Monitoring and data logging services multiply


“Companies are entering the market because the monitoring pie is getting bigger, and niches should provide opportunities for specialized companies to grow,” says Nagendra Cherukupalli, SunEdison’s Vice President of Systems Engineering R&D, based in Belmont, California.
Indeed, solar data logging and monitoring systems are facing ever-increasing competition – from China and elsewhere – as balance of systems (BOS) cost reduction pressures tick onward. And as electronics are compressed across BOS component lines – like the merger of inverter and monitor functions – system compatibility and plug & play capabilities may become necessary for brand survival.
“Within two years monitoring and data logging systems will become a black box with sophisticated onboard computers and plug-and-play attachments for all other PV systems,” reckons Christian Leers, a private owner of 5 MW of PV power plants, based in Melsbach, Germany. “And the more sophisticated the monitoring system you install, the better you will operate your plants,” he adds.

Monitoring capex relatively small

The investment allocated to monitoring and data logging may average two percent of a total plant’s capital expenditure, with that figure somewhat higher in the residential segment, and lower in larger installations, several sources agreed. For a 10 MW plant, monthly monitoring services may cost $10,000, one U.S. source estimates.
Last year, when West Holdings of Japan announced an imminent joint venture with SunEdison to provide PV monitoring system services in Japan, a cost of service in the $30,000 range was predicted for a 2 MW plant, according to West Holdings statements.
In contrast to the cost of installing a monitoring system, risk insurance for production interruption could cost 0.15% of the total plant capex per year, suggests Leers. Thus over the 20 year lifetime of a plant, risk insurance may have cost twice what the cost of installing the monitoring system was. Thus, more robust monitoring systems, which permit active management of production risk, will be in greater demand. And regressive analysis will necessitate deep databases, which SunEdison maintains: “We keep data going back seven years, and have very sophisticated search engines to cull out information,” Cherukupalli says.

More component integration

Separating out the cost of monitoring systems will become more difficult in the future since monitors eventually will increasingly merge with inverters and all other electronics in a PV system, several sources suggest. “In the residential and commercial segments we are going to see more component integration, reducing the need for data loggers, into one device,” says Cedric Brehaut, the Founder of SoliChamba Consulting & Market Research, based in San Francisco.
SunEdison’s Energy & Environmental Data System (SEEDS) monitoring system, for example, enables its control centers to manage “the full range of components and systems within a solar installation including: weather stations; pyranometers; ambient temperature sensors; panel temperature sensors; inverters; string combiners; recombiners; and AC subsystems.” The company came out last year with a new user-definable interface, the SunEdison Connect, notes Cherukupalli.

More inverters embed monitoring

Beyond the control of a PV plant, the monitoring/operating system can make billing, contractual and incentive reporting easier for customers. SunEdison’s Renewable Operations Centers, for example, offer “energy production reports to support Performance Based Incentives […], Renewable Energy Credit programs […], and Power Purchase Agreements.” With 1.7 GW monitored, the company is on track to hit almost 4 GW this year, Cherukupalli says. Offering such an array of functionality will require more companies to adopt a plug-and-play format. Locus Energy for example, in February launched its LGate 360 generation control panel “designed specifically for plug-and-play performance data acquisition for commercial and utility-scale solar photovoltaic installations,” says Adrian De Luca, the company’s Vice President of Commercial Sales and Marketing. The company has 35,000 systems installed in the United States, Europe and Australia, and is on track to double that this year, he notes. Plug-and-play enabled systems also will be increasingly impor

A rising number of inverter manufacturers are including monitoring capabilities within their products, as BOS electronics improve and consolidate. “Each generation of inverters has more embedded capability, like a smartphone, which means that things you used to pay for separately are now included as standard,” says Tucker Ruberti, the Director of Strategic Segment Management for Inverters at Advanced Energy, based in Fort Collins, Colorado. “We have significantly increased the amount of embedded memory and lossless data backup capability, so there are no data holes as a result of an outage,” he says.


SMA embeds Webconnect monitoring in every residential and commercial inverter it sells, and the company has shipped over 30 GW of inverters thus far, according to Tom Rudolph, head of SMA Online Solutions, in Niestetal, Germany. SMA’s residential monitoring product Sunny Beam operates with Bluetooth Wi-Fi, while the medium plant solution is the new Sunny WebBox 20 (Bluetooth WiFi), and the large-scale PV plant solution is the Sunny WebBox 10 (RS485), a multi-functional data logger that offers a variety of options for displaying, archiving and processing data. The latest SMA data logger for medium to large-scale PV plants is the Cluster Controller, designed for decentralized installations with up to 75 string inverters and cloud-based redundant data storage. All these systems can be linked to Sunny Portal, released in 2004, as “the world’s largest web-based PV monitoring platform,” with 100 terawatt hours of energy monitoring as of April, SMA claims.
Similarly, Fronius has included free monitoring in its new Galvo Wi-Fi inverter for the residential market, says Martin Beran, the head of system support, product markets, and research and development at Fronius USA. “There will be a greater convergence of functions into inverters; everything should be in one box,” he says. To help minimize O&M replacement costs, Fronius has developed a hinged back plate mounting for its inverters, which snap into fixed connections, eliminating the need for re-torquing wires.
Enphase based in Petaluma, California, also includes monitoring in its microinverters. The company shipped 107 MW of microinverters during the fourth quarter of 2013, adding to its grand total of 1 GW worth of inverters sold to date. Enphase has supplied individual projects with as many as 9,000 microinverters, which the Vine Fresh Product installation in Strathroy, Ontario, required. Enphase in January unveiled a Wi-Fi option for its Envoy Communications Gateway, which is served by web-based products for homeowners and developers. Its MyEnlighten software is targeted toward residential customers, while the Enlighten Manager is a web-based portal for multiple installations.
And at the commercial and utility scale, Advanced Energy, for example, launched its 1000NX last year, which contains full monitoring and data logging functionality, says Ruberti. “This unique bipolar inverter doesn’t use fuses or breakers, but instead uses contacts or sensors that can sense faults at a more granular level and react more quickly; so on the DC side, performance data – including voltage and current – are available to the customer for free,” he says.

xAdvertisementtant to reduce commissioning costs of monitoring systems, he adds.

Mergers and acquisitions

As PV monitoring customers become more demanding, consolidation in the industry is likely to continue. The market now is “very, very overcrowded,” reckons Tor Blackstad, the CEO of GreenPowerMonitor, of San Jose. Several significant acquisitions of monitoring companies took place last year. Zurich-based systems giant ABB acquired Power-One, of Camarillo, California, in July 2013. Similarly, inverter major SolarMax, of Längfeld, Switzerland, in August 2013 acquired Draker, of Burlington, Vermont, an independent monitoring company with 1.2 GW under management. Then AlsoEnergy, of Boulder, Colorado, acquired Deck Monitoring, of Portland, in October of last year. And in December, Inaccess, of London, acquired Sense One Technologies, also of London.
“There will be massive consolidation among monitoring companies,” predicts Tom Rudolph, head of SMA Online Solutions, in Niestetal, Germany. “It takes a lot of money to run a monitoring system 24/7 and to deliver data to customers, so companies may only exist in the future if they monitor a large number of plants,” he reckons. “There is a big difference between a company that monitors a few thousand plants and one that can monitor hundreds of thousands.”

Fewer independent companies

The need for independent monitoring companies was born out of the multitude of different standards in inverters made around the world, company representatives explain. Today, independent monitoring companies also need global reach to provide high level service to any country where a PV plant may be located. However, the market is still fragmented geographically, says Brehaut: “Monitoring markets are still very localized in nature, so the leading firms in Germany are completely different from those in the United States or Japan or China.” The largest European independent monitoring companies include meteocontrol, Solare Datensysteme, and skytron energy, Leers suggests. Another European independent with global reach is GreenPowerMonitor, based in Barcelona, which has 1.7 GW of PV under management. The company’s North American headquarters in San Jose is its second telecommunications center. In conjunction with its Spanish center, it has near 24/7 capability. A third location is planned soon, says Blackstad. One established 24/7 global network is that of SunEdison, which operates communication nodes in Belmont, California, Madrid, Spain and Chennai, India.
Independent monitoring companies must also be able to configure systems uniquely for each client installation andfor custom data analysis, marketers from Common-Link, of Karlsruhe, point out. “Common-Link’s modular monitoring system is able to control individual generator strings as well as the inverter outputs […] independent of the inverter type or make. Simultaneously, operators and service teams obtain precise data about yield in real time. This is ensured by the finely tuned interaction between the hardware for data acquisition/remote transmission, and the analysis & control software package specially developed for this purpose,” the marketers say.

Integrated verticals

Monitoring companies are expected to form more alliances with vertically integrated PV companies in the near term. “EPCs know PV power systems but are less familiar with networking and the internet side, so they need a (monitoring) partner to help get problems sorted out,” says Locus Energy’s De Luca. “Having the capability to remotely address fault codes through two-way communications is a huge advantage,” he says. One way Locus does that for installer partners is to preregister all components of a system and configure them into the monitoring network so that once the system goes hot, all components are recognized.
In the residential segment, large portfolio operators might be tempted to establish – organically or through acquisition – theirxAdvertisementown fleet monitoring systems, Brehaut suggests. “In the U.S. market we have PPA providers who are potential players – like SolarCity, Sunrun and First Solar.” Among vertically integrated industrials that offer PV monitoring is Siemens, which in October 2013 discontinued much of its other solar business. Now Siemens microinverter products are being managed by Siemens’ Low and Medium Voltage Division.
One tracker supplier that is also providing advanced monitoring services for its own equipment is NEXTracker, of Fremont, California, which operates its system in a wireless mesh network. “We don’t need to roll out communications wire in the field, which is huge,” says Dan Shugar, the CEO of the company. “We characterize the health of every tracker row constantly during the day, and can perform diagnostic predictions on any mechanical element – a huge step forward for the industry,” he says.

Web vs. ERP programs

Apart from universal adaptability to PV components, monitoring programs also need to be able to bridge the gap between simple web-based displays and complex enterprise resource planning (ERP) programs, which can merge data from multiple plants across multiple locations. The future of PV monitoring on the residential level will be in more tailored user interfaces on the web, suggests Martin Beran, the head of system support, product markets, and research and development at Fronius USA, based in Portage, Indiana. Fronius already provides a white-label framework for fleet-level operators, carrying their logo on a web-linked user screen.
GreenPowerMonitor also offers web-based monitoring through its real time

Shanghai Taoke Network Technology – China’s monitoring market leader

A company to watch in the PV monitoring space is Shanghai Taoke Network Technology, headquartered near the site of the 2010 world expo. Taoke has quickly become China’s leading PV monitoring vendor. In October last year the company hit the one gigawatt milestone of PV systems monitored in China. Further rapid growth can be expected in the years ahead, as China’s PV installation market is expected to grow by another 20 – 30% after hitting the 10 GW mark in annual installations in 2013.
At the upcoming SNEC trade show in Shanghai, Taoke will show its data logging and monitoring solutions as well as system planning software that also incorporates key economic data, including electricity pricing, so that investors can assess the return they can expect from a particular installation and business case.
In another initiative Taoke is building an open web-based platform that is not limited to PV power plants using Taoke technology, including proprietary data collector devices that are available either as a GPRS box or a hard-wired Ethernet box, both with FCC, CE and TÜV certifications.
Taoke’s Founder and General Manager Jianzhou Lu points out that GPRS and Ethernet devices are easier to set up than collector devices relying on Wi-Fi data transmission. The open platform will allow any PV system owner in China to provide data to Taoke to monitor power stations remotely and also see the performance data of other stations on the Taoke platform. The idea is to aggregate as much PV performance data as possible, allowing market participants to assess which system configurations are working best and also giving China’s PV market more transparency, which it so urgently needs to attract more investors and other key constituencies like building owners.
Lu is a veteran of China’s PV industry, having started his solar career in 2005, when China’s PV industry was in its infancy. His initial involvement with the PV industry centered on small PV systems and he realized early that there was no convenient way to store and collect data on the performance of such systems. Lu seized on this opportunity to launch Taoke in February 2010 and from the beginning Lu was determined to stay independent and build high quality products. Other vendors typically customize their solution for a particular supplier, for example a Chinese inverter or module manufacturer. This opens up the risk that the data are manipulated to suit the purposes of this particular manufacturer, who might be interested in making their own inverters or panels look better than they actually are. In contrast, Taoke can collect and analyze the data “as is” from the installations in the field.
Taoke has also developed all of its hardware and software independently. Similar to Apple’s approach in consumer electronics, the company has even developed its own operating system to run its data collector boxes. These devices can tap a wide range of data, from weather station data, to electric meter data, to inverter data, or even the data of individual modules, supplied by optimizers or microinverters.
Taoke’s “sweet spot” does not seem to be utility-scale PV installations, even though these have so far been the prominent PV application in mainland China. Reflecting Lu’s background in small installations, the company monitored an impressive 3,000 installations at the end of 2013 with only a very small fraction of these in the utility-scale segment. The bulk of these 3,000 installations are in the residential, commercial and industrial rooftop segments with the latter two segments being the dominant markets served.
Taoke’s focus on the rooftop market bodes well for its future as China’s government puts increasing emphasis on distributed PV (DPV) power generation. While DPV amounted to only 2.7 GW in China in 2013, this year’s goal is a whopping 8 GW, which would make DPV the dominant application in China. Taoke can also benefit from China’s move away from an up-front PV subsidy to a performance-based model. As China’s new expanded feed-in tariff regime takes center stage in China’s PV market, system owners, whether DPV or otherwise, will be interested in tracking the continuous performance of their power generation assets. Poor system performance will translate directly into reduced revenues, making comprehensive, high quality and independent monitoring of these assets an essential part of the PV business going forward.
With the experience gained in its home market Taoke will be in a good position to take this know-how to foreign markets. Lu said that the company is already in the process of setting up server infrastructure in Japan and Germany. Looking at the addressable markets around the world and Taoke’s leadership position in its home market, it will probably take less time for the company to go from 1 GW to 10 GW than it took the 2010 startup to reach the 1 GW mark late last year.

PV Portal product, at the same time it offers PV Scada for individual control room capabilities coupled with a full GPM Power Plant Controller (PPC). “But there are fundamental limitations to what you can do with a browser-based tool,” observes GreenPowerMonitor’s Blackstad. “If you need more flexibility for proprietary algorithms and forecasting, with multiple interconnected screens, then you need a Windows-based tool,” he says. The company’s most encompassing management product, GPM PV+, provides data at a one second refresh rate frequency.
Others disagree with the need for separate Windows programs to monitor PV systems. “Commercial customers don’t want a separate computer for monitoring because they already have a building management software system,” notes Beran. “Maintenance people see the PV system as another appliance, like air conditioning, so they want PV monitoring integrated into their system,” he says.
To provide fleet-level monitoring, cloud-based data storage and off-site computation is also a strong trend among monitoring systems. “The future of monitoring and data logging will be in the cloud; it can deal with more data, offer more features, and modify and calculate better,” says Rudolph. “And in the future with the smart grid, the most important thing will be standards-based communication between the smart home generator/consumer and the utility,” he adds.

Quality control and standards

The U.S. photovoltaics industry’s effort to standardize the multiple proprietary inverter communications interfaces and protocols is still at an early stage, but it is inevitable.
“Progress in standardization was faster in Germany where a lot of work was done over the last 10 to 15 years, although it has slowed a bit; now there is more progress in the United States,” says Fronius USA’s Beran.
“The SunSpec Alliance has done a lot,” adds Brehaut of SoliChamba Consulting & Market Research. California’s upcoming Rule 21, which emphasizes enhanced control between distributed solar PV sources and the utility, will help set monitoring language and protocol standards in that trendsetting state, Brehaut suggests.
One effort to benchmark performance so monitoring systems may uniformly predict failures is the cooperation between GE and the Fraunhofer Institute for Reliability and Microintegration (IZM). The two launched their joint Condition Monitoring for Power Electronics in Photovoltaics (CoMoLeFo) project in 2012 as a method to forecast the remaining lifetime of power electronics.
For the present, cross-continental certification of systems is a necessary duplication of effort because of the lack of an established global standard for monitoring protocols.
In January, Berlin-based skytron energy gained Underwriter’s Laboratories approval for its plant control system marketing in the United States. “The controller’s cETLus approval to the UL/CSA 60950-1 equipment safety standard rounds off UL certification of skytron’s entire instrumentation and control range for renewable power plants and particularly for utility-scale photovoltaic installations,” said Alberto Gallego, the company’s Product Marketing Manager, at the time of the certification. Skytron has installed monitoring and control systems at PV plants with a combined capacity of over 4.5 GW, of which 3 GW are equipped with their proprietary plant controller.xAdvertisement

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