Floating solar farms gained traction in 2018, particularly in countries with high population density and with competing uses for limited available land. These also operate at high efficiency since installing the solar panels on water helps cool the equipment.

The Republic of Korea was among the first to pilot floating photovoltaic (PV) systems. State-owned Korea Water Resources Corporation (K-water) began testing a 2.4-kilowatt (kW) model in 2009 on the surface of Juam Dam reservoir in Suncheon, South Jeolla Province. In October 2012, it constructed a 500-kW commercial plant at the Hapcheon Dam in South Gyeongsang Province after it developed a 100-kW demonstration plant in Hapcheon Dam the year before. This was the world’s first commercial floating solar PV installation using the surface of a dam reservoir and the country’s first floating solar farm.

The country currently operates three commercial floating solar power facilities that aim to contribute toward increasing the share of renewables to 20% of the energy mix by 2030 from the current level of 7%.

What is a floating solar photovoltaic system?

It is an eco-friendly method of generating electric power that combines marine technology and renewable energy technology. Solar modules are made to float on the surface of water, such as a dam or a reservoir. Electricity is sent through underwater cables to a transmission tower.

Figure 1: Floating PV Generation Concept

Source: K-Water

What are the benefits of a floating PV system?

• Promotes land-use efficiency. As the floating PV energy systems are set up on water, the land can be used for other purposes. It requires no construction on land or conversion of forest and farmlands for solar power facilities.
• Provides high-energy yield. The increased energy generation is due to the natural cooling effect of the water, which reduces rises in temperature of the solar modules.
• Saves water resources. It reduces the evaporation of water in the reservoir since the floating PV system blocks the sunlight.
• Uses an eco-friendly system. Natural fish farms thrive under the platform.

Four environmental impact analyses by the Korea Environmental Policy and Evaluation Institute (KEI) from 2011 to 2019, showed that the floating PV facilities caused no harm to the environment, developed a ground for fish spawning, increased aquatic plants, and reduced algae. Also, as of 2018, the floating solar farms in the country has reduced the amount of carbon emissions by 52,414 tons.

What are its features?

A floating solar power plant is composed of the solar module, buoyancy body, and anti-rust material, which includes the vertical frame and horizontal frames, inspection footrest, and module mount assembly.

The solar module should be highly resistant to humidity, lead-free, dust-proof, and protected against the effects of temporary jets of water, and it should have passed the drinking water test. Floating PV Mounting System is applied to solar pv power plant installation on the water. Adopting HDPE material, it should pass the Hunt Water Absorption Test, Anti-Aging Test, Anti-UV Test etc. Moreover, it can bear the pulling force that is much higher than other products. Adopting new module design in floater and main floater, it can realize the array of double row in the same facing or in symmetrical facing, which can increase the efficiency of solar power generation and installation capacity, be easily installed, and save the cost. and its lifetime has more than 25 years.

Figure 2: Floating PV Plant Components

SunEvo Solar Floating System

Solar panel testing and certifications

Like other types of electronics, solar panel modules go through rigorous testing before installation. These tests are critical to determining the quality and performance of panels under particular environmental stresses, as well as confirming they meet mandated safety requirements. In this article, we’ll review the most common testing and certifications for solar panels on the market today.

Why is solar panel testing important?

Solar panel testing is key to assuring both the quality and safety of a module. Photovoltaic Solar Panels have a long lifespan: properly built and installed equipment should generate usable electricity for more than 25 years. Given the longevity of your investment, you want to make sure that any equipment on your roof will perform well and operate safely on your roof.

With solar becoming more and more popular each day, many states, local governments, and utility companies have come out with new mandates that require any grid-tied solar equipment to hold specific certifications. The same holds true for some solar incentive programs; if you’re participating in a state-funded incentive program, don’t be surprised if they have certain testing or certification requirements for your chosen equipment.

Common solar panel testing & certification standards

While reviewing a solar panel spec sheet, you’ll likely notice a bunch of acronyms and random numbers listed under safety and rating certifications – what do these mean? Below are some of the most common solar panel testing standards and certifications to look for when comparing solar panels:

IEC: International Electrotechnical Commission
The IEC is a nonprofit that establishes international assessment standards for a bunch of electronic devices, including photovoltaic (PV) panels. Importantly, the IEC does not test or certify panels themselves – they establish the standards for other testing facilities to adhere to when evaluating solar panel quality.

IEC 61215: Standards for crystalline silicon terrestrial PV modules
IEC 61215 is one of the core testing standards for residential solar panels. If a solar panel module successfully meets IEC 61215 standards, that means it completed a number of stress tests and performed well in regards to quality, performance, and safety.

IEC 61215 standards apply to both monocrystalline and polycrystalline PV modules, which are the most common types of solar panels. The IEC sets different testing standards for other types of solar electric technologies, such as thin-film solar products (IEC 61646).

Solar panels that meet IEC 61215 standards are tested on the following (and more!):

Electrical characteristics (wet leakage current, insulation resistance)
Mechanical load test (wind and snow)
Climate tests (hot spots, UV exposure, humidity-freeze, damp heat, hail impact, outdoor exposure)
IEC 61215 tests also help determine a panel’s performance metrics at standard test conditions (STC), including temperature coefficient, open-circuit voltage, and maximum power output.

What are Standard Test Conditions (STC)?
When solar panels undergo performance testing, they do so at fixed laboratory conditions, known as Standard Test Conditions (STC). Because these conditions are the same across the industry, one panel’s performance metrics (such as power rating, module efficiency, optimal voltage, etc.) can be compared apples-to-apples against other available options.

IEC 61730: Standard for PV module safety
As with any electronic device, solar panels carry the risk of electrical shock if improperly built. That’s where IEC 61730 comes in: this standard address the safety aspects of a solar panel, encompassing both an assessment of the module’s construction and the testing requirements to evaluate electrical, mechanical, thermal, and fire safety. PV modules that successfully pass IEC 61730 tests run a low risk for these types of hazards.

IEC 62716: Ammonia corrosion testing of photovoltaic (PV) modules ammonia corrosion
Do you live on or close by to a farm? If so, keep an eye out for IEC 62716 – this is a test to determine a module’s resistance to ammonia. While most people don’t have to worry about their high concentrations of ammonia exposure with their PV modules, it can be a concern if you install your solar panel system close to farms and livestock. Ammonia corrosion can accelerate degradation in a panel, leading to lower overall electricity production over the lifetime of your system.

IEC 61701: Salt mist corrosion testing
If you’re lucky enough to be installing solar panels on a beach house, it’s worth checking to see your prospective solar panels have successfully passed IEC 61701 tests. With these tests, panels undergo a series of salt sprays in a controlled environment. After the sprays, testers inspect the modules for physical damage – such as corrosion or delamination– and assess their electrical output and overall performance. Panels that successfully pass IEC 61701 tests are definitely a suitable choice for beach-front solar panel systems or systems that will be in close proximity to roads experiencing high levels of salting in the winter.

IEC 60068-2-68: Blowing sand resistance testing
Some solar panels go through IEC 60068-2-68 testing to determine how well they hold up in sandy desert environments. Frequent exposure to abrasive sand can wear a panel down, leading to physical or mechanical defects over time. If you’re installing solar in an area that sees frequent sand or dust storms, try choosing a panel that successfully passed these tests to maximize the durability of your system.

UL: Underwriters Laboratories
Outside of IEC, the other most common acronym you’ll see on a spec sheet related to solar panel testing is UL. This stands for Underwriters Laboratories (UL), a global safety certification company based in the United States. They provide testing services and certifications for many different types of products, including electric appliances, industrial equipment, plastic materials, and more.

UL 1703: Standard for flat-plate PV modules and panels
UL 1703 is an industry-standard attesting to both the safety and performance of solar panel modules. Similarly to IEC 61215 or 61703 tests, panels with this certification go through simulated climatic and aging tests and have been deemed as safe in regards to mechanical loads, fire, and electrical hazards.

You may find that a solar panel spec sheet lists both UL 1703 and IEC 61730 under safety certifications; this is pretty typical for any solar panel sold worldwide. UL 1703 is a mandate for solar panels sold and installed in North America. IEC 61730, on the other hand, is internationally recognized for safety standards and is more widely applicable to the global solar market.

UL 61730: Photovoltaic module safety qualification
UL 61730, a more recent addition to solar panel testing and certifications, combines the testing procedures and standards of UL 1703 with IEC 61730, allowing for complete international approval in regards to a panel module’s safety and performance.

It will become more and more common to see this certification over time–as opposed to both UL and IEC–because it is often the more cost-effective option for manufacturers. In order to complete solar panel testing, manufacturers need to provide multiple solar panel samples. For companies that plan to sell in both North America and international markets, solely completing UL 61730 testing reduces the number of panel samples needed, allowing for reductions in testing time and costs.

The 166mm monocrystalline HJT solar cell developed by SunEvo has achieved a record-breaking conversion efficiency of 25.23% from the recent testing of the authoritative testing institution ISFH, which means SunEvo’s sturdy improvement in HJT solar cell technology, and indicates the company’s unswerving determination and strength in achieving the particular efficiency.

It is understood that SunEvo had achieved a conversion efficiency of 25.06% for the mass production line of 166 HJT solar PV cell on June 8th, before achieving a new world record of 25.23% by adopting the microcrystalline production process when working with leading HJT equipment supplier Maxwell. According to Doctor Wang, the CTO of SunEvo, the record is a new height achieved on microcrystalline craftsmanship that is possible for mass production, as well as a reliable guarantee in attaining a mass production efficiency of 25.5%.

Senior insiders of the industry commented that the regular-sized 166mm Champion cell announced by SunEvo still uses the sputtering TCO film for the PVD mass production process, which offers feasibility in extensive mass production, while the difficulty and gold content are self-evident. The company has been aggressively exploring methods in elevating efficiency and reducing cost, and achieved constant improvement in mere months, as well as multiple critical breakthroughs in N type high-efficiency mono-Si HJT solar cell technology.

Doctor Wang commented that HJT solar cells can be further improved in efficiency by replacing the current doped amorphous silicon with doped microcrystalline silicon or doped microcrystalline silicon oxide (carbide), where both the doping concentration and light transmittance would elevate, and the electrical resistance of the doped layer would reduce, before the current density of the HJT cell is magnified at the end. Doctor Wang said that the company anticipates a constantly improving record of efficiency, and these high-efficiency technologies will be applied on the production lines to achieve extensive production under low cost and applications for GW-grade 25%+ HJT cells.

HJT still possesses a relatively large sum of impedances and difficulties in progression after 30 years of development since 1990; thus, a reinforcement in the guidance and innovation of leading companies are exceedingly important in the expedition of commercial applications of HJT, as well as the actuation of technical upgrades in the relevant equipment and materials of the supply chain. On the occasion of HJT’s 30th anniversary, the Shanghai Solar Energy Society and the TestPV Forum will once again convene the “6th International Forum for the Leading Mass Production and Supply Chain Coordination of HJT”, which centralizes global businesses and experts from the research, manufacturing, application, and investment fields of solar cells, as well as comprehensively probes into the technology and popular market topics of each segment of the HJT industry chain, and penetrates into the future development orientation of HJT cells.

For more than ten years, the classic solar module with a cell size of 156 mm (M0 wafer), later 156.75 mm (M2 wafer), was considered as the standard solar PV module and was very popular.

The times when solar module dimensions have remained on the market over a longer period of time and could be established as a standard are now over. This became particularly noticeable at the beginning of 2020 when solar module producers from China started the trend towards ever larger solar module formats. Increasing wafer sizes are responsible for this.

As recently as 2018, 156.75 mm wafers accounted for about 80% of the market. In 2020, the upheaval came to 158.75 mm wafer sizes. The module outputs here range between 325 and 345 watts, and the dimensions are about 10 to 30 millimeters larger than a classic 60-cells PV module, depending on the design – so they are still very easy to move and process. However, the 158.75 mm solar cell, which was introduced only a few years ago, is already only available to a very limited extent.

Global Market Shares of Wafers by Size

A new size came onto the module market – M6 wafers with 166mm. In 2021, it turns out that this size has become the most widely installed solar module. This is a 120 cell with typically 350 to 380 watts solar panel.

But there seems to be no end in sight. The trend shows that it is possible to go even bigger. Wafer sizes of 182 mm (M10) and 210 mm (M12) have now arrived on the market. With the new cell sizes, a new power class is also emerging: M10-based modules have between 545 and 560 Wp Solar Panel.

According to the leading companies, modules with 182 mm wafers and 210 mm wafers are clearly superior to modules with smaller wafers in terms of manufacturing costs. Therefore, modules with these wafer sizes will probably prevail in the long term and make up the majority from 2022/2023.

Installers will also have to deal with this development. On the one hand, a certain increase in efficiency can usually be provided with the use of larger dimensions. On the other hand, handling according to the manufacturer’s installation instructions is only one aspect that must be considered. Larger module areas set new requirements for the module installation and the substructure, which may have to be planned and executed completely differently, with the same or lower frame thickness.

The ongoing demand for high-performance solar panels at a reasonable cost makes solar companies experiment with the structure of solar cells and tweak the module design. To improve the efficiency of the overall module, solar manufacturers optimize not just the solar cell but its entire cell design. One of such modifications or new innovations is incorporating multiple busbars on a panel.

What is the busbar?

In the solar cell, there is a thin rectangular strip printed on front and backside of the solar cell to conduct electricity, that strip is called a busbar. The purpose of the busbar is simple yet crucial as it separates the cells to conduct direct current from the photons and transfer it to the solar inverter to convert the current into alternating current. The busbars are generally made of copper plated with silver(Ag) paste to enhance the current conductivity in the front side and to minimize the oxidation at the backside. Similarly, multiple busbars are used to wire solar cells together to generate high voltage electricity.

A panel with multiple busbars ensures high cost-saving potential as the metallization process will need less amount of silver coating on the front side. Metallization plays a significant role in the fabrication of PV solar cells because the silver coating for deposition of fingers and buses is one of the most expensive steps in cell fabrication. Multi busbar can aid in decreasing the total series resistance of the interconnected solar cells.

Perpendicular to busbars is the metallic and thin grid finger. The fingers aid in the collection of generated current to the busbars. The cumulative power collected by all the busbars with the parallel tab wired cell strings (ribbons) is then delivered to the junction box. A solar cell grid consists of these thin current-collecting/current-delivering fingers and the current-conducting busbars. The key to efficient solar panel design is to strike an optimum balance between the busbar and the resistance/ shading/ reflection losses of fingers.

How do multiple busbars work?

Nowadays, multi busbar cells have become standard in solar panel design. The minimum number of busbars has increased to 9BB from conventional 2BB. Several manufacturers have intensified their efforts a step further and designing 10BB to 12BB panels. They are focusing on designing panels using PERC (Passivated Emitter Rear Contact) cells with a maximum number of busbars in frontside contacts. Multi busbars aid in the reduction of internal resistance losses, which occur due to the shorter distance between the busbars.

In a typical solar cell, the metallization pattern usually has thin silver fingers that are responsible for current collection and transportation to the thick busbars. These busbars are then connected to the ribbons (cell strings coated with copper wires) in the photovoltaic module design. The increase in the number of busbars minimizes the current in each ribbon and hence lessens the resistive losses.

Additionally, the distance that the current has to travel from collection fingers to the busbar is plummeted further reducing the resistance of the solar cell and consequently the losses. This allows curtailing the usage of silver paste – as it is the costliest consumables for a silicon wafer.

The usage of multiple numbers of busbars also saves the panel from microcracking. Micro-cracks generally happen between busbars, the effect of these cracks is thus diminished towards smaller affected cell slices between two busbars. Therefore, if we compare the conventional counterpart modules with 2BB and 3BB cells, the long-term durability and reliability of multi-bus bars in case of micro-cracks are commonly higher.

Dash-line pattern busbars

Solar manufacturers never stop researching and innovating new module designs to cut the production costs and to increase efficiency. One of such recent inventions is panels with dash-line pattern busbars, it reduces the usage of expensive silver paste. These modules are available with 3-dash, 5-dash, 6-dash and even 8-dash busbars.

Studies have shown that these panels are more sensitive, meaning they are prone to cracking and power degradation. Increased number of dash lines cause the accumulation of thermal stress in the panel which result in cracking at the corners of the busbar.

All things considered

In conclusion, the goal of using multi busbar cells is to reduce the resistive losses by minimizing the flow of current in both fingers and the busbars. It has the potential to decrease the silver paste usage by 50-80%, less amount of silver also helps in eliminating the finger shading as well. It also enhances the efficiency of cell performance.

What is BIPV?

Traditionally, solar is mounted on a building’s roof, referred to as building-applied PV. But more architects are learning how to also incorporate solar cells and modules into things like curtain walls, roof tiles and railings known as building integrated photovoltaics (BIPV).

A BIPV system consists of solar cells or modules that are integrated in building elements or material as part of the building structure. This way, they replace a conventional building element, rather than attaching to one. BIPV modules not only generate electricity, they can also provide added functionality to the building. For example, they can provide sun protection, thermal insulation, noise protection or safety.

Where can BIPV be installed?

BIPV provides several benefits when compared to traditional solar panels. First, there are more available surfaces for integrating the solar cells or modules — BIPV is not limited to roof integration. Solar modules can also be integrated into the building’s facade, skylights, railings and more. BIPV also adds to the aesthetics of the building. For example, the materials used for BIPV allow architects to play around with transparency and color. When integrated in ventilated facades, semi-transparent skylights or windows, BIPV can help keep the building cool.

What are the costs associated with BIPV?

In general, BIPV is more expensive than traditional PV systems used for solar power plants. There is some logic to this since the BIPV system has more functions than only delivering electrical power. However, because BIPV serves multiple functions in a building besides producing power, it may save material and installation cost.

What technologies are involved with BIPV?

The main solar cell technologies for BIPV are crystalline silicon solar cells, thin-film silicon solar cells and other thin-film technologies like organic solar cells (OPV) and dye sensitized solar cells (DSC). Crystalline silicon solar is the most mature technology, though thin-film technologies are grabbing a lot of attention because of their flexible character, ease of integration and better response to indirect light.

Organic solar cells are a relatively new technology that is still in the development phase. However, advantages of OPV can be that it’s a light-weight semi-transparent material, it can be coated inexpensively onto curved surfaces and onto glass, and it can be made in various colors or just color neutral. It also has a superior sensitivity to low light intensities, making the technology fit for maritime climates. Also, the technology is less dependent on the incident sunlight angle, which makes it ideal for aspects such as facade integration.

What is the outlook for the BIPV market?

BIPV is still a niche market, but architects are starting to use BIPV elements more frequently in the design of new public and office buildings. New net-zero energy buildings will help drive BIPV demand.

1. What is Electroluminescence(El) testing?
When current passes through solar PV cells, light emission occurs. This phenomenon is called Electroluminescence(EL). Testing of modules using this phenomenon can detect hidden defects in the structure of PV cells. This method makes the current distribution visible in the solar PV module and helps detect defects.

With the help of an EL test, a PV manufacturer can evaluate the structural quality of the PV cells or any other defects generated while handling.

Defects that can be found from EL are as given below:

• Microcracks
• Cell cracks
• Soldering defects
• PID defects
• Diode failure
• Dead cell
• Backsheet scratches
• Wafer defects

2. Defects & Impact of defects in a module identified by EL Image
A brief description on important of EL defects which may lead to performance failure is given as below

a) Microcracks
Microcracks can create an electrical separation, resulting in inactive cell part. Determining the power loss caused by microcracks is difficult. It can have varying to no effect at all. Microcracks in silicon wafers are minute cracks that appear as a result of damage during manufacture, shipping, installation, or operation.

How to prevent microcracks
To prevent solar microcracks, three areas must be addressed namely manufacturing, transportation, and environment. A solar panel manufacturer must acknowledge this preventive area.

The supplier should have the following:

• A well-defined supply chain
• A testing procedure that ensures each module receives EL testing
• A strong reputation

How do microcracks occur
A major cause of microcracks is manufacturing defects. However, there are some natural environmental causes as well that cause microcracks, such as:

• Thermal cycling (variation of temperature between night and day)
• Humidity and freezing
• Cyclic (or dynamic) pressure loads and wind loading
• Heavy snowfall
• Hail

Microcracks can occur during installation as well, due to variety of reasons, such as:

• Stepping on modules or resting other equipment on modules
• Bumping or dropping modules as they are lifted onto the roof
• Installation on a nonplanar surface, which may cause twisting of the mounting frame and place stress on the module

Figure 1: Sample module with multiple micro-cracks

b) What are cell cracks?
Cell cracks cause isolation of region of cells. Cell cracks seem to be more severe, as current doesn’t pass through this area, and these may cause hot spots or thermal dissipations. When current passes through these hotspots, it heats the PV panel and starts damaging the panel. Hence it is necessary to identify these hotspots before they completely damage the panel.

Figure 2: Sample module with cell crack

c) Soldering defects
When the temperature during the soldering process isn’t high enough, cold soldering happens. The cold soldering interferes with the connection between the cell ribbon and the cell tab, preventing electricity from flowing and resulting in a loss of power production.

Due to its importance, solar module manufacturers frequently undertake EL testing twice during the manufacturing process.

If left unchecked, cold soldering can develop into hot spots, lowering the module’s power and causing a fire risk.

Figure 3: Sample module with soldering defects

d) Bypass Diode failure
When a bypass diode fails during the functioning of a module, one of the three cell strings is normally switched off. The outcome is a one-third reduction in output. Within the yield curve of a string, with good radiation conditions, a fall in yield of this magnitude and in numerous modules is frequently found. The essential interface for conducting electricity to the outside is a junction box at the back of a solar panel.

Figure 4: Sample module with diode failure

The bypass diodes inside the junction box enclosure can become short-circuited and burn out if water or dust penetrates the enclosure.

A burned bypass diode or connector might cause the panel to become an open circuit, preventing energy from being transferred forth. The bypass diode failure can be detected with help of EL. These modules should be replaced immediately to avoid junction-box burn or energy yield loss in the plant.

e) Potential Induced Degradation (PID)
Solar panels are typically connected in long series to generate a high system voltage, often exceeding 1000 V, which is used to power solar inverters.

Figure 5: Sample module with PID

The large voltage difference between the grounded frames and solar cells may be too much for low-quality solar cells to manage, causing them to fail. These defects can be identified with help of EL imaging.

f) Dead cells
Dead cells occur when a particular cell stops conducting current. Dead cells may be caused due to mechanical stress, which may have previously caused a cell crack in that area.

Figure 6: Sample module with Dead cell

3. When should a module get inspected for EL?
Now when someone is aware of the defects it is important to know when a module shall get inspected for EL.

a) During production, to check the cell quality of cells and module, and replace whenever required

Why this is important?

• This will help the manufacturers to identify defects in the very first stage and avoid future loss due to batch rejection or warranty claims.
• Benefits to manufacturer: Avoid rejection of batch supply

b) Third-party inspection by portable EL before dispatch.
This will prevent the dispatch of bad quality modules and reject batches before it reaches field.

Why this is important?

• This will give confidence to the asset owners that the modules supplied are of good quality and future problems of module replacement due to manufacturing defects can be avoided.
• Benefits to asset owners: Avoid rejection of batches or modules

c) Pre-installation EL test:
To check transportation and shipping damages. As we know, transportation on Indian roads can be a veritable roller-coaster. As solar modules are made of cells which are up to 100- 500µm, if modules are not handled properly during transportation or modules are not transported properly this may cause micro-cracks or cracks. It is also possible that the transport truck may get meet an accident in the way of transport, in this condition there is a high risk of broken and damaged modules.

Why this is important?

• To claim transport insurance and get the damaged modules replaced.

d) After installation EL test:
Handling at the site may cause module failures during installation. If the modules are not handled properly while fixing or transporting within sites this may cause micro-cracks or module frame damages. Modules can also be dropped accidentally while movement within the site. These may cause cracks or micro-cracks or even breakage of modules. These defects can be identified from EL.

Why this is important?

• EPC contractor may be held responsible for the damages and the modules might get replaced

e) To claim insurance from natural calamities like hailstorms, cyclones, heavy rains, floods etc. The expense of field EL testing is covered by insurance, and it allows you to protect yourself against future losses as a result of this incidence. While you wait for the power loss or hot spots caused by microcracks in the modules to occur, either the micro cracked modules will be replaced or the money will be kept in escrow.

Most crucially, without EL test data, it would be impossible to claim micro cracked PV modules later when power loss or hot patches become apparent. The window of opportunity for asset owners who wait a few years after the incident has occurred closes: Insurance policies specify a specific timeframe for reporting damage caused by force majeure events.

f) Before buying an Asset, before signing on an O&M contract, and for lenders before disbursement

• Before buying an asset knowing the performance of the plant is important. An EL can help in identifying the defects and protecting new owners from potential revenue loss.
• An O&M contractor can always mitigate the risks by knowing the plant and module health and bidding for a PR suitably, so that performance loss LD, due to a factor not under their control, is avoided.
• For lenders, it is important to know the module health before investing. Hence an EL image of the module can predict the current quality of modules at the site.

4. Impact of Defects if not detected?
It is known that the power of the solar panel decreases with an increase in temperature. The crack in a module caused power dissipation at the inactive cell area, as it limits the current passage through the inactive area thus causing higher temperature at the impacted area. In the Indian climate where the module temperature ranges from 35 degrees to 45 degrees Celsius on average, a higher temperature at an inactive area will further cause a reduction in output.

Consider the following possible scenario of a 100MW plant with 350 Wp with 285714 panels in the field.

• Scenario A: Degradation of 5% panel is 1.18% instead of 0.7% due to inactive area in cells (dead cell)
• Scenario B: Degradation of 10% panel is 0.9% instead of 0.7% due to cracks or inactive area due to soldering defects.
• Scenario C: 10% of panels are affected with PID with approximately 5% degradation instead of 0.7%
• In the above scenario, a 100 MW plant will produce only 99.51 MW if few EL defects are left unnoticed.
• There would be a loss of 8.48 lakhs unit loss in a year which may cost around Rs 40 lakhs loss per annum.
• If the above defects are detected, one can claim for warranty, based on defects, and consider the defects in Energy yield calculation to minimize PR guarantee loss.
• If the defects are not identified this may cause further damage to panels and loss may increase every year.

5) Conclusion
In this paper, the types of defects in a solar module, the requirement of the EL test, and the impact of the EL test if not done were discussed. It was described that cracks, micro-cracks, dead cells can cause hotspots in a module which may further degrade the module and may constrain the pre-mature aging of solar plants. This paper described that what is the potential gain of performing an EL test at different stages of the module life cycle and a brief description with all perspectives was given. The impact on energy loss due to undetected EL failure was discussed.

A solar carport is a photon-capturing canopy covering a parking area. While they have some things in common with traditional carports and ground-mounted solar arrays, solar carports have distinct advantages over both.

Any PV contractors looking to expand their reach and grow their operations should consider adding solar carports to their list of installation services. The market is already huge. And with PV panel prices trending downwards and electric vehicle (EV) sales on the rise, demand for solar carports will only increase in the years to come.

This article explains what solar carports are, how they work and why they’re becoming more popular.

What Is A Solar Carport?

A solar carport is a covered parking area with a canopy made from PV panels. Sometimes these carports are designed for a single parking spot – like in residential driveways. Other times, they might be strung together in a series to cover entire commercial parking lots.

Either way, solar carport owners benefit from cheaper and cleaner electricity, while also providing shade and protection for their vehicles.

How Does A Solar Carport Work?

Unlike with traditional PV installations attached to rooftops, ground-mounted PV systems rely on tilted panels installed several feet off the ground.

Solar carport structures use a ground-mounted model – except that the PV panels are installed even higher off the ground to provide enough clearance for parked vehicles. Many solar carports also come with in-built electric vehicle (EV) charging stations so that drivers can top up their batteries when not using their cars.

How Much Does A Solar Carport Cost?

A standard solar carport system costs about $3.45 per watt, with the bulk of these expenses going to:

• The panels themselves, which range from $16,000 to $18,000 on average for a 5kW system
• The solar carport structure used to support the PV panels costs around $2,500
• The labor, wiring and other components that round out the system

While these are rough averages, there are several different factors that might influence the total cost of a solar panel carport. For example, commercial installations tend to be somewhat cheaper per watt due to economies of scale. With current PV panel prices, for example, a business owner should budget closer to $3.45 per watt. By contrast, residential solar carports hover closer to the $4 per watt range on average.

Either way, solar carports are technically more expensive than their rooftop counterparts are, with a traditional residential PV system costing as little as $2.81 per watt to install. However, not every home or commercial property is suited for rooftop solar due to any number of factors, including:

• Excessive shading
• Chimneys, vents, and gables
• Limited rooftop space
• Incorrect orientation

For those with large enough yards, ground-mounted solar is often an attractive option, with prices hovering in the $3.11 per watt range.

Despite their higher costs, however, solar panel carports provide a host of advantages over rooftop and ground-mounted PV systems.

The Benefits Of Solar Carports

Below are just some of the reasons commercial and residential solar carports are increasingly in demand.

1. Reduced Energy Expenses

Solar canopies represent an easy way to turn unused surface areas into mini power plants. Just as with rooftop and ground-mounted solar installations, clients can generate their own clean electricity on-site instead of buying power from the utility company. As a result, solar carport owners benefit from monthly savings – not to mention smaller carbon footprints. Better still, their energy costs stay constant since sunshine remains the same price forever (free).

With enough installed capacity, users can even sell excess solar energy back to their utility providers under incentive programs like net energy metering.

2. More Efficient Use Of Space

Ground-mounted solar installations take up valuable real estate, with the space underneath not providing much benefit. Similarly, the average parking lot isn’t terribly productive (even when cars are parked there).

Solar carports offer the best of both worlds – allowing users to optimize limited real estate by transforming unproductive parking spots into renewable energy-generation machines.

3. Protection From The Elements

In addition to generating cheaper and cleaner electricity for their owners, solar carports also provide protection from the elements:

• On the hottest days of the year, solar carports help shade vehicles – resulting in more comfortable commutes for their drivers
• Solar carports provide protection from rain, sleet, and snow – helping to prolong the useful lifetimes of the vehicles underneath

4. EV-Charging

This is a relatively recent benefit. But solar carports can be integrated with EV-charging solutions:

• Homeowners enjoy peace of mind in knowing that their electric vehicles have fuller batteries whenever they leave their houses
• Business owners who install solar carports with chargers give EV drivers another reason to walk through the door

5. More Power Generation

Although solar carports carry a higher price tag, they are simpler to manipulate and optimize than traditional rooftop PV systems. It’s much easier to reorient a parking spot than it is to reposition an entire roof. And this allows installers to orient their clients’ carports in the optimal direction to maximize sun capture – and by extension, solar power generation, carbon offsets, and monthly savings.

Is A Solar Panel Carport Right For Your Clients?

Solar carports aren’t for everyone. And your own clients may be better off with a conventional rooftop solar installation, provided their home or business has sufficient space and the right orientation.

However, solar carports are an increasingly affordable option that delivers many important benefits. And with demand on the rise, adding solar carports to your renewable energy services is a great way to attract more business and future-proof your operations.