Blog Post

Using radio waves for more efficient solar power

Using radio waves to efficiently convert solar power — that’s the idea behind startup Array Converter, which spoke for one of the first times this week at the AlwaysOn GoingGreen conference in San Francisco. Array Converter has developed solar power conversion electronics — which are used to convert the solar power made from the panels (direct current) into power that can flow on the grid (alternating current) — using a radio wave technology called amplitude modulation.

Array Converter CEO Wendy Arienzo said at the conference: “Marconi came up with radio and called it amplitude modulation. We are taking a well established technology and applying it to solar.”

Asked about Array Converter’s technology after her panel, Arienzo declined to say more about the company’s research, but said the company plans to make an announcement at the Solar Power International conference next month.

Amplitude modulation involves using radio wave to send information — the technology adjusts the amplitude of the radio wave rather than the frequency (FM) — and Array Converter’s work seems to focus on using pulse amplitude modulation. Pulse amplitude modulation is used in Ethernet equipment and for controlling LED lighting. Eric Wesoff at Greentech Media wrote about the company earlier this year, and patent attorney Eric Lane wrote about the startup’s patents in a blog post.

Array Converter is setting out to develop power electronics that are indeed different than the ones commonly used today to convert DC from solar panels to AC in order to be used on site or feed the grid. Solar systems today use inverters to do the power conversion; the inverter gets its name because its design reverses a conversion process to turn AC to DC (this device is called rectifier).

Although Array Converter hasn’t announced products, its website indicates that the company is working on a modulator and controller. And, yes, the startup promises to deliver power electronics that can reduce the overall equipment and installation costs.

Inverters have been used in solar energy systems for decades. Each inverter is typically responsible for about a dozen solar panels. In recent years, some inverter developers have come up with what’s called a microinverter that is paired with each panel.

The use of microinverter has led to the name “AC panel,” because the DC-to-AC conversion now takes place at the panel rather than at a central inverter that sits in a stand-alone box next to the solar array. Array Converter, incidentally, also calls solar panels that use its devices “AC panels.”

All of these technologies are working on improving the efficiency of converting the electric current – power losses are typical during power conversion. A Google-backed startup, Transphorm, is working on reducing that power loss by using a novel material called gallium nitride.

Array Converter already has lined up investors, including Partech International, Trident Capital, Draper Fisher Jurvetson and Firelake Capital Management.

6 Responses to “Using radio waves for more efficient solar power”

  1. No worries, this is probably not a radio transmitter. At least not an intentional one.

    The technology I invented, with Sorin’s assistance is a type of modulator. We called it an Array Converter and its modulation PAMCC for Pulse Amplitude Modulation Constant Current. As conceived, the noisy Pulse Width Modulation (PWM)of the power switching stage was converted to an almost emi free half sinewave by an ~15khz LC resonate circuit which I named a reconstruction filter. Since a resonate filter cannot change frequency, the energy in the PWM switching stage is converted to a constant width variable pulse amplitude. The filter was set at 1/2 or less of the PWM frequency, hence, low emi half sine wave output current. These pulses were about 30us wide so there were about 500 of them per 60hz grid cycle. Each pulse was amplitude modulated to represent a small portion of the much slower grid sinewave.

    So each Array Converter has a carrier (used to be 30khz) and modulation (PAMCC) but they were not radios.

    The individual Solar Panel / Array Converters sets were synchronized to the utility grid (as a common clock) which allowed them to offset the phase of their carriers from one another. Since the carrier of each Array Converter was the same frequency but with a slightly different phase and each array converter was modulating a set of pulses representing the same grid waveform (in phase) only the grid current waveform was present. Although Array Converters are not radios, the effect was to be something like when two out of phase carriers hit your car antenna and the station fades.

    So to sum up when you have an Array of Array Converters connected together they suppress each others carriers (which a just above audible) leaving only, what can be, a very clean gird current waveform.

    For those in the power field; An array of Array Converters/solar panels converts to something like a scalable distributed multi phase inverter.

    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 up the patent numbers listed in the post, track down the company (what ever they are call in this week) or look me up on linkedin.

    RonDon, please cut her a break. I think you may be taking some metaphors intended to simplify a little to literally.

    As to Solyndra, imo that was a plausible but flawed concept, brilliantly executed. It looked so good on paper that the VC community had $1.1B in before the DOE loan guarantee.

    In 2008, Solyndra was held in such high regard that a VC had them do diligence on my newly formed Array Converter!

    Solyndra is likely the largest private equity loss in history. I lot of very smart people in the valley missed this one.

    I suspect that at least part of the calculus at the DOE was that they were making a small bet next to the big bet the best of the best Venture Funds had already made.

    If anything, Array Converter is the inverse of Solyndra.

    Kent Kernahan

  2. What provisions have been made to contain the Radio frequency energy so that it does not radiate noise ?
    Radio interference in the two way radio and emergency comm fields has become an increasingly important concern.
    Where are the savings if lives are lost due to lost communications because of severe radio interference?

  3. I am very concerned at the radio interference a large array of these would create ! What precautions are made to conatain the “radio waves” so they do not become an unlicensed generator of radio noise? This is becoming a growing problem with many low energy power strategies , causing a multitude of two way radio interference issues to emergency services , especially inside buildings! No communications can translate into lost lives! Where are the savings then?

  4. If I’m reading this right, this is basically a tank circuit transmitter using the PV output as the DC source, the tank circuit as a boost converter to raise voltage to 240 v in the first stage and then ‘transmitting’ the output @60Hz as a standard AM carrier signal (sinewave).

    The cost advantage would mostly be due to the fact it converts to 240v in the first stage which reduces the current in the remaining stages so cheaper (lower current rated) components can be used.

  5. Can you say “Solyndra”? First off, Marconi did NOT “come up with radio and called it Amplitude Modulation”. Heinrick Hertz did the first experiments in electromagnetic radio transmission in 1857 and Prof. Reginald Fessenden is credited with the invention of Amplitude Modulation.

    Solar Energy is about the lease efficient, most expensive way to generate electric. These companies are created for the sole purpose of stealing taxpayer money in exchange to campaign donations as we now see with Solyinda. All these companies manufacture is a failed solution for a non-existent problem and are tanking our economy by producing tons of BS. Maybe shoveling all that BS are the ‘shovel ready’ jobs Obama was talking about!

  6. Can you say “Solyndra”? First off, Marconi did NOT “come up with radio and called it Amplitude Modulation”…It was Prof. Reginald Fessenden who is credited with the invention of AM, and the first radio transmission was actually achieved in 1857 by Heinrich Hertz.

    Solar energy is a failed response to the non-existent global warming scam. The real purpose is to put billions of taxpayer dollars into investor’s and manager’s pockets in exchange for campaign donations and when these companies predictably go bankrupt, the taxpayers get left holding the bag. Array Converter will be gone or begging for more bail-out money in six months.