K.C. Panigrahy, Head, Operations, URJAH, Air Liquide India
The use of conventional energy sources to power telecom towers has resulted in surging energy costs. Poor as well as erratic grid power availability has increased the reliance on diesel generator (DG) sets for powering towers. However, with the rising cost of diesel, the industry is now shifting towards deploying hybrid energy solutions.
Of the several hybrid technologies that are available at present, fuel cell energy solutions are gaining prominence. A fuel cell typically generates electricity by using hydrogen (from a tank) and oxygen (from the air). It emits only water and thus is the cleanest source of energy.
Some of the technologies and solutions used to meet power requirements at telecom tower sites are as follows?
DG-battery hybrids
A combination of DG sets and batteries helps reduce DG set run-hours and consequently lowers diesel usage. Further, the hybrid solution is not site specific and can be deployed at any base transceiver station (BTS) site, irrespective of its location. However, such a combination is not modular, and requires high capacity DG sets and battery banks.
Solar power-DG battery hybrids
A combination of solar power, DG set and battery can be deployed to meet power requirements. This combination also reduces DG set run-hours. However, this is most suitable for outdoor sites. Since this model leverages solar power, shadow-free south space is a prerequisite for it to be successful. Further, it requires a large battery bank.
Fuel cell energy solutions
Fuel cells can be used along with a battery or solar power for meeting the energy needs of telecom towers. Both the combinations eliminate the need for DG sets and, thereby, curb diesel usage. These models are the cleanest hybrid solutions as there are zero emissions at the site. Moreover, fuel cell energy solutions are compact, modular and easily scalable.
Deployment of a fuel cell and battery hybrid solution is possible at all BTS sites irrespective of their location. However, for models that leverage solar power besides fuel cells and battery, the availability of shadow-free south space becomes crucial. While fuel cell technology is undoubtedly the cleanest source of energy, safe handling of hydrogen during its deployment is a major challenge. Besides, it is a very recent technology and lacks the skilled manpower required for its operation.
Cost and volume
Currently, the total cost of ownership (TCO) for fuel cell energy solutions is the highest when compared to other hybrid solutions. TCO for fuel cells is about 10 per cent higher than that for DG-battery hybrid solutions. This is primarily due to the increased capex involved in the deployment of fuel cell energy solutions.
However, as the deployment of such solutions increases in the country, the TCO associated with this technology is likely to reduce. The difference in costs becomes highly significant as the tower base deploying this technology grows. For instance, the annualised TCO for running 1,000 towers on fuel cells is estimated to be lower than that for running the same number of towers on DG-battery hybrids.
Growth drivers
There are several growth drivers that provide significant opportunities for the development of hybrid solutions. Of the 390,000 towers currently operational in the country, about 18 per cent (around 70,000 towers) have no grid supply. Another 150,000 towers have access to less than 14-16 hours of grid supply a day. Moreover, India?s total telecom tower base is projected to increase to 450,000 by 2015. The majority of this growth is expected to be in rural areas, which are served by poor and unreliable grid power. These regions require reliable and affordable power, which can be provided through hybrid solutions.
Further, the government?s mandate to use hybrid energy solutions for powering towers will boost the demand for these solutions. As per the Department of Telecommunications? (DoT) directive, at least 50 per cent of towers in rural areas and 20 per cent in urban areas should be powered by hybrid solutions by 2015. This would be raised to 75 per cent and 33 per cent respectively by 2020.
Going forward, inadequate grid availability, rising diesel prices and the need for a cleaner environment will necessitate the development and deployment of hybrid solutions.
