Microinverters and Maximum Power Point Trackers

Inverters are the gateway to the grid – turning Direct Current electricity from solar PV systems to grid-friendly Alternating Current. Over the past several years, there’s been a revolution in inverter technologies that allow project owners to more effectively regulate system performance. One technology, the microinverter, is installed on the back of individual panels, turning each module into its own unit and providing real-time data on how each is operating. Therefore, if clouds roll over a PV system, the “Christmas tree light effect” is avoided, and each panel still functions normally, maximizing the output of a system – sometimes by 20% or more.

Speaking of maximizing output, that’s where Maximum Power Point Trackers (MPPT) come in. These pieces of power electronics are also installed on the back of individual panels. But they’re not microinverters; instead, they boost voltage to an optimal range for a central inverter, thus allowing the device to run more efficiently. By allowing a system owner to control a PV plant at the module level, you can boost performance on the module level and regulate voltage even as weather patterns change.

Wind Energy Management Tools

SCADA systems that remotely monitor wind farm performance have been around for years – but there are a host of new applications being developed that allow grid operators and utilities monitor system-wide performance in an easier, more compelling way.

The Wind Energy Management System from the Portuguese company Logica is a great example. The company manages over 3 gigawatts of wind farms in the U.S. and Europe using its WEMS, which allows for real-time monitoring of a set of geographically dispersed wind plants – providing the tools to balance voltage, ramp wind farms up and down quickly, and plan for maintenance.

A company like EnerNOC provides the tools for better management on the demand side; a company like Logica provides the tools for better integration on the supply side.

Virtual power plants combine intelligent demand response with supply-side management software, bringing distributed renewable energy plants together to form a “virtual” centralized resource.

We previously wrote about Germany’s Regenerative Combined Power Plant, a project that proved existing renewable energy technologies could provide 100% of the country’s electricity. The project blended three wind farms worth 12.6 MW, 20 solar PV plants totaling 5.5 MW, four biogas systems equaling 4 MW and a pumped storage system with 8.4 GWh of storage. By using geographically dispersed renewable resources that compliment one another, the plant operators were able to meet needs on the grid as supply and demand shifted. The project shows that with better information technologies and a balanced set of resources, the intermittency issue can be dealt with.