Wind Energy for Water Pumping and Off-grid Power Generation

Introduction

Water-pumping windmills, aerogenerators (small wind electric generators), and wind-solar hybrid systems have been found to be useful for meeting water-pumping and small-power requirements in a decentralized mode in rural and remote windy areas of the country. The MNES is implementing a programme on 'Small Wind Energy and Hybrid Systems' to promote utilization of water-pumping wind mills, aerogenerators, and wind-solar hybrid systems for water pumping and power generation.

Water-pumping windmill

A water-pumping windmill pumps water from wells, ponds, and bore wells for drinking, minor irrigation, salt farming, fish farming, etc. Available windmills are of two types, namely direct drive and gear type. The most commonly used windmill has horizontal axis rotor of 3-5.5 m diameter, with 12-24 blades mounted on the top of a 10-20 m high mild steel tower. The rotor is coupled with a reciprocating pump of 50-150 mm diameter through a connecting rod.

Such windmills start lifting water when wind speed approaches 8-10 kilometres (km) per hour. Normally, a windmill is capable of pumping water in the range of 1000 to 8000 litres per hour, depending on the wind speed, the depth of water table, and the type of windmill. Windmills are capable of pumping water from depths of 60 m. Water-pumping windmills have an advantage in that no fuel is required for their operation, and thus they can be installed in remote windy areas where other conventional means of water pumping are not feasible.

However, water-pumping windmills have limitations too. They can be operated satisfactorily only in medium wind regimes (18 km per hour). Further, special care is needed at the time of site selection as the sites should be free from obstacles such as buildings and trees in the surrounding areas. The cost of the system being high, many individual users do not find them affordable.

Achievement

Water-pumping windmills require only medium wind regimes. Considering the availability of required wind speeds and the level of the prevailing water table, potential exists for installing water-pumping windmills in almost all states, except in hilly and rocky regions.

Cost

The cost of a water-pumping windmill varies from Rs 45 000 to Rs 150 000, depending on the type. In addition, Rs 10, 000-Rs 20, 000 is required for the foundation, storage tank, and the installation of the windmill. As the system involves moving parts, it requires frequent maintenance. The repair and maintenance cost of a windmill is about Rs 2000 per year.

Three water-pumping windmills of AV-55 type installed in and around Auroville have become the exclusive source of drinking water for the community, which is fully dependent on the water lifted by these windmills. The maximum number of water-pumping windmills have been installed in Gujarat, for irrigation and drinking water purposes.

Main Application: Wind Energy

Contact:

Indian Renewable Energy Development Agency Ltd.
India Habitat Centre Complex
Core-4A, East Court, 1st Floor
Lodi Road, New Delhi- 110003
Tel: 91 11 2468 2200/ 91 11 2468 2202