Time for use? How to prepare PV systems today for storage tomorrow

solar storage inverters buying advice

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.

We know that a PV system is a 25-year asset, but we maybe don’t think enough about what that means outside the viability of the initial system components. Consider what life was like 25 years ago, 1993, for example. VCRs. Zach Morris phones. Would a PV system installed on a home or business in 1993 meet the demand and performance expectations we have today?

Obviously we can’t predict what life will be like 25 years from now, but one pretty safe assumption is the rise of energy storage. Twenty-five years from now — hell, five years from now — adding storage to a solar project will be an assumption, not a novelty, so the PV systems you design today should factor this in.

Designing for storage starts with:

• A deep understanding of the load profile
• The impact of the PV system generation
• A plan for how the storage will be used

“The designer must conduct a thorough study on load behaviors and based on those results simulate cycle times and discharge levels in order to determine the lifetime of the energy storage and days of autonomy,” says Jani Kangas, VP of product lines and technical sales for ABB. “If the storage design is used for peaks management, then special calculations are to be done based on market value of peak-time shifts . The system should be designed based on ROI models and higher compensation during off-peak times.”

“Start with the basics, by asking your customers if they ever lose utility power. If so, what is the average duration?” says Alan Santos-Buch with Magnum Energy. “Battery backup is not for everyone and should address the needs of the customer, including the approximate length of time they will need battery backup. What are their critical loads? What do they need to keep running in the event of a power failure? Once those loads are determined, plan for a sub-panel to house those essential load breakers.”

If the storage design is used for peak management then special calculations are to be done based on market value of peak-time shifts. The system should be designed based on ROI models and higher compensation during off-peak times.

Component selection

Key to a design is deciding on a battery charge controller. This is the brain that’s running your energy storage system. Regardless of your generated energy input and batteries you choose, designers need to find the right controller to manage storage, loads and battery charge levels. Some examples:

  • As part of its Magnum Energy product line, Sensata has an integrated solution that complements a variety of system designs, including microinverters.
  • The Ideal Power Stabiliti is a multiport inverter that accommodates PV and batteries at different input voltages, without the need for external optimizers or charge controllers.
  • The Tabuchi EIBS is an all-in-one system that includes the inverter and storage battery.
  • The Pika Energy Island [pictured above] allows for a solar-only install today and then an easy plug-and-play storage option down the road.

“It’s crucial to consider future changes: If you want to avoid peak rates, or improve resilience (backup power), or simply net meter solar, it’s relatively easy to find a system that can cover one of those applications well. What has proved more difficult is finding a system that will fit the needs of today and the needs of tomorrow,” says Jeremy Niles, marketing manager for Pika Energy. “For many, it’s very difficult to break away from thinking in terms of AC coupling, 2V battery increments, bank design, hydrogen sensors and giant aluminum conductors. Grid-tied solar-plus-storage is now a plug-and-play proposition with the right system.”

For PV-plus-storage systems, one efficiency metric to consider is the number of AC-DC conversions. The fewer amount of conversions, the more efficient the system and thus the more energy available for system owners. A DC-coupled system is simpler in this way.

“The PV system should be large enough to meet both the requisite energy demands and also charge the battery,” says Lior Handelsman, SolarEdge’s VP marketing and product strategy and founder. “A DC-coupled solution will decrease energy loss from inefficient conversion and increase the amount of energy that can potentially be routed to the battery. This will potentially allow oversizing of the system so that the additional energy can flow directly to the battery.”

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

— Solar Builder magazine

SB Buzz: How to design a perfect solar system — then sell it — with Aurora Solar COO

Aurora Solar solar sales

In our March/April issue, we included a roundup of new technology that could improve a solar company’s customer service capabilities, whether it was through quicker project design, better proposals or advanced monitoring capabilities. Aurora Solar was one company in the roundup, which provides one of the best PV design and proposal systems out there. About 50,000 PV projects a month are designed with its Aurora platform.

The secret sauce is in Aurora’s algorithm for generating a 3D reconstruction of a building, laying out prospective system designs on top and simulating the sun’s path over the site. Using Aurora’s algorithms, installers can quickly generate an accurate report detailing the irradiance and shading. In fact, the US Department of Energy’s National Renewable Energy Lab (NREL) has validated that Aurora Solar’s Shade Reports are statistically equivalent to on-site measurements and rebate authorities around the country will accept its offsite reports in replace of those on-site inspections. Aurora even recently improved upon its system, partnering with Nearmap for a serious upgrade to its site image interface.

All of that sounded pretty neat to us, so we stopped by Aurora’s offices in San Francisco to chat about all of it with COO and co-founder Sam Adeyemo for the latest episode of our Solar Builder Buzz podcast. We get into the keys to off-site design and shade analysis and the evolution of mass customization in the solar industry. We also explore what we consider to be the most impactful piece of this puzzle: how sophisticated sales proposal tools could shape the future of smaller, regional solar companies. Below is an excerpt from that part of the conversation, in which Adeyemo explains the hilarious, arduous, but ultimately satisfying development of that Aurora’s sales proposal tool.

Be sure to listen to the full conversation (and subscribe) at the end of the post.

SB: How did you develop the sales proposal tool?

Adeyemo: “When we were developing our proposal tool … remember we’re technologists. We develop software and infrastructure. And about two years ago we thought, we have this shade and financial analysis, but we need something that ties this all together. We can’t have people taking screenshots or using PowerPoint. We just want to wrap it up in a neat bow and take this all to the customer and wow them.

“So, what are we going to do? We had all of these debates internally about how it should look. Portrait or landscape? Should the company’s logo be on the front? On the back? All of these debates. We couldn’t agree. So, in keeping with our value of being a software platform that applies to the entire industry, we said we’ll develop a tool that allows the customer to develop whatever proposal they want. It’ll be like PowerPoint. You can pick and choose styles and create from scratch. We made this announcement and our clients said, ‘this sounds awesome.’

“We spent a ton of time – almost a year building this. At the end we say, ‘Ta da, here it is!’ And they open it and are like, ‘but it’s blank.’ And we’re like, ‘yea! That’s the point. It can look like whatever you want!’ So, people started to use it, and we looked at some of the results, and it was terrible. Stuff was overlapping … the solar community is good at designing and installing, but visual arts might not be their thing. So, after a few months it became clear we had to do something.

“… We may not be the experts in visual design, but someone out there is. We got this awesome brand consultant Katherine Glass [of SpringMark Branding]. She’s worked with companies like Starbucks and Bank of America. If we can get her expertise and apply it to the whole industry, that would be awesome. So we got her, and she did a bunch of customer interviews. We invited a range of solar installers to our office and had a full day roundtable. We had one guy who said, ‘I’m not a solar installer; I’m an activist who installs solar.’ We had another guy who said, ‘I’m a consultant.’ Another saying they were more of a corporate person. So it was great to get this diversity of opinions. And Katherine presented consumer research and got some good feedback. From there, we had a good design, and then we got some professional artists and designers to put together the proposal. All of this took another year.

‘Now we have a series of four really beautiful templates. You can still create your own, but if you don’t, there is some visually stunning proposals that any solar installer can use. The gratifying part is the mom and pop shop doesn’t have to hire someone like Kathryn to do this.”

— Solar Builder magazine

Meteocontrol, viasys are collaborating on solar site monitoring solution for North America


Meteocontrol North America, a subsidiary of meteocontrol GmbH in Germany, and viasys Intelligent Video GmbH are collaborating is to offer PV-system operators a turn-key solar monitoring solution at a great value and provide North American customers with professional technical support.

Consolidating the systems will result in cost savings for customers because video surveillance can be integrated into meteocontrol’s monitoring portal without the need for any additional infrastructure in solar farms, since the systems can share the same network components, cabling and control cabinet.

“The challenges involved in securing and monitoring solar parks are impressively similar,” said Anson Moran, CEO of meteocontrol North America. “The solution is optimized alarm management. We will conduct high-level data assessments using video, data analysis and artificial intelligence.”

RELATED: How Momentum Solar doubled its business with aerial imaging software 

“The collaboration will solidify our reputation as a reliable partner because our product portfolios complement each other perfectly,” said Martin Schneider, Managing Director of meteocontrol GmbH. “Through our new collaboration with viasys Intelligent Video, we will be able to provide additional value to the market.”

Interlocking the viasys and meteocontrol systems will simplify the technical operation management of solar parks and make them even more secure. When the viasys security system is integrated into an operation manager’s portal view, for example, they will be able to see what is happening near the system at any time and track it with precision all the way up to the access control. The meteocontrol monitoring portal signals the operating status in the status message and provides information as to whether the security system is active.

“There are also other developments in the pipeline,” adds Moran. “The operation manager should be able to receive the alarm messages directly in the ticket system, log them there and create the report for the investor. The messages will no longer need to be processed separately from monitoring in the security control room. We also want to set up an O&M camera-based “Awareness System” designed to provide operation managers with the required view of the system on site without the need to invest in an extensive and complete perimeter security system.”

— Solar Builder magazine

Unirac debuts shared rail version of its Ground Fixed Tilt system

GFT Shared Rail Pro Clamps 4

Unirac, Inc. has launched a shared rail version of its Ground Fixed Tilt (GFT), an engineered system of standard ground mount components supported by North America’s largest ground mount distribution network. The new shared rail design delivers enhanced system and labor optimization for maximum productivity.

Unirac’s commercial project support makes construction easy, from permitting through installation, including region-specific engineering and documentation. Kitted hardware, pre-assembled parts, integrated bonding, lightweight components, and straightforward connections allow for one or two-person assembly, and no specialized labor or training is required. System flexibility enables you to mount 60 and 72 cell modules and select from multiple foundation options. Unirac systems come with a 25-year warranty.

— Solar Builder magazine

ABB offers new code compliant inverters for residential solar installers

ABB Tigo

Following the new SunSpec communication protocol, ABB offers a unique configuration that ensures design flexibility and compliance with 2014 & 2017 NEC 690.12 requirements. The robust energy production of a single-phase string inverter, the rapid shutdown function and an optimizer option provides installers a stronger solution to code compliant solar installations.

“Finding inverters that can perform under the demands of challenging roof configurations and comply with the latest code requirements can be difficult,” said Mario Thomas, string inverter product manager, ABB’s Solar business in the US. “With these new code compliant options from ABB, installers have more options to choose from.”

The UNO-DM-PLUS-US family of single phase solar inverters deliver high performance with excellent power density giving end users the maximum amount of energy production. This flexible inverter comes with embedded connectivity and an efficient communication protocol, which enables the UNO-DMPLUS-US to be easily integrated within any current or future device for smart building automation, smart grid integration and with third party monitoring and control systems. The UNO-DM-PLUS-US also comes with remote Over-the-Air (OTA) firmware upgrade for inverter and components to enable remote software upgrades.

For jurisdictions that have not migrated to 2017 NEC 690.12, ABB’s string-level Rapid Shutdown 2.0 device provides a simple and cost-effective solution to implement. This product mounts directly to the PV mounting rail or PV module, and lay parallel to the roofing surface. It provides a fail-safe solution for emergency responders. Available in two configurations (single and dual), this rapid shutdown device requires no extra conduit, which minimizes additional material cost and associated labor. Shutdown occurs at the rooftop box when the utility power is lost or when the PV system’s AC disconnect switch is opened.

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

Tigo partnership

In conjunction, ABB and Tigo formed an operational compatibility between ABB’s inverter line UNO-DM-PLUS and Tigo’s TS4 optimizer platform. The combined ABB and Tigo module solution is now available. Combining ABB’s world-class inverters with Tigo’s TS4 Platform offers a flexible and scalable solution to meet all the different needs of installers and end customers. The connectivity package of the UNO-DM-PLUS allows for built-in smart grid capabilities such as dynamic feed-in control, which manages the energy fed into the grid, and uses SunSpec-compatible open communication protocols to ensure compliance with future grid codes and maintain off-the-shelf interoperability with other devices in the system.

Advantages of this system

The Underwriters Laboratories (UL) certified third-party solutions offer Rapid Shutdown and optional MLPE configuration with string inverter power generation as well as the following advantages:

• Module-level Monitoring – Predicting and conducting maintenance on solar installations is critical to ensure that they last beyond their expected 25-year lifetime. With full visibility of a system’s performance through module-level monitoring in 2 -second increments, solar fleets can maximize system up-time, identify performance issues, and control operations and maintenance (O&M) costs.

• Safety – The UL-certified module-level Rapid Shutdown Solutions provide installers, EPCs, and PV plant owners the most cost-effective response to safety regulations like the National Electric Code (NEC) 2014 & 2017 requirements. For installations unencumbered by shading, the MLPE option provides the necessary safety and monitoring services to ensure systems meet local fire regulations and performance expectations.

• Optimization of Energy Harvest – With optimized modules, more roof space can be used to max-imize energy production. This fixes module mismatch and increases design flexibility by optimiz-ing each module when shade drops their performance. It addresses system-level inefficiencies and age tolerance while also benefiting from the module-level monitoring and safety features.

Once the inverter is installed, operators can turn to a smartphone to commission the unit via a simple, built-in web user interface. This enables them to gain access to features such as advanced inverter con-figuration settings and Aurora Manager, which facilitates OTA firmware updates (remote software up-dates).

— Solar Builder magazine