The ability to connect solar panels in parallel enables the connection of more 100 thin-film photovoltaic panels on a single cable, according to the startup, eIQ Energy Inc. (San Jose, Calif.). This represents a 20-fold improvement over conventional string architecture, and could reduce installation costs by about 5 percent in large, commercial-scale thin film installations, according to Oliver Janssen, eIQ's CEO.

Janssen said traditional solar panel strings, architected in series, have several requirements, including that the panels on each string must be in balance and cannot exceed a certain voltage. Parallel solar technology is free from such requirements, he said.

"This is just a very fundamental difference," Janssen said. "Parallel is cheaper."

According to eIQ, the company's flagship product, the Parallux system, is built around the firm's proprietary vBoost DC-to-DC converter module. The technology mitigates the effects of panel mismatch due to shading, soiling and manufacturing variations, according to the company.

The vBoost module allows any solar panel to be connected in parallel to a constant high-voltage DC power bus, according to eIQ. It also incorporates distributed maximum power point tracking (MPPT), the company said. The module has been tested with a range of crystalline and thin-film solar panels at eIQ's San Jose test facility and at various ongoing beta site installations, eIQ said.

The DC bus voltage can be fixed at the optimal level for any inverter, according to the company, improving inverter efficiency and reliability. In combination with distributed MPPT, this enables solar photovoltaic systems to harvest 5 to 30 percent more energy than conventional systems, the company said.