Solar + wind + storage makes for a DC-powered microgrid

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There once was a debate between two gentlemen – one was in support of alternating current (AC) for the power grid, while the other sought a direct current solution (DC). Nikola Tesla’s AC power grid won out, but Thomas Edison’s DC is sticking around here and there.

Ensync Energy been contracted by WindStax, a vertical wind turbine manufacturer and wind+solar integrator, to supply energy storage, systems integration, and O&M for 25 years for a new microgrid project for trucking and logistics company PITT Ohio. Construction at the site has commenced, and is projected to complete in the spring of 2019.

The microgrid utilize 495 kW of solar energy and 48 kW of wind energy generation via eight wind turbines.

Ensync will install its DER SuperModule (pdf) with 730 kWh of energy storage. The SuperModule is a plug-and-play 20 foot shipping container system that integrates many Ensync-designed subcomponents (below).

Ensync’s Matrix Energy Management system and DER Flex  IOE software platform run the system command, communication and control. The system works both in the net metering programs, while also providing backup energy during grid disturbances.

The microgrid will be able to operate ‘autonomously’, and in ‘island mode’. The system is sized to meet the Parma terminal’s electricity loads during grid outages, with some space.

The EnSync hardware uses a DC powered bus, and the above noted hardware, to tie together the multiple electricity sources: wind+solar+storage+grid.

Seven WindStax horizontal wind turbines line the entrance to a trucking terminal under construction in Parma, Ohio. Photo courtesy of WindStax

Another PITT Ohio location has installed 180 solar panels at ~355 W each totaling about 64 MWdc, a 38-foot-tall 6 kW wind turbine, and battery storage. Everything in this terminal at the Harmar, Ohio location is powered by a microgrid designed by University of Pittsburgh researchers, including the forklifts, lights, batteries, computers and a DC lighting system.

According to Justine Russo, Director of Sustainability and Business Intelligence at PITT Ohio:

Our electric forklifts are powered by renewable energy that we are able to generate and store onsite and these forklifts are also cleaner and quieter, which employees have said make for a better work environment.  We are now installing electric forklifts at multiple facilities and are looking for where we can add renewable energy to power them.

Jim Fields, chief operating officer at PITT OHIO, said that the Swanson School of Engineering at University of Pittsburgh had given the company system sizing guidance for all future renewable construction plans with their software models.