Intersolar North America Showcase: Here’s what to see at this year’s trade show

APsystems: True three-phrase microinverters

APsystems YC1000

APsystems boasts an industry best-selling 3-phase solar microinverter and the industry’s first true 3-phase (phase-balanced & phase-monitored) unit, the YC1000-3. This model handles 208V or 277Y/480V grid voltages with 900 watts maximum output, 95 percent peak efficiency and comes with ZigBee communication and integrated ground. At 480V up to 11 units (44 modules total, 60- or 72-cell) can be linked in a single 15A circuit, and up to 14 solar modules (7x YC500s) in a string with a 20A breaker. Designed to operate from -40 F to 149 F degrees. Ten and 25-year warranties are available. Booth 9245.

Boviet Solar: Debuting two new solar modules

Boviet Solar

A new 290-W, 60-cell polycrystalline diamond-cut PERC solar module is one of the newest products from Boviet Solar’s full PERC production line completed in 2016. Also on display will be the new 300-W monocrystalline PERC Smart Module designed to harvest 25 percent more energy. In addition to free, 24-hour monitoring per module, the Smart Module also has module-level voltage shutdown to offer greater installer and firefighter safety. Booth 8317.

Ciel et Terre: Making floating PV happen in the U.S.

hydrelio floating solar

Ciel et Terre has completed large-scale floating PV systems in various market applications and countries, showcasing FPV as a real alternative to traditional PV in roof-top and ground-mounted systems. In the past year, the organization increased its U.S. reach with its first public utility project in Orlando, alongside its local Florida representative D3 Energy and in partnership with the Orlando Utilities Commission. Ciel et Terre installed a 31.5-kWp floating solar system on the OUC’s storm water storage reservoir, a dead water space at the facility, and is expected to generate up to 51,000 kWh per year. Booths 9744 and 9745.

Eaton: Control system to simplify microgrid deployment

Eaton microgrid system

Designed for critical applications requiring secure, efficient and reliable power, Eaton’s newest solution is engineered to deploy stand-alone power systems using existing and new assets with the adaptability to easily meet future needs. The system incorporates Eaton’s new Power Xpert energy optimizer controller and provides a modular, scalable approach to microgrid control, as well as accompanying services, such as microgrid feasibility studies, total system design, control system deployment, integration with existing third-party generation assets and critical loads, project implementation, commissioning and system start-up, and ongoing maintenance. Booth 8310.

EcoFasten Solar: New standing seam metal roofing application

EcoFasten

EcoFasten Solar has launched its newest product, SimpleBlock, a solution designed specifically for standing seam metal roofing applications. The versatile SimpleBlock provides a variety of options through compatibility with any rack manufacturer’s connection points (L-feet, posts), and will fit any double-lock standing seam. When used in conjunction with EcoFasten’s Mid-Clamp, SimpleBlock becomes a rail-free racking system featuring integrated bonding. The system meets and exceeds all known building codes and is UL 2703 listed, with product compliance determined through rigorous, uncompromised testing per UL 2703: First Edition. Due to such an overwhelming response to this innovative system, EcoFasten Solar is gearing up for high volume manufacturing to meet industry demand and will also be unveiling additional configurations for more seam options soon. Booth 9433.

Fronius: Offering its next generation solar solution

Fronius

Fronius introduces its next generation of solar systems to the industry, the Fronius Smart Solution. This satisfies all needs for residential and commercial systems: flexible system design, shade mitigation, NEC compliance, high performance and state-of-the art monitoring while keeping the number of components low and installation easy. The Fronius Smart Solution combines the benefits of traditional MLPE such as microinverters or DC optimizers with the ease of installation and cost-effectiveness of string inverters. The Fronius Smart Solution is the combination of cell-string optimized modules, the Fronius Rapid Shutdown Box, a Fronius SnapINverter, the optional Fronius Smart Meter and the Fronius Solar.web online monitoring portal. Check it out for yourself at the Fortune Energy booth. Booth 8519.

Heyco: A solution for every cable need

Heyco solar clips

Heyco’s new Edge Clips are ideal for use where holes cannot be used and adhesives are not acceptable due to temperature issues. If these won’t work, check out Heyco’s new SunRunner Vidrios, which are designed to mount directly onto the glass panel with compression force only — perfect for frameless PV modules. If neither of those pique your interest, check out Heyco’s SunBundler. Though not new to Heyco’s offering, the Heyco SunBundler has been receiving a lot of attention due to its 20 year warranty and unique design. Check them out at the CED Greentech booth. Booth 8311.

Ideal Power: The latest in power conversion innovation

Ideal Power

Ideal Power’s newest Stabiliti Series power conversion system is a grid-resilient 30-kW advanced power conversion system for system integrators and project developers who need to efficiently connect distributed energy resources to the grid. Stabiliti is the next generation of Ideal Power’s patented Power Packet Switching Architecture (PPSA) technology and incorporates numerous new features and benefits for commercial and industrial customers. The Stabiliti Series is available in two versions: dual port AC-DC bi-directional and multi-port AC-DC-DC bi-directional. Ideal Power’s John Merritt will be speaking on July 10 from 12-12.30 p.m. at the ‘‘Islands, Mini-Grids, Microgrids & Energy Storage’’ session. His talk will explain how solar-plus-storage systems can become microgrid-enabled with multi-port conversion technologies, creating energy resilience and reducing reliance on backup generators. Booth 8110.

JLM Energy: Patent-pending ‘microstorage’ technology

JLM Energy Phazr

Phazr, the first in JLM’s MicroStorage family of products, is mounted seamlessly behind the solar panel. Phazr is designed for large-scale, solar-plus-storage applications and is also perfectly suited for smaller residential and commercial installs. The simultaneous nature of electron flow is unique to JLM’s patent-pending technology. This is included in JLM’s energy technology bundle and is operated by Measurz software, which continually observes energy usage patterns and utilizes a variety of strategies to maintain a pre-set budget determined by the customer. Booth 8134.

Pika Energy: Partnership with Panasonic on solar smart battery

Pika_MAY17_006_web

Panasonic Eco Solutions North America and U.S.-based inverter manufacturer Pika Energy Inc. are partnering to offer a DC-coupled solar smart battery — Harbor 10P/15P — that will begin shipping in late 2017 and is available for pre-order today. The solar-ready Harbor Smart Battery combines Panasonic’s Lithium-Ion battery modules and Pika Energy’s power electronics in a slim, floor-standing, wall-mounted enclosure to provides 10 kWh or 15 kWh of usable energy and up to 6.7 kW of continuous power. Booth 8318.

Preformed Line Products: Speeding up rail-less mounting

Preformed Line Products

Maneuvering mounting rails can be the most demanding part of installing rooftop solar modules. But now installers can avoid that — and mount modules faster and easier — with the POWER DISK rail-less mounting system from Preformed Line Products. POWER DISK is a unique roof attachment that can go anywhere on residential rooftops. It does not need to be secured to rafters. Install solar modules in four simple steps: 1. Snap chalk lines. 2. Mount POWER DISK bases anywhere on the roof deck. 3. Set solar modules in place. 4. Spin the disks to vertically adjust height to roof undulations. Booth 9449.

Quick Mount: New series for comp/asphalt shingle roofs

Quick Mount

Quick Mount PV engineered its patented Elevated Water Seal Technology into an integrated L-foot and flashing for cost-effective, super-fast, single-bolt installation with unparalleled waterproofing. The L-Mount Series comes in single- and double-slot options for maximum versatility and works with all leading racks. L-Mounts are designed for simple lag-bolt installation onto existing composition/asphalt shingle roofs. The L-Mount features a 9-in. by 12-in. aluminum flashing with alignment notches and rounded corners to easily slide under shingles and speed installation. No shingle cutting required. Like all Quick Mount PV products, the L-Mount meets or exceeds roofing industry best practices and comes with a 25-year warranty. Available in mill or black finish. Booth 9411.

RBI Solar: Ground mount, ballasted, roof mount and canopy solutions

RBI solar Logo

RBI Solar is one of the top turn-key solar mounting solutions suppliers in the United States for ground mount, ballasted landfills, roof mounts and canopy/carport structures. As a single-source provider for commercial and utility-scale PV projects, all responsibility for the design, engineering, manufacturing and installation of the most efficient PV Racking systems in the marketplace is completed in-house by the RBI Solar Team. Committed to providing value from conception to completion, RBI Solar’s customers receive cost-effective and durable racking solutions for each project site to aide in reducing the overall project costs. Booth L9008.

SimpliPhi: Plug-and-play storage

SimpliPhi - AccESS - 300 DPI

Developed in partnership with installers, SimpliPhi Power’s AccESS has been installed in a variety of locations, including a commercial “glamping” resort, Flying Flags, and is positioned for hundreds of residential installations in partnership with Civic Solar’s SGIP projects. The AccESS provides power security that is safe, reliable, non-hazardous and efficient. The fully integrated solution includes the SimpliPhi award-winning battery technology, Schneider Electric inverter charge controller, associated power electronics and overall system management. Pre-programmed software settings and performance monitoring complete the solution. Booth 8124.

Smappee Plus: New advanced energy monitoring

Smappee Plus

Now entering the U.S. solar market, Smappee Plus is the latest innovation from Smappee’s burgeoning energy monitoring solutions which have seen widespread adoption across Europe since 2012. The product combines Smappee’s patented NILM (Non-Intrusive Load Monitoring) technology with submetering clamps to measure real-time energy use from appliances throughout a user’s home including those with variable output or similar energy consumption patterns, giving previously undetectable transparency to energy use. Head to the Impress Lounge across the street from the Moscone Center for more info.

Solar-Log: Enhanced PV monitoring portal allows for more installer services

solar log pv monitoring

Solar-Log’s new WEB Enerest is an enhanced PV monitoring portal that works in combination with Solar-Log’s data loggers to offer better monitoring and more efficient optimization of solar power usage. The new Solar-Log WEB Enerest portal is available in three different service levels and price classes to respond even more precisely to the differing needs of individual customer groups. The most advanced XL package allows installers and service providers to centrally monitor their entire fleet from one portal. This premium version provides near real-time visualization of plant error messages which can be quickly evaluated and managed. The portal allows the operator to remotely configure the Solar-Log®device, customize the portal design, and define plant owners’ access to the yield and plant information. Automated reports, integrated weather data comparison and the option to combine several plants with one account are just some of the comprehensive functions. Booth 9121.

SunModo: Debuting new solar awnings to shield windows, generate energy

sunmodo awning

The concept is simple: Replace traditional metal and fabric awnings with solar-power-generating panels that provide necessary protection from the elements while also replacing traditional electricity usage. That concept is coming to the marketplace as the SunShield awning system. It is being introduced by SunModo, a company that makes durable, easy-to-install professional racking systems. The SunShield awning system features a durable triangular aluminum frame as structural truss; and expands to a 35-degree tilt angle once installed. This compact triangle frame design easily accommodates both 60 and 72 cell solar panels. What’s more, SunShield opens the awning industry to 30 percent tax credits and provides a substantial new canvas for solar power generation. Booth 9539.

Tabuchi America: Expanded storage capacity

Tabuchi

Originally launched in the United States at Intersolar 2015, Tabuchi America is debuting the 2nd generation model of its Eco Intelligent Battery System (EIBS). Tabuchi’s all-in-one, easy-to-install system includes a 5.5-kW solar inverter and stackable 6-kWh lithium-ion batteries. The Tabuchi EIBS has the intelligence to maximize a homeowner’s savings in real time across different electricity tariffs. This DC-coupled system will meet advanced inverter requirements and will be 9540 compliant. Booth 8121.

Trojan Battery: AGM battery designed for solar installs

Trojan Battery

Trojan Battery Co. is launching a new line of maintenance-free, true deep-cycle absorbent glass mat (AGM) batteries specifically designed for solar and other renewable energy applications. The new Trojan Solar AGM line is manufactured in the U.S. Offering a three-year warranty for stationary applications, and tested to an eight-year design life under IEC 61427 standard for solar batteries, this initial release includes a wide range of Trojan Solar AGM models. With its non-spillable design, the new Trojan Solar AGM batteries enable installers to customize the use and position of the batteries in customer applications. Booth 8128.

— Solar Builder magazine

Panasonic, Pika partner on DC-coupled solar smart battery

pika solar storage

Panasonic Eco Solutions North America and U.S.-based inverter manufacturer Pika Energy, Inc. are partnering to offer a DC-coupled solar smart battery with industry-leading performance specifications. The Harbor 10P/15P will begin shipping in late 2017 and is available for pre-order today, the companies announced.

The solar-ready Harbor Smart Battery combines Panasonic’s renowned Lithium-Ion battery modules and Pika Energy’s power electronics in a slim, floor-standing, wall-mounted enclosure. Powered by Panasonic’s Li-Ion battery technology, this smart battery provides 10 kWh or 15 kWh of usable energy and up to 6.7 kW of continuous power. Harbor 10P/15P can be used for clean back-up power, self-supply, time-of-use and other solar-plus-storage applications.

How it works

Harbor 10P/15P uses Panasonic’s innovative Lithium-Ion battery modules, which feature exceptional energy density and redundant safety protections. The smart battery is directly compatible with the award-winning Pika Energy Island, a single-inverter solution for grid-tied solar-plus-storage. Harbor 10P/15P is installed as a plug-and-play smart battery coupled with solar PV on a common DC bus that feeds the Islanding Inverter. This simple, efficient connection of solar and storage is enabled by Harbor 10P/15P’s internal DC/DC converter using REbus, Pika Energy’s patented nanogrid platform.

“As a world-leader in both the Lithium-Ion battery and solar modules, we understand the value in bringing innovative solar-plus-storage solutions to customers,” said Dan Silver, President, Panasonic Eco Solutions North America. “We’re very pleased to be working with Pika Energy to continue pushing the boundaries of performance and efficiency to unlock even greater benefits for users for a wide variety of applications.”

PV Pointers: How to future-proof PV systems with a storage-ready inverter

What sets it apart

For system integrators, the simplicity and price-performance of the Harbor 10P/15P Smart Battery set it apart from other grid-tied battery systems, said Ben Polito, Pika Energy’s President and Co-founder.

“A single technician can install and commission a Harbor 10P/15P in less than an hour,” Polito said. “Harbor is pre-wired for the Panasonic battery modules, making assembly incredibly fast and simple. Combined with our transformer-less inverter, the Pika Energy Island with Harbor 10P/15P offers a vast improvement over heavy wall-mounted battery systems and outdated multiple-inverter configurations that suffer from low efficiency, extraneous hardware and complex installations.”

Harbor 10P/15P enables customers to take full advantage of the Pika Energy Island’s built-in operational modes for solar-plus-storage. In islanding mode, the Harbor 10P/15P seamlessly powers heavy loads like well pumps and refrigerators without a grid connection, providing customers with a superior backup power system. When grid-connected, its 10kWh (model 10P) or 15kWh (model 15P) capacity provides self-supply of local loads during evening hours when energy rates are highest.

“The smartest, simplest way to build solar-plus-storage systems is by combining batteries and solar PV on a common DC bus,” said Polito. “The Panasonic-powered Harbor 10P/15P Smart Battery brings that concept to life, without compromising power output, scalability or flexibility. As solar PV adoption continues to boom, the grid needs smart, distributed storage. We’re thrilled to be working with Panasonic to offer what we believe is the solar-plus-storage solution the industry has been waiting for.”

— Solar Builder magazine

PV Pointers: How to future-proof PV systems with a storage-ready inverter

You don’t need to install a battery (yet) to give solar customers a next-gen solar-plus-storage system.

Your customer wants reassurance

Solar-plus-storage is finally ready for mainstream adoption, thanks to technology enhancements in DC-coupled inverters and continued cost reductions in smart battery technology. Batteries with grid-tied PV will soon be the standard offering as customers recognize the benefits of storing local behind-the-meter energy. According to Bloomberg New Energy Finance, lithium-based smart batteries are poised to follow the same cost reduction curve as PV modules, crossing the $200/kWh threshold in the next several years.

Pika Energy“We are seeing strong demand for storage-ready grid-tied photovoltaic systems,” says Phil Coupe of ReVision Energy, a solar installer in northern New England. “Today’s battery options remind me of where PV was five to 10 years ago, when the technology was pretty good but retail pricing was out of reach for all but the wealthiest and most progressive consumers.”

ReVision Energy has been installing the Pika Energy Island inverter for clients in the Northeast to prepare them for the day when batteries are more cost-competitive.

The demand for these batteries will grow proportionately with the economic use cases for solar-plus-storage. Already, an increasing number of U.S. markets are introducing time-of-use billing, eliminating or reducing net energy metering, billing residential customers based on periods of peak usage, or, in parts of Hawaii, disallowing new PV permits entirely.

Meanwhile, you have customers dragging their feet with proposals for carefully designed and economically modeled PV installations. And the more they read about solar-hostile policies, the more they may worry that their state could be the next Nevada.

How do you reassure a customer with misgivings about the future of solar-friendly politics in his or her utility region? The answer lies in the inverter you offer.

You can learn all about this and more during the upcoming Solar Builder webinar “Future-ready solar Installations with the Pika Energy Island.” Register here.

Your customer wants a secure investment

By offering a hybrid PV inverter that can operate as a grid-tied “conventional” system, but which has built-in islanding and the capability of directly integrating a smart battery later, you’re giving your customer the reassurance of a future-proof of the investment.

“More and more, people are recognizing that storage costs are beginning to decline, and they want their solar energy system to be able to integrate batteries when the price point justifies the investment,” Coupe notes.
Sometimes, having that reassurance is all a customer needs to move forward with their wise decision to power their home with solar. And for you, that means your solar installations can continue, unimpeded by local policy rhetoric.

Your customer wants options

In addition to reassurance to offset customers’ doubts in uncertain policy markets, hybrid inverters with the innate ability to switch between grid-tied and islanding power can offer customers flexible operational modes for various states of use. For example, customers with such inverters can use them for grid-tied net metering today and have the option to add a battery tomorrow for clean backup power.

ReVision Energy’s customers will use their battery-integrated grid-tied systems for clean backup power during winter grid outages, and, if solar policy grows hostile toward net metering, those customers have a simple step toward recovering their investment.

By offering hybrid islanding inverters that feature the option of adding directly-coupled batteries in the future, installers like ReVision Energy are providing a differentiated option that protects the customer’s clean energy investment, helping solar buyers to feel smart and secure in their decision.

Chip Means is director of sales development at Pika Energy.

— Solar Builder magazine

Pika Energy contracts with local New England company for component manufacturing

pika energy island inverter

Electronics manufacturing services provider MC Assembly is working with Maine-based Pika Energy to manufacture components of the company’s solar inverter product lines. Pika Energy selected MC Assembly in 2016, seeking a New England-based manufacturing partner to meet the company’s increasing production needs.

 

“We looked to MC Assembly when we sought to scale up our manufacturing to meet increasing product demand,” said Chip Means, Pika Energy’s Director of Sales Development. Means said MC Assembly’s location just two hours from Pika Energy’s headquarters was a strong quality in the relationship from early on. “We mutually identified the advantage of working closely, geographically, as partners,” he said.

“We have built a strong relationship,” said Gary Tarallo, Director of New Business Development for MC Assembly’s Boston Facility. “It’s truly a partnership, as we both look at how we support each other as a win-win.”

RELATED: Upcoming Webinar: Future-ready solar installations with the Pika Energy Island™- April 19, 2017 

Pika Energy develops clean power electronics solutions for residential and commercial sectors. Its patented technology takes an input from clean energy sources and distributes power that can be stored in a battery, used in a building or sold back to the grid.

MC Assembly started ramping up to volume production in October at its Boston facility. “There was a lot of collaborative work between both our engineering groups getting it set up and going,” said Thom Hansen, Director of Operations at MC Assembly’s Boston facility. “We worked collectively on engineering changes as they came about and made sure we were both on the same page.”

Hansen said Pika Energy’s products need to comply with specific utility grid standards. To ensure reliability, MC Assembly used its standard robust inspection and testing process. “The best things we can do to ensure reliability is to provide layers of verification,” Hansen said.

 

— Solar Builder magazine

Inverter experts explain how to best calculate levelized cost of energy

APsystems

Photo courtesy of APsystems.

Levelized cost of energy (LCOE) is one of the most important metrics used for judging the value of a PV system. It is also less easily understood and seemingly open to interpretation. How am I really calculating this figure? What is sitting outside this calculation?

Ask five inverter companies, and you might get five answers. So, we asked them all to get all of the answers.

Factor for Failure

A recurring theme when calculating LCOE for a PV system is getting a full understanding of its potential for failure and its ability to mitigate those losses: How many components are there? How likely are they to fail? When and how often could they fail? How much production will be lost during those failures? How much work is involved in getting it running again? This means keeping in mind variables like inverter replacement cost, system engineering cost, interconnection updates (adoption of new codes) and re-inspection cost.

Fronius Diagram

Fig. 1: Courtesy of Fronius USA.

Fronius did a study, examining the costs associated with replacing or repairing inverters 15 to 20 years from the present to account for that full PV system cost of ownership. An example they gave: If the original system cost is $10,000 and the extended cost factor is 1.10, then the total cost of the system over its lifetime is $10,000 x 1.10 = $11,000. Within this study, its SnapInverter resulted in 1.05 cost factor, while a generic string inverter hit 1.19 and a microinverter hit 1.26. The important variable in this calculation was mean time between failure (MTBF), defined in this study as the failure rate during the intrinsic failure period (see Fig. 1).

“Since the industry has grown so rapidly in recent years, the majority of PV systems in the United States are less than five years old, with typical standard inverter warranties being five to 10 years in length,” says Brian Lydic, senior standards and technology engineer at Fronius. “The majority of inverters installed in the field are still under warranty, and the industry has not needed to address large numbers of inverter replacements or repairs due to end of lifetime, though this will become commonplace.”

Yaskawa – Solectria Solar notes the correlation between the number of components and a higher MTBF, which makes sense intuitively. This makes the MTBF discussion a big part of the operations and maintenance (O&M) and LCOE calculation.

“The capability to service your inverter efficiently and in the most effective manner is crucial to keeping uptime high and calculating LCOE,” says Danielle Kershner, channel sales representative, Yaskawa – Solectria Solar, which keeps component count low by integrating AC/DC disconnects and integrates modular power stages to minimizes time and cost for service. The company has also revamped its customer service department to reduce downtime.

Another way to look at this is operational expenditure (Opex). The question answered here is “How much value am I losing during downtime?” So, Opex would include equipment failure, maintenance, repairs, materials and labor lead-time, restructuring, capacity change and so on. This analysis can favor microinverters in certain applications as any failures will only affect small portions of a system in a single moment, versus the entire system in the case of a string inverter failure. As mentioned in our feature on service on page 20, web-based monitoring services can be crucial for improving timeliness and efficiency of O&M functions.

“Since downtime is tied to the loss of generation, this variable must not be taken lightly when trying to maximize the LCOE,” says Frank O’Young, associate VP for Darfon. “The LCOE may be lowered by as much as 20 percent if the system uses equipment that is easy to maintain, quick to troubleshoot and requires minimal repair time.”

Look at Lifetime

Establishing all of the variables that add and subtract from the economic value of a PV system is step one. Establishing a timeframe is step two. Is your LCOE calculation really looking at the broad picture?

“When you compare two systems with a calculated LCOE, be sure the warranties are equivalent because the cost to replace a major component like a string inverter can have a serious impact on that calculation, particularly when those needed replacements occur once, or often twice within a 25-year period,” says Jason Higginson, senior director of marketing, APsystems, which has 10- and 25-year warranty options for its microinverters.

Adjacent to the warranty is service recovery speed. Ed Heacox, GM of CPS America, a leading commercial inverter company, says a key for them is having ready-to-go spares or RMA inverters available. “We are offering service speed commitments as well as onsite spares to help customers reach nearly zero downtime. Innovation of these commercial programs is a big part of our work on LCOE for customers,” he says.

Pika Energy Diagram

Example of “future-proofing” an install with a Pika Energy inverter.

Max Efficiency

Enough of all of this failure talk. Most of the time the system is going to be on and working, and when it is, it needs to be kicking ass and improving LCOE.

“One of the potential drawbacks is that LCOE calculations do not effectively differentiate between upfront and variable costs,” says Peter Mathews, North American general manager for SolarEdge.

His example: The fixed cost of a system, including customer acquisition, permitting and design, are realized regardless of the size of the PV system. Each added module can be installed for a much smaller variable cost.

“The trade-off between fixed and variable costs is more advantageous for systems with more PV modules since they can generate a disproportionately greater amount of energy versus the initial upfront costs,” he says. “LCOE calculations are therefore only part of the financial return. The calculation for return on investment (ROI) should also factor in the revenue generating potential of any site to generate cash from the PV system. The LCOE only calculates the expense. The returns can also vary based on region, rate structure or the ability to switch rate structures. Having a highly flexible PV solution that can add more modules onto projects is a powerful tool in maximizing the return on PV projects.

SolarEdge’s philosophy is to allow for the installation of modules in shaded areas and on roofs with varying angles. This degree of design flexibility means more modules per roof.

Marv Dargatz with HiQ Solar recommends stacking string powers high enough to maximize ROI while the system is up and humming. To do this right, he cautions to be wary of STC ratings.

“STC ratings for modules tend to be optimistic, partly because they are measured with a cell temperature of 25° C. In the real world, cell temperatures in direct sunlight are more likely to be at 60 or 70° C, yielding less power,” he says. “Overall, when orientation to the sun, temperature, time of year, soiling and aging are taken into account, strings put out a lot less power than STC leads you to expect. It’s therefore important to stack the inverter to make sure it is operating as near to its max output as possible to maximize ROI.”

He also says having a single MPPT per string rather than paralleling helps maximize harvest.

RELATED: How to achieve low LCOE utility-scale solar without cutting costs 

Seriously, Really Look at Lifetime

Pinpointing the lifetime of a system at 25 years from 2017 puts you into 2042. We did the math three times just because that number looks insane. We might all be in an Escape from New York post-apocalyptic future, but those PV systems will still be kicking, and one has to assume energy storage is going to be in a completely different position than it is now. And assuming that, you must assume your customers are going to want to move to upgrade to solar+storage, if they haven’t already, which throws all of your previous LCOE forecasting out the window of your 2042 flying car.

So yes, understanding cost and performance metrics for batteries is an important factor to consider today. Batteries introduce multiple new variables into the financial model and can have a positive or negative impact on LCOE depending on the technology used and how it is sized relative to the PV array and loads.

“A battery has both an instantaneous power rating [in watts or kilowatts] and an energy capacity rating [in kilowatt-hours] and they both factor into the financial model,” says Paul Dailey, director of product management, OutBack Power. “In addition, battery life is often expressed either in cycles or calendar life, but you need both metrics to determine the value of the battery in your application over time.”

The future of energy storage is why Chip Means, director of sales development, Pika Energy, says DC voltage is by far the most underrated and under-appreciated variable in LCOE.

“Too many solar inverter products use a low voltage range, typically 48 volts. Solar is rapidly changing to require the addition of battery storage behind the meter. Using 48-volt equipment simply doesn’t make sense for this evolving reality,” he says. “Low-voltage inverters are typically AC-coupled to add a battery to grid-tied solar, which requires using two inverters. This clunky, 48-volt arrangement means the customer’s roundtrip efficiency will be typically around 80 percent.”

Pika Energy’s products use an internal bus voltage of nominally 380 Vdc, and all of its components — PV Link solar optimizers, Islanding Inverters and Pika-compatible smart batteries — use this bus voltage to connect, communicate and transmit power. This results in a system with roundtrip efficiency of closer to 90-92 percent. That 12 percent increase on roundtrip efficiency pays major dividends in terms of LCOE.

Magnum Energy’s MicroGT inverter also comes ready to talk to the MS-PAE inverter/charger, to ease that solar-plus-storage transition.

“Installing storage-ready PV systems now will save significant time and resources when returning in the near future to add energy storage,” says Mike Dixon, sales and marketing director, Magnum Energy. “Not only considering current equipment investments, but future equipment investment — which doesn’t fall under the O&M umbrella — can save on the most expensive part of the solar formula.”

Unless all of these lifetime costs and realistic max output calculations are included and explained clearly to customers, a backlash will occur once they are surprised by replacement costs or any other unforeseen variable. And no one wants a line of customers wielding lightsabers outside their door in 2042, demanding satisfaction. 

This feature is from our March/April “Inverter Issue.” Get your FREE subscription to print here or digital versions here.

— Solar Builder magazine