Udit Chaudhuri

Mumbai's Energy Needs: Some Fresh Options

Instead of a mono-culture approach, this city's energy managers must look at both conventional as much as non-conventional options. And our policy-makers in the energy sector, instead of relegating the promtion of solar energy solutions to rural areas and subsidised / Government funding, must now look at the city and consumer-financed projects, to reduce pressure on State resources. To begin with, buyers of property in Mumbai must be made to invest 10% of the property cost in solar energy equipment, to reduce burden on the State grid. Appropriate tax rebates and legislation can help this.

Mumbai considerably owes its vantage point on the world’s business map to its well-planned and relatively well-run infrastructure, which makes it feasible to provide a variety of critical services efficiently and predictably. In the traditions of the Bombay Plan and successive generations of forward-looking city-fathers, it is now time to look afresh at the energy sector, to retain this supremacy.

High growth in energy consumer population apart, the average city-dweller now uses more automation, both at home and at work. Food processors, geysers, washing machines and refrigerators are as much part of a middle-class home, as are fax and zerox machines, electronic typewriters, PCs, watercoolers and digital telephones in almost any office. Adding liberalisation, one sees a bludgeoning growth in new service industries like the networked Stock Exchanges, software development, merchant bankers, share registrars, foreign investors, investment bankers, computerised health-care facilities, life-support systems, the Internet and related services, E-Mail networks, cable TV, computerised banking systems, satellite communication and electronic security systems. All these contribute to a higher and increasing energy demand per capita.

New infrastructural services show a new class of energy consumers. Unlike factories or large establishments, their individual demand is critical, not large. Their services are crucial to one sector or the other of modern society. They can afford the capital to atleast part-finance their own energy self-sufficiency. Ironically, they are heavily dependent on the state - for quality ie stable voltage, frequency and ideally uninterrupted. A State already under pressure to spend more on the poor and deprived.

Further, there are industries like film processing, digital audio-video editing centres, plastic moulding, mould-making, garments and accessories where Mumbai traditionally accounts for their highest share. Their viability relies heavily on this city’s infrastructure. They are here to stay and grow.

Energy management needs understanding of the base and peak demands or loads. In a city, the load changes pose formidable challenges to the load manager in maintaining stability in voltage and frequency. In the mornings for example, suburban trains and working establishments start this cycle, including the large number of one / two-shift factories with their motor load. Again, between 5-7 pm, about 100,000 electric bulbs, tubelights and TV sets together are switched on. This can cause voltage dips. Sometimes the demand rises in excess to the predetermined load factor, calling for load-shedding unless additional power sources can be switched into the grid. At late night, the large drop in load often causes high voltages and low frequency.

The load manager tackles such load behaviour by anticipating the level and category of load followed by correct planning of base-load and peak-shaving generating capacities, transmission and distribution switchgear. And above all by vigilant switching of power sources, links and loops to ensure maximum load servicing with minimal voltage variations. Fortunately, the TEC and BSES have done a fairly good job in Mumbai’s load management, which is responsible for a lower rate of grid-level power failures compared to many other cities and states. However, peak load generating capacity is likely to fall short. How quickly and how large an amount can be raised by the State for this purpose to this city in the face of growing social-political pressure to service the poorer areas, remains a big doubt. Till then, the power scene in Mumbai can be threatened with going the Calcutta way of day-long power cuts!

In this light, here is a glance at conventional options first:

Large thermal power stations within the city akin to Indraprastha and Rajghat in Delhi are not likely to be permissible due to their emission levels and shortage of open land. Such plants, even earmarked for Mumbai, will be atleast 100 KM away, at the mercy of the State grid. It also needs consideration that on an all-India average, 30-40% of the power generated is lost in the transmission and distribution system.

Next, generating sets in the 5-12 MW power range providing backup, at the Load Despatch Centre or Substation levels. These can be driven by multifuel piston engines or turbines, to start at short notice and inject the peak-having energy. Natural gas or heavy fuels may be considered. The engines mostly start on diesel, which again is prone to sporadic shortages. Here, there is a possibility of utilising combustible gases from city wastes and effluents, as done at Peerana ETP in Ahmedabad and other locations in India on an experimental basis. Biogas as a fuel is already quite popular in our villages. Energy planners here too must consider gasification plants at major Effluent Treatment Plants, garbage dumping sites and waste collection centres, linked by pipelines to a system of backup generators. With noise-proof and heat-shielding enclosures, generators in the MW range are known to be installed in building basements and terraces as well.

Other options such as portable generators, battery-backed on-line and off-line UPS and invertors are at best stopgap arrangements for short failures, relying on supplies of fuel and primary power. And the once hyped suitcase-sized nuclear reactor to energise domestic homes by this century’s end remains the Nuke’s fantasy till date.

Now two renewable options, which are no longer noncoventional in terms of being proven: hydroelectric and wind energy. Even though we have utilised only about 10% of our hydel resources at the national level, some planners only associated hydel with large dams and irrigation schemes. Fortunately, over the years this has been corrected. Data on potential sites for wind as well as hydroelectric power is compiled and under compilation with a number of governmental agencies. A medium-rated windmill in the 500 KW range needs 10-15 Mt/Sec of wind-speed, whereas a micro-hydel set below 1 MW needs a stream with as little as 2 Mt of head. Under the (Government’s) Wheeling Scheme, corporate houses can purchase such equipment, claim depreciation (at 100% for renewable energy equipment ) and supply the power to the State grid, for which an offset is credited to the owners against their energy bills. The Ministry of Non-conventional Sources (MNES) and Indian Renewable Energy Development Authority (IREDA) and Maharashtra Energy Development Agency (MEDA) can provide relevant guidance as well as soft loans. This will be of great benefit to companies with large energy bills, while it will relieve the burden on state-funded generating capacity, in an eco-friendly manner.

Entrepreneurs with larger budgets can also take the combined advantage of the above with the new Licencee policy and the BOLT scheme, using larger hydel and wind generators. Some manufacturers claim a generating cost of at around Rs 2 per KWh while the State would purchase power at about Rs 3 per KWh. However coloured that claim is, the raw material - wind and stream-water are free. Possibilities are ample and may be investigated by those interested. Then the argument that the peak generating hours are not necessarily peak demand hours should not deter small and medium-sized power stations at most sites.

However there is only one source of energy that a city-dweller can convert into heat and electricity directly at the point of use. And without any noise, smoke nor fuel costs: the solar option. Both types, solar thermal as well as solar photovoltaic (SPV) systems have now come of age, with an all-India installed population reaching six digits over the last 20 years. The MNES and its Nodal Agencies deserve their share of credit for encouraging this. On the domestic front, solar water heaters in the range of 100-250 LPD and solar cookers have become popular in many towns and villages. On the institutional / industrial front, larger systems in multiples of 1,000 LPD are used by hotels, dispensaries, dairies, textile and other process plants having a large requirement of hot water or steam. The water delivered is typically at 60-70oC and pay-back period between 3 and 5 years, notwithstanding the depreciation benefit. Additionally, solar distillation and desalination units as well as solar hot-rooms are also being used. All these systems require a shadow-free terrace and/or ideally a South-facing wall. Most buildings in Mumbai have this. Nominal work has to be done on the building for mounting brackets, grouting pockets and plumbing as applicable.

On the solar photovoltaic or SPV front, the relatively high price-tag has acted as a deterrent, as much as the earlier tight control of the public sector on the production of silicon-cells, which resulted in poor deliveries. Another drawback was in the life of batteries and tubelights. These have been overcome in the past 5-6 years, with incorporation of the C-100 / 120 Class of long-storage slow-charge-slow-drain batteries and the PL class of halogen-arc lamps which deliver 80-90 Lumens per watt. This means a battery (Design) life of 10-12 years, lamp life of minimum 2 years and overall system (Design) life of 20 years. An average of about 3-5,000 village homes and chowks in the No-Electricity Zones of most States have been illuminated. In addition, about 50 % of the total SPV production reaches the strategic sectors of defence, oil,-field, survey, pipeline and railway, for energising communication systems, lights, corrosion protection (ICCP) systems and sophisticated instrumentation.

Solar energy converting systems continue to function wherever the local Nodal Agency most notably GEDA in Gujarat, or owners have taken the pains to supervise their working and provide basic maintenance training to the beneficiaries. Such training would not be needed by the city-dweller who would dust the absorbtion panels, top up distilled water and replace bulbs as a regular matter of course, taking help from the neigbourhood wireman or plumber if required. Besides, most manufacturers have service set-ups.

Solar equipment manufacturers may be blamed for lacking the initiative in marketing these products to the smart city consumer in the same manner as, say, air-conditioners, vacuum cleaners or portable generators, which keep a very high presence in showrooms as well as the media. To an extent the Nodal Agencies, by their large centralised purchase Tenders and preferences to SSI units are responsible, taking away the need for open-market retailing with its inherent risks. This calls upon Nodal Agencies and marketers of solar equipment to look again at the city market and showroom selling strategies.

As for finance, Nodal Agencies have part and full subsidy schemes, applicable to various beneficiaries. Unfortunately this has lead many potential buyers to believe themselves eligible for full funding. Instead, leasing companies being eligible for depreciation must take advantage of the 100% depreciation benefit by leasing and financing hire-purchase of solar equipment. This can also take the form of low-interest / interest-free loans to Housing Societies, builders and developers. When luxury car finance is already available on such terms, why not solar equipment? Nodal Agencies and leasing / finance companies need to work on this. SEB Licencee companies like the BSES, (which has been investing in the stock market) can also be roped into financing this type of equipment.

As mentioned earlier, the high price of SPV-based systems was a deterrent. The investment is about Rs 400-500 per Watt. The scope includes 35 Watt SPV Module, 5-day Storage Battery, Electronic Ballast and 11 Watt halogen-arc lamps. Each lamp can illuminate a room of 10’X10' on a 11 Watt electrical input, while each 35 Watt Module produces about 140-150 Watt-hours of energy. This means 6 hours average operation for two such lamps, ie over a 20’X10' space. With this, the investment would be a maximum of Rs 100-200 per square-foot, assuming higher illumination levels for reading, etc. which is 2% of the property price in Central / South Mumbai and 10% for outer Mumbai. The maintenance involved is in dusting of the Module and a weekly watch on the battery’s distilled water level. This is about all the maintenance and its cost. The battery normally stores power for 5 ‘No-Sun Days’ being designed for a daily drain not exceeding 15-20% of the battery’s storage capacity. Hence, except for standby charging, an SPV system is free from the grid. A number of designs of SPV-based systems are standardised by the MNES, which can provide details including approved manufacturers’ names. The time has come for every flat-owner to put at least their lighting load on SPV- based power. They may continue to use the grid power for fans and appliances ie motor and heater loads.

Legislation can also aid this cause in a number of ways. One would be by imposing a ceiling or stiff surcharge on grid power demand beyond a reasonable number of Watts per Sq Ft of property owned. Another would be a statutory requirement of solar equipment installation on all new buildings, prior to issue of the Completion Certificate, on the Israel model. Buyers of property could also be given a tax rebate at 10% of the value of that property, over and above that which is already available, to bear the cost of solar equipment.

This discussion solicits the participation of the infrastructure users towards bearing its costs, with a fair number of incentives for assimilation of new technologies and disincentives for sticking on to State-subsidised conventional energy sources. This will make for judicious application of the State’s scant resources while allowing those who require higher infrastructural inputs to pay for them and in an environment-friendly manner.