Solar Water Heating Systems

Power cut is a consistent problem at the peak hours in summers as well as winters in most of the North Indian cities. In such cases, switching the heating load over to non-conventional sources of energy from the conventional type of resources can eradicate this problem and inconvenience that arise especially during early hours of peak winter season when the hot water is needed the most. The gap between the demand and supply of electricity can be bridged to a great extent by using solar energy based appliances such as Solar Water Heater.

China stands at the top position in the world in the Installations of Solar Water Heating Systems with approx. 80.3% of total installations in the world.

Solar Energy Appliances not only bridge the gap between demand and supply of the electricity but also save a lot of money due to their negligible running cost and also they help in maintaining the ecological balance by reducing pollution.

Solar Water Heaters are designed to heat water by using the solar energy which is available on earth free of cost. Water can be easily heated to a temp. of 60-70˚C.

A typical solar water heater

Main components of solar water heater system are:

A) Solar Collector (to collect solar energy)

B) Insulated tank (to store hot water)

C) Supporting stand

D) Connecting pipes and instrumentation etc. 

Solar Water Heaters can be of following two types:

1- FPC :Flat Plate Collector based

2- ETC :Evacuated Tube Collector based

In FPC based Solar Water Heaters the solar radiation is absorbed by Flat Plate Collectors which consist of an insulated outer metallic box covered on the top with  tempered glass sheet. Inside there are blackened metallic absorber sheets with built in channels or riser tubes to carry water. The absorber absorbs the solar radiation and transfers the heat to the flowing water. Most flat plate collectors have two horizontal pipes at the top and bottom, called headers, and many smaller vertical pipes connecting them, called risers. The risers are welded to thin absorber fins. Heat-transfer fluid (either water or water-antifreeze mixture) is pumped from the hot water storage tank (direct system) or heat exchanger (indirect system) into the collectors' bottom header, and it travels up the risers, collects heat from the absorber fins, and then exits the collector out of the top header.

In ETC based Solar Water Heaters Evacuated Tube Collector is made of double layer concentric borosilicate glass tubes evacuated for providing insulation. Since heat loss due to convection cannot cross a  vacuum, it forms an efficient isolation to keep heat inside the collector pipes.The outer wall of the inner tube is coated with selective absorbing material. This helps absorption of solar radiation and transfers the heat to the water which flows through the inner tube.

Flat plate collectors are generally more efficient than ETC in full sunshine conditions. However, the energy output of flat plate collectors is reduced slightly more than evacuated tube collectors in cloudy or extremely cold conditions.

FPC based systems with metallic collectors are costlier than the ETC based systems with glass tubes for the same system capacity (Ltr/Day).

Odisha Govternment : Harnessing Solar Power

The Odisha state government has approved a proposal for installation of solar panel in roof top of all government establishments in Bhubaneswar and Cuttack area under PPP model and has directed the implementing agency to sign agreements with International Finance Corporation (IFC). 

Last week, the government declared the newly floated company GEDCOL (Green Energy Development Corporation Ltd ) as the nodal agency for on-grid solar energy projects in the state whereas off-grid generation such as solar cooking, pumping, refrigeration, heating and industrial process will be Odisha Renewable Energy Development Agency (OREDA)’s responsibility . 

In the first year of the implementation, the government has decided to use the office rooftops of government offices, agencies, directorates and state PSUs situated in Bhubaneswar and Cuttack, and later the scheme will be planned for other districts. read more..

The Biju Patnaik airport in Bhubaneswar will generate 100 KW electricity from solar power plant to meet the daily electricity requirements.

This was an eco-friendly initiative of the airport to generate electricity.

The airport has signed a power purchase agreement (PPA) with a Gurgaon-based private firm, Lanco, for setting up the plant. The firm will sell power to the airport. About 360 solar photo voltaic (SPV) panels have been installed near the airport. Each panel will generate 300 W electricity. 
"The solar power plant will supplement the power requirement of the airport, which requires 3,000 KW of electricity, to run both the new domestic and proposed international terminals," said airport director Sharad Kumar.read more..

 

Wind and Solar Forecasting System by IBM

IBM has announced a power and weather modelling technology that will help utilities increase the reliability of renewable energy resources. The solution combines weather prediction and analytics to accurately forecast the availability of wind power and solar energy. 

HyRef forecast system graphic via IBM

Jibei Electricity Power Company Limited—a subsidiary company of the State Grid Corporation of China is the first client to use this software. It hopes to increase the integration of renewable power generation by 10%. 
 

The solution, named "Hybrid Renewable Energy Forecasting" (HyRef) uses weather modeling capabilities, cloud imaging technology and sky-facing cameras to track cloud movements, while sensors on the turbines monitor wind speed, temperature and direction. When combined with analytics technology, the data-assimilation based solution can produce accurate local weather forecasts within a wind farm as far as one month in advance, or in 15-minute increments. read more..

H.P. and M.P. - Policy to Harness Renewable Energy

Himachal Pradesh government has decided to come out with new power policy to harness solar energy. According to Chief minister Virbhadra Singh, the state government was endeavouring to preserve the depleting conventional resources to meet the increasing demand of power.

He said state government soon would come out with a new Power Policy with a view to harness the solar energy. Besides, possibilities of more hydro power and other non-conventional power resources were also being explored in the state, he added.

Madhya Pradesh govt. is also making efforts for tapping renewable energy on the same way. 800MW wind energy projects will be set up in Madhya Pradesh state by December this year. Similarly, 1800MW capacity wind energy projects will be set up by December 2014.
Madhya Pradesh government has formulated Wind Energy Policy-2012 to ensure prompt implementation of estimated 5500 MW capacity projects through private sector. So far, 324 MW capacity wind energy projects have been set up in the state.