Case Study: India

RE support and subsidy

The Government of India has enacted several policies and laws to support the expansion of renewable energy use, including:

 

  • The Electricity Act 2003, which mandates that each of the State Electricity Regulatory Commissions (SERCs) establishes minimum renewable power purchases; which allows the Central Electricity Regulatory Commission (CERC) set up in 1998 under the Electricity Regulation Act to set a preferential tariff for electricity generated from renewable energy technologies; and which provides open access of the transmission and distribution system to licensed renewable power generators.
  • Rajiv Gandhi Grameen Vidyutikaran Yojana (RGGVY) 2005, which supports extension of electricity to all rural and below poverty-line households through a 90% subsidy of capital equipment costs for renewables and non-renewable energy systems.

 

Husk Power Systems, under the RGGVY 2005, receives a capital expenditure subsidy of up to 66% per system from the Indian Ministry of Natural and Renewable Energy.

Private model

Husk Power Systems is a private enterprise established using savings from its founders and competition prize money won as it seed capital.  Its main aim is to provide electric power using decentralized biomass gasification technology for villages with 1000-1200 households to meet their lighting needs. HPS operates mainly in rural areas where majority of the households are not electrified.  By using risk husk, a waste product of rice production obtained from local farmers, and local materials such as bamboo for poles, and by collaborating with local businesses to produce its gasifiers, HPS has been able to supply power at a lower cost than other local alternatives such as kerosene and lanterns.

 

HPS operates under three different models: 

 

(1) Built, owned and operated by HPS; 

(2) Built, owned and maintained by HPS but operated by local investor; and

(3) Built and maintained by HPS but owned and operated by local investor.

 

In the first model it takes 3 months to reach operational profitability and 3-4 years to recoup capital expenditure depending on whether (and how much) subsidy is received from the government.  Additional revenues are also obtained from the sale of rice husk ash used in incense making, and from carbon offsetting.  In the second model HPS builds and sells the plant to an independent owner once their investment has been recovered, but continues to provide maintenance to the system.  In the third model, HPS builds a plant for a local owner who takes responsibility for all costs and revenues, paying HPS for maintenance and repair.

Biomass gasification

The mini-grid utilises proprietary gasification technology to convert rice husk and other abundant agricultural residue (procured from local farmers) into electricity, which is then distributed to rural households and micro-enterprises through a low voltage micro-grid system consisting insulated overhead wires strung on bamboo poles within a 2km radius around the plant.

 

Each of the approximately 75 Husk Power Systems plants consists of a gasifier, series of filters for gas cleaning, dual fuel gas engine and a 35 kW electric generator. Every 30 to 45 minutes sack loads of rice husk or other biomass are poured into the gasifier hopper where they undergo partial pyrolysis (burning in restricted air supply of 1.5-1.8 kg of air per kg of husk/biomass,  drawn downwards in a cylindrical combustion chamber).

 

This results in a 'producer' gas that passes through water for cleaning and cooling and a series of filters to remove tar and particulates before being used as fuel for the dual fuel engine that drives an electric generator.  The plant operates mainly in the evening for approximately eight hours supplying single phase 240V 50Hz AC and consuming 10 tonnes/month of husks/biomass.  The basic load connection consists of two 15W CFL lights and phone charging for connected households.