Water Is Not A Fuel

Each week I receive press releases about "game-changing technologies" in the energy space. The number of these technologies that ultimately end up as game-changers is pretty close to zero, but I don't immediately disregard such claims unless they clearly violate laws of science.

I am, nevertheless, naturally skeptical until convinced otherwise.

Such was the case this week when I received a press release from Australian-Israeli startup Electriq~Global. The press release read in part:

• Australian-Israeli company Electriq~Global and Dutch company Eleqtec have entered into an agreement to launch Electriq~Global’s water-based fuel technology in the Netherlands. Together they plan to launch Electriq~Fuel’s recycling plants, and introduce eMobility applications for trucks, barges and mobile generators.
• Comprised of 60% water, Electriq~Fuel is a game-changer in zero-emissions energy. The innovative fuel is a cost-efficient alternative to batteries and compressed hydrogen. When compared to green energy storage solutions like lithium-ion batteries or compressed hydrogen, Electriq~Global achieves a greater range at a lower cost. The energy density potential of the technology is up to 15 times that of electric batteries currently in use in electric vehicles."

When a claim implies that water is being used as a fuel, it always increases my skepticism. But, I replied to this particular press release and told them I would need additional information before acting on the press release:

• I would need to know some details they probably aren't willing to give up. For example, water itself can't be a fuel. It's a combustion product. The only way to turn it into a fuel is to add energy somewhere. I could boil the water and turn it into steam. I could electrolyze the water to make hydrogen. I could add something (like sodium metal) that would react with the water to produce hydrogen. But each of these steps involves energy addition into the system."

That's the catch with any of these systems that seemingly rely on water as a fuel. Water can't be a fuel, just like carbon dioxide can't be a fuel. These are combustion products. They can both be converted into fuels, or into energy carriers, but that requires additional energy inputs. (In the case of hydropower, nature has added those energy inputs). And the laws of thermodynamics require that the energy inputs to create a fuel will always be greater than the energy you get back when using that fuel.

For example, I can create hydrogen from water by passing electricity through it. I can then burn that hydrogen for energy, but it will always be less than the amount of energy I consumed in producing the hydrogen.

It might, for instance, require four British thermal units (BTUs) of electricity to create three BTUs of hydrogen from water. There are cases where that's economically justified, but you want to be sure that the four initial BTUs that were used couldn't be used to power the final application. It is generally more efficient to use four BTUs of electricity to power a vehicle than to convert that into three BTUs of hydrogen to power the vehicle.

I did receive a response, but it was just a press kit that went into a few more details. The press kit did acknowledge that the water "reacts" with a catalyst to produce hydrogen. As a nitpick, a catalyst increases the rate of a chemical reaction without itself being consumed in the reaction. If the substance is actually reacting with water it isn't a catalyst, it is a reactant.

For example, as I mentioned in my response, sodium metal reacts -- violently -- with water to form sodium hydroxide (NaOH) and hydrogen (H2). The reaction evolves energy so rapidly that the hydrogen can explode. In the process, the sodium metal is converted to sodium ions. Thus, sodium is a reactant and not a catalyst. Further, it is highly energy intensive to convert sodium ions back into sodium metal.

I don't know for a fact that this is the case with the Electriq~Fuel, but the press kit does say that the "catalyst" is a salt chemical they call BH4. I suspect it is a metal hydride (like sodium hydride, NaH). This class of compounds will produce hydrogen when reacted with water, but are themselves energy intensive to produce.

Thus, a car running on such a system could claim to be a zero carbon emission vehicle, but those emissions do occur where the salt itself is produced. Much like an electric vehicle running on coal-fired power releases zero emissions, but there are emissions associated with the production of its electricity.

This is clear from the press kit, which says "The footprint of our technology is zero when we use renewable energy to recycle our fuel. We consume low purity industrial H2 that is produced as by product of other chemical processes (eg: production of chlorine or steel)."

That may well be true in theory, but far too many technologies invoke the magic wand of renewable energy to claim zero emissions. What we would really like to know are the actual required energy inputs to produce enough salt to propel the vehicle X miles. That way, we could compare this technology to the energy efficiency of an internal combustion engine or an electric vehicle.

Further, in my experience "low purity industrial H2" is typically used on site for fuel, rather than transported elsewhere to an end user. There isn't an abundance of such hydrogen available to users.

In conclusion, it was by no means my intention to discredit or disparage the Electriq~Fuel technology. As I mentioned in my reply to them, I would need more details before I could make a determination on whether I view this as a "game-changer." My intent here was rather to help readers understand the kinds of questions you should ask when assessing these sorts of claims.