Potential energy savings from heat retention/storage through insulated systems in households

Introduction

Heat retention is an old-age technology and simple, operating on the principle of thermal (heat) insulation to retain heat in a container. Some of the basic and most important applications in the households include cooking (for instance simmering rice), keeping food warm or storage of hot water.

Heat retention has a big potential for cost effective conservation of fuel/electricity consumption. In addition, this technology is very essential for harnessing energy from renewable sources such as solar energy (solar cooking) and biomass which are fluctuating or limited in nature. However, materials for heat insulation and system design have to be optimized in order to perform within the expectations of the users.

Some materials for insulation include: unused old blankets/clothes, sheep wool, hay, rice straw, feathers, cotton, cardboard and other locally available materials.

Source: http://solarcooking.wikia.com/wiki/Heat-retention_cooking

Some interesting results

In this article, the results of a simple experiment of insulating plastic bottle containing one litre of hot water using pillow material (nicely wrapped around the bottle) are presented in the graph below.

The results indicate that boiled water (at about 90 degrees centigrade) can be maintained at temperatures of at least 50 degrees centigrade (desired temperature for domestic hot water) for over 8 hours under insulated conditions. Therefore, this means that the temperature loss rate is roughly 5 degrees centigrade per hour from simple and easily set up system. Note that the system was not optimized for operation and therefore better results can be achieved if the system is designed and optimised properly.

Conclusion

Heat retention systems complement boilers and cookers and they are very simple and cheap. They also have a big potential for saving energy (both electricity and thermal) in households. They can eliminate or minimise the use of energy guzzlers such as microwaves and electric kettles as well. Look, babies and kids can enjoy warm food all day long without warming!!  

Save energy, Store energy, Save the world (3S)!!