Despite India’s rapid growth, many parts of rural India have less or no access to electricity. This decreases total productive working hours since people hesitate to go out of their homes at night. This shortage in basic infrastructure can be an obstacle in the education sector as well and create an unsafe and insecure environment for residents since accidents and crimes take place mostly in the dark. Solar street lights offer clean public lighting and in a country like ours where we have regions that often suffer from power outage, off-grid solar street lights can be quite convenient as they do not depend on grid electricity.
Traditional solar street lights used lead acid batteries in a battery box to power the lights at night. However, they had a few disadvantages:
- Lead acid batteries were relatively inexpensive but they needed to be stored in a battery box, so the overall installation charges were higher. The battery box had to be attached on the bottom of the street light pole which resulted in frequent thefts and damages.
- Lead acid batteries were bulky and required more time to charge and gave less backup and released noxious gases while charging. Transportation was challenging due to the heaviness of the battery and all the extra components of the solar street light system.
- The solar panel and lights had to be connected to lead acid batteries with the help of a long cable since the battery was installed at the bottom of the pole and panel and lights were on the top.
- In India, stray animals like dogs and cattle live on the streets. Since the battery box is placed towards the bottom of the pole, animals bumping onto it can damage the box and the battery and this also can cause injury to people and animals.
- Lead acid batteries need frequent maintenance as flooded batteries periodically must be refilled with distilled water to keep it running.
Modern solar street lights with lithium-ion batteries are the best choice for solar street lights due to their multiple advantages compared to lead acid batteries. Both All-in-One and integrated solar street lights with in-built lithium ion batteries are perfect for a country like India.
- Lithium-ion batteries are compact and lightweight and the lights with Li-ion batteries can be easily mounted on top of a pole and this makes the installation of solar street lights quite easy with very less manpower.
- Unlike lead acid batteries, Li-ion batteries do not need any topping off and once the lights are installed, they keep working without the need for any maintenance.
- Li-ion batteries charge faster at high rates of 1C without releasing any unhealthy gases. Lithium ion batteries can be fully charged within 5 to 6 hours and can run up to almost 13 hours. In remote areas of India where continuous electricity is a major problem, batteries with quick charging and more backup can be very useful.
- They offer long cycle life and typically give a 5-year life at least.
- In modern street lights, Li-ion batteries are integrated into the LED and the entire fixture is placed far up the pole which makes it impossible for thieves to steal easily.
- Li-ion batteries have high energy density which makes the batteries lightweight. The batteries are almost 10 times smaller in size compared to lead acid batteries.
- The overall small size of Li-ion battery in an integrated solar street light system makes the transportation of the lights much easier.
- Damage from rodents can be avoided since there are no cables at the bottom of the pole to connect the batteries.
Since the 1990s, Li-ion batteries have been commercially available. Over the years, the solar industry has been evolving technologically and LiFePO4 battery is a premium and latest technology which is a variant of lithium-ion batteries. LiFePO4 batteries offer a life of 10 to 12 years and are considered the safest technology used in batteries so far. Many of the modern solar street lights use LiFePO4 (lithium phosphate) batteries which are able to withstand extreme climate conditions and work with smaller solar panels.
Certain parts of India have many rainy days and Li-ion batteries help the charge last longer and continue to light up the LED for a few non-sunny days. The solar street lights and their components available in India are designed for the Indian environment. There are both Government and NGO schemes working towards lighting up the country’s remote and rural areas, so it is necessary to install cost-effective solar street lights that need less maintenance. Lithium-ion batteries are made based on the active cell balancing technology and provide a longer lifespan. Most of the public lighting schemes have a limited budget, hence solar street lights with lithium-ion batteries are the best choice as they do not cost you any installation or operational charges.