Mayor D Venkatesh Murthy’s plan to offer residents the option of setting up wind power turbines in residential areas with subsequent plans to make these mandatory is nothing short of building castles in the air by floating ideas with no basic research on whether such projects would be feasible or not.
“We are already planning to put up windmills in BBMP (Bruhat Bangalore Mahanagara Palike) areas. Citizens who are interested in doing the same can get permission from the BBMP,” he said during an interaction organised by Federation of Karnataka Chamber of commerce and Industry (FKCCI) on August 3, adding that it would be made mandatory in time.
Experts have scoffed at the idea for the very infeasibility of such a project that would involve humungous costs, that too for deriving power from a source of energy is not be completely reliable considering the wavering intensity of wind in Bangalore.
According to the website howtopowertheworld.com, which in part deals specifically with wind energy source, residential wind power is the use of wind energy for domestic use, with small scale wind turbines designed for the purpose.
Criticising BBMP’s ambitious plans of alleviating the city’s electricity problems by installing windmills in the city, renewable energy experts fear that the effort will simply be a waste of resources.
“It is impossible, especially for domestic purposes,” says Prasanna Kumar, managing director, Karnataka Renewable Energy Limited.
“First of all, the wind potential of Bangalore is low and the available wind potential is in small pockets in the city,” he says, adding that BBMP does not even have a clear idea of what the wind potential in Bangalore is.
H Naganagouda, director, National Training Institute for Solar Technology, says according to the Central government guidelines to install windmills, there has to be a wind velocity of at least four metres per second and there should be no obstruction to the wind (like trees, buildings and structures) within a 100 metre radius of the place where the windmill is planned to be installed.
“It is nearly impossible to find such places in a city like Bangalore,” he says. “Even if you do find such a place and set up a windmill at a height of 18 metres for a three floor building, at the rate at which the city is growing, what guarantee is there that no taller building would come up near your home in the future? The investment (about Rs2.1 lakh for a windmill producing 1 kilowatt energy) will go completely wasted,” he says.
Besides, he says, although wind turbines have been set up in some places in Bangalore (like near Iskcon Temple, KSRTC Regional Workshop in Kengeri, KSRTC Bus Station on Double Road, Kempegowda Bus Station and Banashankari Devasthana in Subramanyapura) the energy accrued was not sufficient. “The wind velocity was found not to be enough or uniform to produce energy,” Naganagouda says.
Another problem is the vibration from the wind turbines if set up to power a multi-storeyed building. Anchoring, storing the power are other problems, he adds.
“Bangalore is not a city for windmills at all,” says MG Prabhakar, member, energy committee, FKCCI. “For a small household, generating enough energy for a few bulbs may be possible, but it will not be cost effective. It would cost a few lakhs at least to put up a windmill that will be able to produce at least 1 kilowatt of energy. But in order to do so, you need a flat surface, or a tall building such as the UB City. It will not work in apartment blocks because they have windows and balconies where the energy gets dissipated.”
“Even if it did, how many days in a year will it work and what will a large apartment do with a few kilowatts of energy? It will not even meet a fraction of the requirements,” says Naganagouda.
He says an ideal solution would be a hybrid using both solar and wind energy. “At least you are guaranteed that solar energy is available for most part of the year,” he says.
However, Prasanna Kumar suggests waiting for a few years till proper technology was available. “Even if a hybrid wind mill using solar energy was used, the energy from the wind mill would be very small. Instead, focus on solar energy,” he advised.
Experts feel that residential wind turbines are inappropriate unless it is being used in exposed, windy area and that these turbines, if used in urban/suburban areas of a city like Bangalore, are likely to provide nothing more than a mere trickle of power at very high costs.
High cost, low yield solution for city
Experts say that a typically large wind turbine can generate up to 1.8 MW of electricity or 5.2 million KWh annually, under ideal conditions – which is enough to power nearly 600 households.
The idea has not been implemented anywhere in India, but has been tried quite successfully in countries like Germany, USA and UK, where vast expanses of land are available closer to city suburbs to set up wind power generation units.
According to British Wind Energy Association (BWEA), an ideal residential wind power turbine for generating 2.5KW of power could cost in the range of £12,000. This works out to a whopping Rs10,44,000, that too without including the relevant taxes applicable.
BBMP’s plan, as described by Mayor Murthy, is to make these subsequently mandatory, and will apply mainly to buildings which are five floors and above. In Bangalore such residential buildings are generally inhabited by middle- and upper-middle class citizens who, even through the power of their respective apartment associations, would find it financially difficult to contribute to muster up such a huge amount for setting up the required wind turbines. Although this would mean at least 800 households could benefit from the supply of power from a clean source of energy, the wind, the logistics would require as many households to come forward to make their contributions. This would mean that such a wind turbine would be more beneficial and cost-effective if it was meant for a larger area rather than just a residential building.
According to website howtopowertheworld.com, the two merits of residential wind energy are reduced energy bills and energy independence.
Reduced energy bills: Depending on how windy the area is, the energy bills can be much smaller than they are otherwise. Also, surplus energy could mean selling the excess power to the power distribution company.
Energy independence: Depending on the kind of system, and the availability of other domestic energy sources like solar panels or ground heat pumps, citizens using wind power turbines could effectively be independent from the grid.
Wind turbines can’t always run at 100 percent power like many other types of power plants, since wind speeds fluctuate. Wind turbines can be noisy if you live close to a wind plant, they can be hazardous to birds and bats. Also, since wind is a relatively unreliable source of energy, operators of wind-power plants have to back up the system with a small amount of reliable, non-renewable energy for times when wind speeds die down. Some argue that the use of unclean energy to support the production of clean energy cancels out the benefits, but the wind industry claims that the amount of unclean energy that’s necessary to maintain a steady supply of electricity in a wind system is far too small to defeat the benefits of generating wind power.
Is there enough wind? Wind speed is affected by surface friction: trees, buildings, hills and such all slow the wind speed and, near the surface, make it rather turbulent. According to website howtopowertheworld.com, residential wind power, therefore, makes most sense if you have quite a lot of flat space around the wind turbine. It is still possible in suburban areas, but you would expect a greatly reduced power output. It would need to be on a high tower as well, as wind speeds at roof level are pointless. This means that if you live in an urban or densely populated suburban area, it is unlikely that you would benefit from a wind turbine. This is just a general rule, and will have exceptions, but unfortunately this does apply to most people.
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