The sun’s thermal energy heats the fluid inside the solar collector. In open systems, the heated fluid is directly the water used by the client. In closed systems, the heated fluid passes through a heat exchanger in a storage tank transferring the heat to the client’s water.
This depends on the period of cloudy cover and low temperature. Usually in Egypt this does not last for long and thus for some days in winter the heaters can be produce hot water. Nevertheless this is why it is recommended that a back up system is to be installed and used when the weather conditions are not favorable to reach the desired water temperature.
Flat plate collectors work very well in warm, sunny conditions, or where a strict budget is a concern. Evacuated tube collectors, which cost about more than flat plate, work very well in cold, cloudy or otherwise unfavorable conditions. There are a number of factors to weigh when choosing between the two.
It greatly depends on the application of the heaters. Solar Water Heaters used in houses to heat domestic water can thermosiphon systems as they are cheaper and in these applications more controlled systems as in forced circulation systems is not needed. Where in industrial application controlling the flow rate and water temperature at all times is mandatory so thermosiphon systems are not used instead forced circulation systems are recommended.
These systems require regular cleaning specially in dusty and desert conditions as in Egypt. In addition, to regular preventive maintenance provided by maintainers to check on the system components and any leakages.
A solar hot-water heating system can take care of the bulk of your hot water needs. However, in some instances, such as when it’s cloudy or rainy, the solar hot-water system may not be able to provide all the hot water you need. It is recommend that you install a solar hot-water system in conjunction with your existing system, or install the system with a solar storage tank that has an electric or gas backup.
The heaters can be installed to feed in hot water directly into the industrial process or can be used to heat the feed in water of the boilers consuming less energy by the boilers to heat the water from around 95⁰C instead of 25⁰C.
Solar Water Heater systems can cover a percentage of your factory’s thermal energy demand. Due to unreliable and unstable weather conditions it is not possible to completely replace the boilers/existing thermal energy system. Solar Water Heaters are integrated in the process to help reduce your energy bills.
A feasible reasonable installment of Solar Water Heaters in industrial applications would have a payback period of around 7-8 years and the less the more feasible the installment is.
The Egyptian market of SWH systems has experienced constant growth in market sales from 2011 to 2014, then the market has started to grow at almost 9% annually until 2018. The current annual market sales amount to 4.5 million USD with approximately 4,000 SWH covering an area of around 16,200 m2.
Solar Water Heating Egypt platform aim to connect and synergize relevant stakeholders in the Egyptian SWH market.
