How Do Photovoltaic Cells Support Green Energy | Emission, Maintenance, Versatility

Photovoltaic power generation zero operation emission, per kWh can reduce emission about 0.7 kg CO₂;

Module lifespan 25 years, maintenance only cleaning and inspection.

Suitable for rooftop, power station and other multi-scenarios, elevate energy utilization rate.

Emission

No smoke, no gas

From global energy data, the power and heat production sectors contributed exceeding 40% of carbon dioxide emissions, while photovoltaic power stations generate one degree of electricity's life cycle carbon footprint (LCA) only is 12.5 grams to 44.8 grams carbon dioxide equivalent. Compared to this, traditional coal-fired power generation per degree electricity will emit about 820 grams to 1050 grams of carbon dioxide, natural gas power generation then at 430 grams to 490 grams.

Photovoltaic cell's carbon emission intensity is only 4% to 5% of coal-fired's, emission reduction efficiency extremely considerable. If a family consumes electricity 10,000 degrees, a medium-sized family completely uses photovoltaic, every year can reduce 8.2 tons to 10.5 tons of greenhouse gases. This is equivalent to 400 trees to 500 adult trees in one year through photosynthesis absorbing carbon dioxide. In the 25-30-year service period inside, one set of 10 kW system cumulative emission reduction amount can reach 200 tons above.

Although in manufacturing 99.9999% high purity monocrystalline silicon's process inside needs to consume 150kWh/kg to 200kWh/kg of electricity, but as long as the system operates 0.6 years to 1.4 years, its produced green electrical energy then can completely offset the production link consumed total energy. In the remaining 20 more years of usage cycle, its outputted every degree of electricity all is solid "net energy revenue".

Besides carbon dioxide, this kind of greenhouse gas, photovoltaic technology in controlling atmospheric pollutants is even approaching 100% emission reduction rate. Thermal power generation in the combustion process inside will release massive amounts of sulfur dioxide (SO2), nitrogen oxides (NOx), and diameter smaller than 2.5 microns fine particulate matter (PM2.5).

· Sulfide emission reduction: Every generate ten thousand degrees of photovoltaic electricity can reduce about 30 kilograms to 50 kilograms of sulfur dioxide emissions.

· Nitrogen oxides emission reduction: Same power generation amount, can reduce about 15 kilograms to 25 kilograms of nitrogen oxides entering the atmosphere.

· Dust control: Avoided coal-fired boiler produced smoke dust, emission reduction rate high reaches 99% above, effectively reduced surrounding 10 kilometers to 50 kilometers range inside's smog days.

· Heavy metal isolation: Traditional fossil energy combustion will release trace mercury, arsenic etc. heavy metal elements, photovoltaic power generation process inside's chemical reaction completely sealed at 3.2 millimeters thick tempered glass and backsheet between, to soil and air's heavy metal pollution rate is 0.

Thermal power plants, nuclear power stations all need massive amounts of cooling water, and on average, every generating one degree of electricity wants to consume 1.8 liters to 2.5 liters of water. While photovoltaic cells in the power generation process do not need any cooling medium, only at regular maintenance time do they need an extremely small amount (per square meter about 0.5 liters to 1 liter) of water used for washing. In lacking water severe arid areas, photovoltaic power station's water consumption intensity compared to thermal power generation is low out 90% above. One set 1MW photovoltaic project every year can save about 15 thousand tons to 22 thousand tons of freshwater resources, this to ecological fragile area's groundwater level maintenance possesses important significance.

From the waste processing angle, although photovoltaic modules scrapped after will produce solid garbage, but current recycling technology can already realize 90% above material re-utilization.

· Glass recycling: Module inside weight proportion about 70% tempered glass can 100% crush recycle, re-enter building material market.

· Aluminum material recycling: Proportion about 10% to 15% of aluminum alloy frame can 95% return furnace, unit energy consumption only is raw aluminum production's 5%.

· Precious metal extraction: Through chemical extraction, per ton of waste old modules can recycle about 0.5 kilograms to 0.8 kilograms of silver, as well as 20 kilograms to 40 kilograms of copper.

· Silicon wafer remanufacturing: Crushed silicon material experiencing purification can re-act as 3% to 5% doping material entering the ingot casting link.

In many "photovoltaic+" projects inside, panel under's evaporation amount can reduce 20% to 35%, soil humidity increase 10% to 15%, this makes originally desertified land vegetation coverage degree from insufficient 5% to 40% above. This kind of "shading effect" not only protected the bottom part's microbial diversity, but also through the plant root system realized every year per hectare 0.5 tons to 1.2 tons extra carbon sequestration.

Maintenance

Not much work

The photovoltaic system's physical structure is extremely stable, and the whole set of power generation equipment does not have gears, bearings, or any need for lubrication rotating parts. This lets its daily maintenance workload compared to coal-fired generator units or wind turbines be lowered 90%. One set standard 10 kW rooftop system, in 25 years of operation cycle inside, 95% of the time is at automatic operation state.

Hardware damage rate extremely low, mainly relies on 3.2 millimeters thick ultra-clear patterned tempered glass to protect cell pieces. This kind of glass can bear a diameter of 25 millimeters, a speed of 23 meters/second's hail impact, and static mechanical load can usually reach 5400 Pa (approximately equals to per square meter bear 550 kilograms of weight). Due to not having mechanical loss, photovoltaic module's annual average failure rate usually maintains at 0.2% below, besides regularly checking the mobile app's power generation data, users almost do not need to conduct any heavy physical labor.

In air quality general areas, 1 to 3 microns fine particulate matter piles up on the glass surface will produce shading effect, leading to photoelectric conversion efficiency drop 3% to 15%. If it is approaching construction sites or arid dusty zones, this kind of loss will even soar to 30% above. Most photovoltaic modules at installation time will set a 15-degree to 35-degree tilt angle. This is not only for capturing more oblique sunlight, but also for utilizing gravity and rainwater to conduct "self-cleaning".

As long as the rainfall amount reaches 5 millimeters above, then it can wash away 60% of the floating dust. For stubborn bird droppings or thick heavy dust accumulation, usually every quarter needs to conduct one time simple water washing, average per square meter consumes 0.5 liters to 1 liter's deionized water. Through this kind of low-cost manual maintenance, can the system's performance ratio (PR) long-term maintain at 80% above high position?

Besides panel surface's dust removal, electrical connection's safety checking is also ensuring system's 20-year lifespan's key point. The photovoltaic array outputted is direct current, and the system voltage is usually between 600V and 1500V, therefore, the protection requirement for connectors (such as MC4 connectors) is very high. These connectors possess IP68 level's waterproof performance, can guarantee at 1.5 meters deep water inside soaked 30 minutes not leak electricity. But at long-term high-low temperature cycle (-40°C to 85°C) and ultraviolet ray irradiation, cable's insulation layer may appear tiny cracks.

Professional maintenance flow suggests every 12 months use infrared thermal imager to combiner box and circuit breaker conduct one time fast scanning. If a certain node's temperature is discovered to be 10°C above the surrounding high, it explains poor contact or internal resistance too large risk, timely replace a value less than 5 US dollars connector, then can avoid subsequent possible produced whole string system downtime or potential electrical fire risk.

Currently, mainstream string inverter's mean time between failures (MTBF) is 100 thousand to 150 thousand hours, and the design lifespan is usually 10 to 15 years. In photovoltaic panels, as long as 25 years service period inside, users usually need to reserve a sum of cost, at 12th year, to replace one inverter. This budget accounts for approximately 10% to 15% of the system's initial investment cost. Along with the development of intelligent technology, current inverters all integrate IV curve scanning function, can automatically diagnose system problems in 5 minutes, such as shadow shading, diode damage or cable aging, accuracy rate reaches 95% above. This kind of remote operation and maintenance ability lets a single person manage a 50MW above scale large power station become possible, largely reducing manual costs.

In climate severe areas, bracket system's anti-corrosion checking also cannot be ignored. Most photovoltaic brackets adopted are 6063-T5 aluminum alloy or hot-dip galvanized steel, galvanized layer thickness usually between 65 and 85 microns, enough to resist 20 years of salt spray corrosion. But at coastal 5 kilometers range inside areas, salt concentration is relatively high, so suggest checking one time fasteners' torque every two years.

Once discover bolt loose (loose proportion usually lower than 1%), need re-according to 40Nm to 60Nm's standard torque screw tight, in order to prevent module flutter occurring at wind speed exceeding 30 meters/second (level 11 hurricane). Through these details on's "micro maintenance", the photovoltaic system's annual average power generation amount degradation rate can be strictly controlled at 0.4% to 0.5% within, ensuring that at 25th year time still can maintain 80% above's initial combat power.

Versatility

Everywhere can use

The photovoltaic cell's size flexibility is extremely high, from 0.5 centimeters square's microchip to 210 millimeters large size silicon wafer, all can be realized on different carriers energy conversion. In the microelectronic equipment field, monocrystalline silicon photovoltaic cells can provide 10 milliwatts to 5 watts of weak electricity, enough to support a calculator, smart watch, or sensor at 200 lux low light environment under continuous work, every year saving dry cell processing fee, then can reach equipment cost's 20% above.

While once entering the megawatt (MW) level, even the gigawatt (GW) level large ground power station stage, through tens of thousands of pieces of 600W above large power modules series connected, single unit project's covering area can reach 500 to 2,000 hectares. This kind of scaled deployment at 15 degrees best tilt angle under, per square meter every year's power generation amount usually at 150 degrees to 250 degrees between, energy density compared to biomass energy high out 10 to 20 times.

Typical 210mm size PERC cell piece, single piece power is about 10.5W, open-circuit voltage is 0.7V around, through 132 pieces cells' tight packaging, can the single piece module's front side power steadily push up to 670W, its unit area's power output has already broken through 215W/m².

Transform into building material

Current photovoltaic modules no longer are only installed on rooftop "patches", but directly replace building's glass curtain wall, sunshade board or roof tiles. This kind of BIPV (Building Integrated Photovoltaic) technology uses two layers of 2.0 millimeters to 3.2 millimeters tempered glass to clip cell pieces in the middle, maintaining 10% to 40% light transmittance at the same time, still can block 80% above thermal radiation, making building's air conditioning energy consumption lower 15% to 25%.

For a 50-story high office building, if the 40% facade is replaced with photovoltaic curtain wall, every year it can produce about 500 thousand degrees of electricity, directly covering 30% of the building's above public lighting and elevator electricity usage budget. This kind of module's weight is usually controlled at per square meter 15 kilograms to 25 kilograms, completely conforms to the current high-rise building 5kN/m² structural load design standard, and fireproof level reached A level.

High light transmittance BIPV module at visible light wave band's transmittance can be adjusted between 5% and 50% according to demand, its U value (heat transfer coefficient) can be low to 1.1 W/(m²·K), and at the same time, it provides superior thermal insulation performance to ordinary triple hollow glass.

Float on water surface

Water surface's environment temperature is usually compared to land's low 5°C to 10°C, due to silicon-based photovoltaic cells possess about -0.35%/°C's temperature coefficient, water power station's actual output power compared to same latitude land power station high out 5% to 12%. Besides, the photovoltaic array on the water surface can block 70% of direct sunlight, effectively reduce water body evaporation, and every year per hectare of water surface can save 15 thousand cubic meters to 25 thousand cubic meters of water resources. Pontoon system usually adopts high-density polyethylene (HDPE) material, can stably float on the water surface for 25 years, and due to its 100% light-avoiding characteristic, can inhibit algae's photosynthesis, making water quality's transparency elevate 10% to 15%.

While walking, generate

Currently, mainstream VIPV (Vehicle Integrated Photovoltaic) systems power at 200W to 500W, in a sufficient sunshine situation, every day can inject 1.5 to 3 degrees of electrical energy, equivalent to increased 15 to 30 kilometers of pure electric endurance mileage. For a hundred kilometers, a passenger car consumes electricity 15 degrees, and the whole year about 20%'s commuting charge can be borne by sunlight directly. In long-distance cold chain transportation, the roof's 1 kW photovoltaic array can independently support the refrigeration unit's 40% electricity demand, and at engine flameout state, it can also maintain the cargo compartment inside at -18°C constant temperature environment. A single vehicle can save fuel fees of 800 to 1,200 US dollars every year.

Flexible photovoltaic cell's bending radius can be smaller than 50 millimeters, thickness only is 1.5 millimeters around, gram weight low to 2 kg/m², this makes it fit at not breaking car aerodynamics design's premise under, fit at complex roof surface.

Land exhausted its use

Photovoltaic power generation and modern agriculture's combination realized "one land two uses", namely at 3.5 meters to 5 meters high bracket below plant shade-loving crops or conduct animal husbandry breeding. Through adjusting the cell pieces' arrangement spacing, can the below's light transmittance be precisely controlled at 30% to 60% between, both satisfied ginger, potato etc. crops' photosynthesis demand, and avoided summer high temperature caused leaf burn, making agricultural crops' irrigation water amount reduce 20% to 30%. This kind of photovoltaic array also can act as a natural windbreak wall, making near-ground wind speed lower 40% to 50%, significantly improving the field's microclimate environment.

Data shows, in this kind of "agriculture photovoltaic complementary" mode, land's comprehensive economic revenue compared to purely planting grain is elevated 3 to 5 times. Per mu land every year's photovoltaic rent and power generation dividend can then bring 3,000 to 5,000 RMB extra income to farmers.

In agriculture, photovoltaic complementary projects inside the bracket's span are usually designed as 5 meters to 8 meters, ensuring large harvesters and tractors can smoothly pass through. This kind of design's land equivalent ratio (LER) can usually reach 1.6 above, far higher than single-purpose land.