic panel, one machine 8 kilowatts' inverter as well as one group 10 degrees electricity (10kWh)'s lithium iron phosphate cell, equipment total weight roughly is 2.4 tons. Vehicle goods total weight reach 4.2 tons, very close to 5 tons' bridge structure yield limit. On this kind of non-paved road surface, vehicle speed must be controlled at every hour at 15 kilometers to 20 kilometers.

· Soil contains water amount exceeding 20% muddy road section, vehicle wheel slip rate will rise 60%.

· Road surface pothole depth exceeds 150 millimeters, vehicle chassis ground clearance must be greater than 250 millimeters, to prevent knock break oil pan.

· Environment altitude every elevate 1,000 meters, naturally aspirated diesel engine's output power will drop about 10%, need advance calculate power attenuation.

Pick vehicle

Load weight at 1.5 tons to 2 tons' light type pickup truck or all terrain vehicle is this kind of terrain's main force. Enter mountain before, tire's tire pressure needs to be from standard's 2.5 bar (Bar) manual lower to 1.8 bar, tire ground contact area increases 30%, can effectively disperse vehicle body weight. Tire tread depth must reach 12 millimeters above, use off-road special use's MT mud tire. The vehicle suspension system's shock absorber stroke needs to have at least 150 millimeters of compression space to absorb road surface transmitted high frequency vibration.

In full load, 1500 kilograms of equipment's situation under, often need to hang 1st gear or 2nd gear climb slope, engine rotate speed long term maintain at 2500 revolutions per minute. This will lead to a hundred kilometers oil consumption from 12 liters to 22 liters. Towards round trip mileage exceeding 150 kilometers, the vehicle must have an extra installed volume of 60 liters' backup oil tank.

Wrap tight a bit

One piece standard's 550 watts monocrystalline silicon photovoltaic panel, length 2278 millimeters, width 1134 millimeters, thickness 35 millimeters, single piece weight 27.5 kilograms. Leave factory time, they are vertical upright placed on a pallet inside, one pallet contains 31 pieces of panel, the whole pallet's total weight reaches 880 kilograms. The wooden pallet's base bottom height is 150 millimeters, convenient hydraulic pallet truck insert.

Outer layer's corrugated paper box thickness reaches 7 millimeters, burst resistance strength is every square centimeter 15 kilograms. In 10 Hertz to 50 Hertz's transport vibration frequency, silicon wafer very easily produces naked eye unable see's hidden crack.

· Every 5 pieces photovoltaic panel between need stuff into thickness 50 millimeters' EPE pearl cotton carry out physical shock reduce.

· Pallet outer surround needs wind 6 circles thickness being 20 micrometers' stretch wind film.

· Wind film needs to provide 30 Newtons' horizontal direction pull force, prevent panel in vehicle cabin inside from happening displacement.

· Transport whole journey, pallet's tilt angle strictly forbidden to exceed 15 degrees.

Last few miles

Motor vehicle drive to dirt road end, remains 2 to 5 kilometers, usually still have 400 meters' altitude climb. Use mule horse pack transport is a common scheme. One adult mule's maximum load amount is 80 kilograms. Two pieces photovoltaic panel plus prevent knock bump's soft cushion just right 60 kilograms, fixed at special make's wooden pack saddle two sides. Mule's 15-degree slope walk speed is every hour 3 kilometers.

Encounter weight 120 kilograms' gel storage cell, then need four name workers to use a 60-millimeter diameter seamless steel pipe to carry up the mountain. The average person's shoulder bears 30 kilograms' weight. Manual transport's speed will drop to 1.5 kilometers per hour, every walk 500 meters needs to stop down to let muscles rest 10 minutes. One contains 40 pieces of panel, 4 pieces of heavy-type cells, and 300 kilograms of aluminum alloy guide rail's 20 kilowatt system, 8 name workers need whole whole 3 working days then can all transport finish.

If the budget allows, rent a light type helicopter. The machine's belly hook's safe hoist load weight is 750 kilograms. The 5-kilometer single trip time is 4 minutes, 2 tons' equipment divide 3 times take off land, then can transport finish, helicopter every fly hour's rent fee is roughly 1500 dollars.

Unload goods prevent fall

Manual unload goods time, equipment contact ground's instant fall drop height cannot exceed 50 millimeters. From a 100 millimeters' height free fall body, will produce 400 Newtons' impact force, this has a 45% probability of shaking a photovoltaic panel surface 3.2 millimeters thick' tempered glass. Transport down weight 85 kilograms' lithium cell cabinet, need erect one set portable aluminum alloy gantry crane. gantry crane's aluminum alloy I-beam cross beam can bear 500 kilograms' static load, manual chain block every pull moves one time, cell cabinet drops 20 millimeters.

Environment temperature lower than below zero 5 degrees Celsius, cell plastic outer casing's polymer material flexibility will drop 20%. This time, if the side surface receives an exceed 150 Newtons' squeeze force, the plastic outer casing is extremely easy to break. Inverter internal electrolytic capacitor towards gravity acceleration extreme sensitive, transport time's tilt angle cannot exceed 30 degrees. Unload down's photovoltaic panel must use 75 degrees' include angle lean on solid's wall surface or rock on, prevent wind speed exceeding every second 10 meters' gust take it blow fall, bottom part still needs pad on thickness not lower than 30 millimeters' rubber pad prevent slip.

Mounting

Explore ground bottom

Remote region's soil density spans very big. Encounter contains water amount reaching 30% of clay layer, soil's bearing capacity usually only has 80 kilopascals, bracket system very easy in rainy season happen millimeter level sink down. Encounter hardness reach Protodyakonov coefficient 6's rock geology, soil bearing capacity will exceed 400 kilopascals. We need to install before excavating a depth of 1.5 meters' test pit, measure the underground water level line and frozen soil layer thickness.

The environment's air temperature if winter drops below zero 20 degrees Celsius, soil inside's water moisture freezes ice will produce volume expansion, leading to ground surface appearing 50 millimeters to 100 millimeters' frost heave displacement. Bracket foundation's bury depth must exceed the history maximum frozen soil layer depth by at least 300 millimeters, then can guarantee the whole photovoltaic array in experience 25 times above's spring summer autumn winter freeze thaw alternate after, tilt angle's physical deviation rate strictly smaller than 1%.

Smash steel pile

In geology, relatively soft wild outside, length at 1600 millimeters to 2200 millimeters between's hot dip galvanized spiral ground pile is the first choice scheme. This kind of ground pile's pipe diameter is usually 76 millimeters, pipe wall thickness 3.75 millimeters, and the bottom part's spiral blade width is 200 millimeters. Construction personnel use output torque as high as 4000 Newton meters' crawler type hydraulic pile driver, using every minute 20 revolutions' low speed to take ground pile spin into soil layer.

Spin into depth reach 1.5 meters, single root spiral ground pile able to provide 15 kilonewtons' vertical pull resist force and 20 kilonewtons' horizontal shear resist force. Encounter gravel proportion exceeds 40% Gobi terrain, spiral ground pile unable to penetrate through, need change use bottom area being 1 square meter, height being 0.6 meters' precast concrete counterweight block. Single concrete counterweight block's weight reaches 1.4 tons, through pure physical gravity, take bracket firmly press on ground surface, resist every second 35 meters' gust.

Foundation form	Applicable soil density	Drill hole depth (millimeters)	Single pile pull resistance force (kilonewtons)	Construction consume time (minutes/root)	Material cost estimate (dollars)
Spiral ground pile	1.2 - 1.6 grams/cubic centimeter	1500 - 2000	15 - 20	10 - 15	35 - 50
Pour cement pile	1.8 - 2.5 grams/cubic centimeter	1200 - 1500	25 - 35	120 - 180	80 - 120
Cement counterweight block	Sandstone/hard rock surface	0 (ground surface place)	Relied on own gravity	40 - 60	150 - 200
Expansion anchor rod	Hard rock layer	800 - 1000	30 - 40	30 - 45	45 - 65

Piece iron frame

In order to cope with annual precipitation exceeding 1500 millimeters' humid climate, steel material surface must pass through hot dip galvanizing treatment, and zinc layer thickness strictly requires 85 micrometers above, take every year's corrosion speed rate control at 2 micrometers within. The main upright column uses a cross-section size of 100 millimeters multiplied by 50 millimeters' C type steel, through M16 specification's 8.8 level high strength bolt with foundation flange plate connect.

Cross beam's install height distance ground surface at least retain 500 millimeters' physical clearance, use to prevent winter thickness reach 400 millimeters' accumulate snow cover photovoltaic panel bottom part, simultaneously give back surface's air circulation leave out every second 2 meters above's wind duct, lower summer module working temperature about 5 degrees Celsius. Fix solar energy panel's tilt angle needs to be adjusted according to the install place's latitude, from 15 degrees to 40 degrees not equal, every change 5 degrees tilt angle, system's annual power generation amount deviation rate at 2% to 4%.

Screw on

The standard thickness being 35 millimeters' aluminum border frame panel, must match thickness being 4 millimeters, length being 40 millimeters' special use middle press block. Workers use hand-held type electric torque wrench, take M8 hexagon socket stainless steel bolt's tighten torque accurately set at 16 Newton meters. Torque is lower than 12 Newton meters, panel under wind load will happen high frequency resonance; torque exceeds 20 Newton meters, pressure will conduct to panel internal, leading to thickness only having 160 micrometers' silicon wafer happen hidden crack.

Adjacent two pieces panel between force retain 20 millimeters' physical gap, absorb below zero 30 degrees to above zero 50 degrees extreme temperature difference brings 0.5 millimeters to 1.2 millimeters' thermal expansion contraction deform amount. Panel all lock tight after, every square meter can bear a front surface 5400 pascals' static snow load, equal to 550 kilograms' weight pressing on the top surface, back surface then can resist 2400 pascals' wind load, equivalent to bear every second 45 meters' 14 level hurricane wind pressure.

Prevent rust

Take anodic oxidation aluminum alloy border frame stick fit on hot dip galvanized steel bracket in, in relative humidity exceeding 80% 's morning will trigger serious electrochemical corrosion. Aluminum's potential is lower than iron, electron transfer, leads to aluminum border frame in 3 months inside surface appearing 0.2 millimeters deep corrosion pit. At the aluminum and steel's contact surface, a must pad into thickness being 2 millimeters' ethylene propylene diene monomer (EPDM) insulation rubber gasket, thoroughly cut off 12 volts above's micro current circuit.

Back part's cable fix clip needs to avoid carbon steel material, change to use polyamide 66 (PA66) nylon cable tie or 304 stainless steel wire clip. Nylon cable tie's pull resistance strength needs to reach 220 Newtons, and added anti-ultraviolet (UV) absorbent, guarantee in ultraviolet irradiance reach every square meter 1000 watts' plateau environment under, continuous exposure 10 years will not happen physical embrittlement break, maintain 150 Newtons above's remain grab force.

Maintenance

Wash photovoltaic panel

In arid little rain's remote region, photovoltaic panel surface accumulates 2.5 millimeters thick's sand dust, which in 40 days will let the overall power generation amount sharp reduce 18% to 22%. Panel surface's light transmittance from leave factory time's 93% drops to 75% below, leading to arrive silicon wafer's solar radiation intensity every square meter reduce about 150 watts.

Maintenance personnel usually every 45 days to 60 days carry out one time water wash operation. Every wash, 1 square meter's panel needs to consume 1.5 liters to 2 liters of pure water. Water inside's total dissolved solids (TDS) must strictly control at 200 milligrams per liter below, water quality too hard will leave a down thickness of 0.05 millimeters' calcium carbonate water scale. This layer of water scale will let light rays refract, causing a secondary light loss of 3%.

"In the environment, the air temperature exceeds 35 degrees Celsius at noon, and the photovoltaic panel surface's physical temperature will soar to 65 degrees Celsius above. This time, if the temperature is 15 degrees Celsius, normal temperature water carries out spray, as high as 50 degrees Celsius' instant temperature difference will produce extreme big's thermal stress, has 12%'s probability lead to 3.2 millimeters thick's tempered glass happen irreversible's physical shatter."

Wash tool must choose bristle diameter smaller than 0.1 millimeters' special make nylon soft brush, brush wash time apply physical downward pressure on glass panel's cannot exceed 15 Newtons. If use force too fierce, border frame gap inside's tiny quartz sand particles will scratch glass surface's anti-reflection coating, making panel in service 10 years after's photoelectric conversion efficiency extra attenuate 1.5%. In water resource lack's desert edge, maintenance team will change use rotate speed being every minute 800 revolutions' dry type electric roller brush carry out remove dust, remove dust rate can reach 85%, single time operation's electricity consume amount is only every hour 0.5 degrees electricity.

Check wire

Direct current side cable long-term exposure to strong ultraviolet rays and below zero 20 degrees to above zero 45 degrees' big temperature difference environment inside, insulation outer skin's aging speed compared to indoor cable fast 3 times. System run time, direct current cable inside transmits 600 volts to 1000 volts' high voltage, current usually at 10 amperes to 15 amperes between. Every six months, must use infrared thermal imager towards all MC4 plug joints to carry out full load scan.

Under normal conditions, the plug's surface temperature compared to the environment temperature is high, out 5 degrees Celsius to 8 degrees Celsius. If the thermal imager's crosshair measures some joint's local temperature exceeding 65 degrees Celsius, explain that place's contact resistance has already broken through the 0.5 milliohms' normal threshold.

"Contact resistance every increases 1 milliohm, in 15 amperes' full load current under, joint place then will produce 0.225 watts' abnormal thermal loss. When the local temperature exceeds 85 degrees Celsius, the mechanical strength of cross-linked polyethylene (XLPE) insulation material will drop 40%, and the probability of trigger pull arc catching fire will present an exponential level rise.

Wild rodent animals' gnaw bites occupy remote regions, cable fault total number's 14%. Mouse teeth's bite force can reach every square centimeter 150 kilograms, able to easily bite through a thickness of 1.5 millimeters' cable sheath. At the cable's bare section outer layer, must slip on pipe wall thickness being 0.5 millimeters' 304 stainless steel metal corrugated pipe carry out physical defense.

Check distribution box internal time, worker need use torque screwdriver to re-tighten all busbar's M6 bolts, apply torque standard is 4.5 Newton meters, prevent metal thermal expansion contraction lead to connect loose, take whole strip circuit's voltage drop strictly control at nominal voltage's 2% within.

Look inverter

Inverter takes direct current and converts it into 230 volts or 110 volts alternating current's process inside, the highest conversion efficiency is usually maintained at 97.5% to 98.2% between. Remain's 1.8% to 2.5% energy will all convert to thermal energy and be released. One machine's 10 kilowatt inverter full load work time, heat generate power as high as 250 watts.

Outer casing's aluminum made heat dissipation fin if by thickness exceeds 1 millimeter's dust cover, heat dissipation efficiency will drop 30%. When the inverter's internal IGBT module temperature sensor reading reaches 70 degrees Celsius, the system will force start derating run program, active cut down 20% to 30% of output power to protect electronic module.

"Inverter internal's aluminum electrolytic capacitor towards working temperature extreme sensitive. In an environment temperature of 40 degrees Celsius, the capacitor's expected life is as long as 80,000 hours; but if the temperature rises 10 degrees Celsius, the capacitor's internal electrolyte's volatilize speed will then double, and the expected physical life will directly halve to 40000 hours."

Carry active heat dissipation fan's machine model, need every 3 months to take down air inlet's polyurethane dust proof sponge, use compressed air blow strike, wind pressure keep at 0.4 megapascals around. Regular download inverter's history fault log, key point check past 90 days inside power grid voltage fluctuation exceeds 253 volts or frequency lower than 49.5 Hertz's times number. If the daily average report error exceeds 5 times, explain the far end alternating current line exists impedance too high's problem, line loss rate maybe already exceeds 5%, need to extend towards outside check 3 kilometers range inside's aluminum core overhead line.

Measure storage cell

Off-grid system energy storage terminal's state of health (SOH) decides no light illumination condition under's usable discharge time. Towards lead acid gel cell, depth of discharge (DOD) strictly limited at 50% within, cycle life can reach 1500 times. Measure 12 volts single body cell in static place 2 hours after open circuit voltage, 100% full electricity state under reading should locate at 12.6 volts to 12.8 volts between. If the single piece cell's open circuit voltage is lower than 11.8 volts, the internal electrode plate has already suffered serious sulfation, leading to its actual ampere hour (Ah) capacity permanent loss of 15% above.

"Lithium iron phosphate (LiFePO4) cell pack allows depth of discharge to reach 80%, cycle life as high as 6000 times, but its charge receive ability at 0 degrees Celsius below will happen a cliff style drop. At below zero 10 degrees Celsius, a time force injected 0.5 C's big current, will lead to lithium ions at the negative electrode surface large amount precipitate out form lithium dendrites, pierce through the thickness of only 16 micrometers' separator, cause internal micro short circuit.

Every separate half year, the cell pack needs to carry out one time length being 4 hours' equalize charge, take charge voltage elevate to 14.4 volts, let all series single body's voltage range shrink to 0.05 volts within. Regularly check cell pole's tighten nut, use a multimeter to measure the connect bar's voltage drop, in discharge current being 50 amperes, voltage drop absolutely cannot exceed 10 millivolts. If the discover cell plastic outer casing appears to exceed 3 millimeters' physical expand bulge bag, explain the internal safety valve's exhaust pressure has already failed, bear exceed 30 kilopascals' abnormal internal air pressure, must in 48 hours inside carry out cut off isolate.

Remove weeds

Spring and summer are two seasons, precipitation amounts as long as exceed every month 50 millimeters, module direct below's gramineous weed every month's grow speed can reach 150 millimeters to 200 millimeters. When vegetation height exceeds 500 millimeters, its shadow will then block the live photovoltaic array's most bottom part's single row cell piece. The area only occupies whole piece panel 5%'s local shadow, will force back plate junction box inside's bypass diode in 0.1 seconds inside conduct. This physical protection action will lead to a single piece photovoltaic panel's output voltage dropping from 42 volts to 28 volts instantly.

In the autumn season, the relative humidity drops to 30% below, withered yellow weeds contain water amounts insufficient 15%, and are extreme flammable. Equipment surrounding a 3-meter radius inside must be marked as absolute clearance zone. Maintenance personnel need use gasoline lawn mower, take vegetation height force press at 50 millimeters below. Lawn mower's blade rotates at a speed of 3000 revolutions per minute, operation time splash out's diameter 5 millimeters around's gravel possesses 20 joules' kinetic energy. In order to prevent gravel hitting the brake back plate, the thickness only has 0.3 millimeters' fluorine-containing polymer film, the lawn mower must equip a full close metal protect cover, and the operation direction must be back face photovoltaic panel's tilt surface.