Originally Posted by
luctor-et-emergo
So, @
Peace Piper,
Can you give me an overview of the pro's and cons between electric vehicles powered by batteries and those running on hydrogen?
In terms of:
Price
Maintenance
Safety
Lifespan
Weight
Range
I do see a clear advantage with this on a global scale. Around here there are now many plug-in hybrids and electric vehicles. A lot of those are company cars, driven daily and when people get home, they plug in. There is talk of how the electricity grid is disrupted by this peak in consumption. Hydrogen generation on the other hand could stabilise the electricity grid by consuming electricity only when it is not in peak demand. It can then be stored as well, removing the need to wait for a full charge on a long trip, which is one of the biggest downsides of electric vehicles imho.
Price: Both battery EV's and Hydrogen Electrics are more expensive than internal combustion engine equivalents now. Toyota expects to achieve price parity with ICE in the early 2020's, and, depending on who you believe, battery EV parity will happen around the same time.
Maintenance: Hydrogen electrics have a bit more maintenance than battery EV's because of the hydrogen system. Still, the only moving parts in a fuel cell system are the fans that blow H2 and outside air into the stack. The tanks need re-certification after 13 years (IIRC) while no one knows exactly how long an EV battery will last. Degradation depends on both time and number of cycles. The early Leaf batteries were not temperature controlled very well and resulted in many Leaf owners having to replace the battery (at $6,000 per, plus tax and installation). Current Leaf's have better thermal management. The oldest Tesla Model S batteries are ~6 years old. Some battery experts are expecting 10-13 year lifespan. A new Tesla Model S battery costs -depending on who you ask- $12,000, $18,000 or upwards of $30,000. Not many people are going to throw $10,000+ into a used car though, so it will be interesting to see what happens here.
Safety: There are safety concerns with both batteries and hydrogen, of course. Each poses its own set of potential problems. Tesla batteries have caught fire both while charging (Norway) and just simply driving down the street (Hollywood). To damage the hydrogen tank in a Toyota Mirai, Toyota had to shoot the tank with a 50 caliber bullet, smaller bullets bounced off. Escaped Hydrogen flies into space at 45 MPH so, unlike Propane, leaked H2 is only dangerous for a few minutes. A study done in Florida some time ago compared leaking gasoline and leaking hydrogen - both catching fire, and the results show that hydrogen is generally safer than gasoline.
Hydrogen Car Fire Surprise
Video documents results of hydrogen and gasoline car fires.
On a dark Florida night in 2001 an unusual and revealing experiment took place. Dr. Michael Swain with the University of Miami at Coral Gables attempted to simulate two car fires, one created by a 1/16th inch puncture in a gasoline fuel line, the other by a leaking hydrogen connector. He video taped the experiment to document what would happen if the leaks ignited. As the photos below clearly demonstrate, consumer fears about hydrogen as a transportation fuel would seem to be pretty much unfounded...more:
http://evworld.com/article.cfm?storyid=482
Lifespan: Expected EV battery lifespan - see above. Today's fuel cells have an expected lifespan of at least 5,000 hours continuous operation and the latest from AC Transit bus lines in California show Fuel Cell stacks can go over 30,000 hours. Recycling of Li-Ion batteries is not cost effective and will be something to consider, while today an expired Fuel Cell stack can be 95% recycled according to Ballard Fuel Cells in Vancouver, Canada
Weight: The Tesla Model S battery weighs around 1,325 pounds, a fuel cell stack in the Mirai somewhere b/w 1-200 pounds but also have to add the hydrogen tank and related hardware, bottom line, there is not much difference in weight between the two now.
Range: Tesla claims range of >300 miles, the Toyota Mirai claims around 315 miles and the Honda Hydrogen Clarity claims around 360 miles and the new Hyundai H2 Nexo around 380 miles. The recharging is the most important thing for those who value their time, as it will take 30-45 minutes to add significant range to a Tesla, while hydrogen electric cars can be completely refilled in about 3-6 minutes.
Originally Posted by
luctor-et-emergo
Hydrogen generation on the other hand could stabilise the electricity grid by consuming electricity only when it is not in peak demand. It can then be stored as well, removing the need to wait for a full charge on a long trip, which is one of the biggest downsides of electric vehicles imho.
Called "Power to Gas" and it is becoming popular in Europe and soon Australia
also see: https://vimeo.com/216635873
And this from California:
In a national first, UC Irvine injects renewable hydrogen into campus power supply
Power-to-gas technique offers new way to store and use excess wind and solar energy
“Storage of the hydrogen in existing natural gas infrastructure could produce a massive hydrogen battery that could become the most important technology for enabling a 100 percent renewable future.”... https://news.uci.edu/2016/12/06/in-a...-power-supply/
Leeds, UK is presently experimenting with injecting hydrogen into citywide gas lines. Before the North Sea natural gas discoveries the UK used "Town Gas" which was around 50% hydrogen so it has been proven to work already, the study will show whether the expense is worth it today. With a small modification, almost all Natural Gas appliances can burn hydrogen.
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