Experimental solar array gives Illinois unique research opportunities
In the last four years, solar generation in the US has more than doubled, according to the US Department of Energy. In that same time, the cost of solar power systems have dropped by 80 percent.
As interest in solar energy is increasing, the Illinois Center for a Smarter Electric Grid (ICSEG) is helping lead renewable energy research with the new installation of an experimental solar array on the south side of campus.
“As a country, we’ve set ambitious goals to have a certain percentage of energy sources be renewable, and the goals trickle down to states and municipalities,” said Scott Pickard, Information Trust Institute associate director for technology and business development and ICSEG solar array project manager. “Converting to renewable energy is going to happen and we want to make sure it’ll happen in a trustworthy manner.”
The array, which is made up of 60 solar panels, separated into five blocks of 12, is intended to provide power to enable research and validation into novel photovoltaic (PV) inverter and control technologies. Inverters are the devices that convert the direct current (DC) output of a solar panel into grid-compatible alternating current (AC). In particular, the system features a number of leading edge microinverters based on advanced power electronics, including some based on technology developed at Illinois. These new microinverters convert to DC on a per-panel basis, and potentially enable safe, low-cost and expandable PV installations on scales from residential on up.
Co-principal investigators and ECE professors Robert Pilawa-Podgurski and Alejandro Dominguez-Garcia will coordinate experiments and guide student research on the facility in areas such as innovative control, grid connections, and further advances in microinverters and power electronics. The array allows the researchers to test their work out on a real system in the real world, rather than just on a small laboratory scale. For example, this setup lets the researchers integrate custom firmware and hardware into the commercial power inverters for testing and validation.
“This is a unique test bed that lets researchers go in and replace actual hardware and have it actually attached to a grid,” Pilawa said. “It’s a large-scale test bed, but we have commercial solutions installed as well, so we can benchmark against them and can verify how well our hardware works and compare it to existing commercial solutions.”
The array was built to the specifications of the researchers to allow for flexibility in trying out new devices and new products. The setup uses three types of inverters from three different manufacturers – SMA, Tigo and SolarBridge – and each block of panels includes different configurations. This enables the current commercial technology to be compared to ICSEG’s new designs.
“I think that it brings us some unique capabilities for future research that positions us pretty exclusively compared to other schools,” Pilawa said. “We can do larger scale studies, benchmark different technical solutions for the industry, and we’ll have the possibility of external funding because of this added capability we have.”
In addition to research, the array will also be a learning opportunity for participating students, as they will be appropriately trained in working with devices connected to the power grid.
“It’s a good hands-on opportunity to test their experiments on real hardware and we will also be able to monitor the test bed remotely, so we can gather a lot of data and the students will be analyzing field data over a year,” Pilawa said.
The solar array is part of the smart grid validation and test facility that has been the basis of ICSEG’s mission since it began in 2010. The main test bed, located in the Coordinated Science Laboratory (CSL), contains extensive substation equipment, capabilities for “hardware-in-the-loop” simulation using this equipment and sophisticated test harnesses for experimental setup. The solar array expands test bed capability by providing access to microinverter technology and a facility that actually generates power.
“We’re working on developing embedded electronics that can go into the panels themselves, so right now we have a lot of nice results from the lab, but we’d like to scale up these very promising lab results to prove the concept in a larger setting,” Pilawa said.
Planning for the array has happened over the past year and the solar panel is now located near the Research Park behind the Building Research Lab #344 off St. Mary’s Road in Champaign. It is connected to a building that is equipped with power and Ethernet jacks to enable solar energy from the array to be sent into the building and for the array to be monitored remotely. Since the array is connected to the power grid, the energy it creates will be fed back into campus to help reduce energy costs.
“That’s not the main motivation, but it’s an extra added plus and over its lifetime, it may pay for itself,” Pilawa said.
ICSEG researchers have high hopes for the array and plan to begin hands-on research with it in the fall. They plan to create a dashboard where the public can track the power the panel creates, as well as a live video feed of the panel.
“I’m excited about it and we’re going to put it to good use,” Pilawa said. “This will be a long term laboratory asset that we have at the university.”
ICSEG is a five-year project that began in 2010 and operates within the Information Trust Institute (ITI), located at the Coordinated Science Laboratory. It is funded through a grant from the Illinois Department of Commerce and Economic Opportunity.