Functioning as the brain of the PV system, advanced inverter solutions are now responsible for communications, monitoring, smart energy management, storage, grid interaction, safety and more.
Advances in Inverter Technology
Lior Handelsman | SolarEdge
Please tell us a bit about SolarEdge and your role in the Alternative Energy Industry?
Today, SolarEdge is a global leader in inverters. We started our company with the innovative concept of breaking apart DC and AC operations when we introduced optimized inverters. Our intelligent inverter solution revolutionized the way power is harvested and managed in a PV systems. We continue to be a market leader with innovative and cost-effective technology that broaden the availability of clean, renewable solar energy.
What do you think the future trend of inverters will be? What new roles will inverters take on – i.e. grid functionality, home energy management, storage, etc?
There are two trends that we will see. The first trend is that the functionality of inverters will expand. The inverter was originally named for its main function of AC-DC conversion, but its role has since expanded in PV systems. Functioning as the brain of the PV system, advanced inverter solutions are now responsible for communications, monitoring, smart energy management, storage, grid interaction, safety and more. This will continue to expand, we will see inverters taking of roles of managing smart homes, such as load control for energy shifting. On a macro level, smart inverters could allow a more decentralized power structure with mini-power stations versus a large single source for energy.
The second trend is that as the industry evolves we will be forced to make smaller inverters with an improved power/kg ratio. Inverters will get smaller and become more cost effective. The industry will have to continually innovate to meet these growing demands.
What trends are you seeing in the commercial PV segment? i.e. O&M, monitoring, trend to string inverters, etc
As commercial systems are becoming more common and also aging, there is a greater appreciation of these systems as assets that need to be correctly managed in order to improve their profitability. As such, PV Asset Management tools are becoming a necessity. Module-level monitoring and remote troubleshooting are key tools for providing PV Asset Management.
Another trend in the commercial segment is the movement from central inverters to string inverters due to ease of O&M, simple replacement (requires less employees on site), higher system uptime, and lower land use. Following this trend is the movement to module-level optimization in commercial systems. Scalable MLPE systems, such as SolarEdge’s DC optimized inverter system, offer higher revenue and lower OPEX for a superior lifetime value.
Another trend that we are seeing is longer strings to reduce BoS costs. Several new products recently introduced to support input voltage of 1500Vdc. Higher voltage allows for strings as long as 50% more than strings of 1000Vdc. While longer strings offer an important advantage for commercial systems, this specific topology suffers from numerous disadvantages and limitations, such as safety concerns, electrical codes, equipment availability, and unknown effects to modules, such as PID. Another way to reach longer strings is with fixed-string voltages. Fixed voltage mode is an advanced operating mode for string inverters. It requires power optimizers to match current level drawn from the inverter, while the inverter maintains string voltage at optimal voltage for DC/AC conversion – regardless of string length or temperature. This means that string length is no longer governed by voltage, but by power. And in fact, it allows for even longer strings than 1500v inverters.
Policy support and large cost improvements were the focus of the PV industry during the past decade. Looking forward, what do you think will be important for growth in the next ten years?
With the market looking for a way to overcome the discrepancy between PV production and PV energy use, we are also seeing a trend towards smart buildings that promote both energy independence and efficiency. Besides our StorEdge™ solution, we will continue to explore additional solutions to support the market’s evolving needs.
In addition, we also believe that the commercial market will continue to grow around the world. As the commercial market matures, system owners are becoming savvier about their investments and want to continually improve system RoI. This includes both upfront costs, such as BOS costs and ongoing costs, such as O&M. With MLPE offering commercial systems, both higher system uptime and improved PV asset management, we believe we will see growth for MLPE in the commercial sector in the next years, just as we have already experienced in the residential market.
Is the industry still dependent on government support in the form of subsidies etc. or is it self-sustaining at this point?
To reach a broader level of solar deployment, two main hurdles need to be overcome. First, we need to reach grid parity more quickly in more countries around the world. Second, we need to deal with the inherent problems of solar energy: solar intermittency and grid stability. Many industry professionals claim that the best way to make solar energy more economic and compelling is through government incentives and subsidies. My concern with this outlook is twofold. First, many developing countries with a growing energy demand cannot afford to offer such subsidies, and their populations often do not have the capital to make such investments. Subsidies do not solve the original problem; they simply transfer the burden from the private to the public sector. Secondly, subsidies end, sometimes abruptly, which can cause instable market conditions. But innovation, driven by the ingenuity of the human mind, only moves in one direction - forward.
With this being said, I believe that it is the responsibility of the private sector to create demand by offering the market products that provide value at economical prices versus only depending on subsidies to create a market.
Please tell us about your HD-Wave technology inverter. How is the technology different and what is your rollout plan through 2016?
SolarEdge’s HD-Wave inverter technology is one of the most significant leaps in solar technology in the past 20 years. The technology uses a novel power conversion topology that significantly decreases inverter size and weight while achieving record efficiency. It does this by using distributed multi-level switching and a DSP processor to create a clean sine wave. This means 16x less magnetics and its efficient design has minimal heat loss so cooling components are reduced by 2.5 times.
The initial market release will be localized in Europe in 2016 and we plan to expand the market as the introduction continues.
In this past year, SolarEdge significantly increased its shipments of power optimizers? How was the company able to reach such scalability while maintaining quality?
To meet the quickly growing market demand for power optimizers, SolarEdge needed to rapidly increase its production capacity, while maintaining and improving production quality. In order to achieve this goal, SolarEdge partnered with a leading automated assembly line manufacturer to develop an assembly line for power optimizers. Creating the line required a rethinking of both the product design for manufacturability and building an assembly line to exact specifications.
The line allows a fast ramp up for higher capacity during periods of increased demand, without the need for a training period. The automated line also helps us significantly reduce the likelihood for human error.
Would you like to discuss any other technologies or developments that SolarEdge is working on?
As the role of monitoring continues to improve system uptime and the efficiency of O&M activities, communications are having a growing role in inverters.
The first link in the communications chain is from the module to the inverter. For instance, with SolarEdge power optimizers, the communications from the module to the inverter is conducted via Power Line Communication (PLC), so no special wiring is required. However, the link from the inverter to the cloud can be more complicated. Typical communication strategies require installers to enter the premises for setup and then for the system owner to maintain that connection through their router throughout the system’s lifetime. Both of these requirements can be burdensome.
There are newer technologies that are now coming online, such as Wifi, ZigBee, and newer cellular-based strategies which eliminate the need to access the premises. Cellular-based communication solutions can also remove the requirement for the system owner to maintain connectivity and can be useful in locations without internet access or broadband infrastructure. With the cellular option, the inverter contains a cellular card just like a mobile phone and can connect directly to the cloud through a mobile network. This allows a simple communication setup and virtually no maintenance for the system owner.
SolarEdge recently launched its GSM cellular kit for wireless connections. The kit can be used in combination with any single phase SolarEdge inverter, including SolarEdge’s StorEdge™ solutions to provide online battery monitoring and the SolarEdge revenue-grade inverters to provide an end-to-end revenue metering solution.
About Lior Handelsman
Lior Handelsman, VP of Marketing and Product Strategy, founded SolarEdge in 2006 and currently serves as our Vice President, Marketing and Product Strategy where he is responsible for SolarEdge’s marketing activities, product management and business development. Prior to founding SolarEdge, Mr. Handelsman spent 11 years at the Electronics Research Department (‘‘ERD’’), one of Israel’s national labs, which is tasked with developing innovative and complex systems. At the ERD he held several positions including research and development power electronics engineer, head of the ERD’s power electronics group and manager of several large-scale development projects and he was a branch head in his last position at the ERD. Mr. Handelsman holds a B.S. in Electrical Engineering (cum laude) and an MBA from the Technion, Israel’s Institute of Technology in Haifa.
The content & opinions in this article are the author’s and do not necessarily represent the views of AltEnergyMag
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