Solar panels have proven to be one of the best available options to power your appliances. Installations have proven feasibility at utility, commercial and residential scale with remarkable results, saving a lot of money in electricity.

Moreover, as a backup power source when the grid fails, solar panels are the eco-friendly solution that will last over 25-years and that is noise-free and that does not require refilling diesel or gasoline to run. 

Since they are the best option for the off-grid market, we have developed a short guide that will show you some of the most efficient solar panels along with some valuable tips that you will appreciate at the time to buy photovoltaic modules. Let’s get started.

Types of Most Efficient Solar Panels

Solar panels can be classified according to technology and mounting type.

If we refer to technology, then the most efficient solar panels can be classified into two main groups: monocrystalline and polycrystalline modules.

Polycrystalline vs Monocrystalline Technology

Monocrystalline modules are the top efficiency option in most cases. These solar panels are made from a single silicon crystal using a method called Czochralski that results in large cylindrical ingots which are sliced to make silicon wafers. 

On the other hand, polycrystalline modules were the first to enter the market and are less efficient than their counterparts. Depending on the brand, they can compete with other low-quality monocrystalline modules, however, if we compare top quality brand polycrystalline solar panels against top quality monocrystalline modules, the higher efficiency will always be referred to the monocrystalline option. The greatest advantage of these models is related to their balance between costs and power outputs.

Fixed vs Flexible Modules

The other classification is mainly referred to the type of mounting that the module is suitable for. 

Traditional solar panels are designed to fit rigid or square spaces, ideally roofs or ground mounted scenarios where the modules have a flat shape. These modules are known as fixed solar panels and they need a flat surface that supports them.

However, due to the expansion of the solar energy market, photovoltaic modules needed to reach other sectors as well, such as trailers, boats, cabins, and cars where curved surfaces do not allow fixed solar panel installation.  

The solution that came out was to create a flexible solar panel that could be installed on curved surfaces and bend as much as possible without breaking or reducing power output. These modules are known as flexible solar panels and they can be integrated either for flat or curved surfaces.

10 Best-selling Most Efficient Solar Panels

1. SunPower® 100 Watt Flexible Monocrystalline Solar Panel

SunPower® 100 Watt Flexible Monocrystalline High Efficiency Solar Panel

SunPower is definitely the most efficient brand in the market. The brand manufactures monocrystalline solar panels that reach the top efficiency levels of the industry and comply with top quality standards.

In this occasion, they offer a very unique product alternative that is related to a flexible solar panel that can be used to fit curved surfaces in boats, campers, trailers, and RVs.

The modules can bend up to 30° which makes them suitable for surfaces where a standard solar panel model would not be able to fit. Moreover, the module weighs only 2kgs, which makes it ideal for regular roof-type PV systems.

Regarding some specs of the product, the module has a 100W power output and a 23% efficiency value (one of the highest in the market). The product has been designed with IBC solar cell technology and with a power temperature coefficient of -0.35%/°C (ideal for low-temperature loss impact).

Finally, the product is also ideal for off-grid purposes to charge a 12VDC lead-acid battery.

2. Newpowa 175 Watt 12V Moncrystalline Solar Panel

Newpowa 175 Watt 12V Moncrystalline Solar Panel High Efficiency Mono Module

Newpowa is an American solar panel company founded in 2014 that manufactures monocrystalline and polycrystalline modules of high-efficiency values. 

The Newpowa 175W model is also a great option to consider to power your appliances. Designed with 36 monocrystalline cells that connected in series and parallel provide an average open-circuit voltage of 23V and an MPP voltage of 19V (voltage at maximum power), good enough to fit off-grid installations of 12V for lead-acid batteries.

The module is also integrated with a junction box that has water and dust protection. Moreover, each solar cell is encapsulated within an ethylene-vinyl-acetate (EVA) that is placed in a high low iron tempered glass and a durable Tedlar-polyester-Tedlar (TPT) back sheet for maximum protection against the environmental conditions and any possible damage.

3. Trina Solar 245 Watt Polycrystalline Solar Panel

Trina Solar 245 Watt Polycrystalline Solar Panel

Trina Solar is one of the giants in the solar industry. A brand with over 20 years of experience manufacturing solar panels for commercial and residential scale installations.

The TSM-245PA05 model of the brand is a 245W output solar panel that was manufactured on polycrystalline technology. This module has been designed using IBC solar technology and also has been tested to endure harsh environmental conditions (snow loads up to 5400Pa and wind loads up to 2400 Pa). 

Moreover, the module has a guaranteed power output tolerance that varies between 0-3%. In other words, the company guarantees that the module will generate at least 245W under maximum power peak production.

Among other specs, the model has been designed with 60 cells and has a junction box protected with an IP65 rating that refers to maximum protection against dust and also against water jets. 

An important detail of this module is that product warranty reaches 10 years and the performance warranty is the typical standard rated 80% at 25 years.

4. Hanwha Solar 235 Watt Polycrystalline SLV/WHT Solar Panel

Hanwha Solar 235 Watt Polycrystalline SLV/WHT Solar Panel

Hanwha Q Cells is one of the most innovative brands available in the market. The developer of the dual cell and Q.Antum technology.

The Q.Pro-G2-230-250 series models are one of the most traditional and iconic solar panels of Hanwha Q Cells. The module is designed with polycrystalline technology and 60 solar cells that have an estimated maximum power output that surrounds 237.5W in the 235W (nominal power) model.

The module is designed with anti-PID (potential induced degradation) technology which prevents power loss resulting from undesired leakage currents in long string configurations.

Moreover, the module is protected against hot spot which guarantees the module will not suffer delamination or fire ignition due to hot spot formation. Among other things, the performance of the product is guaranteed to have 10 year-warranty protection and a positive tolerance above 5W regarding its nominal power.

Besides, the module has a guaranteed performance over 25 years that represents at least 83% of its nominal power.

5. Renogy 100 Watt 12 Volt Monocrystalline Solar Panel (New Edition)

Renogy 100 Watt 12 Volt Monocrystalline Solar Panel (New Edition)

Renogy is one of the most renowned solar brands available in the market.  The brand develops solutions for off-grid installations: solar kits, charge controllers, batteries, inverters and more.

The brand has an advanced encapsulation material with multi-layered sheet laminations that enhance cell performance and that also protect it against hot spot formation. The module has bypass diodes integrated to mitigate the effects of near shadings.

Moreover, the 100 Watt model has a positive power output tolerance between (0-3%) that withstands high winds (2400Pa) and snow loads (5400Pa). The product is also integrated with an EVA film, a TPT back sheet, an anti-reflective cover, a low iron-tempered glass, and an anti-corrosion layer. On the other hand, the module has an IP65 rated junction box that protects all bypass diodes and connections from dust and low-pressure water jet as well.

The module can be used for different applications thanks to its Z-Brackets, Pole Mounts and Tilt Mounts as well. You can place the Renogy 100W model in trailers, PV systems, RVs and more.

6. HQST 100 Watt 12 Volt Polycrystalline Solar Panel

HQST 100 Watt 12 Volt Polycrystalline Solar Panel

HQST is one of the common selected brands when referring to portable solar panels or solar kits that include modules, charge controllers and wiring.

In this occasion, we are looking at a polycrystalline solar panel that has an anti-reflective cover with high transparency and a low iron-tempered glass that is able to withstand high-speed winds and snow loads. Moreover, the module is also integrated with IP65 protection that covers against dust and water jets and the frame of the solar panel has an anodized aluminum alloy design.

On the other hand, the module is protected against the hot-spot formation and the TPT back sheet secures a long-term smooth performance. Moreover, the module has a 5-year product warranty protection and a 25-year performance warranty protection.

Regarding some important specs, the module is guaranteed to work up to 600VDC string configurations and needs a maximum 15A fuse rating to provide protection to the solar panel under fault condition.

7. Nexttechnology 100 Watt Ultra Thin Outdoor Solar Panel

Nexttechnology 100 Watt Ultra Thin Outdoor Solar Panel

Another valuable option that fits curved shape surfaces is the ultra-thin solar panel from Nexttechnology.

This module has also been designed with a flexible capability that allows it to adjust to multiple surfaces that are either flat or curved. Common applications are related to boating solar panels, RV or trailer solar panels, homes with curved shape roofs and even solar-powered cars.

Applications like these cannot use a rigid module type and therefore, leave a great market for flexible solar panels like the Nexttechnology model.

The module also integrates stainless-steel iron loops that allow it can be easily attached to any surface by simply using suction cups, facilitating installation procedures, unlike fixed type models. 

Moreover, this module has endured and passed over 23 quality control tests to ensure stability and reliability of each module.

Among other important specs to consider, the module has a power tolerance between equation.pdf3%, an open circuit voltage value of 20V,  and an operating temperature between -40°C to 85°C. 

8. ACOPOWER UV11007GD 100 Watt Foldable Solar Panel Kit

ACOPOWER UV11007GD 100 Watt Foldable Solar Panel Kit

Acopower is one of the most recognized solar powered product companies, especially in the off-grid market sector. The brand manufactures solar panel kits, charge controllers, batteries, portable generators, and other products as well. 

In this case, we have a 100W foldable solar panel kit that combines two 50W monocrystalline modules with 15.4% efficiency and a great performance in low light scenarios. The kit is composed by a suitcase that also includes a 10A PWM charge controller, pre-installed on the rear side of the solar panel kit that has been designed to provide protection against system overcharging, over-discharge, overheating, overloads or reverse connection. 

All the connection between the modules and the charge controller is already integrated as part of the kit and also includes the alligator clips to get connected to the 12V DC solar batteries

The combination between the modules, charge controller and a 12V lead-acid battery (not included) allows it to charge multiple appliances in off-grid scenarios such as camping, caravans, motorhomes, and boats as well. 

The suitcase has also MC4 connectors integrated and a corrosion-resistant aluminum frame that is suitable for any outdoor use and that is protected against multiple weather conditions.

9. BougeRV 100 Watt 12V Solar Panel

BougeRV 100 Watt 12V Solar Panel

The strategic allegiance between a high-quality RV products promoter (BougeRV) and the top solar panel company (Sunpower) is the perfect mix to power the appliances inside your RV: TVs, microwave, refrigerator, radios, electronics, etc.

The 100W Sunpower monocrystalline module offers an average 23-25% efficiency value, which is the highest in the market and is also integrated with an internal blocking diode to prevent reverse currents over the night.

Moreover, this module has been designed with multiple layers, from the TPT anti-corrosion frame, two EVA films, the MAXEON technology solar cells and an exceptional ETFE film specially designed for BougeRV which is a lightweight and highly transparent glass structure that is also strong and provides high transmittance of light to optimize solar power generation.

The solar panel is also water-resistant, ultra-durable and has been designed with enough flexibility as to bend 30° without suffering any damage. 

The module also has a unique solid copper backing that makes it almost invulnerable to corrosion (reducing 85% probability of failure) and the solar cells absorb more sunlight thanks to its design where no grid lines are present in the front-side of the module (avoiding extra near-shadings).

10. ECO-WORTHY 100 Watt 12 Volts Polycrystalline PV Solar Panel

ECO-WORTHY 100 Watt 12 Volts Polycrystalline PV Solar Panel

Eco-worthy is another giant of the solar panel industry. Manufacturer of solar panels, pumps, off-grid solar systems, solar cells, inverters, charge controllers, batteries and more products. With over 15 years in the industry, the brand is a reliable developer for any solar powered product.

In this occasion, we are viewing at a polycrystalline solar module that has the perfect size to charge a 12V lead-acid battery for multiple off-grid applications like boats, RVs and camping purposes. Actually, by wiring in series more solar panels, charging voltages can reach up to 24V and 48V.

Each module has an integrated pre-drilled hole with a 90cm and 12AWG cable that allows connection to the charge controller. Moreover, the module has an IP-65 rated junction box that protects it against dust particles and low-pressure water jets. This junction box has bypass diodes integrated to maximize shading optimization and also provides short circuit and reverse current protection

All of these features and especially the brand that manufactures it makes it an ideal option to consider for your independent renewable energy power source.

Most Efficient Solar Panels Buyer’s Guide

What additional components should be selected to install a solar power system?

The solar panel is the heart of the PV system. Each module absorbs sunlight and converts it into DC electricity across the day. 

The DC power generated fluctuates across the day according to weather conditions. Now, since the electrical loads work within an established range of voltage and electrical currents, then the solar panels need a regulator that ensures the voltage and electrical current values are located within that boundary.

  • Charge Controller

Here, the charge controller performs an essential role. This device is designed to adjust the voltage input that the electronic device will receive to the pre-determined values (typically 12V, 24V or 48V). 

  • Batteries

On the other hand, you also need to consider an energy storage device, typically a lead-acid battery in off-grid systems. These batteries are generally connected to the charge controller, receiving their nominal voltage to store the solar energy for later use. 

  • Inverter

Finally, since all these components work in DC current, there is also the need for a converter that switches to AC electricity. This is the work of the power inverter, which is an electronic device that turns the DC signal into a sinusoidal AC signal (similar to the grid) that allows the connection of AC loads such as refrigerators, microwaves, laptops, and others.

Which Factors Should I Consider When Selecting Most Efficient Solar Panels?

Power Output and Efficiency

One of the most important details that you have to take into account is related to the power output and the efficiency of the modules that you select.

The power output must be linked to the loads that you want to power. Keep in mind, that a 100W does not mean that you will be able to power 100W appliances permanently. 

The solar panel generates DC electricity as it receives solar radiation throughout the day. The 100W nameplate rating is only a reference of the amount of power that the solar panel is able to produce under specific Standard Test Conditions (STC). These are laboratory conditions that are not always a reference for the real conditions. Therefore, you must always select the power rating above the load demands.

On the other hand, efficiency is also an essential factor to consider, especially for off-grid applications. In applications like these, the availability of space is not large, therefore, every inch of solar cell needs to be producing as much electricity as possible. For this, keep in mind that traditional solar panels should have efficiency values above 15% and that the most efficient ones (generally Sunpower modules) could reach values close to 23%.

Weight and Dimensions

The weight is a very important factor in both grid-connected and off-grid scenarios. A heavy solar panel will demand a harder work for the solar installer, and sometimes installations on the roof can be complicated, therefore, handling lightweight modules is always preferable. Lightweight solar panels are also easier to transport in off-grid cases.

Dimensions are also important as well. The amount of space available on the roof of your RV or in your boat is limited, therefore, the dimensions of the solar panel limit the quantity of power that you can obtain from a specific module. Obstructions are also common, so keep in mind to make a preview sketch based on the dimensions of the module before purchasing.

Warranty

Is not desirable that you find yourself in a situation where you need to claim your warranty. However, having a long product warranty is always something that you need to look at when selecting any module.

Keep in mind that there are two types of warranties associated with solar panels. 

The first one of them is the performance warranty. This type is associated with the minimum power output that the solar panel should be producing by the end of its lifetime. However, these warranties are only a reference of quality and durability, they are really hard to claim and almost all solar panels have a 25-year performance warranty.

The second type is associated with the product warranty. This is the type that you must look deeply into as this is the warranty that you would be most likely able to claim under malfunction or damage. Most solar panels have between 5-10 year warranty, but some even reach the 15-years.

What Installation Tips Should I be Aware of?

Off-grid solar panel installations are perfect for DIY projects. Despite that there is a little electrical knowledge required, you can always make your own research to make the installation yourself and save some money. These tips will give help you in some steps of the process if you are installing on top of an RV:

  • Draw a schematic of the PV array in the rooftop.
  • Install the mounting brackets on the ground.
  • Drill a hole to fit the cable entry plate and install it.
  • Take the solar panels to the roof
  • Install the solar panels using the mounting brackets and drilling four holes for each one
  • Wire the series or parallel connections and attach them to the cable entry plate.
  • Make the connection from the cable entry plate to the location of the charge controller.

Conclusions

We have examined some of the most interesting solar panels available in the market with good efficiency values.

Brands like Acopower, Renogy, Trina Solar, Eco-worthy, and especially Sunpower, are quite familiar in the market and provide us confidence in the product quality and the specs established by the brands.

Moreover, as we have discussed previously, keep in mind factors such as warranty, power output, efficiency, weight, dimensions, brands, technology, and the mounting system as well to make the most accurate choice for the application that you need.

The solar panel is the heart of the PV system and should last over 25 years, therefore, making a wise choice is extremely important to ensure the reliability of your PV array.