ABOVE 3.5 IS A GOOD SCORE. The nominated scores are structured through available technical data and only limited discretionary values are available to the writer. Therefore, the majority of the values are in comparison to the industry best and worst. Considering that 5 stars are handed out far too liberally in the modern world for inferior products, the Solar Review module assessment criteria considers the industry average value (the middle) as 2.5 stars, accurately awarding those of which go above and beyond in diverse areas.
Within each of the above major categories are a variable amount of the common elements which may influence a purchases decision. Below are the sub-categories and in-depth module assessment criteria.
Cell Type | Contact | Enhancer | Encapsulate | Build
Cell Type. Understanding the base cell type offers a perspective of innovation towards greater efficiency. Currently, N-type monocrystalline solar cells provide the greater efficiencies on a commercially viable scale. Closely followed by P-type monocrystalline. Multicyrstalline and polycrystalline are the same base material which lacks superior efficiency, although often surpasses when affordability is a key selection criterion.
Contact. Performance and efficiency are often further enhanced through the cell contact configuration. Delving into the specific contact configuration will provide insight into how electron flow is assisted. The current Solar Review module assessment criteria categorise the industries best-performing contact designs against down to the most out-dated contact designs.
Enhancer. The next level of module design considers contact and cell enhancement features such as PERC (Passivated Emitter Rear Cell), PERT (Passivated Emitter Rear Totally Diffused), PERL (Passivated Emitter Rear Locally Diffused), Bifacial, and Rear Contact cell technologies. All of which is an advanced design feature integrated to enhance solar energy production.
Encapsulate. One of the most important design features and the least considered is without a doubt the solar panels encapsulate. All solar modules posses heat strengthened safety glass on the front surface due to its ability to withstand extreme temperatures and environmental conditions with little to no degradation. Although the front safety glass will vary in quality from the manufacturer, for the purpose of design Solar Review module assessment criteria, greater focus is placed on the rear back sheet/ encapsulate as this affects both longevity and performance.
Build. The only design feature based on a discretionary assessment. Looking at the overall international market and what solar module types are commercially available at the time of writing, the Solar Review writer, with an educated opinion selects whether the particular module is either innovative, inspiring, standard, uninspiring or out-of-date.
Awards. Internationally recognised awards within the solar and energy storage industry don’t come much more esteemed than an Intersolar award. Both top place and runner-up present an exceptional product within a nominated year. Some products, however, may not flag on an Intersolar award radar yet still cause ripples within alternative respected avenues. This should not be ignored if a certain body is a respected voice.
Mechanical Loading | Front Wind Loading | Rear Wind Loading | Damp Heat Test | PID Resistance | LID Resistance | Salt Mist Resistance | Ammonia Resistance | Hail Impact
Snow Loading. Hard to understand for those of which reside in the warmer climates of the globe, snow loading is real. Even though snow is usually associated with less light intensive of areas of the world, none-the-less the demand for solar energy still exists. In these parts of the world, the requirement for snow loading must be considered.
Front Wind Loading. How does a solar panel withstand the windiest environments? Head-on! Consideration toward front wind loading is a must.
Rear Wind Loading. Perhaps the more relevant aspect of wind loading. A solar panels ability to withstand certain gusts is often truly tested from where the wind is likely to grip a solar panel. From behind. Understanding rear wind loading in accordance with manufacturer installation guidelines can truly assist a solar panels durability likelihood in a diverse array of environments.
Damp Heat Test. As the most difficult test for many solar panels to pass. The damp heat test simulates an accelerated environmental aging test to both high temperatures and humidity. Particularly more testing toward the lamination, and sealing points, the more a solar panel can withstand with minimal degradation the better the prevention of delamination, corrosion and internal component failures.
Thermal Cycle Test. The many internal connection points within a solar module can be tested by simulating extreme temperature shifts. An accelerated simulation, thermal cycle testing is similar to desert conditions where temperatures are likely to vary widely within 24-hrs. The greater a solar module can endure repeated temperature shifts is an important factor for any environment.
PID Resistance. Potential-Induced Degradation is caused when low-quality materials promote minor unwanted currents to induce a rapid deterioration in a solar modules performance. Selecting a solar module which is either PID Free or PID Resistant ensures a combination of high-grade componentry.
Salt Mist Resistance. Solar modules intended for installations in coastal locations should consider nothing less than solar panels manufactured with a salt mist resistance less than IEC 61701 maximum severity 6. Regarded as the highest possible salt mist resistance level for solar panels, those of who know greater should send evidence and testing certifications to firstname.lastname@example.org.
Ammonia Resistance. Solar modules intended for installations in agricultural locations should consider nothing less than solar panels manufactured with an ammonia resistance less than IEC 62716. Considered as the highest possible ammonia resistance level for solar panels, those of who know greater should send evidence and testing certifications to email@example.com.
Hail Impact. The ultimate gauge of durability for most. Will your solar panels withstand hail impact? Potentially so if you select beyond IEC standard toward hail impact, the likelihood of exceptional durability is assured.
Module efficiency | Temperature Coefficient | Power Tolerance
Module Efficiency. An excellent marker toward innovation and define a solar panels ability to maximise any nominated space. Why asses efficiency over nominated power? Quite simply, not all solar panels share the same physical dimensions. Therefore, an insight into efficiency provides a greater understanding of the product evolution and the ability to maximise a nominated area.
Temperature Coefficient. Gauges how much a solar module will derate in performance for temperatures greater than 25oC. Therefore, the lesser the better.
Power Tolerance. Good quality solar panels possess a positive power tolerance to a certain degree. What this means is that a solar modules actual output at Standard Test Conditions should be between 0% and X% greater than the nameplate value. Where a manufacture nominates a negative / positive power tolerance, there is the likelihood of a power output less than the nameplate value.
1st Year Degradation. All solar modules will surrender to an initial stabilisation period when first exposed to the sun. What must be understood is exactly how much degradation will impact the solar modules performance after the 1st year of operation in the field.
Annual Degradation. The source which ultimately gives a solar module life is the same source which degrades a solar modules performance over time. Higher quality components will limit annual degradation toward solar module performance.
Performance Warranty Period. 25-years is becoming an industry average and extreme caution should be taken if a solar panel is promoted with anything less. The justification of the performance warranty period though should be assessed with the above annual degradation rate to truly gauge the performance warranty period.
Assurance. Often the forgotten element of any manufacturers module performance guarantee. Who covers the cost of the freight and repair in the event of a performance warranty claim? As it appears, not always the manufacturer. In many cases, certain manufacturers will offer a simple credit to compensate for the loss of output as opposed to paying for the replacement of a module. It’s important to understand how far a manufacturer will go to adequately support the performance of a solar module once it is installed in the field.
Years | Assurance | Authorised (trained) Installer Network
Years. How many years is the solar modules structural integrity guaranteed? An entirely different prospect over a performance guarantee and the most important guarantee to seek out when making a solar module buying decision.
Assurance. Often the forgotten element of any manufacturers module product guarantee. Who covers the cost of the freight and repair in the event of a product warranty claim? One would assume the manufacturer. Unfortunately not many manufacturers are too forthcoming for freight and repair. Many offer a simple credit of one form or another. It’s important to understand how far a manufacturer will go to adequately support a product once it is installed in the field.
Authorised Installer Network. More and more these days proactive manufacturers are offering greater assurance to end-users which purchase through a manufacturer accredited channel. Why? Because trained professionals achieve greater results for the products integrity in the field. Beyond an industry endorsement such as a licence, products have unique features which are not common knowledge presented by industry training. Therefore, it’s recommended that end-users seek out industry endorsed and manufacturer accredited professionals.
Technology Aggregate | Market Pricing Index
Technology Aggregate. Factoring the aggregated average score of the above 5 main categories presents a current market technology reference into the overall affordability of a solar module. Why must this be considered in conjunction with the price alone? Some milk is cheaper than other milk because it’s out of date. Price isn’t everything in the affordability stakes and the market comparison in USD against the incorporated technology value is essential in any affordability assessment.
Market Pricing Index. The Solar Review module assessment criteria Affordability Market Gauge references the more commonly used USD to determine scoring values.
Detailed Scorecard Report (COMING SOON).
Detailed Solar Review Module Assessment Criteria reports will be available for purchase within each individual product review. If you require an in depth product analysis for a purchasing decision, the Solar Review Module Assessment Criteria reports are a must.