ABSTRACT
In the Himalayan foot hills, there is a significant amount of electricity generated by isolated run-of-river hydro schemes. Load factors are often as low as 18%, and yet evening peaks are sometimes difficult to meet.
Against this background of “spare” energy, there is enormous pressure on fuel wood, and suppressed demand for alternative fuels such as LPG. This paper looks at ways of improving load factors, to reduce CO2 emissions, and improve the economics of present and future mini hydro schemes.
In an example from Sri Lanka, the rural grids in some areas were suffering “brown-outs” during the peak evening load time, and a massive upgrading of the lines looked inevitable. In an innovative move, several rural industrial consumers (mainly tea and rubber factories) were offered a reduced tariff if they accepted dual tariff meters which charged high rates between the hours of 6pm and 9pm (”peak” times). The factories found no problem in modifying their production schedules, they made savings to their bills, and the “brown-out” problem disappeared. All parties gain in this situation, at very little added cost or complexity.
Storage type appliances (storage heaters, insulated hot water geysers and storage cookers) can be combined with dual tariffs to significantly increase domestic load factors. Low cost timer units are available which can tolerate power cuts, and switch appliances on and off automatically at pre-set times. At least 6 countries including UK use this method. The paper looks at pricing off peak electricity to compete with domestic charcoal, LPG, coal and fuelwood.
In India, small connections are sometimes given on a fixed monthly payment basis. This has advantages as no meter or meter reading is needed, but can lead to overloading problems if there is no precise control on the peak current drawn by the consumer.
In Zimbabwe, Nepal, Eritrea and elsewhere, current limited connections are common, where the customer buys 100W, or 250W, or even 1kW, on a fixed tariff basis. Tamper proof auto-resetting current limiting devices then control the maximum current going to the dwelling. Load limiting connections can be 50% cheaper than metered connections to install. The paper looks at the potential for these techniques in India.
The paper also looks at international experience in innovative tariff collection systems, including community involvement and pre-payment meters, and how it may help in the Indian situation.
Electrification is one of the largest industries in the world. New consumer connection technology is being developed in India and elsewhere. Indian industry is well placed to benefit from innovations in this sector.
This section of the Hilly Hydro Project is very challenging and complex, but the relative lack of innovation in demand side management, combined with an ample resource of off-peak electricity, provides significant opportunities for change. Whilst reductions in fuelwood use for poor rural consumers will be difficult, there are many other users who can switch from fuelwood and other CO2 producing fuels. The national potential is very significant.
