Telecom networks require continuous power because even short outages can disrupt communication services. For many years, telecom towers in India depended heavily on diesel generators to keep operations running during power cuts. According to industry estimates, India has around 824,000 telecom towers and nearly 2.98 million base transceiver stations, which together consume about 70,000 GWh of electricity annually. A large number of tower sites are located in areas where grid supply remains unreliable, which continues to create dependence on diesel-based backup power in many regions.
However, telecom operators have gradually started reducing diesel usage over the past several years. Industry data shows that the number of diesel-free towers increased from around 90,000 in 2016 to more than 223,000 by March 2024, helping save an estimated 550 million litres of diesel annually. Parallelly, energy demand in the sector is rising because of the rapid roll-out of 5G networks. Industry studies state that a typical 5G base station may consume two to three times more power than a 4G site. Even today, around 35-40 per cent of telecom tower sites in India are estimated to still depend on diesel generators for backup support.
The economics are also changing rapidly. Utility-scale solar power now costs around Rs 2.25-Rs 3.50 per unit, while diesel-based generation can cost nearly Rs 25-Rs 30 per unit. Because of this large cost gap, telecom companies are increasingly turning towards battery energy storage systems (BESSs) and hybrid renewable power solutions to reduce operating costs and improve reliability.
BESS architecture
A BESS used at a telecom tower generally includes batteries, a rectifier or inverter, and a monitoring system that controls charging and safety. Most telecom towers in India run on a 48V DC power set-up, so the batteries are connected directly to the tower’s power system. Depending on the site design, batteries may either be connected through a DC set-up or charged from the AC grid using rectifiers and inverters. A battery management system (BMS) monitors battery temperature, voltage and charging levels to avoid damage or overheating.
The biggest advantage of a BESS is that it provides immediate backup power during outages or voltage fluctuations. Unlike diesel generators, batteries respond instantly, helping telecom equipment continue operating without interruption. For example, if solar generation drops during cloudy weather or the grid suddenly fails, the battery can immediately support the tower load. Towers can also store electricity when demand is low and use it later during peak hours when power is more expensive.
Available solutions and requirements
Different types of battery technologies are now being used or explored for telecom backup power. The most common options today are lead-acid batteries and lithium-ion (Li-ion) batteries. Newer technologies such as sodium-ion batteries, flow batteries and hydrogen fuel cells are also being explored for future telecom applications.
VRLA batteries
Valve-regulated lead-acid (VRLA) batteries have been used in telecom networks for many years and are still common at many tower sites. Their main advantage is low upfront cost and long operational experience in the industry. These batteries are widely available, relatively simple to deploy and highly recyclable. In fact, lead-acid batteries have one of the highest recycling rates among battery technologies.
However, VRLA batteries also have several limitations. They are bulky and heavy, and they store less energy compared to newer battery technologies. They are also less efficient and usually last around three to five years, especially in hot climates as in India, where high temperatures reduce battery life more quickly. Since many telecom sites are located outdoors or in remote areas, maintaining these batteries can become expensive over time.
Li-ion batteries
Li-ion batteries are now becoming the preferred choice for telecom backup systems. Among them, lithium iron phosphate (LFP) batteries are especially popular because they are generally considered safer, last longer and perform better in difficult weather conditions. Compared to VRLA batteries, Li-ion systems are lighter, smaller and more efficient. They can also operate across a wider temperature range, which makes them suitable for telecom infrastructure in hot regions. They also have a longer lifespan. Modern LFP batteries can handle thousands of charging cycles and may last around 8-12 years, which reduces replacement and maintenance costs over time. Further, the cost of Li-ion batteries has also fallen over the past decade, which has made them more affordable for large telecom deployments.
However, these systems are more advanced and require BMS to monitor charging, temperature and safety conditions. Without proper controls, there can still be risks of overheating.
Sodium-ion batteries
Sodium-ion batteries are a new technology currently being developed for applications such as grid storage and telecom backup power. One major advantage is that sodium is widely available and cheaper than lithium, which could help reduce battery costs in the future. Early sodium-ion batteries have shown promising performance, including good efficiency and the ability to handle many charging cycles. They also perform well in very cold temperatures.
However, they still store less energy than Li-ion batteries, which means they are larger and heavier for the same amount of power storage. At present, sodium-ion technology is still at an early commercial stage and is not yet widely used in telecom towers. However, industry experts believe it could become an important option in the future if production increases and costs continue to fall.
Flow batteries
Flow batteries, especially vanadium redox flow batteries, are another emerging energy storage technology. Unlike conventional batteries, they store energy in liquid electrolytes kept inside external tanks. This allows them to supply power continuously for long durations. Flow batteries also have a long operating life. They can run for many years with relatively low performance degradation. They are considered safer than many other battery systems because they are non-flammable and have low fire risk.
However, flow batteries are very large and require additional equipment such as pumps and storage tanks. Because of their low energy density, they take up much more space than Li-ion batteries and also require more maintenance. For these reasons, flow batteries are not suitable for most telecom towers where space is limited. They may be more useful for large telecom hubs, microgrids or utility-connected systems that require long-duration backup power.
Hydrogen fuel cells
Hydrogen fuel cells is another technology being explored for clean telecom backup power. These systems generate electricity using hydrogen, with water vapour released as the main by-product instead of harmful emissions. They can provide backup power for long periods as long as hydrogen fuel is available. This makes them attractive for remote telecom towers where reliable electricity supply is difficult. Several pilot projects have already tested hydrogen fuel cells as an alternative to diesel generators at rural telecom sites.
However, this technology still faces challenges. Hydrogen production, storage and transportation infrastructure remain expensive and are not yet widely available in many countries. This increases the overall deployment cost.
Current scenario
India’s renewable energy capacity has been growing steadily, and the country has already crossed the milestone where more than half of its installed electricity capacity comes from non-fossil fuel sources. Alongside this, the government is also planning large-scale battery energy storage deployment over the coming years to support renewable integration and improve grid reliability.
The telecom industry is also moving in the same direction. Policy discussions and Telecom Regulatory Authority of India recommendations have encouraged operators to gradually increase the use of renewable and hybrid energy systems at tower sites, especially in rural areas. According to industry data, around 1,250 MW of solar capacity is currently being planned for telecom infrastructure projects. India ranks third globally in renewable energy capacity while also operating one of the world’s largest telecom networks. The industry’s transition towards cleaner energy systems aligns with India’s broader commitment to achieving net zero emissions by 2070.
Moreover, the rising fuel prices and global energy uncertainty are increasing pressure on industries to reduce dependence on diesel generators. For telecom operators, this has become both a cost and reliability issue. Towers that depend heavily on diesel backup remain vulnerable to fuel price fluctuations and supply disruptions, especially in remote regions where fuel transportation is expensive and difficult.
Future outlook
Battery storage is expected to play a much bigger role in telecom infrastructure over the coming years. Falling battery prices, increasing renewable energy adoption, and growing pressure to reduce diesel use are gradually pushing the industry towards cleaner and more reliable power systems. The economics of this transition are also becoming stronger. Rising diesel costs and government support for clean energy are making renewable-powered telecom sites more practical and cost-effective. In the future, telecom operators may also adopt smarter energy management systems that help monitor and manage battery usage across multiple tower locations.
Energy security is becoming another important factor. Telecom networks are critical infrastructure, especially during emergencies or large-scale power disruptions. Towers powered by solar energy and battery storage can continue operating even during extended grid outages or fuel supply problems, making them more reliable in the long run.
By 2030, dependence on diesel-only backup systems is expected to reduce, particularly in areas where renewable energy and battery storage become more affordable. Telecom tower companies are increasingly viewing tower sites as small energy systems that combine solar power, batteries, and other backup technologies to improve reliability while lowering emissions and operating costs. In the long term, this transition could help build telecom networks that are more energy-efficient, less dependent on fossil fuels, and better prepared to handle future power-and fuel-related challenges.
