SMA America further simplifies its Power+ MLPE inverter solution

SMA inverters

With speed as a top priority for solar professionals in today’s market, SMA has revealed an improved Power+ Solution, which builds on SMA’s MLPE solution to provide even more speed and simplicity. The UL-listed Power+ Solution, which the company claims is the fastest residential PV system to install, is currently available through its Authorized Distributor network.

“With the introduction of the improved Power+ Solution, we are addressing the need to accelerate and simplify the installation process,” said Nick Morbach, executive vice president of SMA’s Residential and Commercial Business Unit. “This includes fewer components, reduced labor and a single, simple monitoring platform. We are excited to introduce this next-generation solution to solar installers.”

One of the most significant improvements to the Power+ Solution is a major reduction in system components within a new Rooftop Communication Kit. This means faster installation, fewer potential points of failure throughout the system, and less equipment to service.

Additionally, a single plug-and-play communication connection speeds installation and reduces labor. The new Power+ Solution offers 50% faster commissioning within Sunny Portal, which was ranked the number one monitoring platform worldwide by GTM Research in 2017. SMA was also ranked number one in residential monitoring and energy management in 2017 by Navigant Research.

The Power+ Solution now also features SMA Smart Connected, a proactive service solution that can decrease truck rolls, lengthy service calls and system downtime, saving installers time and money and maximizing a homeowner’s power production.

Solar professionals looking for technical training can attend The New Speed of Solar Tour, where they will receive valuable instruction and gain access to SMA personnel. Installers will also benefit from training provided by solar sales and design expert Aurora Solar at select stops.

— Solar Builder magazine

PV Pointer: Find the hidden value in ‘oversizing’ inverters

Fronius oversizing inverters

While inverter oversizing is not new to the solar industry, there are still inverter manufacturers that do not offer an attractive DC:AC ratio for their inverters. This highly impacts cost and profitability of a solar system. Therefore, it’s important for system designers and solar installers to have a closer look on the oversizing capabilities of inverters, and to tap into their hidden power.

Inverter oversizing refers to adding more DC power to an inverter than it is rated for. For example, if you connect 6 kWp of DC power to a 5 kW inverter, you oversize the system by 20%. This makes total sense, because the peak power of 6 kWp will only come up in very few and short moments – so using a 6 kWp inverter (no oversizing) would be unnecessary and therefore a waste of money. In situations where the system actually generates more than 5 kW, the inverter would clip are so rare and so short, that it is negligible. The advantages you gain by oversizing clearly outweigh the effects of clipping.

Modern, high-quality inverters like Fronius SnapINverters can handle DC power of up to 150% of the inverter’s nominal output power, which would be for example 7.5 kWp on a 5 kW inverter, which is a lot of hidden power. Let’s have a closer look on the advantages of oversizing.

Cost savings

A main advantage of oversizing are the initial cost savings. For the price of a 5 kW inverter, you get to support a 7.5 kWp system – benefitting from 2.5 kW of hidden power in your 5 kW inverter (for free). Inverters with a poor DC/AC ratio, or no oversizing capability whatsoever, do not provide this cost saving, increasing the cost per Watt significantly.

In commercial, rooftop or ground mount systems, oversizing reduces the number of inverters needed to support the available array size and its kWp on a given roof. This not only reduces the initial cost, but also the O&M expenses – both resulting in a better return on the investment.

More DC power without an AC panel upgrade

Residential AC panels only allow a certain amount of solar power (AC) being connected to them. For example, 3.8 kW AC is the highest power that is possible on a 100 A service panel, 7.6 kW on a 200 A service panel and 11.4 kW on a 300 A panel. As the cost of upgrading a service panel can be very high, it is useful to fit the largest system possible on the existing AC panel. Inverter oversizing helps to maximize the DC power of your solar system. If you have a 200 A panel and a 7.6 kW AC inverter with 50% oversizing, you can actually get 11.4 kWp of DC power. If you were to choose an inverter without oversizing capability, you would be stuck with only 7.6 kWp, or you would have to invest in an expensive panel upgrade.

Higher yields

While the efficiency of high-quality inverters is quite stable over the whole power range, it’s still getting higher the closer the inverter operates to its nominal power. By oversizing a system, the operating point of the inverter is at a higher power, closer to its AC rating, and reaches its capacity earlier in the morning and stays there until later in the afternoon. This not only improves the inverter’s efficiency, but also maximizes the overall energy yield, while keeping inverter cost low – for maximum return on investment.

Conclusion: Look twice when choosing inverters. Make sure to take their oversizing capabilities into account and to tap into the hidden power of high-quality inverters. Fronius SnapINnverters, for both residential and commercial, are capable of 50% oversizing (DC:AC ratio of 1.5:1) – which is a lot of hidden power, so system designers can really maximize the above advantages of oversizing.

— Solar Builder magazine

Panasonic, Enphase to partner on high-efficiency AC module

panasonic

Panasonic Corp. of North America and Enphase Energy Inc. are partnering on the development of high efficiency AC Modules (ACMs). To support this partnership, the 320W Enphase IQ 7X Microinverter offers compatibility with Panasonic’s N Series Photovoltaic (PV) Modules HIT (N325/N330), and will be made available to distributors starting May 2018.

“Panasonic prides itself on its dedication to delivering reliable products to our customers,” said Mukesh Sethi, Group Manager, Panasonic Residential Solar Group “This partnership with Enphase Energy will enable us to combine our products and expertise to offer a new solar solution that can help our customers meet their renewable energy needs. We look forward to our future with Enphase Energy and what we are able to achieve within the residential solar industry.”

A recent Enphase market survey of installers nationwide affirmed the value-add of AC modules, with significantly lower install times, and additional savings on logistics and overhead costs, making it a preferred choice for installers. Installers and Integrators also benefit from fewer inspection steps with factory-assembled and tested ACM products.

Panasonic’s N Series HIT® Modules are among the most efficient panels on the market, with high power outputs and greater energy yields due to their industry-leading temperature coefficient of -0.258% /⁰C. Panasonic solar modules keep at least 90.76% of their initial power output even after 25 years of use.

“The N series PV Modules are manufactured for peak performance, making them an ideal partner for the Enphase IQ 7X Microinverter,” said Mr. Sethi. “With a unique heterojunction technology and advanced bifacial cells, these high efficiency panels offer homeowners state-of-the-art features and maximum solar production.”

As part of Enphase’s seventh-generation microinverter platform, the IQ 7X Micro will support 96-cell PV modules up to 400W with peak AC output power of 320W and a Maximum Power Point (MPP) tracking range of 53-64V.

When combined with the Enphase Envoy Gateway, AC Combiner 2.0 with built-in Revenue Grade Meter (RGM) and disconnects, the Panasonic-Enphase ACMs will provide highly advanced PV systems to home owners and quick installation time for integrators and installers. Compliant with Rapid Shutdown Requirements of NEC 2017, the IQ 7 Microinverter System will significantly lower overhead costs and offer homeowners a safe residential PV systems solution.

— Solar Builder magazine

Rapid Shutdown and Beyond: Inside NEC 2017 and the effort to streamline PV design

collaboration illustration

New codes and regulations are notorious for raising prices and halting innovation in industries, but the new rapid shutdown requirements facing the solar industry are having the opposite effect. Thanks to a coalition of manufacturers and interested parties across solar, the solutions being developed to meet NEC 2017 Module Level Rapid Shutdown requirements will achieve something solar technology has long needed: common language.

“The intent is to create an open protocol for any manufacturer to apply,” says Michael Mendik, head of solution management, Solar Energy Division at Fronius USA. He has been an active member of the SunSpec Alliance, the group that has developed these standards. “Inverter manufacturers can build and design their own transmitters and then the rapid shutdown boxes will also be tuned to that language and can receive the signal. There is no proprietary stuff.”

“The current systems were designed to meet the previous rapid shutdown requirements using mostly proprietary communication systems,” says Mario Thomas, product manager at ABB. “Future system design will be vendor independent, allowing a better choice for the customer and the installer.”

“The solar industry is experiencing significant growth with new requirements, so we welcome the vendor coordination efforts and the wide adoption by many vendors working to improve the safety of clean energy production,” says Danny Eizips, VP of engineering at Tigo. “This is a great opportunity for multivendor support.”

This standard protocol has ramifications beyond the context of rapid shutdown, but let’s start there.

NEC 2017 changes

The 2017 edition of the National Electrical Code (NEC 2017) includes an update to section 690.12 Rapid Shutdown of PV Systems on Buildings. The update pushes the requirement to “module-level” rapid shutdown instead of the “array level” that was listed in NEC 2014. Effective Jan. 1, 2019, this requires conductors inside the array boundary to be discharged to 80 volts or less within 30 seconds of initiating a rapid shutdown event. This requirement comes in addition to the outside the array boundary voltage being limited to 30 volts or less.

At first glance, the changes didn’t require such a collaborative effort. Module-level electronics could have done the trick and piecemeal proprietary products and one-off collaborations from various manufacturers could have continued as usual. Luckily, that wasn’t the case.

The SunSpec solution

Formed in 2009, the SunSpec Alliance is a trade alliance of more than 100 solar and storage distributed energy industry participants, together pursuing information standards to enable plug-and-play system interoperability.

After nearly two years of intense technical collaboration, the Communication Signal for Rapid Shutdown Interoperability Specification was published in September 2017 as a method to comply with NEC 2017. This spec defines a communication protocol that uses the cabling of the solar array to transmit messages over the DC power lines between the PV modules and a master control device located near the inverter.

In addition, PV module manufacturers can implement the protocol on intelligent devices embedded in the junction box of each PV module. A master control device associated with the inverter communicates with the PV modules. Altogether, the specification enables plug-and-play interoperability and any-to-any rapid shutdown solutions.

“This open standard delivers multiple benefits to the distributed energy industry, most notably lower integration costs and the freedom to choose from an array of interoperable products,” saysTom Tansy, chairman of the SunSpec Alliance.

What’s this mean for me right now?

  1. If you are a big fan of installing microinverters, you’re already meeting these rapid shutdown requirements.
  2. As mentioned earlier, the implementation date for NEC 2017 is Jan. 1, 2019. Depending on the Authority Having Jurisdiction where you do business, you may not even be held to the NEC 2014 requirement right now, let alone NEC 2017 when it arrives. The Northeast portion of the country will be the earliest adopters, followed by California.
  3. If you are going to be held to NEC 2017 — or just generally would like to comply on your own — sit back and wait for these SunSpec-certified products to hit the market and design systems the way you always have.

“The complexity here is not on the installer end,” Mendik says. Manufacturers had to develop a transmitter that’s hooked to the DC line and puts in the signal.

Some of these solutions are already available, like the Fronius Symo. Other companies announcing immediate plans to incorporate the technology into their product lines include ABB, Maxim Integrated, Omron, Outback, SMA and Tigo. You can expect to see most of these around Q2 this year. There is no UL testing protocol yet to certify these products, but UL is part of the SunSpec Alliance, and you can expect this to happen soon.

Why else is this a big deal?

Not to be flippant about the importance of safety, but this protocol opens the door for way more impactful product developments. There’s an opportunity here to make your life even easier and bring the costs of a system down even more.

1. Proprietary boundaries will come down.

For starters, the array-to-rapid-shutdown-box-to-inverter architecture is more flexible. Prior to any updates, you had to procure the rapid shutdown box and the inverter from the same manufacturer. No more.

“The installer can install the systems as before and doesn’t have to worry about matching inverters of rapid shutdown boxes,” Mendik says.
So, that’s cool, but that flexibility goes way beyond the rapid shutdown, inverter pairing. “There’s no specific [module-level electronics] on the roof,” Mendik continues. “If there are different panels, they will be working with different rapid shutdown boxes. If one type of inverter in a system breaks, it can be replaced with another, and it will still work. A distributor can have different inverter types in stock for replacement, and everything will still be in line with the protocol.”

2. System designs will be streamlined.

Today, that rapid shutdown box is just an added expense, even now, after the protocol. This is why many installers prefer module-level electronics like microinverters, which meet rapid shutdown module-level requirements while also adding optimization, monitoring and design flexibility.

In the not-too-distant future though, this rapid shutdown box will be gone completely, even in a string inverter design. Soon, using this common language, module manufacturers will be including supped up junction boxes or chips from a company like Maxim instead of diodes. These will meet NEC 2017 and provide MLE performance with a string inverter design. This will keep costs and industry part counts down.

“An integrated module in the future, where the installer doesn’t have to buy and wire a specific rapid shutdown box … it’ll be like going back in time to when he didn’t have to worry about that,” Mendik says. “This also means you won’t have complex electronics on the roof. The standard forces you into more complexity for rapid shutdown, but the solution we’re looking at is simple electronics, not power electronics and doesn’t convert power from DC to AC.”

Thomas sums it up: “The customer in the end has a choice. I think that’s a big benefit. Customers don’t want to get stuck with one vendor and want the right to choose between different manufacturers. Having this choice and competition will reduce costs in the end.”

— Solar Builder magazine

Enphase Energy debuts seventh generation IQ microinverter

Enphase microinverter

Enphase Energy came out with its seventh-generation Enphase IQ microinverters to complement its Home Energy Solution this week. The Enphase IQ 7 Micro and Enphase IQ 7+ Micro have already started shipping to distributors in the United States.

What’s new in Gen 7?

Seventh-generation IQ icroinverters are powered by Enphase’s software-defined architecture which results in an efficient design, and a single hardware SKU worldwide. Enphase says its IQ 7 family of microinverters produce 4 percent more power, and are 19 percent lighter and 17 percent smaller than the IQ 6 family of microinverters. The new IQ microinverters offer the same ease of installation with two-wire cabling, and leverages semiconductor integration for higher reliability and better economies of scale.

The 250 W AC Enphase IQ 7 Micro and the 295 W AC Enphase IQ 7+ Micro will be followed by a new, high-power 320 W AC variant, the Enphase IQ 7X Micro, to address 96-cell modules. Enphase IQ 7X Micros are expected to be introduced in the second quarter of 2018.

“With the IQ 7 family of microinverters, we continue to deliver on our vision of innovation and high quality,” said Badri Kothandaraman, president and CEO of Enphase Energy. “This in-line upgrade to the IQ family of microinverters represents another milestone in our mission to reduce manufacturing costs, and reach our 30% gross margin, 20% OPEX, and 10% operating income (30/20/10) target operating model by the fourth quarter of 2018.”

— Solar Builder magazine