With energy experts forecasting substantial increases in solar power in the coming decades, scientists at GE Global Research are working with Arizona Public Service, the state’s largest electric utility, to understand how large amounts of solar can best be integrated into today’s grid. The first-of-its-kind study, which was approved earlier this month by the state’s regulators and is part of the utility’s ongoing smart grid efforts, will focus on methods and technologies to make the grid more reliable and efficient in a setting in which solar power is generated and delivered in close proximity to its customers.

Here comes the sun: The team at the Arizona Public Service Solar Test and Research Center studies a wide variety of solar technologies, such as this array made up of many different types of photovoltaic panels. Photo: APS

As Kathleen O’Brien, Project Leader for GE and an Electrical Engineer in GE’s Smart Grid Lab explains: “Much of the focus has been on new cell developments and system improvements to make solar more cost competitive, but the larger question is how to reliably integrate the higher penetrations of solar power expected. Through this study, we hope to gain more insight and answers.”

Kathleen says her team will also look at the effect fluctuating solar power production has on the power network’s stability and how new features on GE’s Solar Inverter technology — which plugs solar power into the grid — can improve stability. The work in Flagstaff, Ariz. has been green-lighted by the U.S. Department of Energy — which recently awarded APS, along with four partners including GE, a $3.3 million High Penetration Solar Deployment grant to pursue it. In the project, APS will integrate 1.5 megawatts of solar power — about one-third each from residential, commercial, and solar park sites. That’s enough power for about 500 homes.

Middleman: GE’s Brilliance Solar Inverter was adapted from the technology used with GE’s fleet of over 13,000 1.5 MW wind turbines. It turns the direct current generated by solar cells into the alternating current that we use with our appliances. It also has advanced grid functions that meet critical needs for utilities, such as regulating voltage and adjusting for voltage dips — known in the industry as “low voltage ride-through.”

The solar power in this study is known as “distributed energy” because it is generated and delivered in close proximity to its customers and is often decentralized from the larger electric grid network. The researchers say that’s an important distinction for this demonstration project — as it will help the teams simulate what will happen when larger amounts of solar power eventually impact the grid from many locations. Although 1.5 megawatts of solar by itself is not a lot of power, it will represent a substantial amount for the study area’s distributed energy system.

As Kathleen writes on the GE Global Research blog today: “This evaluation is more complex than it sounds because both the load (the amount of power being drawn from the feeder) and the source (the amount of power being created by the sunlight) are constantly changing.”

* Read the announcement
* Hear straight from our scientists on their blog

Learn more about our solar technologies in these GE Reports stories:
* “From the lab: ‘Why it’s time to take solar seriously’
* “Cracking the thin film solar code in GE’s 4 global labs
* “The GE Genius Series: Catching rays with ‘solar sails’
* “Sipping on sun-water at SOS Children’s Village in Haiti
* “Smart grid wind technologies breeze into solar
* “Reflecting on solar’s bright side at industry confab
* Read more Global Research stories on GE Reports