Li-ion batteries are becoming the preferred choice for large off-grid PV systems due to higher efficiency, longer life, and lower total costs, according to an IEA PVPS report
Case studies like Haiti’s hospital project show Li-ion PV systems significantly reduced diesel use and operational costs
Sustainable operation of Li-ion systems depends on site-specific design, proper installation, local maintenance, and remote monitoring, according to the analysts
A new IEA Photovoltaic Power System Programme (IEA PVPS) report highlights the role lithium-ion (Li-ion) batteries are playing in reshaping off-grid PV systems and expanding access to reliable, sustainable energy in remote areas.
The IEA PVPS team reached this conclusion following a detailed analysis of this technology for off-grid PV systems covering technical performance, system classification, simulation studies, and operational recommendations.
The report compares Li-ion and lead-acid technologies across various applications, showing Li-ion’s growing economic advantage for large off-grid PV systems in the MW and MWh range. Li-ion batteries also offer higher efficiency, longer lifetimes, and lower total costs vis-à-vis lead-acid, while the latter is a more feasible option for small battery energy storage systems (BESS).
Analysts refer to a case study from Haiti, where a hospital relied on 4 diesel gensets, 2 rated at 200 kVA and the other 2 rated at 400 kVA, in the absence of a centralized electricity grid. Around 4 years ago, the hospital was equipped with Li-ion systems of 224 kWh and 332 kWh, along with solar energy generated by 2 PV fields of 232 kW and 210 kW.
The system also includes a monitoring system to continuously track and assess the performance and status of the components. Together, the PV system and storage capacity maximize renewable energy utilization while lowering the hospital’s reliance on diesel gensets.
According to the assessment, “The installed solar panels and batteries are now reducing the fuel costs by approximately 200,000 CHF per year. These savings are being redirected to enhance healthcare services for the local population. HAS Haiti is the only 24/7 full-service hospital in the region, providing 200 beds and serving over 350,000 people.”
Such case studies show the strong potential for BESS in providing clean energy access through off-grid and edge-of-grid PV systems to around 770 million people living without electricity globally, claim the writers.
The IEA PVPS report says that it is essential to design Li-ion battery systems for off-grid PV projects based on local conditions, including technical, logistical, and maintenance factors, to run them sustainably. It adds that implementing installations with proper setup and BMS adjustments suited to the site is equally important. These also need to operate with local maintenance support and continuous remote monitoring to track performance.
The report also presents a classification table that recommends battery systems for different types of microgrids, while offering an overview of the current state of Li-ion technologies in off-grid applications.
The report titled Li-ion Battery Systems in Off-Grid Applications is available for free download on the IEA PVPS website.
