EV alternative for light/medium duty trucks

RambleOnNW wrote:

map40 wrote:


Green: produced with renewable energy. The most expensive production method and the most inconsistent as wind and solar are not constant. For this reason Green hydrogen production normally uses also fosil fuel when renewable energy is not available to keep the production equipment running otherwise the investment never pays off. This forces Green hydrogen to produce between 25 to 50% of Carbon emmisions than Fosil Fuel production because they run 25 to 50% of the time on fosil fuel.

Not sure where you got this definition but it is false. Green hydrogen is only green if it is made with renewable energy. If there is some fossil fuel involved then it is termed ‘low carbon’. And you forgot the renewables hydro and geothermal power, which of course have 100% availability. And hydro is inexpensive power.

There are multiple types of electrolyzers, PEM, alkaline, and solid oxide. Of the 3 only PEM can ramp its power input rapidly up and down to follow fluctuations in renewable power input.

There is also ‘pink’ hydrogen which is that produced using nuclear power.

The definition comes from the European Commision of energy. The US secretary of energy has a less detail definition, stating that is has to be green, but no further details. Reality is that once you connect to the grid (instead of your own power) you don't know what you are using. As far as hydro and thermal energy, they are normally used at 100%, so any variance energy consumption is produced by Fosil.
As far as the electrolizers, if you are using electrolizers means that you are controling the reaction and you are not doing direct extraction, which means that production of hydrogen is more expensive that gasoline. That is why I made the comment that the best aternative is direct extraction. You control the production by controling the energy and the energy is constant being produced at the extraction point from the ocean floor. That is what makes it economically viable.