Data Drivers: Inverter monitoring system trends in the residential market

data monitoring inverters

This is an excerpt from the 2018 Inverter Buyer’s Guide. Be sure to download the full free report, complete with specs on 136 inverters at the bottom of this page.

Don’t let the hard, boxy exterior fool you — today’s inverters are all about transparency. A key in inverter selection is knowing just how transparent it is: What portals are set up for you and your customer to use? What do they show? And when? Just after it’s failed or maybe just as it sees something’s wrong? How do the alerts work? Can you make adjustments? Will it make its own adjustments?

Basically: How well can you see inside that box?

We asked each inverter manufacturer to share with us how their inverter monitoring system works and what came back was a variety of strategies, from increased flexibility and visibility for the operator and homeowner to innovations in predictive analytics and automated processes. Some come standard, some are subscription-based, but all are slick, boost PV performance and improve your company’s O&M services.

Here are the trends among the manufacturer-provided inverter monitoring systems on the market.

Download the 2018 Inverter Buyer’s Guide

Apps for that

Mobile-friendly platforms are fairly common now, with differences coming in how much data is presented and what remote capabilities are offered.

APsystems provides complimentary module-level monitoring through its cloud-based EMA service for both homeowners and installers. With the EMA app, users can see the energy their system is producing at the panel level, so if the app shows that a particular PV module is underperforming, the owner knows to check for shading issues, debris, damage, etc. The online EMA portal also emails alerts to the installer if a system or unit is operating outside its standard parameters. This is particularly handy when a PV module fails or is somehow disconnected.

Some solar customers invest in a PV system because they want to fully take ownership over their energy bills. They are hands on and want insight into what’s happening and how the system is performing. There are more options than ever for providing this service.

Enphase comes with MyEnlighten for homeowners, which presents system energy production, overall health, historical performance and energy equivalents all on one mobile-friendly display. Real solar enthusiasts can take advantage of a paid upgrade to per-panel monitoring, which is available via the installer who activated the system.
The flipside for the solar installer is the Enphase Enlighten Manager, which provides: fleet management, upgrade management for existing fleets (based on production and consumption data) and simplified repeat-business generation tools to reconnect with existing customers through additional services like battery management, EV charging solutions and system upgrades.

Diagnostics and remote updates

Fronius software updates

The free Solar.web platform from Fronius offers remote diagnostics and alerts such as proactive notifications in a variety of dashboards.

At Fronius, the free Solar.web platform offers remote diagnostics and alerts such as proactive email notifications concerning performance and state codes, as just two examples, to help determine whether a truck roll is necessary or not. Remote Update via Fronius Solar.web eliminates another category of O&M complexity and cost. In just a few clicks, any Fronius SnapINverters is updated remotely from any web-enabled device.

ABB’s Aurora Vision Plant Management Platform and Plant Viewer lets homeowners get a real-time view of how much energy has been harvested along with dashboard views for fleet-wide performance management through reports, diagnostics, analytics or event alerts. ABB inverters also come standard with a wireless connection that enables system monitoring and over-the-air upgrades to ensure units are operating with the latest functions.

Satellite monitoring

Recently, SolarEdge added satellite performance ratio and mismatch reporting to its cloud-based, module-level monitoring platform (free for 25 years). The company says this satellite performance ratio service eliminates the purchasing, installation and O&M of sensors. The mismatch report helps to streamline the process of identifying underperforming modules by comparing each module’s peak power and energy production to the average of all modules in the site, and presenting each module’s mismatch as a percentage above/below the average.

Storage integration

The plus sign in a “solar + storage” system says all you need to know about the monitoring system capabilities — there are more added in.

Magnum Energy provides data monitoring through the MagWeb line of monitoring kits. The MagWeb provides live internet monitoring of the inverter, battery monitor and automatic generator start module. Using an internet connection, MagWeb makes live and historical conditions available through a web browser at data.magnumenergy.com. The MagWeb GT provides an integrated dashboard of the MicroGT system engineered for PV + storage systems. With the MagWeb GT, the production data from the array and the battery bank status of the storage system are accessed via your local network from one simple dashboard.

Tabuchi provides data monitoring via the Tabuchi Cloud. Here, customers can monitor PV generation, household consumption, the amount of power bought and sold to and from the grid and the battery charge. It also allows customers to compare data hourly, daily, monthly and yearly. The service is included with purchase of the Eco Intelligent Battery System (EIBS). Tabuchi Cloud allows installers to make sure everything is working as intended, while the simple interface allows homeowners to quickly see how they are saving on energy costs.

Automation

The next evolution in system monitoring is taking all of this data and having the system apply its own fixes. Pika Energy‘s REview Dashboard is provided to the customer with every Pika system to view performance metrics in comprehensive real-time reports, but its biggest advances come from system automation. While some inverters may notify users that grid or environmental conditions have changed, the Pika Energy Island acts automatically to meet these new conditions. When peak rate periods set in, local demand spikes or the grid goes down, the Pika Energy Island manages energy flows to keep system owners powered up and saving money.

SMA’s latest development in monitoring and alerts is SMA Smart Connected. Now available with the Sunny Boy-US residential line of inverters, SMA Smart Connected is a proactive service package integrated into Sunny Portal that automatically detects and evaluates system events and initiates remediation or repair activities. This decreases truck rolls, lengthy service calls and system downtime. Once it is operating, SMA Smart Connected will actively monitor a residential system at all times through Sunny Portal’s intelligent monitoring technology.

For more info on the newest inverters on the market download our free 2018 Inverter Buyer’s Guide

— Solar Builder magazine

Alencon Systems updated its DC-DC optimizer for large-scale solar — here’s what’s improved

Alencon SPOT

Alencon Systems LLC is unveiling the latest generation of its DC-DC optimizer, the SPOT-ES V5, at the Energy Storage Association’s (ESA) Annual Conference, April 18 – 20 in Boston. The newest generation of the SPOT-ES features several exciting features and enhancements specifically targeted at achieving more cost effective and reliable DC-coupled Solar + Storage and Microgrid projects.

The Alencon SPOT – which stands for String Power Optimizer and Transmitter – is a string level DC-DC optimizer which optimizes the power from four PV string inputs with voltages ranging from 600 to 1500 volts. The SPOT outputs power through two outputs at any range of voltage that is completely configurable from one deployment to the next. The ES suffix designates “Energy Storage.” The SPOT-ES family of products has been specifically designed for the needs of DC-coupled Solar + Storage deployments.

The improvements in the SPOT-ES V5 are vast from previous generations of the SPOT family of products. The enhancements include a true 1500-volt input based on 1700 volt rated Silicon Carbide (SiC) rated mosfets, a unique ability to map a wide battery charge/discharge voltage range, reliability enhancements developed in concert with leading Solar + Storage technology providers and integrators as well as more flexible communications options for more better integration with Solar + Storage and Microgrid control systems.

RELATED: How to optimize performance and profit through O&M monitoring 

Higher Input Voltage

The SPOT-ES V5 is the first utility scale PV DC-DC optimizer capable of supporting true 1500-volt string input. The SPOT-ES 1500 can accept four 1500-volt string inputs and provides the two outputs. Two outputs have been provided to allow for the use of standard rated PV connectors at high power and current. The SPOT-ES 1500 can achieve higher voltage input because it is based on state-of-the-art 1700 volt rated Silicon Carbide (SiC) mosfets.

Wide Voltage Control Range

The SPOT-ES V5 takes advantage of Alencon’s patented galvanically isolated design. The SPOT-ES’s galvanic isolation concept completely isolates the PV input from the output by attaching isolation transformers to each PV input. This technique provides for a particularly unique benefit in the DC-coupling of Solar + Storage because the integral magnetics to the SPOT can be easily configured from one deployment to another to easily support a broad battery charge/discharge DC-bus voltage, where the voltage range could vary by as much 20% from complete discharge to full charge. This feature provides a significant benefit when connecting lower voltage batteries to 1500-volt PV systems.
Enhanced Solar + Storage Reliability Features

The SPOT-ES V5 includes a new, ultra-fast circuit to protect the SPOT from sudden system power output overloads. Such overloads can happen with greater frequency in DC-coupled Solar + Storage and Microgrids than traditional PV installations due to the increased complexity of such systems. The result of such occurrences can have very grave consequences to the entire system and hence the SPOT’s ability to better protect itself in such events offers a great deal of additional reliability.

Improved Communications Architecture

Communications between major components in Solar + Storage systems and Microgrids is critical. Such systems typically utilize master system controllers that directly interface with all components in the system including the battery, inverter and of course the SPOTs. The SPOT-ES V5 features enhanced communications features to allow it to be interfaced with third party system controllers via either Modbus TCP, for communicating to the SPOTs wirelessly, or Modbus RTU, which allows for hardwire communication to each SPOT directly. The enhanced communication functionality offered in the SPOT-ES V5 allows for unprecedentedly granular control over the PV including the ability to curtail production at the string level.

— Solar Builder magazine

Heyco introduces four new cable tie products

Heyco has recently added multiple new products to its already extensive line of Cable Ties including Nylon 12, Blind Mount, Releasable, and HEYBite Cable Ties. Let’s meet the newbies.

Heyco cable ties

Heyco Nylon 12 Cable Ties are weather/UV resistant and suitable for high moisture, corrosive (zinc chloride and dilute acids) and low temperature indoor or outdoor applications. These ties are available in various lengths to accommodate a variety of different bundle sizes ranging from 1.44″ all the way up to 4.00″ bundles and the tensile strengths range from 40lbs all the way up to 100lbs.

Heyco blind mount cable tie

Heyco Blind Mount Cable Ties have a low insertion force with high pull out retention capabilities and can be mounted in either a through hold or a blind hole of proper depth. Due to the blind mount being assembled to the cable tie, no additional components are required.

Heyco releasable cable tie

Heyco Releasable Cable Ties have a locking mechanism that can be released so that wires can be added or removed from the bundle without cutting or otherwise damaging the cable tie.

Heybites

The HEYBite Clip mounts easily to frames and panel edges without the need for mounting holes or adhesives. The metal locking teeth bite easily into frames and panel edges, yet provide high removal resistance. HEYBites’ two piece assembly easily adjusts to various bundle diameters.

— Solar Builder magazine

New Solar-Log monitoring gateway aimed at price-sensitive PV projects 15-kW and under

Solar-Log

The all new Solar-Log 50 Gateway, a compact, advanced residential solar monitoring solution, is now available in the U.S.  Officially launched in Germany in December 2017, the Solar-Log 50 is ideal for the price-sensitive residential solar market segment, for plants up to 15 kW. Its modular hardware and software pricing means users only pay for the features they need.

“The solar monitoring landscape is changing. Policy changes can lead to uncertainty, meaning that having a cost-effective option for the price-sensitive residential market is important now more than ever,” says Anthony Conklin, President of Solar Data Systems, Inc. (Solar-Log). “The newest generation of Solar-Log offers a modular pricing structure to help keep O&M costs down, without sacrificing the reliable Solar-Log data that the industry depends on.”

How’s it work?

This gateway is designed to be used in combination with the Solar-Log WEB Enerest portal and provides reliable PV yield and plant performance data through inverter direct communication. The Solar-Log aggregates data from over 100 inverter brands through RS485 or Ethernet connection. Data is transferred via wired internet connection (required) and visualized on the Solar-Log WEB Enerest portal. The compact, din rail mountable hardware can be installed in as little as 10 minutes.

Keep Watch: How the PV monitoring landscape is evolving

The included Solar-Log WEB Enerest M monitoring subscription is a simplified solution for homeowners who want to monitor their plants themselves. The monitoring subscription can be upgraded, for a subscription fee, to the L or XL package at any time, for installers offering O&M service contracts to their customers. The Solar-Log WEB Enerest processes the recorded data, making numerous reports possible, and has analysis tools for the efficient use of solar energy. The user is continuously informed about plant performance and potential malfunctions.

Numerous add-on functions for the Solar-Log 50 Gateway are available through corresponding licenses. Add-ons include feed-in management, increased plant size compatibility, and integration of additional components. The Solar-Log 50 will be available through a wide variety of distributors and installers across the nation.

— Solar Builder magazine

DC decisions: Large-scale PV wiring trends are leaving behind DC combiners, cables

inverter pad

Closer to the grid connection, interrupt ratings are higher, which is why SolarBOS recommends fuses instead of breakers.

All large-scale PV projects will involve a ton of modules and only one grid connection, so all of the aggregation decisions made in between comprise a big chunk of a profitable project pitch. We asked two major eBOS suppliers for the trends leading the way in large-scale PV wiring in 2018, and both of them point to huge reductions in traditional DC wiring and an emphasis on fuses.

Goodbye DC combiners

The most significant DC wiring trend for Jason Whitaker, president of Shoals, has been the migration away from the traditional combiner paradigm to harness assemblies, which is a big step toward simplification and reducing the amount of DC cable needed. The Big Lead Assembly (BLA) is a prime example.

“What previously had been the feeder cable, running from the inverter to the combiner, has now become the entire solution in itself: The BLA, a large conductor, tailored for each site, in which all the PV circuits are combined as they branch off from the BLA at the optimal electro-mechanical positions within the array,” he says. “This allows for a streamlined, plug-and-play installation.”

Pre-paralleling PV strings and incorporating in-line fuses can further reduce the amount of cabling needed.

“If the ILF [in-line fuse] saves more than 25 ft of PV cable, it has paid for itself,” Whitaker says. “ILFs can significantly reduce both the amount of cable required within a PV array and the number and/or size of combiners deployed.”

On a typical tracker installation with combiners and component harnesses (ILFs), a 39 percent reduction in DC string wiring can be expected. Then, factor in the BLA, and that number moves to about a 51 percent reduction. Note: Shoals also recently partnered with Array Technologies on a solution tailored to its tracker system, which improves those economics even more.

“Optimization of the electrical and mechanical systems together will result in a decreased installation time while simultaneously increasing system reliability,” Whitaker says.

All that, coupled with significant labor savings will result in the lowest installed cost solution. The BLA not only provides value from a CAPEX perspective, it also offers significant savings in OPEX when you consider the increased reliability and the elimination of components that require operations and maintenance (O&M).

Shoals’ Big Lead Assembly

Diagram of the streamlined design of Shoals’ Big Lead Assembly combined with in-line fuses.

Hello AC combiners

The philosophical shift in the industry from central inverters to string inverters in larger-scale applications has big implications for eBOS decisions. What was typically all DC aggregation is a big mix of DC and AC. Coel Schumacher, CTO of SolarBOS, sees this as a chance to install fused AC combiners and recombiners instead of breakers.

“Breakers are great for applications with variable loads — plugging too many devices into an outlet, a hair dryer in a bathroom. In a solar application there aren’t any variable loads or hair dryers, so if an overcurrent protective device [OCPD] trips, there is a real problem, and resetting the OCPD is the least of your concerns,” he says. “Breakers degrade with every use, so the more times they are used as a disconnect, the more likely they are to nuisance trip at some later time when they shouldn’t.”

Four trends leading ground-mounted solar in 2018 from IHS Markit

As you get closer to the grid connection, interrupt ratings are higher. Fuses offer higher interrupt ratings and are more cost effective at these higher ratings than breakers.

“When a fuse is replaced, it will operate as it did when the original was new. A breaker on the other hand, after being reset, may not,” Schumacher says. “Breakers can also be more difficult to replace when they do eventually fail.”

Remember that every connection in a design is a source of contact resistance which generates heat, so one way to reduce potential for failure is to reduce those contact points. An example: Some systems are designed to connect the output lug to the copper bus bar using neutral bars attached with fasteners. This would mean one or more connections than is necessary and relies on small fasteners. Instead, SolarBOS uses a distribution block that directly connects to the incoming string wires and the output lug.

“Similarly, our positive bus bar typically connects to the next component directly with a bolted connection rather than using additional busbars or unreliable clamps,” Schumacher says. “Not only do all of these connections perform better, but there are fewer of them, which reduces the number of connections that need to be checked in maintenance efforts.”

— Solar Builder magazine