Solar energy is one type, or one form, of Renewable Green Energy. Solar energy can be tapped and exploited in several ways; one such way is the heating of water and this is called: Solar water heating. Solar water heating is the process and technology that uses solar collectors which collect the sun’s rays, converts them to heat which in its turn is used to heat water using a solar water heater.
Solar heating is used in areas where there is enough solar energy and it is particularly efficient and effective for needs which are seasonal and have the peak need of hot water during the summer months during which we observe extensive sunshine and high temperatures.
Solar water heating
Where is solar heated water needed? It is needed everywhere we need hot water. The four main application areas indentified and targeted by the industry are the following:
- Residential Homes: to heat the hot water used for home needs which vary from uses in the kitchen, bathroom or washing.
- Drinking and service use for commercial and industrial use
- Floor heating: a new trend in home heating
- Heating of swimming pools which are either indoor or outdoor, for homes or in sport centers.
The idea is simple. Sun ray collectors are used in order to collect the sun’s rays. In other words they collect the heat radiation which is its turn is used to heat the water. In most of the cases the water that is heated is not the one used for consumption but it is the one used to heat the water for consumption. For this to happen we need to use solar water heaters. Hot water is stored in storage tanks so that it is used as and when needed. One of the key factors of this technology is the efficiency of the heat collectors and as the efficiency increases so does the price of the heat collectors, thus increasing the solar water heating cost.
Solar water heating collectors
There are basically 3 types of solar water heating collectors, and these are listed below in increasing efficiency order:
- Ordinary seasonal collectors: Simple in design which circulate the water in pipes and are not so efficient since they are not, usually, insulated.
- Flat plate collectors which are insulated and they release the heat through a heat exchanger
- Evacuated and well insulated tube collectors which are the most efficient.
How many solar water heating collectors are needed?
One of the questions which come up when designing and installing a solar water heating system is: How many solar water heating collectors are needed? The answer is simple and it all depends on the needed quantity of hot water. The number of collectors has to do with the application need, whether the project concerns a residential home or a commercial one and the size of the building, which determines the size of the load. It is all part of the design of the solar water heating system.
Solar water heating systems
Solar water heating system installers and designers take several factors into consideration when designing and implementing a solar water heating system. These, design, factors are:
- Load of the system. This has to do with the application need, home use Vs commercial or industrial use.
- Efficiency of the solar collector.
- Budget available for the project.
- The solar radiation available at the site and this depends of purely geographical facts of the site.
- The hot water storage that is possible to have at site.
Any solar water heating project should be treated as any other project and a cost Vs benefit analysis together with the Total Cost of Ownership, TCO, should be two of the deliverables by the system designers and project managers.
It should be noted that for solar water heating systems, as it is the situation with all solar energy systems, the orientation of the system should be South with an unobstructed access to the sun so as to be able to capture the full potential of the Sun.
In conclusion, as it is with every renewable energy system, certified professionals should be involved in a solar water heating project in order to ensure accurate and best design and implementation of the solar water heating systems. Solar water heating is just another way of capturing solar energy, a renewable green energy source, and thus save energy and reduce the C02 emissions therefore reducing the impact on the environment.