OCV Reinforcements Manufacturing Limited is a daughter company of the US company Owens Corning Inc. In India OCV Reinforcements is a market leader of glass fibre products. The total annual production capacity is 18,500 Tonnes. The annual sales turnover during the year 2012-2013 was around INR 1.20 Billion.
Hot water is required for mixing of chemicals. The required hot water temperature is about 85°C. The factory is operating continuously in three shifts a day.
Conventional heat supply
The back-up heater to the SWHS is an electrical heater of 4.5 kW capacity.
Conventional fuel used
Beside solar thermal energy, only electricity is used for water heating.
Motivation to use solar thermal energy
The company aims to increase energy efficiency and reduce electricity consumption by using solar water heater.
Description of the solar thermal system
Non-pressurized solar water heater system with ETC collectors with a solar water storage tank of 2000 litres.
The SWHS system was commissioned in 2010.
8 evacuated tube collectors (ETC) are installed in parallel with 6.93 m2 total gross collector area per collector and 55.4 m2 in total.
The panels are installed on the flat roof of the factory building.
Solar hot water storage tank of 2000 litres.
The SWHS is a non-pressurised system. Demineralised water (DM) is stored in the DM tank at ambient temperature. If the hot water in the manifold reaches 85OC due to thermosiphon circulation from the ETC collectors, the pump at the DM water tank is switched on and DM water is pumped through the ETC collectors into the solar hot water tank installed at the rooftop of the unit building. The hot water is flowing to the process by gravity, since the hot water requirement is on the ground floor. There is a control valve for ON/OFF purpose. The hot water from the storage tank is utilised in the chemical mixing process.
The solar system was designed, delivered and commissioned by:
M/s Photon Energy Systems Limited
Unit 19, Mount View Enclave
Road No. 12, Banjara Hills
There are no data logged.
It is assumed, that the factory requires 2000 litre per day of 85°C hot water and the cold water temperature is about 30°C. Then the energy demand per day for hot water heating is: Qdaily = 2 m3/day * (85°C − 30°C) * 1.16 kWh/(m3*K) = 128 kWh/dayThe energy demand per year is: Qannually = 350 days * 128 kWh/day = 44,800 kWh/year(The temperature difference in °C is measured in K (=Kelvin), it is assumed, that the factory is operating 350 days a year)
The site receives an average annual solar irradiation of 5.18 kWh/(m2*day), this means 1,891 kWh/(m2*year) on horizontal surface. On collectors with an inclination of 30° the irradiation is 1.05 * 1,891 kWh/(m2*year) = 1,986 kWh/(m2*year).The site is located at 17.17o N Lat. and 78.29o E long.Source: NASA RET SCREEN.
The solar radiation on the collector surface is
55.4 m2 * 1,986 kWh/(m2*year) = 110,000 kWh/year.If a system efficiency of about 30% is assumed, the useful solar energy is about 110,000 kWh/year * 0.3 = 33,000 kWh/year.
A SWHS system efficiency of 30% is assumed
Since each kWh provided by solar energy is replacing a kWh of electricity, about 33,000 kWh electricity per year are saved.
Emissions saved from saving of 33,000 kWh electricity is about
28 t CO2 per year (Assumption: emission factor 0.85 t CO2 /MWh for southern grid)
Investment costs: INR 5 lakhs = INR 5,00,000 (€ 7,080)This corresponds to INR 9,000 per m2 collector area (€ 127 per m2)
No Subsidy is availed.
Based on an electricity price of INR 4.5 per kWh, INR 1,48,500 are saved per year. Payback period without considering interest on debt is 3.4 years.
No malfunction known.
Owner is satisfied about the operation and savings due to implementation of SWHS System.