Smart grid wind technologies breeze into solar

As momentum builds for making power grids smarter, so too is the need to harness and integrate more renewable energy sources on a large scale for utilities. One way in which that is happening at GE is by sharing the technological advances being made in two key renewable sources — wind and solar. As science blog Earth2Tech recently described the work: “Solar, like wind, is intermittent — power from the sun fluctuates when clouds pass overhead and wind doesn’t blow consistently. Now General Electric, which has been a major player in helping to integrate wind into the world’s power grids, wants to do the same for solar.” One way in which GE Energy is doing this is by taking the converter technology that plugs wind energy into the grid to make a “solar inverter” — basically a technology that takes the direct current generated by solar panels and converts it to alternating current used on the power grid.

Moment in the sun: Because the energy output of a solar power plant is directly related to the availability of the sun, anticipating the load that the solar power plant will provide can present a challenge for the utility grid, causing the plant to trip off-line. In order to ensure that solar power plants stay online, the variability needs to be managed so that it is more predictable — even during disturbances such as intermittent cloud cover.

As Earth2Tech explained: “To modify the inverter for solar, GE changed the way it connects to power projects, because solar panels generate direct current, which must be turned into the alternating current used by most appliances, whereas wind turbines generate alternating current… GE also modified the software to enable utilities to monitor and control the solar power plants. And the inverter had to be packaged with a new skin suitable for outdoor installations, as wind inverters are usually kept inside the towers, while solar inverters need to be able to survive the elements.”

Family tradition: Engineering and design of GE’s Brilliance Solar Inverter was completed at GE’s controls center of excellence in Salem, Virgina. GE already makes 4,000 wind converters annually and has increased production at the Salem facility to include solar. The technology was adapted from that used with GE’s fleet of 1.5 MW wind turbines — over 12,000 of which are in the field.

According to New Energy Finance, demand for solar energy has grown about 30 percent per year for the past 15 years, while hydrocarbon energy demand typically grows less than 2 percent a year. As wind and solar power plants increase in size and number to meet these demands, they are beginning to have a greater impact on the grid, displacing more traditional sources of power generation.

“We believe that there will be significant growth in large-scale projects as the United States and the world strive to meet renewable energy targets,” said Victor Abate, vice president-renewables for GE Power & Water. “The challenge will be integrating these larger solar projects — which are also powered by a variable fuel source — in a reliable way.”

Solar’s mission control: SunIQ is the name of GE’s suite of solar plant monitoring and controls systems. “The software that comes with the inverter presents information about solar projects in the same way that utilities and power-plant operators are already familiar with viewing power plant data,” Earth2Tech notes. GE’s work in renewables includes a global services organization that offers 24/7 remote monitoring and diagnostics centers and parts support.