Idea Analysis

Analysis of the ideas so far.
1. Using a dynamo to charge batteries to provide a source of energy for thermal energy production, like lamps.

a. Rechargeable batteries will be more cost-effective and easier for the poor, as they rarely have to be replaced.

b. However, batteries can be lost easily, as they are quite small.

c. Dynamos and batteries may also make the people targets for thefts as they contain metals, which can be worth quite some money.

d. Rechargeable batteries do not work as well in cold weather, as the chemical reactions that create the electrical current occur at a slower rate, shortening the battery life.

i. However, this can be easily remedied, as warming up the batteries can restore the battery life. So, the lamp/source of heat can be used to warm up the battery to speed up the chemical reactions.

e. When unused and uncharged, rechargeable batteries will slowly lose their charge because of leakage. Therefore, once winter is over and the people do not have a use for the batteries, the batteries will eventually become unusable by the next winter, meaning the homeless people will have to buy new batteries each winter.

f. Bringing newspapers/cardboard around may be quite troublesome. Lamps are also fragile, and could also be another target of theft.

g. Running can be easily completed, so generating energy through the dynamo would be easy.

h. However, how to generate energy using a dynamo by running? One possible method: using the movement of the knees to turn gears and generate electricity: http://www.dailymail.co.uk/sciencetech/article-512944/Human-dynamo-How-energy-knees-power-Ipod.html



2. Using an overall to create a layer of air around the body, then connecting a tube to conduct thermal energy (via hot air) from external sources (such as fires) to warm up the air around the body.

a. Since air is a poor conductor of thermal energy, the people can be kept warm for longer periods of time.

b. The overall can be carried around like a piece of clothing, so it is easily portable and also will not be easily misplaced by the user due to its size.

c. However, it relies on the presence of external sources of thermal energy like fires, lightbulbs, etc. making it an unreliable source of warmth.

d. For the double-layered overall to work well as an insulator from the cold environment, one way could be to trap air within the overall too, as the solid overall can still conduct thermal energy better than air.

e. The overall could be heavy, especially if it is made of thick materials, and could be quite troublesome to carry around.

f. Any holes in the overall would greatly reduce its effectiveness as the warm air inside the overall can easily escape to the environment, and cold air can enter inside the overall. Since the homeless may not have the materials or money to repair any holes in the overall, this idea may be unsuitable for the homeless.

g. The tubes used in the transfer of hot air might be easily misplaced as they are small.

However, the second idea seems to be the most suitable, as it modifies an existing invention (winter clothing), and makes it more effective in keeping the homeless warm, while the first idea is relatively new, and using a dynamo may cost significantly more money than just a simple overall. There is also a lower chance of losing the overall and tubes than the dynamo, batteries and lamp as the overall and tubes are bigger.

Information about rechargeable batteries:
http://chemistry.about.com/od/howthingsworkfaqs/f/coldbattery.htm
http://www.andybrain.com/archive/nimh-lion-nicad-rechargeable-battery.htm