Crunching the Numbers on a Hydrogen Economy

mattnyc99 writes "In its new cover story, 'The Truth About Hydrogen,' Popular Mechanics magazine takes a close look at how close the United States is to powering its homes, cars and economy with hydrogen — including a calculation of where all the hydrogen would come from to meet President Bush's demands. Interesting that they break down the future of hydropower not by its advantages but by its challenges: production, storage, distribution and use."

Comments

Hydrogen Not A Fuel?

[mrdrivel]

From the article:

But unlike oil and gas, hydrogen is not a fuel. It is a way of storing or transporting energy. You have to make it before you can use it -- generally by extracting hydrogen from fossil fuels, or by using electricity to split it from water.

How is hydrogen not a fuel? I always thought fuel was a substance that when it goes through a chemical reaction releases energy. While many fuels are burned, the process of generating energy in a fuel cell is still a chemical reaction.

Secondly, aren't there other fuels that have to be made before we can use them? Gasoline and diesel have to be refined -- it's not like we find them naturally in the ground.

So hydrogen is just a way of "storing and transporting energy". I thought the use of fuels was a way to "store and transport energy".

Climatology is full of scientific uncertainties

[Morgaine]

It's not as clearcut as you make out. Try reading some actual scientific papers on the topic, instead of just listening to the media and politicians with an agenda. Scientists make a distinction between their actual scientific correlations and their preferred personal interpretation --- the latter is not Science.

Climatology is full of uncertainties, and the general agreement among scientists goes only so far. The most important area of agreement is that CO2 operates as a greenhouse gas, but the extent of its contribution within the overall system is commonly misrepresented.

CO2 is not the most important greenhouse gas, by a long chalk. Water vapour is the primary greenhouse gas on Earth, directly responsible for 95% of the global warming that keeps the planet from freezing solid to a dreadful -19 C or so. Global warming is essential.

Climate modellers who want to highlight CO2 choose not to make that known to the man in the street, and the way they treat water vapour as a "feedback" in the GCM models instead of as a key mechanism of "forcing" tends to brush the importance of water vapour under the carpet. It's a somewhat questionable scientific approach because pure feedbacks should really be invariant linear amplifiers and not highly variant in their own right (as is water vapour), but what's worse is that this creates a hugely inaccurate public perception.

The simple fact is that we live on an ice, water, and water-vapour covered globe moving in a somewhat complex way around a somewhat variant Sun, and that is the PRIMARY driver of climate, with water as its main agent of heat distribution and with just enough natural global warming to make it liveable, in between ice ages. CO2? Yes, it's relevant and it does have an effect, but it's not even close to being a primary player, and reducing our CO2 emissions will not have a significant effect in anybody's realistic scenario.

And that's not under dispute by any scientist --- they know the maximum extent of possible direct warming per ppm of CO2, and they also know the maximim warming amplified through water vapour feedback in a cloudless atmosphere. But they're not even close to understanding well the magnitude of interactions in the upper atmosphere nor being able to model cloud formation well enough to determine what the real effect of 2X or 3X CO2 would be. To claim that anything in that area of climate forecasting is "established without doubt" is a total distortion of the truth.

What's more, the natural variation in temperature across glaciation cycles totally swamps the changes calculated by any existing climate model, which just shows how we know very little in the larger context. We're right at the "natural" end of the current 18,000-year inter-glacial period, so expect a massive drop in temperature any century now. Can the GCMs predict that? Of course not.

The uncertainties in this area are LARGE. They will be worked out. In the meantime, only non-scientists claim clearcut knowledge.