Author: Carter Reames
There is a solar power home application that stands out as the place to begin, it almost always is the making of solar hot water for domestic consumption. The reason for this is that this application is almost always the most cost-effective and the easiest house solar application that can be accomplished. Normally, the cost of generating domestic hot water by conventional methods accounts for between one-fourth and thirty-three percent of total house energy costs, and a solar hot water system can reduce this between two-thirds and over three-fourths of this utility cost.
Of additional importance in beginning with solar hot water in changing a conventional power home to solar is the numerous possibilities of handy do-it-yourself (DIY) solar water tools, either from scratch or buying easy to install kits available on the internet that are simple to implement and much less costly than a full contractor installation. Furthermore, if complete or partial solar water house heating is a possibe prospect, such a system can be very economically and efficiently integrated.
Generally solar water systems have solar heat collectors, a liquid system to transport the collected heat from the heat collector to storage or its place of usage; and a method for transporting the liquid between the collector and storage or the place of usage.
Electrically powered pumps and controllers are components in an active system used to transfer the liquid, and passive systems employ only thermosyphon and gravity to naturally move the fluid as it heats. However, in some passive systems an integral collector-storage system (ICS or “batch system”) may be used if usage conditions are appropriate. These systems have one or several black storage containers inside a glazed insulated container where cold water is preheated in the solar collector tanks before moving into a fossil energy water heater.
If a fully green active system is required, there are also some outstanding, inexpensive DIY solar energy electricity kits which make it possible to generate sustainable onsite electricity with which to move the water and to operate its control electronics. Regardless of whether an active or passive system is employed, both normally have a supplemental heat source included to heat the water as required to maintain adequate temperatures.
There are two reasons that flat-plate collectors are almost always used in home solar applications: they achieve adequately high temperatures (less than 200 degrees Fahrenheit), and they are significantly less expensive than the closest collector alternative.
A flat-plate collector usually consists of
(1) a dark metal or plastic plate to capture the solar heat,
(2) a transparent glass or plastic cover which allows the solar heat to transmit to the absorber but reduces the loss of heat, and
(3) a plastic or metal insulated container with which to surround the heat absorber. The heat transfer fluid moves through pipes that are usually integrated with the heat absorber. The usual installation affixes flat-plate solar collectors with a unmoving orientation to the sun. And, the best solar capture efficiency is effected if the collector faces toward the sun and slopes at an angle to the horizon equal to the latitude plus about 10 degrees.
In this as in all solar energy applications, there is the double benefit of reducing unsustainable power expenses while reducing the associated environmental impacts of conventional power generation.
About the author:
Carter Reames is an engineer who first became involved in solar and other alternative energy activities during the oil embargo of 1973. Interest waned somewhat during the era of unreasonably cheap fossil energy, But, with fossil fuel’s ever increasing costs and solar energy’s steadily decreasing costs, his interest in solar power is now back with a passion.