Sungrow’s 2-kV inverter installed on a pilot project overseas.
In this uncertain time for the large-scale solar industry, with federal incentives up in the air and tariff wars on overdrive, any potential cost savings are welcomed. A change from 1.5-kV to 2-kV solar projects could provide just that to developers.
When voltage increases, current decreases, while power output remains the same, per the equation power (P) = voltage (V) times current (I). Allowing for less current while increasing voltage has many positive implications for system costs and designs.
“We’re going to really enable the reduction of balance-of-system (BOS) costs by going to 2 kV,” said Brian Nelson, renewables segment leader at ABB. “You’re going to be able to add roughly 10 more modules per string, which means fewer strings per megawatt, which means fewer combiner boxes, which means less wiring. When current decreases, we can actually improve efficiencies through resistive losses.”
ABB stopped making inverters in 2019 but is still involved in solar through its BOS manufacturing. The company makes the switch-disconnector, one of the elements in a utility combiner box. All elements of an array must be rated to 2 kV, including that switch, surge protectors and fuses. Manufacturers are slowly announcing 2-kV compatible products but still waiting on standards to catch up to allow widespread deployment.
“We’re trying to enable what the module OEMs are doing, what the inverter OEMs are doing, because we’re the guts, or some of the guts, on the inside,” Nelson said. “One of the limiting factors to how quickly 2 kV will take off is the supply of these components.”
Just a handful of module-makers, including JinkoSolar and Trinasolar, have received UL certification for 2-kV panels, and racking manufacturers like GameChange are also beginning to verify that their tracker products are compatible with 2 kV.
“I’ve been really bullish about the speed at which this is happening. I think the more people that know it exists, the faster it’ll be adopted. But yeah, absolutely need folks like GameChange out there saying, ‘Hey, we’re ready,’” Nelson said.
ABB’s 2-kV switch.
GE Vernova is one of the few inverter manufacturers with a 2-kV inverter deployed on a project in the United States. It’s been in operation since mid-January and has been running smoothly since then.
“GE Vernova has lots of medium-voltage power electronics, so 2 kV is not anything that concerns us. It’s just a good step for the industry to take in solar and storage,” said Owen Schelenz, GE Vernova’s power electronics leader.
The unnamed entity executing that pilot project gave GE Vernova the push to roll out the 2-kV FLEXINVERTER, and the company expects more interest from there.
“Everybody’s trying to find that one thing to do to differentiate themselves a bit more. So I think the first to actually do this at scale and install 30% fewer inverters, 30% fewer strings is likely going to be the one that then is a bit more competitive, that then forces others to follow, if we take history as a guide,” Schelenz said. “There’s going to be some time here to evaluate the pilot, and then after that, it’s going to go pretty rapidly, because savings are savings.”
Sungrow has made a 2-kV version of its SG 3600 inverter that is currently deployed on two utility pilot projects overseas. Utilities are the first to test new voltages like 2 kV since they’re mostly subject to their own regulations vs. third-party developers that must follow stricter standards under utility purview.
“We are actively right now looking to team up with a U.S. entity that wants to try this out,” said Daniel Friberg, director of product and engineering at Sungrow.
Friberg understands the industry hesitation to start working on 2-kV projects when standards aren’t yet in place, but thinks it’s up to manufacturers like Sungrow and others to start building their case.
“It has to be a push from the stakeholders, including inverter suppliers, to push for a change,” he said. “Get some of the big utilities to install some of these, and then you de facto have these operating in the system. When people see that, that would lead to an enormous pressure on the standardization organizations to adopt and change.”
Once developers can build with 2-kV components without utility preapproval, some projects that were on the edge of penciling may become viable.
GE Vernova’s 2kV inverter on a pilot project in the U.S.
“This is going to help projects become more cost-effective,” Schelenz said. “It might enable a few more projects, because now we have a better return.”
The transition from 1 kV to 1.5 kV took around three years. Schelenz and Friberg expect this next jump to take about the same amount of time, but it won’t end there. Manufacturer working groups are already looking ahead to 3-kV architectures.
“3 kV — now, you’ve got to get into supply chain issues that are maybe not as readily available as 2 kV,” Schelenz said. “I can find 2-kV cables. I can find 2-kV fuses. There’s lots of stuff that’s already available for 2 kV.”
A more immediate next step will be an increase to 2 kV for storage systems.
“Those conversations have been also happening, because similar advantages play into the battery world as they do in the PV world. You get less cables, you get more power density, which is a big deal for battery energy storage sites,” Schelenz said.
Smaller string inverter-based projects may take more time to adopt 2 kV, but ABB is working on 2-kV-compatible circuit breakers for when that time comes.
“The big needle-mover is going to be the grid-scale stuff, but the C&I space is very exciting as well,” he said.
Source: Read More