Chatted to a generator salesman recently and they did hydrogen generators as a substitute  for diesel. They guy pointed out that only green sourced hydrogen is actually green otherwise to generate hydrogen via conventional means is up to 4 times worse than coal 🤣,(reply>), @Martijn Maas "its no alternative for planes and rockets yet"  ???<br>we've been flying lots and lots of hydrogen rockets ever since the late 50s!<br><br>as for "then how does the rest get its renewable energy?": we were only talking about those peaks that are threatening to crash the grid, werent we? and for that i think it still is an excellent solution. <br><br>and adding a small cooling tower for a hydrogen plant, it dont think thats gonna put a noticable dent into the overall efficiency (it already is crap).<br><br>as for the overall energy supply. well we better get started building those turbines and panels and pumps and tidal dams and whatever else cool technology there is out there!,(reply>), @Martijn Maas The very localized increase in humidity caused by many hydrogen powered machines could be an issue (as it was for the steam-powered factories of the 19th century).  However the average atmospheric H2O concentration is almost entirely dependent on average air temperature.  Unlike CO2 excess water falls out of the air on its own, the water cycle is very rapid compared to the carbon cycle.<br><br>So the fact that water is a greenhouse gas is irrelevant to climate policy, and the fact that using hydrogen as a fuel emits water is unimportant.<br><br>Also the combustion of fossil fuels produces water vapor.  I do doubt that the excess H2O emissions from a fleet of all hydrogen powered vehicles is significant compared to the incidental H2O evaporation inherent in people's day-to-day water usage but feel free to crunch the numbers yourself and post them.  Additionally you should establish that this excess humidity causes adverse weather (moreso than other urban characteristics like the heat island effect).,(reply>), @VitalVampyr Your point of view is a very common misconception.<br>CO2 as well as water vapour are both produced and consumed in a natural way. Adding large quantities of either will disturb the ballance as we already learned from CO2.<br><br>It ignores the effect of more unpredictable, extreme and violent weather conditions. Adding water vapour to the atmosphere is adding potential energy to the atmosphere and we don't control how or where that energy is released.<br><br>I would strongly recommend to study the physical processes in a huricane, wich are triggered by large ammounts of water vapour condensating when warm, saturated air is meeting cold air.<br>Some claim that flash floods due to heavy rain (not caused by huricanes) are a side effect of the greenhouse effect on the current climate, adding more water (or rain) to the atmosphere will most likely increase this issue since we just don't control where that rain is falling.<br><br>Mayor problem still is that there is no "zero emision" system yet and as long as the atmosphere is used as part of the chain we will not solve the problem, only shift it.<br>So next step is making it part of a closed loop system but that requires a bit more than the current efforts. "Net-zero emission" needs to become absolute zero emission for CO2 as well as watervapour if we want to use it in our global scale energy demands.,(reply>), @Martijn Maas Water vapor is technically a greenhouse gas but it doesn't remain in the atmosphere long-term.  You've heard of rain right?  <br><br>Since releasing any amount of water into the air won't have any lasting effect on its concentration emissions of it don't matter as far as climate policy is concerned.,(reply>), @Lord of Nothing If that energy is used for H2 production, how is the rest of that country getting its "green" energy?<br><br>Using H2 will produce H2O vapour. Closed loop would sound perfect but is sofar not considered in any known proces. The means needed to set up and maintain the required infrastructure have a substantial impact on the efficiency.<br>Worst thing is, water vapour is a greenhouse gas just like CO2.<br><br>The energy density of H2 is very low, therefor it is no alterative for planes and rockets yet.<br>Cars are actualy very well possible, storage at low temperature under pressure in small, well insulated tanks is easier than large tanks. There were also studies of binding the H2 to solids but I have no idea how usable these are in real life.<br><br>Your final solution is absolute the best! Less over consumption and -production. Save a world, eat your kids. ;)