Because technology, regulations and software are evolving rapidly in the solar industry, it’s important for contractors, designers and engineers to stay informed about the latest ways to design solar systems.
While it may seem daunting to track industry changes, you benefit by learning how to design more quickly, efficiently and at lower costs. This will help you be competitive and create more cost-effective systems, says Ryan Mayfield, president of Renewable Energy Associates and instructor for HeatSpring’s Megawatt Design course, which focuses on designing large-scale solar systems.
Of the many advances in the solar industry, it’s important for you to keep an eye on 1,500-volt systems, new software for designing systems, and the new National Electrical Code, Mayfield says.
The industry is now moving from 1,000-volt solar systems to 1,500-volt systems, a trend that affects design, commissioning and testing and offers important benefits, he says.
These higher-voltage systems contribute to lower system costs, said Greentech Media Research in a research report. “Similar to the global switch from 600 volt to 1,000 volt PV systems that occurred in 2012 and 2013, we expect the transition to occur rapidly as the supply chain scales and the value proposition is proven,” said GTM Research.
In the last 12 to 18 months, building codes and the technology have converged to allow for the 1,500-volt systems, but manufacturers are just now beginning to offer them, says Mayfield. “It takes time for the codes and the industry to align for changes like this,” he says.
With a 1,500-volt system, designers can plan for more modules in a string. “This means higher voltage and lower current; you can run more power on smaller wires,” explains Mayfield. “This saves money and labor costs because you’re working with smaller conductors.”
However, it’s best for designers, contractors and engineers to look at a number of different scenarios to determine when it makes most sense to use the higher-voltage systems.
“You need to analyze where the advantages are, what is the breaking point for certain sized systems,” he says. Factors such as the location of the equipment and the location of the utility all affect the cost and efficiency.
Contractors, engineers and designers also should also educate themselves about how to size and spec transformer voltages to meet the requirements of utilities.
Transformers are often required in small systems because there’s a mis-match between a solar system’s inverter voltage and the utility’s voltage. Transformers aren’t always required, however. If you’re installing a large rooftop system—up to 1 MW, for example—the voltage may already match the utility’s voltage, Mayfield says.
In addition to learning about voltage, solar system designers should keep an eye on new software systems that aim to help you design more quickly.
One of the systems Mayfield uses is Helioscope. This allows designers to quickly evaluate potential sites, analyze design decisions and simplify workflow, according to Helioscope. Now available is a faster version of the software for large commercial designs that boosts layout speed, the company says.
“Almost all software systems now are cloud-based; you type in your address and using your browser can draw rectangles and circles and squares to outline your building,” explains Mayfield. “You say, ‘I want to use this module or inverter’ and it auto populates and you can do it in a number of minutes instead of hand drawing,” he says.
Another option is to use the National Renewable Energy Laboratory’s System Advisor Model, which is free. The latest version adds new abilities to the PV and battery storage performance models, according to NREL.
A third option is Aurora Solar software, says Mayfield. That product allows you to model the site, conduct a shading analysis and model your customer’s electric load profile, among other things, according to Aurora’s website.
As you keep up with advances in software, it’s critical to also follow what’s happening with electrical codes. A new National Electrical Code establishes new requirements for 2017, says Mayfield. However, not every state uses the new code; California, for example, is three years behind, using the 2014 code.
The new code modifies what’s required for installation of solar systems, among other things.
A code change can be a big surprise if you’re not following closely. The 2014 electrical code addressed rapid shutdown of systems, for example.
“There was no such thing in 2011. All of a sudden we had to have a way to disconnect conductors on the roof. The code is constantly evolving,” Mayfield says.
If you educate yourselves on codes and other important issues, it’s less likely you’ll be thrown off by surprises like the rapid shutdown code addition. You’ll likely be more efficient, more cost-effective and more competitive.
“If people optimize their systems for design and operation, they can build them faster and smarter,” says Mayfield.
Sponsored by Megawatt Design
Ryan Mayfield and Randy Batchelor teach this top rated course for HeatSpring, all made possible by the great people at SolarPro Magazine.
Is this the time you decide to take it? Make sure you know it is a challenging course with lots of content. Check out the full outline here. You will need to set aside about 60 hours to complete all of it. Set aside more if you plan to do the full design project and have Ryan and Randy review it.