About 70 per cent of new telecom towers contracted in India every year are installed in rural areas where grid power is not the primary source of energy. As a result, most of these towers are heavily dependent on diesel to meet their power needs. Over the years, diesel has not only emerged as a very expensive fuel, but has also contributed to greenhouse gas emissions significantly. Rising energy costs, especially in the context of the current financial state of operators and tower companies, have driven a shift towards alternative sources of energy. In this regard, several renewable technology solutions are being considered by the industry. These solutions, besides being environment friendly, result in operational and cost efficiencies in the long run.

tele.net takes stock of key renewable energy solutions that have been deployed or are at various stages of testing at telecom tower sites in India…

Solar energy

Solar power has emerged as the most preferred renewable energy technology largely due to its abundant availability in the country. Solar panels can serve as an important alternative to diesel, particularly for towers located in remote areas with no grid access. According to a consultation paper released by the Telecom Regulatory Authority of India in 2011, deploying solar power instead of using diesel will help save an estimated $1.4 billion in operating expenses of telecom tower companies annually. Further, a solar-powered tower installation provides value for 30-40 years on account of easy maintenance.

A drop in the price of solar panels during the past few years has made solar energy an economical alternative to conventional energy sources. Further, the government has taken major steps towards encouraging the deployment of solar solutions in the Indian telecom industry. In September 2013, a panel set up by the Department of Telecommunications mandated Bharat Sanchar Nigam Limited (BSNL) to expedite mass solarisation of cell towers in several rural zones, with financial support from the Universal Service Obligation (USO) Fund.

Wind energy

Wind energy has gained importance in recent years as an attractive source of power at tower sites. Small wind turbines can be mounted on existing radio masts. Wind power generation becomes an attractive alternative for sites located in areas with an average wind speed of 4.5 metres per second and above. It is a mature technology and several regulatory and policy incentives are available for the technology, which encourage its application in telecom towers. These incentives include 10 per cent foreign direct investment, 35 per cent accelerated depreciation (AD) and excise duty exemption. Further, the Ministry of New and Renewable Energy (MNRE) offers 30 per cent capital subsidy (up to Rs 100,000 per kW) for telecom applications. BSNL has taken up wind power projects at six USO Fund-supported sites in Rajasthan, Gujarat, Tamil Nadu, Karnataka and Maharashtra.

Biomass

A biomass system generates biogas on site, which is used to run modified natural gas generators. Biomass residue such as pellets and wood chips can be used instead of diesel to run towers. The advantage of this technology is that the associated emissions and noise levels are lower than that of diesel generator (DG) sets. Further, it is suitable for rural sites with an unreliable grid. However, the deployment of this solution has been very low, primarily due to fuel-related issues.

Fuel cells

Fuel cells are devices that electrochemically combine hydrogen and oxygen to produce electricity. Fuel cell-based systems can be designed to match the actual power demand at a site. In addition, any increase in the demand at the site due to higher tenancy can be met through capacity addition to the fuel cell system. Further, fuel cells have higher efficiency than other renewable energy solutions. Owing to these advantages, fuel cell systems can be used to better address the energy requirements of a telecom site as compared to DGs. Currently, fuel cell technology in India is at a trial stage. The Twelfth Plan proposes AD-based field trials for hydrogen fuel cells for providing backup power at telecom towers. Foreign funding is also being made available to promote the use of fuel cells. In December 2013, Idea Cellular received a grant of over $1 million from the US Trade and Development Agency to fund a pilot project involving the deployment of solar hybrid methanol-based fuel cells at its telecom sites in India.

Key challenges

While the aforementioned advantages make a compelling case for renewable energy adoption for the tower industry, these technologies face major issues in terms of high capex and deferred returns on investment. Energy storage is another area of concern, as most of these solutions are intermittently available during the course of the day. Further, there are several operational challenges related to each of these solutions, which poses deployment challenges. The viability of wind power, for instance, depends on the duration of the useful wind speed availability and wind density. Therefore, site selection is very important. Moreover, wind power involves high operational expenditure.

Similarly, deployment of biomass involves the challenge of securing a fuel supply chain. In addition, the plant is run on manual operations and, therefore, involves high maintenance. The use of fuel cell systems has largely remained at the trial stages so far in India as the deployment of this technology necessitates continuous hydrogen supply at identified locations and covered storage space for hydrogen storage. Along with this, there are safety and security issues related to hydrogen cylinders.

Solar- powered systems also face reduced utility on cloudy or non-sunny days. Moreover, often a site is too large for a solar power solution to be viable and, therefore, alternative hybrid solutions are needed to improve energy efficiency and reduce operational costs.

Moving towards hybrid solutions

On a stand-alone basis, solar and wind, the two most mature renewable energy solutions, face several operational and financial challenges which hinder their deployment for telecom tower operations. The use of solar power as a stand-alone alternative involves certain issues as each kW of solar energy requires 7 square metres of shadow-free, south-facing space, and not all tower sites meet this requirement. In such a scenario, deploying hybrid models can be an alternative. Currently, new solar-DG hybrid and solar-wind hybrid solutions are being explored in India.

Solar-DG hybrid systems are estimated to result in a 50 per cent reduction in energy-related costs of stand-alone solar systems. Further, these systems can reduce daily DG run hours from 20 to 5. This would help reduce carbon emissions from pure DG systems. Bharti Infratel has been pioneering the use of this technology. So far, it has deployed this solution for an aggregate capacity of 6 MW at over 1,200 sites in the Bihar circle. In addition to reducing carbon emissions, the solution has helped improve the life of the battery banks installed at project sites.

For rural sites with a wind velocity of 5-6 metres per second, a hybrid wind-solar system offers a viable alternative to stand-alone systems. In fact, wind power generation complements solar power generation. During bright sunlight availability, solar energy is utilised for charging batteries and creating enough energy reserve for use during the night, while wind turbines produce most of the energy during the monsoons when solar power generation is minimum. These hybrid systems assure a daily uninterrupted power supply of 2.8 kW.

Conclusion

Currently, less than 1 per cent of the country’s 440,000 towers are powered by renewable energy solutions. Debt-laden telecom companies, operating in an uncertain environment, have not been able to earmark significant capex for such solutions in the past few years. However, with regulatory clarity returning to the sector, this space is expected to witness some action. Further, the government’s mandate to run telecom towers on hybrid power in both rural and urban areas will facilitate the adoption of renewable energy technologies in the long term.