National News

Solar plant gets green signal
20 Dec 2008, Vibhor Mohan, Times of India
 
          CHANDIGARH: Spreading sunshine on a cold and overcast Friday, The Energy and Resource Institute (TERI), in its pre-feasibility report, gave UT administration the go-ahead to begin work towards realizing its Solar City dream by 2012. To begin with, the city will have a 25 MW solar photovoltaic (PV) plant. "Chandigarh is among the first lot to be identified by the Centre to become solar cities," said PJS Dadhwal, additional director, department of science and technology, UT. Based on city's demography and amount of sunshine it receives, TERI said it wouldn't be financially viable to install a single solar plant. "A segmented approach should be adopted, with the size of each unit varying from 1 to 5 MW," it was recommended. Twelve gardens with more than 18 acre have been identified to set up mini solar plants. Of 1,030 acre available area in green belts, 6.8% will be occupied, with no solar unit spreading over more than 31.1% of any park.
          "The estimation of area and annual cost has been done by using the best available variant of solar cell with an efficiency of 14.3%. The power plant of 1 MW capacity can be segmented as 250 KW units, but all at one location. Hence, small gardens and parks are not considered in the action plan," read the report. Some 24 of city's 900 small and big parks maintained by the municipal corporation have also been identified as potential locations for tapping solar power. And the green-city campaign may not be necessarily based in green belts alone. TERI recommends rooftops of parking lots in central markets of all sectors to be used effectively for this purpose. Similarly those at Sukhna Lake, Rock Garden and railway station have been okayed for setting up solar PV plants. Even though the cost of power generation of these power plants is higher than that involved in conventional methods, officials said they were following global trends. With the estimated cost of power generation from solar PV being Rs 15-20/kWh, some believed this could result in consumers being charged more.
          "But it is a little early to say anything as UT may decide to provide solar-based electricity at the same cost in keeping with its commitment to the larger issue of environment protection. Moreover, the administration is also be eligible for incentives from the government of India for this project," said a UT official. Aiming to promote sustainable development, boost renewable sources of energy, create awareness about the dangers of global warming and mitigate effects of climatic changes, UT administration has been pressing for a Solar City status, with TERI being retained as a consultant to prepare the master plan in achieving this goal. With an installed peak power of 23 MW (updated), the solar park at Jumilla, Murcia (Southeastern Spain) is the world's current highest capacity PV plant and the most efficient to-date.The plant covers an area of 100 hectares where 300 days of sun a year are guaranteed. Its total annual production is the equivalent of energy used by 20,000 homes.

20MW power a day from garbage
23 Dec 2008, Times of India

          KOLKATA: Don't think this is rubbish. Kolkata Municipal Corporation (KMC) can generate 20 mw of electricity out of 4,000 tonne of waste it dumps at Dhapa daily. That is enough to light 16,000 middle income homes in summer. All that civic bosses need to do is streamline the disposal system and set up power plant with an investment of Rs 120 crore. From the third year on, it can draw precious power out of the waste with no additional requirement and barely any recurring cost. Not just that, the civic body can bid for a clean development mechanism (CDM) project under the Kyoto Protocol and earn lakhs of rupees for tapping methane, an extremely hazardous greenhouse gas (GHG). For the present though, West Bengal Green Energy Development Corporation (WBGEDC) is not attempting the Herculean task of getting KMC's act together. Instead, it is trying to ensure that the mindless, unscientific dumping that has led to the catastrophe called Dhapa is not repeated at other major urban centres like Salt Lake, Siliguri, Durgapur, Asansol, Haldia and New Town.
          "To be frank, the situation in Kolkata is beyond redemption. KMC has to locate an alternative landfill site and begin work afresh to make it work. But there is a lot of scope to adopt scientific municipal waste disposal in other major urban civic body clusters. We are creating a blueprint for major corporation and municipalities to adopt a technique called engineering landfill' so that methane can be tapped to generate power," said WBGEDC managing director S P Gon Chaudhuri. He has had several rounds of discussions with municipalities of Siliguri, Durgapur-Asansol and Salt Lake and hope to start the first project early next year. Explaining the waste to power mechanism, Gon Chaudhuri said a 20 feet deep pit on a 1.5 km? 1 km plot would serve as the waste collection centre. The pit will be lined with geotextile to prevent seepage of chemicals. Special perforated PVC pipes are to be then set up in grid formation with vertical pipes 42-43 feet tall that can be sealed at the end. "These pipes will channelise the methane that is generated from the decomposing waste. Once the pit is filled with garbage (for a municipality that generates 1,000 tonne a day, it will take a year and a half to fill the pit), 20-feet-high embankment is to be created after the pipe ends sealed. Over the next year and a half, waste can be dumped in the embankment, thereby creating a 40-feet stack of waste. At the end of third year, enough methane will be generated from the pit to power a 5 mw power plant for next three years," explained Gon Chaudhuri.
          Careful layout of landfill will ensure that a second site is ready for methane tapping once the first is exhausted. By the time the methane generation stops, the waste would also have converted into earth and can be used for landscaping. Gon Chaudhuri has discussed the issue with Housing & Infrastructure Development Corporation chairman and housing minister Gautam Deb. That latter is believed to have evinced interest in adopting the technology for New Town, the showcase satellite township that is projected to have a resident population of 10 lakh and floating population of 5 lakh. At 0.5 kg of waste generated per capita, the township will generate 750 tonne waste daily. "We need to manage the waste properly because methane leakage is a major cause of global warming. That will be one of the biggest challenge in future," said the winner of the Ashden award (Green Oscar) in 2003.

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