Dusting PV on roof for lantern recharging, Chennai Photo: Martin Wright

Solar PV has enormous potential to replace existing fossil-fuel based energy services in India.

In addition to providing new services.  Aurore provides technical, financial and management support to partner organisations, enabling the installation of PV water pumps, solar home systems and solar lanterns.  

I have not seen so much profit from farming in my life, all thanks to the solar pump.

Valji Hirji Ramjiyani, 72-year-old farmer

Aurore is a hub of expertise. Not just technical expertise, but also critical financial and management expertise. By providing such a suite of skills, Aurore enables partner organisations across India to install and operate PV water pumps, solar home systems and solar lanterns providing cheaper, more sustainable energy than diesel-based alternatives. 

By 2009 lighting systems had been set up in 17,000 homes. Even more significantly, over 7,000 PV pumps have been installed bringing huge benefits to local communities. In Gujarat alone over 3,000 villages are using PV pumps to provide drinking water or wider irrigation.

Some installations are government-subsidised. However, as Aurore has long-recognised, and as their current support for ‘solar entrepreneurs’ who rent out lamps to street hawkers demonstrates, the long-term success of PV systems ultimately depends on their commercial viability.

Key points:

  • PV water pump generates a power rating of 900 to 1800 Wp to lift water from a well or borehole for drinking or to run an irrigation system. 
  • Solar home system designed to supply light in individual homes, providing enough power to run two 11W fluorescent lamps for three hours every night. 
  • Solar lanterns used as small solar home systems to provide light in homes and outdoor market stalls. 
  • Users of solar home systems pay an initial charge of US$ 22 and then a rental fee of US$2 per month. Government subsidies provide up to 80% of initial cost of installing a PV powered water pump, with the rest paid through user loans. Solar lanterns rented out to users, who pay a refundable deposit of US$2 and fee of US$0.30 per night, equivalent to the cost of fuel for a kerosene lantern. 
  • By 2004, 845 PV powered water pumps, 8,700 solar home systems and over 6,000 lanterns had been installed, bringing electrical services to over 20,000 families. 
  • PV powered water pumps replace the use of about 1,750 litres of diesel every year. They also put a more continuous load on groundwater supplies and do not lead to overpumping.
  • Running small appliances off the PV supply also saves the cost of batteries.

Update

  • By 2009, an additional 6,600 solar powered water pumps installed in 15 Indian states and 2,000 solar home systems. Some 50 independent enterprises now renting out solar lanterns. 
  • In western state of Gujarat, PV water pump programme has been scaled up from nine to 3,000 villages. 
  • 2,500 solar water heaters have been distributed, solar PV systems introduced into five schools and 500 vandal proof street lights installed. 
  • An estimated 50,000 people now benefitting from PV water pumps and PV heating and lighting systems, both in homes and schools.
  • Additional schemes include extension of ‘Rent-a-lantern’ idea to solar water pumps; developing local supply chain for solar water heaters; and establishing a rural energy store to market energy efficient and solar products.
Solar lantern at market stall.  Photo: Martin Wright

The organisation

Aurore is a non-profit organisation established in 1998 by the trustees of the Auroville Centre for Scientific Research in Auroville,Tamil Nadu, to research and develop renewable energy solutions.  In 2009, 20 people were employed by Aurore. 
Aurore provides ideas and technical, financial and management support to partner organisations. It plays a key role in linking input from other organisations, for instance coordinating financial organisations to make best use of government subsidies. It is also able to buy from suppliers at significant scale, thus reducing costs. 

The technology

How does it work? 

PV modules are very useful for powering water pumps, because both the source of water and the use for it may be at a distance from mains electrical supplies.  The pump lifts water from a well or borehole, and may also be used to run an irrigation system.  The solar home systems used by Aurore are designed to supply light in individual homes, providing enough power to run two 11W fluorescent lamps for three hours every night. Solar lanterns can be used as very small solar home systems to provide light in individual homes. Another important use, and one where Aurore sees significant business potential, is to provide light for stalls in outdoor markets, which are common throughout India.  

How much does it cost and how do users pay? 

US$1 = Rs 45 (Indian Rupees) [2004]

The Indian Government funded a major programme to electrify the 18,000 off-grid villages in the Ladakh region of India.  Aurore worked alongside BP Tata in managing the supply of components to this very remote region, the installation of systems and the financial involvement of users.   For solar home systems, users pay an initial charge of US$22 (Rs 1,000) which is about 10% of the system cost, and then a rental fee of US$2 (Rs 100) per month. 

For PV powered water pumps, Aurore negotiates deals for the bulk supply of the pump equipment, which brings down the cost to users. It also coordinates access to Government subsidies, which can provide up to 80% of the initial cost of installing a pump; and it negotiates with banks to provide suitable loans to users. 

As a pilot project, Aurore helped five young people to set up a business which rents PV lanterns to street hawkers and market stalls in Chennai.  Users pay a refundable deposit of US$2 (Rs 100) and fee of US$0.30 (Rs 15 rupees) per night, which is equivalent to the cost of fuel for a kerosene lantern.  The lanterns are charged from a static PV array, and maintained by the five owners.  These businesses run without any subsidy.

The technology in more detail

The PV water pumping systems installed by Aurore use between about 900 and 1800 Wp of PV.  Two types of pump are used.  One is a centrifugal pump mounted on the ground, running on the d.c output from the modules.  Water is pumped out of the borehole through a suction pipe.  This type of pump is easily accessible for maintenance. The other type is a submersible pump, sunk to the bottom of the borehole or well.  This requires a.c power, and the PV output is therefore fed via an inverter which converts from d.c. to a.c.  

Each solar home system has a 37 Wp PV module with a 12 V lead-acid battery providing 75 Ah storage capacity.  The batteries are designed for PV use, with tubular plates to allow much more of the capacity to be used than with a standard car battery. Most of these systems are installed in the Ladakh region, where temperatures fall well below freezing in winter.  The batteries are therefore mounted in insulated boxes and use a high specific gravity electrolyte to reduce the risk of freezing.  A charge controller prevents overcharge and excessive discharge of the battery.

Home solar lanterns are supplied with an individual 10 Wp PV module.  Market lanterns have a single fluorescent tube, rated at between 7 and 11 W, and a lead- acid battery.  They are charged during the day at a central charging station, with one 37 Wp PV module charging four lanterns.  Aurore has worked with users in improving these lanterns, for instance making the market version more durable and incorporating an additional socket for a radio in the home lantern. 

Water pumps 

A PV-powered water pump is quiet and reliable compared with a diesel pump, and replaces the use of about 1,750 litres/year of diesel per year. Thus the pumps provided by Aurore save about 1.5 million litres/year of diesel, avoiding the emission of about 4,000 tonnes/year CO2

Because PV pumps operate over the full day, they put a more continuous load on groundwater supplies and do not lead to over-pumping.

Solar home systems and solar lanterns 

Solar home systems bring safer and brighter light than kerosene lamps or candles. Each systems saves about 60 litres/year of kerosene, giving total savings of about 0.5 million litres/year of kerosene, and avoiding the emission about about 1,300 tonnes/year CO2.

Being able to run small appliances such as radio or television off the PV supply saves the cost of batteries and opens up possibilities for both entertainment and education.

Solar lanterns have similar benefits to solar home systems when used indoors, albeit with lower output.  The benefits of good quality light are particularly appreciated in the outdoor markets, where food can be displayed better and without the smell of kerosene fumes.  

 

Update: what happened next?

By 2009, Aurore had provided an additional 6,600 solar powered water pumps in 15 states in India, bringing the total to nearly 7,500. The  programme’s biggest success with PV powered water pumps has been in the western state of Gujarat.  Here Aurore’s local network partner worked with the Gujarat government to provide drinking water to remote villages. After rigorous field trials with nine villages, the Government agreed to scale up the programme to cover 3,000 villages. Aurore has also provided a total of nearly 10,000 solar home systems, and some 50 independent enterprises that have taken on the ‘rent-alantern’ model developed by Aurore in Chennai.  

Since its 2004 Ashden Award, Aurore has also started providing solar water heaters (2,500 in total); launched solar PV systems in five schools, giving children access to the internet for the first time; and introduced vandal-proof solar street lights. Other schemes in progress include: 

  • Extending the ‘Rent-a-lantern’ idea to solar pumps. Instead of owning a system, a farmer would rent from a local entrepreneur
  • Developing a local supply chain for solar water heaters rather than importing them from China
  • Establishing a rural energy store to market energy efficient and solar products