Let’s Get Technical – Choosing the Best Products for your Commercial Solar Project
You’ve decided to invest in solar energy for your business, now comes the fun part: selecting the best solar panels and inverters. As part of the project development process with Srinergy, we will recommend equipment for your system, however, let’s discuss the options and how to make sure you are getting the best-in-class equipment for your project.
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Is There a Difference Between Residential and Commercial Solar Panels?
Solar panels are generally the same in terms of the basic technology. Besides specialized solar panels for specific applications, almost all solar projects use mono or poly crystalline technology. Major manufacturers of solar panels generally produce solar panels that will have similar form factors. Let’s get into the different types of panels available.
Monocrystalline vs. Polycrystalline Solar Panels
- Monocrystalline and polycrystalline solar panels are the two most common types of solar panels. Like all solar panels, they capture the sun’s energy and convert it into electricity. Both types are silicon based, a material that’s abundant and durable.
- The most significant difference between the two panels is the silicon crystal technology used. Monocrystalline (mono) panels use a single silicon crystal, while polycrystalline (poly) panels use multiple crystals melted together. Mono-crystalline panels generally perform better.
- Whether mono or poly, Commercial solar panels tend to be larger than residential panels. Measuring around 40″ x 90″ a commercial panel is designed to produce more energy compared to their residential counterpart that measuring in around 40″ x 70″.
In addition to size there are some aesthetic differences between residential and commercial solar panels.
Clear Frame vs Black Frame Solar Panels
Solar panel aesthetics can vary. Commercial solar projects on flat roofs, ground mounts and carports tend to have solar panels with silver frames, known as “clear” or “mil” and will have a white backsheet. This type of panel will make the cells of the panel appear to be more blue and don’t blend with the roof as nicely as the typically as a black frame and black backsheet solar panel (black on black). Depending on your project goals and the building aesthetics a black frame panel with a black backsheet may be preferred for visual reasons. There is a small premium to use black panels, but if your building aesthetics would be improved through black panels, your business may consider that. The panels will appear black and on a pitched asphalt roof so they will blend in more to the roof and give a more streamlined look to the building. If your project is a ground mount or on a flat roof, aesthetics might not be as important of a determining factor as they are unlikely to change the visual aspect of the facility.
Bi-Facial Solar Panels
Many of our commercial installations use a bifacial solar panel. This type of panel produces energy from both sides of the panel, from direct sunlight on the top to the sun’s reflection on the backside. These panels are ideal for flat roofs where the panels are tilted up and even some ground mounts. On a white flat roof, there will be a bounce back effect with light hitting the roof and then the back of the panel. This will increase production of the solar panel and improve the performance of the solar array overall.
What Are The Best Commercial Solar Panels?
Srinergy has been installing solar panels and inverters for 15 years. We have learned a lot and will guide you in the selection of a top solar panel for your projects. Here are the key factors we consider when recommending a solar panel for your project:
- Cost
- The Solar Panel Efficiency – the portion of energy in the form of sunlight that can be converted via photovoltaics into electricity by the solar cell. The efficiency of the solar cells used in a photovoltaic system, in combination with latitude and climate, determines the annual energy output of the system.
- The Solar Panel Specifications and Dimensions
- Durability of the solar panels
- Warranties – A solar panel comes with two warranties. The product warranty covers the equipment and typically guarantees at least 10-12 years without fail. The power or performance warranty often guarantees at least 90% production at ten years and 80% at 25 years.
- Manufacturer’s reputation & financial stability.
There are many great panel brands to choose from, but several stand out to our product selection team. The two main brands we offer currently to our commercial customers are Philadelphia and MSolar.
All solar panels used by Srinergy are listed as tier 1 on the Bloomberg list:
What goes into the Bloomberg Tier 1 Rating for Commercial Solar Panels?
To see how Bloomberg evaluates solar panels check out this document:
What Are The Best Commercial Solar Inverters?
While the solar panels are a very important part of your solar project, the solar inverter is the other crucial component of a commercial solar panel system and has just as important of a role in your project as the solar panel. It is essential to dedicate time to researching the various types of inverters and the brands available. The choice of inverter can have a significant impact on your return on investment (ROI) as it affects the cost, production, and efficiency of the solar system. Use this breakdown to assist you in selecting the best commercial inverter for your solar panel system.
Three main types of inverters:
- String Inverters
- String Inverters with power optimizers.
- Microinverters
String Inverters:
A string inverter is connected with a string of solar panels or a number of strings of solar panels, which is called the solar array. There are many different ways of connecting a string of solar panels. A typical solar array string can consist of around 15-30 solar panels ranging from in watts per panel of 400-550W.
In a string inverter, the array will be broken up into the number of strings needed based on the voltage input limit of the inverter. Depending on the kW rating of the Inverter the solar array will be broken up into strings and each string will have a positive and negative home run that will be wired to the inverter.
The inverter combines all the direct current received from each individual solar panel and, at once, converts it into alternating current that matches the voltage of your building. Most common voltage configurations for buildings in either 208V or 480V.
Srinergy recommends SMA and CPT string inverters for many projects. We also use SolarEdge inverters for some projects and on smaller projects we consider Enphase Microinverters.
SMA: https://www.sma-america.com/products/solarinverters/sunny-tripower-core1
Inverters recommended by Srinergy:
- SolarEdge – String Inverter with DC Optimizers
- SMA – String Inverter
- Chint Power Systems (CPS) – String Inverter
- Enphase – Microinverter – Generally for Smaller Projects
All four brands have established a reputation for providing top-quality products with lengthy warranties at an affordable cost.
Advantages of using string inverters
String inverters are the most common type of solar inverter and have been around for decades. The main reason for their success is their simplicity, robustness and durability. String inverters have also been available on the market for much longer than other types of inverters.
1. Ease of Maintenance and Troubleshooting
String inverters are installed can be installed in the most strategic location as part of the project. At Srinergy, we most commonly will install the inverters either on the roof with the solar panels This facilitates the ease of maintenance, as one does not have to go back and forth to the field for troubleshooting. This is a serious benefit in places with extremely cold or hot climates.
2. Safe and Trusted Technology
As mentioned earlier, string inverters have been around for decades. As a result of this, most string inverters are reliable and it’s a technology well understood by electricians.
3. Lower costs
When it comes to the costs, string inverters are currently cheaper than micro inverters. You only need one string inverter per installation, while for micro inverters, one would need one inverter per panel.
Disadvantages of string inverters
1. Single point of failure
If the inverter breaks down, the whole solar array or the section of solar panels dedicated to that inverter will be inoperable. This could be a significant loss of electricity production and will require technical support to solve the problem.
2. Expandability
Future expansion of your solar array can be challenging unless the inverter is sized for expansion going into the project. It is possible that you would need to buy an additional inverter in the future to be able to expand.
3. Shading
String inverters are the most used inverters for commercial ground mounts. A string converts energy for several solar panels. The downside – if the production drops on just one solar panel in the string, the entire string of panels is impacted.
Each type of inverter has its own set of benefits and drawbacks that should be carefully considered in relation to your specific goals and objectives for installing solar energy.
Whereas with a microinverter or a power optimizer, production drops are limited to the impacted solar panel since they are installed on each panel for module-level optimization. This comes at a much higher cost.
String Inverters with Power Optimizers
SolarEdge Technologies has pioneered string inverters with power optimizers. These inverters offer the best of both worlds between string and microinverters.
It is also possible to use 3rd party brand optimizers and to pair them to a string inverter. This will add cost to every panel installed on the roof, but it will maximize production of the array by limiting the impact of shading. Even if one panel in a string is shaded, optimizers will eliminate the impact of one panel dragging an entire string’s performance down.
Benefits of SolarEdge inverters
There are many benefits to SolarEdge inverters related to the inverter itself, the optimizers and the monitoring portal. As with any renewable energy project, your company will benefit from energy savings and a reduced carbon footprint. Demonstrating your company’s commitment to sustainability will attract likeminded people to your company whether as potential employees or customers. Other, less obvious benefits are outlined below.
1. Greater electricity generation
Power optimizers installed with solar panels allows for greater levels of electricity generation because each individual panel has maximum power point tracking. This is a feature unique to SolarEdge inverters. In fact, SolarEdge offers up to 150% DC oversizing or power.
2. Performance monitoring
The SolarEdge monitoring platform offers customers and installers the capability to check their solar panel’s performance and each solar panel’s individual performance. There are also automatic alarms and alerts to notify the customer should a technical issue arise. Panel performance monitoring can be accessed on any device from anywhere if there is an internet signal.
3. Safety
SolarEdge also offers the ability to shutdown each solar panel in case of emergency. This feature automatically shuts down the DC voltage from the solar panels, protecting any nearby solar installers, maintenance staff or firefighters.
4. Efficient operations
The simple function and design of a SolarEdge inverter makes for a more efficiently operating solar project. This also makes for simple installation and servicing which saves customer time and money.
5. Longer warranty
SolarEdge offers a 25 year warranty for power optimizers and a 12 warranty for inverters. This warranty is longer than its competitors.
Disadvantages of string inverters
1. Single point of failure
SolarEdge still is based on a centralized string inverter, so just we noted above, If the inverter breaks down, the whole solar array or the section of solar panels dedicated to that inverter will be inoperable.
Microinverters
Microinverters are another great option, however every solar panel will need a microinverter so they can be cost prohibitive compared to the additional benefits they can add to a project. As a solar project can scale up to be very large systems, we generally don’t recommend microinverters for commercial applications. On smaller commercial projects we will consider them.
The main microinverter brand that Srinergy uses are the Enphase IQ8 Series Microinverters for three-phase commercial applications. Enphase IQ8P-3P and IQ8H-3P Microinverters simplify design, improve energy harvest with higher uptime, and offer true peace of mind during operation and maintenance. The Enphase Installer Portal and Enphase App provide seamless monitoring and analysis of microinverter and system performance for both Srinergy and the end client. We can ensure the system is producing at expected levels and have visibility into any issues with the system using the app.
One of the great benefits to Enphase is that they have a standard 25-year limited warranty.
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