Indian vs. European SWHS

Comparison of Indian and European SHIP systems

There are a lot of differences between Indian and European Solar Water Heating Systems for Industrial Processes (SHIP). The most important ones are explained in the following. Some of the differences are caused by different framework conditions (e.g. necessary freeze protection and usually no available space on the roof for the installation of a storage tank in Europe) and some of them are caused by different technological development (e.g. the use of automatic controllers in Europe).

To identify the best SHIP system concept for India, it is recommended to compare the technologies used in India and Europe, try to understand the reasons for the different solutions and develop well-adapted solutions to the Indian market with the best value for money.

 
Typical name / Philosophy »1000 LPD system«
(1000 Litre per day) Objective: To deliver a specific volume of hot water with a specific temperature per day
»100 m2 system«

(100 m2 collector area) Objective: To deliver a specific amount of thermal energy over the year by using a specific collector area

Collector sizing According daily hot water demand According annual energy demand
Storage tank sizing According daily hot water demand According load profile and variation of irradiation
Hydraulic design Thermosiphon and forced circulation Mostly no freeze protection In some systems process water is flowing through the collector field Only forced circulation Almost always freeze protected Collector circuit is always decoupled from the process water circuit
System planning Excel-calculations are made based on experiences, specific conditions (weather, demand profile) are roughly taken into account Planning software is used, which optimises hydraulic design as well as collector and storage tank sizes, and delivers data on expected solar yield
Type of operation Partly “batch systems” are used: solar energy heats up the water in the storage tank during the day, the heated water is transferred to another tank for use in the evening or the next day Only “continuous supply systems” are used: solar energy heats up the water in the storage tank via a heat exchanger, the heat of the storage tank is continuously used by the process
System pressure Most SHIP systems are non-pressurised (in addition to the static pressure) All SHIP systems are pressurised with e.g. static pressure plus 1 bar
Pumps Fixed flow pumps are used, often 2 pumps are installed in parallel for redundancy Usually fixed flow pumps are used, variable flow pumps and high efficiency pumps are available
Controller Some of the forced circulated systems are operated manually, automatic controllers are specifically designed

Only automatic controllers are used, specialised controller manufacturers deliver high elaborated controllers, which have monitoring functionalities included

More detailed descriptions of the differences are available in the flyer MONITORING AND POSSIBLE IMPROVEMENTS OF SOLAR WATER HEATING SYSTEMS FOR PROCESS HEAT APPLICATIONS.