Blog Post

ArrayPower: Solar panels meet distributed conversion

Stay on Top of Enterprise Technology Trends

Get updates impacting your industry from our GigaOm Research Community
Join the Community!

Solar panels need to be attached to devices that convert their current from direct current (DC) to alternating current (AC) to be used by a home or to feed the grid. Sounds like a pretty standard process right? Well a startup called ArrayPower (formerly Array Converter) has engineered a new way to do the process by distributing conversion between multiple solar panels, and the technology promises to deliver more power at the price of conventional power conversion electronics, according to ArrayPower’s CEO, Wendy Arienzo.

Arienzo is divulging more details about the company’s technology after giving a short and cryptic description of it at a cleantech conference last week. The technology makes use of pulse amplitude modulation, a concept that has been used in Ethernet equipment and in controlling LED lighting, but now is being applied to solar. ArrayPower, which is based in Sunnyvale, Calif. and founded in 2007, has also lined up $22 million in venture capital funding.

Here’s how it works: each ArrayPower silicon-based device is attached on the back of a solar panel to boost the voltage of the direct current from 60 volts to 208 volts before being connected to three circuits of resistors and capacitors, which send out the current in pulses. Those pulses alone aren’t enough to form the current with the right frequency for an electric grid. But when combining at least four of them, you have the right AC wave to supply to the grid.

“It’s like a symphony where you have different instruments playing and they all come together,” she said.

Conventional power conversion devices are called inverters, and each produces AC at the right frequency. Each inverter typically is paired with about a dozen solar panels, though startups have emerged in recent years to develop microinverters that go on the back of each solar panel. Microinverters can better monitor and adjust the power output of each solar panel, and as a result promise to reduce power losses. But microinverters are also newer products to the market and more expensive than centralized inverters.

ArrayPower’s device, which the company calls a “sequenced inverter,” promises to offer the benefits of microinverters (more power harvested) at the price of centralized inverters, Arienzo said. That’s the idea anyway, since the company hasn’t shipped its products commercially yet. It intends to sell them to solar panel makers, who will assemble them into the panels, and it has lined up one customer who will launch an integrated panel at the Solar Power International conference in Texas later this month. ArrayPower expects to start shipping its devices early next year and will hire a contract manufacturer to produce them.

The U.S. will be the first market, though the company is doing field trials of its gear in Germany to get ready for the commercial launch in Europe. The company’s investors include Partech International, Trident Capital, Draper Fisher Jurvetson and Firelake Capital Management. ArrayPower’s chairman is Kevin Surace of Serious Energy, and its board includes Solaria’s CEO, Dan Shugar.

Photo courtesy of ArrayPower

2 Responses to “ArrayPower: Solar panels meet distributed conversion”

  1. Update: The Array Converter may have grown to 10×12 inches! Based on a photo above and a new one including the edge of the module and a hand released on SolarServer, Array Converters are now more than twice the physical volume of SolarBridge or enphase. I hope this is not a reflection of the cost or weight!

  2. The technology I invented, with Sorin’s assistance was a new topology to utilize more reliable coils of wire in place of unreliable liquid filled capacitors.

    This was the critical first step to economic viability which consisted of the four corners of reliability, cost, efficiency and operation at high temperatures. At that time, the other corners were met by the simplicity of the design, redundancy and construction techniques.

    With skilful implementation, the Array Converter topology had the potential to be the best in class in each of its four corners.

    In 2008 when I filed the first of the patents and incorporated the company, the principle was to chop the unrefined power from a solar panel into refined, short pulses which could be stored in a magnetic field.

    These pulses of current were emitted into the utility grid at a rate (carrier) just above human hearing. The pulses passed through an inductor capacitor filter to give them an electrically quiet shape and avoid radio interference. Since resistors consume power, they were not used in the power pathway of the Array Converter at that time. The original modulation system was Pulse Amplitude Modulation Constant Current (PAMCC).

    To further refine the grid power, each Array Converter was set to emit its series of pulses at the same rate but slightly shifted in time (phase) from one another. As the carriers combined out of phase on the utility grid, they canceled each other out leaving only the final, pure waveform.

    The effect is like a choir of identical singers, each singing the same note on key. The resulting sound is a clear pure tone.

    For those doing diligence on this as a power deal, an array of Array Converters is equivalent to a very large distributed inverter. Each solar panel/array converter being a component part of the larger inverter.

    The conductor for this choir is the utility grid whose frequency forms the clock and whose shape the tone.

    What you just read is a summary of what is in my patents and published patent applications. To read more, go to the and look me up, track down the company (whatever they are calling it this week) or look me up on linkedin.

    Kent Kernahan