Dausa Milk Chilling Plant, Rajasthan

General Information on the company using solar thermal energy

Description of the company

Jaipur Dairy is a cooperative and handles the milk processing activities in Jaipur District. The dairy plant has a capacity of 1.5 Lakh LPD with a powder plant of 10 MTPD for service of thousands of rural farmer families of Jaipur. Various milk and milk products are marketed under the brand name of ‘SARAS’.

At district level chilling plants are attached to the dairy plants. Cattle herder sell their stock of milk which is stored in the chilling plants before sending to the milk processing plant.

The milk chilling centre at Dausa is attached to the Jaipur Dairy Plant and has a capacity of 70,000 LPD. The facility is used for chilling the milk at 4-5 °C and sent to the Jaipur Dairy for further processing.

Type of Industry

Dairy Industry

Location of the company and the solar plant

The SWH System is installed on the roof top of the building of:
Dausa Milk Chilling Centre
Agra Road, Dausa

Heat demanding processes

Hot water of 75°C to 85°C is used for washing of milk tanks and cans. The hot water requirement is for about three to four hours a day for all 365 days a year.

Conventional heat supply

The plant has 8.5 TPH furnace oil based conventional boiler.

Conventional fuel used

Furnace oil is used in the boiler. The price of the FO was Rs.35 per litre at the time of installation of the SWH System in 2010. The energy content of the FO is about 9800 Kcal/kg.

Motivation to use solar thermal energy

The Rajasthan Dairy Federation has implemented the SWH Systems in around 13 chilling centres across the state to reduce fuel consumption and save fuel costs.

Description of the solar thermal system

Type of solar plant

Non-pressurized thermosiphon SWHS with flat plate collectors to provide hot water for washing processes.

Year of installation

The SWHS was commissioned in the year 2010

Solar collector field

48 flat plate collectors with a total area of 110 m2 are installed on the roof-top of the building.

Flat Plate Collectors of Solar Water Heating System at Dausa Milk Chilling Plant

Water storage

Two solar water tanks with a total capacity 5,000 litre, insulated with rock-wool, are installed above the level of the collectors aside the collector field.

Dausa Dairy SWHS water storage tank

Hydraulic scheme and operation of system

Hydralic scheme of the SWHS at Dasu Milk Chilling Center, Dasua, Rajastan

Hydraulic Scheme of the SWHS at Dausa Milk Chilling Center, Dausa, Rajasthan

Supplier/ manufacturer of the solar system

Photon Energy Systems Limited
Unit 19, Mount View Enclave,
Road no 12, Banjara Hills,
Hyderabad - 500 034,
Andhra Pradesh

Data recorded

There are no data measured

Energy balance and economy

Heat demand

It is assumed, that the factory requires 5,000 litre per day of 80°C hot water and the cold water temperature is equal to the annual average ambient temperature of 25°C.

The daily energy demand for hot water heating can be calculated with:
Qdaily = 5 m3/day * (80°C 25°C) * 1.16 kWh/(m3*K) = 319 kWh/day

The annual energy demand for hot water heating is:
Qannually = 365 days * 319 kWh/day = 116 MWh/year

Solar radiation-on site

The site receives an average annual solar irradiation of 4.97 kWh/(m2*day), this means 1,814 kWh/(m2*year) on horizontal surface. On collectors with an inclination of 40° the irradiation is about 1.1 * 1,814 kWh/(m2*year) = 2,000 kWh/(m2*year).

Useful solar energy delivery

The solar radiation on the collector surface is
110 m2 * 2000 kWh/(m2*year) = 220 MWh/year.

Assuming a system efficiency of about 20%, the useful solar energy is about 220 MWh/year * 0.2 = 44 MWh/year, which corresponds to 121 kWh/day.

The useful solar energy delivered by the SWHS per m2 of collector is: 1.1 kWh/m2.

Fuel saved by solar energy

Assumed, that the boiler has an efficiency of 70%, the energy content of furnace oil saved by the SWHS System is 44 MWh/year / 0.7 = 63 MWh/year. This corresponds to 63 MWh/year / 10 kWh/litre = 6,300 litre/year or 17.2 litre/day.

Emissions saved

The CO2 emissions saved by the SWHS can be calculated to:
6,300 litre/year * 2.52 kg CO2/litre = 16 to CO2/year


Investment costs

The total cost of the system is Rs. 6.48 Lakh, corresponding to Rs. 5870 per m2 collector area.


The project proponent has availed the MNRE subsidy of 30% on the total investment cost. I.e. Rs 1.9 Lakh.

Economics of the solar system

Based on a furnace oil price of Rs 35 per litre (2010 prices), around 6,300 litre/year * Rs 35/Litre = Rs 2.2 Lakh is saved per year.

Simple payback time (without considering interest on debt) is therefore (Rs 6.48 Lakh - Rs 1.9 Lakh) / Rs 2.2 Lakh/year = 2.1 years.


Operation experience

Since the installation of the system, the SWH system at Dausa Milk chilling plant is working properly and the project personnel never faced major O&M problems.

Statement of the owner

The plant personnel is very satisfied with the operation of the system and the financial benefits of the SWH project.