Parallel Solar Architecture Increases Performance, Decreases Costs

Instead of focusing on improving the efficiency of the solar panel itself, eIQ Energy is increasing solar system output by improving the entire system. The San Jose company’s improvements on thin-film photovoltaic arrays are electrical rather than technological in nature.
Series vs. Parallel

In most solar arrays, solar panels are wired as part of a series circuit, meaning that panels are connected along a single “string” of wires, similar to the way the solar cells themselves are connected within a conventional solar panel. In a series circuit, the current running through each panel is the same, but the voltages add up along the string. Therefore, string lengths are limited by voltage totals, especially for thin-film panels which produce higher voltages than standard solar panels.

In a parallel circuit, each panel or set of panels is wired in a separate loop, all connecting to a single “bus” line. In this way, each panel has is its own circuit, resulting in significant advantages for overall system performance.

Independence

Think of a series-connected solar array like a string of Christmas lights: if one bulb fails, the whole string fails. Likewise, if one solar panel in a series is shaded, dirty, or damaged, then the whole series fails. In a parallel design, if one panel fails, the others will not be affected because each panel is independently wired to the main line.

Less Wiring

eIQ Energy’s design also facilitates less wiring (and therefore labor and equipment costs). If series circuits are limited in length, that means that a system would need more wires running from the end of one series to the inverter, compounding the load on that inverter with each series line connecting to it. According to eIQ Energy, their Parallel Solar design enables more than 100 thin-film solar panels to be connected along the same bus line. That means instead of, say, 10 lines running the inverter, you have only one, thus allowing the inverter to operate at peak performance.

Reduced Cost, Improved Performance and Monitoring

The result of a parallel circuit design is reduced costs for wiring, combiner boxes and labor required to assemble a thin-film PV system. Voltage swings due to panel temperature, shading and other environmental concerns are also eliminated. Furthermore, shading or other single panel failures can no longer crash the whole series, thus improving overall performance.

eIQ Energy’s line of products, known as Parallux, also enables system monitoring down to the single-panel level, further enabling easy location and real-time assessment of system problems.

According to the eIQ website, running PV arrays in parallel rather than series increases system performance by anywhere from five to 30 percent. With what the company dubs its VBoost converter module, each panel on the array becomes its own fully independent energy producer. Instead of a solar system that comprises a single power plant wired to the larger grid, Parallel Solar architecture turns each solar panel into its own power plant and the entire PV system operates like a miniature electrical grid.

Sources:

Reuters

eIQ Energy

Posted on September 11th in Solar Products by Dan.