Waste-to-energy can help meet the twin objectives of energy generation and waste reduction. Despite the obvious benefits of introducing such projects in India, the technology is still at a nascent stage in the country.
According to the Ministry of New and Renewable Energy (MNRE) Annual Report 2009-10, over 55 million tonnes of municipal solid waste (MSW) and a large quantity of liquid waste are generated every year by the urban population in India. This translates into a potential for generation of over 2,600 MW of power from urban wastes in the country. Likewise, there is a potential for recovery of about 1300 MW of energy from solid and liquid wastes generated by the industry sectors like sugar, pulp and paper, fruit and food processing, distilleries, tanneries, slaughterhouses, poultries, etc. The energy recovery potential is expected to increase to about 1,600 MW by 2012 and 2,000 MW by the year 2017. Today, however, the country has hardly tapped about 2 per cent of its waste-to-energy (WTE) potential.
Besides generating a substantial quantity of energy (electricity, gas, and heat) which can mitigate the growing energy deficit in the country, WTE conversion through proper technologies allows for treatment of wastes before their disposal, thus minimising the quantity of waste to be disposed, leading to less demand for landfill sites, saving on the cost of waste treatment and its transportation to landfill sites, etc. This will also reduce environmental pollution, as most wastes now find their way into land and water bodies without proper treatment, causing severe air and water pollution.
With increasing awareness of these issues, WTE is slowly garnering support from several quarters including Central/State governments, industry/corporates and NGOs. The MNRE which has developed a National Master Plan for Development of WTE in India is taking several measures like assessing various conversion technologies, providing financial assistance for research studies and setting up WTE projects under various schemes. All the same, WTE conversion is yet to take off in a big way in the country due to several barriers and challenges.
The WTE exercise which involves two industries - waste disposal and energy production, is hampered by several technical and non-technical issues. Lack of awareness, non-supportive regulations, slow project approvals, high costs, etc., are some of the non-technical problems countered.
´It is not smooth sailing,´ says Lt. Col. Suresh Rege (Retd.) Executive Director, Mailhem Ikos Environment Pvt. Ltd, as he lists out the issues involved: ´Difficulty in getting land, lack of success stories to prove economic viability of WTE projects, weak financial status of many municipal corporations, lack of proper collection and segregation of MSW, delays in environmental clearances, high interest rates, hesitancy on the part of banks/financial institutions to finance the projects due to high risk factors, lack of infrastructure for proper utilisation of energy produced and the ´Not In My Backyard´ attitude of the masses.´ Mailhem Ikos, a joint venture with French Lhotellier Group, specialises in Anaerobic Digestion and has set up over 250 plants all over India for several organisations including the Pune Municipal Corporation, Arcot Municipal Council, ITC, Wipro, Jindal Power, Mahindra & Mahindra, MTR Foods, Indian Oil Corporation, Tata Consultancy Services and General Motors India.
Ineffective policy is another major barrier, opine several industry professionals: ´Though several policies are in place, they fail at the execution level due to lack of connect between the regulatory committees and local bodies,´ avers Rumi Engineer, Head of Green Building Consulting & Energy Conservation at Godrej & Boyce Mfg Co Ltd: ´Although the Central government sets the overall policies, local authorities are involved in formulating supplementary policies and their implementation. These local authorities are ill-equipped to determine specific technologies that are better suited for their areas and the type of waste generated. Hence it is important to rationalise the approval process and engagement with the government machinery so that appropriate inputs guide the process.´
Absence of documented economic, environmental, and technology performance metrics, lack of specific project management expertise to successfully plan, finance, deploy, and manage WTE projects are the other major reasons behind the lack of interest in WTE conversion among corporates and industries, adds Engineer.
Corporates and industrial houses with their financial, management and manpower resources can no doubt play a significant role in the WTE conversion field.
Difficulty in acquiring land parcels is another deterrent, reveals Lt Col (Retd) Monish Ahuja, Managing Director, Bermaco Energy Ltd: ´There is a huge requirement of land space for these projects. The low bulk density of biomass (30 to 40 kg/m3) requires 25 times more storage space compared to coal. Even for baled fuel, space requirement would be 8 to 10 times. Land costs plus other costs for fuel storage, large transportation fleet, paddy straw fuel handling equipments, etc., make the project financially unviable.´ Bermaco with expertise in paddy straw based power plant has set up a pilot 12 MW biomass power plant (Punjab Biomass Power Ltd) at Ghanour, Patiala, Punjab. Running on 100 per cent paddy straw and set up at an approximate cost of Rs 90 core including fuel handling equipment, the plant began its commercial operation in 2010. Four more biomass power plants - two in Punjab and two in Bihar are in the pipeline.
There are some challenges peculiar to certain kind of plants as evinced by Lt Col Ahuja: ´Paddy straw is not a processed fuel unlike husk and bagasse. The window for collection of agri-residue is too short due to harvesting pattern in India. Paddy straw requires bailing, handling and de-bailing, fuel processing for combustion. There are some specific requirements of 100 per cent paddy straw fired biomass power plant like the large combustion chamber for its thermal output. Collection of paddy straw requires several capital equipments like cutters, bailers, tractors and trolleys and manpower in the short harvesting period of 45-60 days. Chopping operation for preparation of paddy straw as fuel is also a challenging job.´
Other challenges include lack of assurances for buyback from concerned government agencies, reliability of power purchase agreements and premium available on renewable energy, lack of minimum guaranteed quantity and quality of feedstock and compensation in lieu thereof from municipalities, etc.
The cost of WTE conversion process is definitely higher than other renewable sources due to high capital, replacement and maintenance costs. Due to the presence of high abrasives and corrosive materials, all WTE plants suffer severe wear and tear and corrosion of machinery. This entails high specifications for construction materials leading to higher capital costs. Still, frequent breakdowns are common at MSW plants which means high repairs and maintenance cost. Further, the feedstock delivered at the plant often has ´high entropy´ characterised by mixed wastes and converting it to a state of high enthalpy is again expensive.
Ultimately, the outputs do not generate as much revenue to make it commercially viable for a private player . ´The cost challenges also include lengthy payback periods and lack of information on the full burdened cost of waste and a clear value proposition that could help justify the WTE project costs,´ states Engineer.
Several technologies like Plasma Arc, Pyrolysis, Incineration, Refuse Derived Fuel and Anaerobic Digestion are now available in India for WTE conversion. However, most of these technologies have been imported and their suitability to Indian waste and environment is yet to be adjudged.
´There is a lack of well-demonstrated technology as innovations are still underway. Right now we cannot recommend any proven technology, ´ reveals an official from Waste to Energy Research and Technology Council India (WTERT India) co-founded by the National Environmental Engineering Research Institute (NEERI) and the Earth Engineering Center (EEC) of Columbia University to address various issues related to sustainable solid waste management in India.
The WTE systems are highly complex too, says Engineer: ´WTE systems are too complex for tactical operations due to various reasons - uncertain performance in comparison to incumbent technologies; ability to handle non-homogeneity and seasonal variations in moisture content of waste streams as well as the need for further development and demonstration of gas purification systems, bio-refining, and hydrogen delivery and distribution.´
So it is all under experimentation, with the option of selecting technology left to individual players. ´Plasma arc and Pyrolysis are expensive options and still in the nascent stage as far as WTE options are concerned. While Incineration and Refuse Derived Fuel projects are big tickets for mass burning of waste, anaerobic digestion can be installed from small to mid large scale as per space availability and requirement. Around two decades ago, when anaerobic digestion technology was already being used to treat cow dung to generate energy, Mailhem thought of designing a system to treat different organic substrates with high solid content and generate renewable energy through anaerobic digestion,´ says Lt. Col. Rege.
Way Forward for WTE
Evidently several measures are required to accelerate the pace of WTE and smoothen its implementation. Mass awareness programmes, setting up of several pilot projects to demonstrate its feasibility and viability, changes in policy and regulations, collective implementation of projects, fiscal and financial incentives including viability gap funding are some of the suggestions put forward by industry professionals.
Lt. Col. Rege suggests the following measures: ´Mass awareness campaigns, improvement in the level of segregation, setting up of pilot projects to showcase the project viability, changing the archaic tendering system of L1 to quality and cost based system, user-friendly power purchase agreements, supportive policy, simplified procedures for various clearances, performance linked subsidies, change from royalty to tipping fee, and the will to do something for better environment at corporation/council levels, will all provide a big boost to this sector.´
In the industry sector, many small and medium enterprises often find it unviable and unfeasible to go for WTE. Engineer suggests grouping them together: ´For many of these companies, the quantum of waste may not be sufficient to make waste to energy installations feasible. Cluster formation and collective project implementation may be the solution where groups of waste producers can share investment outlays and the benefits. Although this is already being done, it should be scaled up for effective results.´
Lt Col Ahuja outlines the need for providing land on lease and some subsidies: ´There should be separate tariff for paddy straw based power plants by State Electricity Regulatory Commissions (SERCs). Financial institutions are not willing to invest due to the SERC´s unfavourable tariff for paddy straw based power plants. The government should also offer land on lease to the biomass developer for storage of biomass, subsidies for fuel handling equipments and offer single window clearances.´
WTE is no doubt the way forward, more so since it serves the dual purpose of energy production and waste disposal and consequent reduction in pollution as compared to other forms of renewable energy. But it is a long road ahead for all the stakeholders.