After streamlining construction of photovoltaic arrays as far abroad as New Caledonia and Zambia, French developers are starting to roll out a new generation of inverters across their home market.
France is gently warming to the utility-scale projects that have come to dominate global photovoltaic installations, but according to Guirec Dufour, CTO of green energy producer Quadran, the French solar sector remains beset by regulation. He says that lengthy processes to obtain building authorizations, restrictions on the use of farmland, and exceptionally demanding national construction codes are typical French syndromes.
Over the past decade, Dufour has made a career of solving technical holdups on renewable energy construction sites. His efforts have been met with success. When he joined Quadran in 2008, he was one of just four workers. Following a period of brutal market consolidation, the firm has emerged with 250 employees, operating some 250 MW of solar plants, 500 MW of wind farms, and 20 MW of hydroelectric and biogas recovery units. Its achievements have attracted two acquisitions in the past two years, the latest from oil giant Total.
Quadran attributes its growth to the company’s agility in reaching new markets and implementing new solutions. The company has learned tricks in solving offbeat challenges that have given it a competitive edge in its core market. Two years ago, Dufour put this resourcefulness to the test when he set out to design the first 11 MW solar farm in New Caledonia, a French territory located in the South Pacific, 1,200 kilometers east of Australia – and about as far removed as geographically possible from Quadran’s offices in Béziers, France.
Further and Smaller
“The time difference between headquarters and New Caledonia is nine hours,” Dufour says. “If you need to call someone in Europe, it is simply impossible.” That proved problematic. Conducting maintenance tasks on key components such as centralized inverters would typically require specialized technicians and heavy equipment that was unavailable on location and expensive to import.
“PV in New Caledonia basically did not exist two years ago when we started building the plant. You couldn’t find trained personnel to maintain centralized inverters,” says Dufour, “And if you trained workers yourself, they were likely to go work for the competition in the following 15 days, leaving you constantly training new staff.”
Instead of meeting the human resource challenge head on, Dufour shifted construction of Quadran’s New Caledonia solar park to string inverters, which were lighter and easier to install than centralized. He connected all 43,000 solar panels of the project to the grid using 300 Huawei FusionSolar string inverters, each with a capacity of 33 kW.
“In the past, large projects had to adopt central inverters because decentralized inverters were not powerful enough,” explains Dufour. “Now, Huawei products can reach power outputs of up to 100 kW, so we can use string inverters on large plants too.”
Smaller and Simpler
In terms of maintenance, decentralized string inverters offer an advantage over central in that they require no specialized engineers or lifting equipment to install. Three workers can transport the hardware on-site by hand, and connect it without risk. If an inverter malfunctions, instead of flying in heavy equipment or representatives from its manufacturer to repair the device, local workers can simply unplug it and install a replacement.
“We just simplified everything in our solar plants using these inverters,” says Dufour, explaining that the entire fleet of Huawei products in New Caledonia have only recorded two faults since their installation. “They are much more reliable and require absolutely no maintenance. If we have a fault, we just swap the component.” It is still early to quantify these benefits, but he expects that the string inverters in the project are drastically reducing its maintenance costs.
Since its experience in New Caledonia, Quadran has commissioned Huawei inverters to connect close to another 100 MW of installations both at remote sites and in mainland France. Among the technology’s perks, Dufour says that Huawei is the only supplier he knows of that embeds ICT in its inverter hardware to supervise plant operation. The product offers voltage of 800 VAC, reaches energy conversion efficiencies of 99%, and has helped meet French construction codes for stringing PV modules in parallel.
“Because you only have two strings per entry point, you don’t need to use fuses on the DC side. That makes the installation more reliable,” says Dufour, adding that higher AC voltages allow for lower losses on the connection to the transformer, avoiding the use of AC combiner boxes, and that the in-built ICT supervises the system with no need for additional monitoring equipment. “We just have an inverter and cables – that is it. That means less equipment, and less equipment means fewer faults.”
Simpler and safer
Xavier Barbaro, President of Neoen, France’s leading independent renewable energy developer, agrees that the downtime of a PV plant is substantially reduced when using string inverters. To date, his company has brought 2 GW of solar into construction across four continents. For bankability purposes, Neoen signs turnkey engineering, procurement, and construction (EPC) contracts with its subcontractors, but it still specifies the subcomponents that it wants installed.
The company placed its first order with Huawei in 2016 after winning a 50 MW photovoltaic project in Zambia as a pioneer of the Scaling Solar program run by the World Bank. Treading new ground, Neoen wanted to anticipate logistical challenges by supplying the landlocked country with small and easy-to-deploy inverters.
“We paid a visit to Huawei in Shenzhen, China, not really knowing what to expect,” says Barbaro. “But we liked what we saw. In terms of manufacturing, it was really world class.” He initially valued the small scale of the FusionSolar inverter for the project in Zambia, and has since grown fond of its convenience and performance as well.
“Huawei has proven a reliable supplier with a very convincing product,” he says. “So far, we have had no issues with any of the Huawei inverters that we have installed.” Since 2016, Neoen has ordered FusionSolar inverters for some 300 MW of photovoltaic plants across Zambia, Argentina, and the largest carport installation in France, which it inaugurated in April 2019.
Safer and Cheaper
Barbaro says that simplicity offers advantages beyond construction sites, as lenders for Neoen’s renewable energy projects are cautious about the industrial choices that his company makes. He says that Huawei products have proven bankable, reassuring financial backers, and bringing down the overall cost of projects. “What we value is experience and expertise,” says Barbaro. “If you have dozens of gigawatts of installed installed capacity, you have a lot of experience covering a lot of differ-ent situations.”
Neoen is notably building a 200 MW solar plant in Argentina, located 4,000 meters above sea level. Not all inverters work at this altitude, but Huawei products have been deployed successfully under similar conditions in China. “We tend to go with suppliers that can prove their point when they argue that their product offers the right choice for a situation that we face,” says Barbaro. “That is something that we have with Huawei.”
In today’s competitive market, Barbaro says that even curtailing financial pro-visions for inverters can have a decisive impact on the operation and maintenance budget of a photovoltaic project. “Solar is now reaching prices under $20 per MWh, and that is really a game changer,” he says. “Every step in the proj-ect has been a part of that achievement, including the inverters. They represent 6-7% of a PV installation’s capital expen-diture and play an even bigger role in its operating costs.”
Whereas capex optimization has dominated LCOE improvements over the past five years, Barbaro argues that the next frontier is probably opex optimization, and there is a lot to gain from inverters in this area. “That is how we decided to also use Huawei inverters in France,” says Barbaro. “Of course, logistics in France is easier than in Zambia, but the product remains relevant.” He explains that FusionSolar is low-risk, user-friendly, and increasingly geared towards interoperability, concluding that “Huawei wants to make sure that their product is easy to package with substations and hardware coming from other suppliers,” and he concludes: “That is something that we like.”