Analysis of photovoltaic inverter market trends in 2019

As grid parity approaches, cost reduction, efficiency improvement and intelligent upgrading have become urgent needs of the photovoltaic industry. As a key equipment for photovoltaic power generation, inverter technology has been continuously updated and iterated under the stimulation of favorable policies, becoming the "engine" to promote the era of grid parity. According to the latest forecast of IHS, in 2019 alone, more than 11 million photovoltaic inverters will be shipped around the world, most of which will be connected to the software platform and controlled by inverter companies. At the same time, the new development situation has also put forward higher requirements for the power level, voltage level, capacity ratio, overload capacity, etc. of the inverter, which has brought the development of inverter technology and market into a new stage.

So, driven by many trends such as distributed photovoltaics, household photovoltaics, photovoltaic energy storage, photovoltaic heating, subsidy-free projects, and smart photovoltaics, what new trends will emerge in the inverter industry? What new reshuffles and industry integrations will occur? How will the digitalization and intelligent upgrades of inverters bring about functional expansion? How will new trends lead to the reintegration of inverter technology routes? What new business opportunities and business models will these changes bring? I hope that the seven major trends in the development of inverters will help readers learn and understand.

String inverters become mainstream

As technology continues to mature and the market develops and changes, the global inverter market has shown a new development pattern. Influenced by advantages such as more flexible system design, lower losses when failures occur, and lower lifecycle maintenance costs, string inverters have been widely used around the world, and in 2017, shipments exceeded those of centralized inverters for the first time. According to the GTM Research report, in 2017, the total shipments of three-phase string inverters worldwide exceeded 46GW, a year-on-year increase of 49%, nearly 4GW higher than centralized inverters. String inverters have surpassed centralized inverters for the first time, and their share continues to increase.

In 2018, the photovoltaic inverter market was still dominated by centralized inverters and string inverters, with micro and distributed inverters accounting for a relatively small proportion. With the rapid growth of the distributed photovoltaic market and the increase in the proportion of string inverters in centralized photovoltaic power stations, the market share of string inverters reached 60.4%. Distributed photovoltaic inverters improve the MPPT control effect compared to centralized inverters, and have lower construction costs than string inverter solutions. Therefore, the market share shows an upward trend year by year.

1500V becomes the mainstream in the industry

According to a report by authoritative research institution IHS Markit, the scale of global 1500V photovoltaic power stations will exceed 100GW in the next two years. Compared with the traditional 1000V system, the 1500V system has a higher voltage level and longer string length, which greatly reduces equipment costs, cable costs and construction costs. While increasing power generation, the system BOS cost is reduced by at least 5 cents per watt, making it the only choice for photovoltaic project design in countries with no or low subsidies.

As 1500V systems are on the rise in the global photovoltaic market, 1500V inverter shipments are also on the rise. According to an IHS report, in the global photovoltaic market excluding China in 2017, 40% of three-phase inverter shipments were 1500V, and this proportion increased to 62% in 2018, surpassing 1000V. IHS predicts that the share of 1500V three-phase inverters will continue to increase to 74% in 2019 and soar to 84% in 2020.

Digital and intelligent upgrades aim at smart IoT

In recent years, mainstream photovoltaic inverter suppliers at home and abroad have all set their sights on the field of smart Internet of Things, successively developing new intelligent software technology platforms and building digital services to create new sources of revenue.

The key function of an inverter is to convert solar energy into electrical energy for use by the grid. In the past, solar inverters were considered independent and decentralized, not connected to each other. However, in the new digital energy world, software platforms are unlocking what were once isolated and separate equipment components.

Several international solar inverter suppliers have developed their own proprietary in-house IoT software platforms to sell solar, energy storage hardware and digital services to commercial chains, large utilities and other non-traditional customers, extending their business reach to thousands of independent owners.

AI technology will also be gradually integrated into photovoltaics, including the intelligent IV technology that is now being successfully applied on a large scale. The photovoltaic system will be centered on the inverter, and the digitalization and intelligence will continue to improve. While comprehensively improving power generation and operation and maintenance efficiency, it will build the ultimate platform for future comprehensive energy services.

Inverter extension functions cover up core functions

As photovoltaic inverters move toward digitalization and intelligence, more and more energy management functions will be added. The first is photovoltaic energy storage management. The importance of energy storage for large-scale grid connection of photovoltaic and other new energy sources is self-evident. The application of photovoltaic storage systems further drives the inverter to evolve into a power station energy management center. The second is safety management. Inverters equipped with DC arc detection, component rapid shutdown and protection capabilities will evolve the safety protection of photovoltaic power stations from passive to active. The third is automatic monitoring and early warning operation and maintenance management functions. The fourth is household microgrid management functions.

In addition to the functions of energy management itself, more external expansion functions will be added. The first is the function similar to that of household appliances. For example, an LED light can be added to the outer shell of the inverter, which can be used as a lighting lamp when the inverter is not working at night. The position of the LED light is designed to be 12 points to form a circle, and the inverter can also be used as a clock; using the data collection and transmission function of the inverter, and adding a camera, the inverter can be turned into a network monitoring device; using the communication card of the inverter, the inverter can also make calls. The inverter of the future = ordinary inverter + lighting lamp + wall clock + network monitoring + telephone

Secondly, it can increase the function of meteorological collection. The current meteorological station coverage density is not very high, and the collection accuracy is limited. The inverter can collect data such as temperature, sunlight intensity, humidity, wind speed, air quality, ultraviolet intensity, etc. The number of installations is thousands or tens of thousands times that of meteorological stations. Providing the data of the inverter to the meteorological department can reduce costs on the one hand and increase data accuracy on the other.

Re-aggregation of inverter technology routes

Traditionally, there are five major technical routes for inverters, namely centralized inverters, distributed inverters, string inverters, microgrids and power optimizers, and super inverters. With the intelligent upgrade and diversified development of inverters, the functions of inverters with different technical routes will be re-matched, and new functions will be added to meet market needs, resulting in the emergence of new inverter types, such as string inverters.

The mainstream inverters are centralized inverters and string inverters. Each has its own advantages and disadvantages. The centralized inverter has high power per unit. Its advantages are single-stage electronic conversion, fewer components, and high reliability. Its disadvantage is that the DC lines vary in length. For a 500kW inverter, the component installation area exceeds 6,000 square meters. The farthest component may be more than 100 meters away, and the closest may be only a few meters away. The line impedance affects the MPPT function. The string inverter is just the opposite.

These two types of inverters can be combined, that is, a unipolar string inverter. This inverter has only one level of DC-AC conversion, using three-level and power modules. A 50kW inverter has only three power switching devices, just like a centralized inverter. The installation area of ​​the peripheral components of a 50kW inverter is about 600 square meters, and the farthest distance is less than 25 meters, with very little DC loss. Currently, unipolar string inverters are also available on the market, but they are not used in large power stations. The reason is that the output voltage is 400Vac, and the input voltage range is narrowed to 580-850V, which limits the scope of application. In fact, this problem can be solved with a little workaround. The output voltage can be changed to 315V. Just like a centralized inverter, the input voltage range can also reach 500-850V. Connect a step-up transformer at the back, and the scope of application is very wide.

String inverter = string appearance + centralized core + power module + 315V

Competition in the overseas photovoltaic inverter market is becoming increasingly fierce

At the beginning of 2019, with the decree issued by the National Development and Reform Commission and the National Energy Administration on actively promoting the grid-parity of photovoltaic power generation without subsidies, the grid-parity of the domestic photovoltaic market officially kicked off. At the same time, new energy in the United States, Europe, India, Latin America, the Middle East and other regions are rapidly entering a new stage of grid parity.