Until recently, most photovoltaic systems ran blind. Maybe you'd know how much power was being produced by the total system at the central inverter. But you didn't have a lot of good diagnostic info to go on. If one of the panels or strings failed or was starting to fail, it was both guess work and trial and error to locate the right panel on the right string.

But the solar boom has produced a number of firms specializing in the monitoring function or providing the monitoring function as a feature in their product.

Energy Recommerce (ERI) provides Web-based solar monitoring and management for the commercial market. The firm was founded in 2004 with funding from Dry Creek Ventures and has a background in smart homes and building automation.  I recently spoke with Peter Rexelius, the CEO.

According to a report from Rexelius, ERI's revenue growth in 2008 exceeded 300 percent, with 80 megawatts being monitored in more than 300 installations.  According to the CEO, ERI also achieved profitability in the third quarter of 2008 – an impressive achievement in this economy and even more impressive for a startup.

"We don't do it just to show off, we do it to get the most performance out of the system. It's a necessary evil to provide monitoring – in order to get access to performance-based incentives you have to have monitoring," said Rexelius.

"We monitor at different levels," said Rexelius, "At the highest level, we monitor at a utility-grade meter, which gives the user access to rebates or renewable energy credits." 

The monitoring system provides real-time data at 15 minute intervals.

Most of the PV systems monitored by ERI are large commercial projects with a client list that includes Tioga Energy, Borrego Solar, Chevron Energy, MMA Renewable Ventures, Solar Power Partners, BP Solar, SunPower and end-users such as Costco and Walmart.

ERI monitors at the string level as opposed to the panel level which is done by some of the new inverter companies like EnPhase, Tigo and Solar Edge.  ERI focuses on commercial installations and the PPA provider is their target customer.  And according to Rexelius, companies like MMA, SPP, and Tioga, "have standardized around our monitoring product."

Other vendors on this space include:

Draker Labs: A renewable energy monitoring company, raised an Round A from strategic investor Campbell Scientific and FreshTracks Capital in August 2008.

Fat Spaniel: Fat Spaniel provides monitoring, reporting, and remote management for PV and other renewable energy systems. It closed an $18 million Series B in January 2008 from investors Ignition Partners, Element Partners, Chrysalix Energy, PCG Clean Energy & Technology Fund, and Applied Ventures. The firm closed a $7 million Round A in 2006 (see Fat Spaniel Launches Open Platform and Fat Spaniel Gets Fatter).

Mythos Solar Power: Funded by The Hartley Family Trust, Mythos builds Web-based renewable energy monitoring applications designed to monitor and manage any widely dispersed renewable energy power supply.

A wild card in this market and possibly a threat to these monitoring firms is the new distributed inverter architectures offered by firms like Enphase, Solar Edge and Tigo.  These new inverter architectures offer monitoring as part of their feature set and seem to have a head-on trajectory with these monitoring specialists.  It should be interesting to watch the competition unfold.

Eric Wesoff is a Senior Analyst with GTM Research contributing to Greentech Media News.

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