Even though there is constant talk about solar modules, their technology and prices, there are several other equally significant parts without which the smooth functioning of a solar system cannot be guaranteed. Touted as the brain of a solar power system, inverters connect a solar system to the grid turning direct current (DC) power to alternating current (AC) power, thus ensuring solar power generated is used by those it is meant for. But of course, everyone knows that.

What’s increasingly interesting now a days is that inverters are not just grid connecting devices but are smart tools, compatible with various software and other electronic devices, integrated with PV technology as its foundation. With an increasing number of businesses and households opting to become prosumers, thanks to a renewable energy technology as solar PV, how does one know how efficient or smart a solar inverter is, which is the best fit for a residential and commercial & industrial (C&I) use, and what are the latest dynamics in this space?

TaiyangNews brought together leading solar inverter industry players and experts to delve into these questions during our virtual Inverters for Rooftop Solar Conference on October 19, 2021, our 1st conference in the space.

Presenting preliminary results of TaiyangNews upcoming and 1st Market Survey on Rooftop Solar Inverters Of Leading Manufacturers Heinz Neuenstein shared that the survey covers 11 global leading manufacturers of rooftop solar inverters with the bulk of these from China. According to the many survey findings, the authors see implementation of grid service features PV systems role will change from grid-led to grid-supporting devices. There is also an increase in demand for hybrid inverters going forward.

Cyril Allenspach, Research Associate Photovoltaic at Zurich University of Applied Sciences (ZHAW) focused on an efficiency and performance comparison of PV string inverter systems (SINV) and module-level power electronic (MLPE) during his presentation. Allenspach reflected on the various findings of ZHAW simulations for rooftop solar in Switzerland and shared that MLPE components helped increase system efficiency by 1.2%, relative to string inverters.

However, he insisted that there must be a standard to define the values for power optimizers in the datasheet to which data points should be checked. There should also be standards to measure string inverter systems (SINV). A discussion followed on the economics of optimizers, but especially in the rooftop segment, where system prices are higher, a little more expensive PV systems won’t be a problem. At least, the world’s largest inverter supplier, Huawei, sees the potential of optimizers and has recently introduced a product in addition to their string inverters.

Pointing out the significance of independent testing for string inverters Sishir Garemella, in charge of  International-Business Development at US based testing lab PV Evolution Labs (PVEL), argued that it brings in accountability for both manufacturers and their products. At the same time, an inverter having undergone independent testing apart from standard certifications also lends confidence and credibility to the installer.

Supporting Garemella’s arguments, inverter maker Solis’ Product Manager Travis Snyder said customers these days insist on a 3rd party certification for the company’s products. While stressing on string inverters for high power generation, Snyder pointed out how solar inverter makers have had to keep up with the rapidly changing solar panel sizes and efficiency levels, which according to him is important since inverters need to be able to accommodate power generated by modules.

Growatt’s Technical Manager Robert Van Keulen said his company realizes the desire for end consumers to live a carbon-free life to contribute to the overall climate debate, hence it introduces integrated solutions based on PV technology for households. The offerings of a smart home system are integrated with solar, energy storage, smart EV charger, water heater, VPP interface and IoT devices to increase a household’s rate of PV self-consumption. Currently, this full solution offering is only for the Australian market, but Keulen said Growatt plans to roll it out in other strong rooftop solar markets soon.

Stressing on the importance of sustainability matters in solar inverter production and its working life, Leonhard Peböck from Fronius’ Product Marketing shared the Austrian company’s work on life cycle assessment (LCA) of Gen24 Plus product. He explained that the inverter accounts for 8% of the climate impact of the whole PV system, hence it receives 8% of the climate benefit. Peböck sees LCA as holding both climate and business importance as in the long term it saves cost for the manufacturer.

Panel discussion

Moderated by TaiyangNews Managing Director Michael Schmela, the panel discussion revolved around the most interesting trends in the solar rooftop inverter segment.  

Solis’ Travis Snyder admitted the ongoing shortage of chips in the global supply chain as having slowed down business temporarily, but added that the company is now catching up and is looking forward to deliver the products on time. He also shared that for Solis COVID-19 impacted 2020 was one of the best year’s for its business, that points towards the resilience of solar PV market.  

Seeing how the rooftop solar PV inverter market looks 5 years’ from now, Growatt’s Robert Van Keulen believes solar and storage will become a norm for homes by then in various markets. There could be a number of reasons for this to happen, ranging from the combo making economic sense, grid power supply issues, or even government mandates.

When Schmela probed the panelists if this would mean no decision-making power in the hands of end consumers, PVEL’s Sishir Garemella said in the future there will be a lot more of home technology with smart electronics and devices inside a house, and PV inverter makers will have to factor in these dynamics when designing their products, all due to consumer demand. So, the power should still remain in the hands of consumers, one way or the other.

Recordings of conference presentations will be available on our TaiyangNews YouTube channel by end of the week, like for our previous conferences.