Monday, April 16, 2012
Honey, I Shrank The Car!
Readers might recall my recent post on an electric truck I did some rewiring work on. In the few short weeks since that post, prices at the gas pump have risen sharply. While electric vehicles are by no means a panacea, the need to find practical, alternative fuel/power sources is painfully obvious.
Not only has there been much talk about electric and hybrid-electric vehicles, but many entities have been involved in trying to perfect the use of hydrogen fuel cells as a means of powering cars. A fuel cell is a device that takes hydrogen and oxygen gas as inputs and produces electricity and water as outputs. Water is the only "waste" product during this portion of the energy cycle. If a clean way of producing hydrogen could be devised, this could be a clean energy source overall. A fuel cell can extend the range of an electric vehicle and/or perhaps help recharge its battery bank. If the issues of hydrogen production, transportation, and storage could be worked out, it could possibly be a viable alternative sometime down the road.
About 3 weeks ago, I had the pleasure of working with a hydrogen fuel cell powered car. Unlike the electric pickup truck in my previous post, this was a scale model car. Called the "H Racer 2.0", it comes as a kit is made by Horizon Fuel Cell Technologies. They manufacture hydrogen fuel cells and educational kits which use them. You can reach their website here: http://www.horizonfuelcell.com/products.htm
Their educational kits - including the H-Racer 2.0 - are a ton of fun for kids of all ages - and would be a wonderful father-son (or daughter) activity. Definitely beats the mind-numbing garbage on TV any day!! The educational kits are listed here: http://www.horizonfuelcell.com/education_kits.htm Check online for prices - I've seen them cheaper elsewhere besides Horizon's web site. Some "bricks and mortar" retailers such as "Hobby Lobby" also carry part of the line.
A student at my university had already assembled the H-Racer 2.0 kit; I was asked to test it and get it running for a lecture and demonstration.
The kit consists of an IR remote controlled model car, fuel cell, a hydrogen fuel station which uses electrolysis of water to produce hydrogen, a small solar panel, and miscellaneous bits and pieces to make it all work.
The Hydrogen Fuelling Station:
The hydrogen fuel station can either be run from the included solar panel or on two AA type flashlight cells. It consists of a small water reservoir and an electrolysis module. On AA cells, I found the fuelling station took about 10 minutes to generate enough gas pressure for fill-ups. When running, the fuelling station gives a cool light show with bright, flashing green LEDs. To avoid contamination of the electrolysis cell, the instructions warn you to ONLY USE PURE DISTILLED WATER. Nothing else is added to the water.
The hydrogen fuel station connects to the car via a small hose and fitting. An inflatable bladder inside the car provides storage for the hydrogen. This stored hydrogen supplies a fuel cell which provides a nominal voltage of 0.6 to 0.7 volts DC.
Electronics Inside The Car:
A circuit board inside the car performs two main functions: It handles the IR remote control signals. It also, presumably using a switching power supply, takes the 0.7 volt DC from the fuel cell and steps it up to about 2.4 volts DC for running the motor and IR control circuit.
Before running the car, the fuel lines and storage bladder have to be purged of any air. This is done via a purge valve on the car and a syringe, which was also provided in the kit.
Once the system was purged of air, charged with hydrogen and functioning, I measured typical run times of about 30 seconds on a fill-up.
A note about the fuel cells used:
These fuel cells are warrantied for a year by the manufacturer. The instructions also warn you to return the car's fuel cell to its aluminum foil pouch if the car won't be run for several days or more. Apparently the fuel cell deteriorates with age, and allowing it to dry out accelerates this process. Using anything but distilled water in the fueling station risks contaminating the car's fuel cell as well as the electrolysis module. I haven't priced out replacement fuel cells, but I know they aren't cheap - as they use a platinum catalyst.
I had hoped to use these fuel cells as a possible emergency power source for small electronic devices such as the Ten Tec radio I built or to recharge small batteries, but their fragility and short lifespan would be quite problematic.
The pictures on this page pretty well tell the rest of the story.