For the solar energy system, the supplier’s technical capability and product quality of both inverter and battery directly influence the energy conversion efficiency and reliability of the system. Using the typical household photovoltaic system as an example, the inverter has to convert the direct current (DC) output of the photovoltaic panel into alternating current (AC), and its conversion efficiency increases by 1%, the revenue of annual power generation can increase by 2%-3% (e.g., Huawei SUN2000 series inverter efficiency of 98.6%, while traditional models have 95% efficiency, A 10kW system is 400 to 600 KWH per year and is worth 60−90). Battery suppliers need to provide suitable energy storage products, such as CATL LiFePO4 battery cycle life greater than 6000 times (80% capacity retention rate), charge and discharge efficiency of 95%, compared with lead-acid battery (life of 1200 times, efficiency of 75%) life cycle electricity cost reduced by more than 50%. Reached with the assistance of an inverter-battery matched well-supplier following a study at the National Renewable Energy Laboratory (NREL) 2023: it can increase self-absorption capacity from 65% to 85% from the application of an inverter-battery suitably matched supplier. Reduce dependency on the grid and avoid top-tier peak price (such as 0.48/kWh top-tier tariff, 0.16/kWh valley tariff through California NEM 3.0 regulation).
At the cost optimization level, the technology upgrade and mass production of inverter and battery supplier significantly reduce the upfront system cost. The average inverter price globally in 2023 has fallen to 0.08/W (47% down from 0.15/W in 2018), while smart lithium prices have come down from 600/kWh (2020) to 320/kWh (2023). German producer SMA, for instance, launched an “integrated optical storage system” which incorporates the inverter with the battery management unit (BMS) to cut the installation cost by 30% (saving 1,500 on a 10kW system), decrease battery wear by 0.0248,000 due to dynamic load regulation, and minimize the return on investment period to 3.7 years.
System stability and security rely strongly on the inverter and battery supplier’s technical standards. The inverter must get certified by UL 1741 and IEC 62109 to give an assurance that THD (total harmonic distortion) will be less than 3% when grid voltage fluctuates ±10% (such as the voltage in rural India normally reaches up to 250V-260V) so that it does not harm precision gear. Battery producers have to break through the risk of thermal runaway, e.g., BYD blade battery by acupuncture experiment (thermal runaway trigger temperature ≥800℃) and heat dissipation efficiency increased by 20%, compared to ternary lithium battery thermal runaway probability reduced by 90%. For the extreme environment scenario, in January 2021, Texas experienced a cold wave. One home that had been equipped with Generac PWRcell batteries and inverters supplied electricity uninterruptedly for 72 hours at -18 ° C while the traditional system had an offline rate of up to 35% with the breakdown of BMS low temperature protection.
Policy trends and markets increasingly highlight the strategic value of battery and inverter suppliers. EU’s 2023 recast Energy Performance Building Directive (EPBD) requires more than 60% new residential photovoltaic penetration and mandatory configuration of energy storage systems, with inverter annual shipment growth of 23% (380GW globally in 2023). China’s “14th Five-Year Plan” indicates access standards for lithium battery suppliers whose cycle life is ≥5000 times (capacity ≥80%) and retires 40% of under-efficient capacity. Technologically, Tesla Megapack 2 XL energy storage system (individual unit capacity 3.9MWh) and SolarEdge HD-Wave inverter (power density 5.2W/cm³) of 2023 redefines the standard, reducing the cycle of large optical storage power station construction to 9 months from 18 months. According to Bloomberg New Energy Finance (BNEF), the global market for optical storage systems will be more than $1.2 trillion in 2030, and technical synergies between inverter and battery suppliers will contribute more than 60% of the energy efficiency improvement and 30% of the cost-saving opportunity.