01. “Parity Formula” 2020
Since 2019, the development of power stations has been attaching great importance to LCOE, which is the levelized cost of energy; efficient equipment combination, while improving generation, usually increases BOS costs of the system. The year 2020 marks the implementation of parity. Parity project proposes higher requirements for system design, equipment selection, product performance and intelligent operation & maintenance, and the success of a project relies on LCOE-oriented comprehensive evaluation of the entire system.
From the system perspective of power station, the technical development of inverter is consistent with the target of system LCOE, said Zhou Hongwei, chief engineer of TBEA Xi’an Electrics Technology Co., Ltd. (hereinafter “XET”), wholly-owned subsidiary of TBEA Sunoasis. Both integrated and series inverter solution are pursuing higher voltage, bigger unit power, higher power-capacity ratio, stronger output overload ability and active and safe technology, all centered on lowering LCOE.
Zhou pointed out that the effective solution for solar plant to reduce LCOE in 2020 is using “1,500V + large silicon chip dual module + large power inverter + large subarray + tracking holder + intelligent operation & maintenance”.
02. Four solutions for Parity
Based on the features of system technical development under the background of parity, XET launched the system solution based on 1,500V new large power series inverter, which reduces overall LCOE by more than 7% utilizing higher voltage, larger power, higher power-capacity ratio, larger subarray and technology in active safety. This brand new series inverter with large power, rated at 228kW, is one of the industry’s high-level series inverters and the “best solution” for parity. The system structure constituted by the inverter is simpler without the exchange and combiner box and reduces the specifications and costs of AC cable. This kind of inverter has high power-capacity ratio and easier access to the grid, and is safe, reliable and capable of intelligent operation & maintenance.
Zhou Hongwei further elaborated on the strategy of lowering LCOE:
1. Current solar modules have higher power, especially with the recent 210mm silicon chip combined with dual module technology, which generates higher working current while improving output power of module. “This product can support by maximum 36 solar series and 12 MPPT, lowering generation loss from mismatch of series or parallel connection; maximum switch efficiency ≥99.02%, power-capacity ratio over 1.5 times, output overload ability over 1.1 times, which can meet the needs of global market. System solution based on this product can reduce LCOE by 2-3%.” said Zhou Hongwei.
2. TB-eCloud platform, independently researched and developed by TBEA, adopts the technology of big data, cloud computing and AI to realize intelligent operation & maintenance, and as a result, generation is improved by more than 2% and LCOE lowered by over 4%.
3. Solar plant usually locates in areas with rather weak grid structure and forms weak grid on the end terminal. This product, by utilizing innovative reliable synchronizing technology and impedance restructuring technology as well as broadband damping adjustment technology, realizes reliable control of inverter under extreme weak grid (SCR between 1.5-3) and ensures a stable grid-connected operation. It can achieve active harmonic wave suppression based on the background grid harmonic wave, reduce interactive effect between converter and grid harmonic wave, improve quality of grid-connected current and support most solar application scenarios in the age of parity.
4. Protection of entire machine is IP66, anti-erosion level C5 and it can fully fit in severe environments such as salt mist, high humidity and intensive sand wind and prolong the use life of equipment; it has I-V curve intelligent monitoring and DC arc monitoring functions and can reduce LCOE by 1%.
03. Future of Parity
In the cloud seminar held by TBEA Sunoasis on March 20 themed “Bright Future of Wind and Solar Power in the Age of Parity”, several experts including Wang Sicheng and Qin Haiyan held that even if after parity is achieved, solar and wind power industry are still faced with many challenges such as competition with traditional energy and grid stability under high permeability. How does TBEA Sunoasis, the representative of solar power industry, fit in the grid and build its ecology?
“We have already prepared for this. In the age of parity, we will focus on the change of energy structure: connection of high-permeability energy such as wind and solar power into the grid will generate certain question that’s hard to predict or schedule and has low inertia; utilization of global energy is moving towards low carbon, digitalization and decentralization. Local autonomy of distributed energy brings a new solution for this, which is the micro-grid system.” Zhou Hongwei said, “based on such, TBEA Sunoasis launches the solution for micro-grid ecology featuring “one core, two drivers and multiple scenarios” where one core refers to the multiple-port power router, two drivers the EMS and storage system and multiple scenarios the application environment such as island, industrial and commercial park, data center, non-electric area; provides multiple technical solutions for AC, DC and mixed AC-DC micro-grid; and has demand response, scheduling response, isolated operation, low carbon operation and other operation modes. We are capable of providing clients with entire ecological solution customized for multiple scenarios and products. Core product of micro-grid system is the power router whose switch efficiency reaches over 98.2%, leading in the world of its kind.”
Zhou Hongwei suggested that, power router can be used in area of new infrastructure construction such as medium voltage grid-connected generation of new energy, storage power station, charging station of electric vehicle and power supply of data center. XET realizes panoramic perception and precise forecast for multiple application scenarios as well as the mixed model forecast of self-correcting and multiple time dimensions based on multiple algorithm, both industrial leading.
He pointed out that, with the rapid development of intelligent grid and global energy Internet, power system is becoming more and more digitalized and TBEA Sunoasis boasts advanced power and electronic products with grid ports from “generation - transmission - distribution - consumption”, including a whole set of core products and technical solutions covering generation of new energy, flexible HVDC, intelligent micro-grid power distribution and consumption and energy management.