Is hydrogen really a clean enough fuel to tackle the climate crisis? Backers say hydrogen projects should be first in line for almost $26bn in US taxpayer money – but should we believe the hype?  Hydrogen is the smallest, lightest and most abundant molecule in the universe. On Earth, it does not occur by itself naturally, but can be separated from water (H2O) or hydrocarbon compounds (fossil fuels) like gas, coal and petroleum to be used as an energy source. It’s already used for rocket fuel, but it is now being pushed as a clean and safe alternative to oil and gas for heating and earthly modes of transport. Political support is mounting with almost $26bn of US taxpayer money available for hydrogen projects thanks to three recent laws – the Inflation Reduction Act, the Bipartisan Infrastructure Act and the Chips Act. Hydrogen is politically hot, but is it the climate solution that its cheerleaders are claiming?  Why all the hype about hydrogen? The short answer is that the fossil fuel industry sees hydrogen as a way to keep on drilling and building new infrastructure. Friends of the Earth has tracked how the industry has successfully deployed its PR and lobbying machines over recent years to get policymakers thinking that hydrogen is a catch-all climate solution. Research by climate scientists (without fossil fuel links) has debunked industry claims that hydrogen should be a major player in our decarbonised future, though hydrogen extracted from water (using renewable energy sources) could – and should – play an important role in replacing the dirtiest hydrogen currently extracted from fossil fuels. It may also have a role in fuelling some transportation like long-haul flights and vintage cars, but the evidence is far from clear. However, with billions of climate action dollars up for grabs in the US alone, expect to see more lobbying, more industry-funded evidence and more hype. Extracting hydrogen is energy intensive, so the source and how it’s done both matter. Currently, about 96% of the world’s hydrogen comes from coal (brown) and gas (grey), with the rest created from nuclear (pink) and renewable sources like hydro, wind and solar. Production of both grey and brown hydrogen releases carbon dioxide (CO2) and unburnt fugitive methane into the atmosphere. This super-polluting hydrogen is what’s currently used as the chemical base for synthetic nitrogen fertilisers, plastics and steel among other industries.   Blue hydrogen is what the fossil fuel industry is most invested in, as it still comes from gas but ostensibly the CO2 would be captured and stored underground. The industry claims to have the technology to capture 80-90% of CO2, but in reality, it’s closer to 12% when every stage of the energy-intensive process is evaluated, according to a peer-reviewed study by scientists at Cornell University published in 2021. For sure better than nothing, but methane emissions, which warm the planet faster than CO2, would actually be higher than for grey hydrogen because of the additional gas needed to power the carbon capture, and likely upstream leakage.     Green hydrogen is extracted from water by electrolysis – using electricity generated by renewable energy sources (wind, solar, hydro). Climate experts (without links to fossil fuels) say green hydrogen can only be green if new renewable sources are constructed to power hydrogen production – rather than drawing on the current grid and questionable carbon accounting schemes. What’s at stake? In addition to $26bn in direct financing for so-called hydrogen hubs and demo projects, another $100bn or so in uncapped tax credits could be paid out over the next few decades, so lots and lots of taxpayers’ money. Fossil fuel companies are also using hydrogen to justify building more pipelines, claiming that this infrastructure can be used for “clean hydrogen” in the future.             https://www.theguardian.com/environment/2023/mar/07/hydrogen-clean-fuel-climate-crisis-explainer     

Hydrogen Reality Check: Distilling Green Hydrogen’s Water Consumption. Water access and requirements for green hydrogen production can be effectively managed if intentional sourcing, project siting, and efficient use is prioritized. August 2, 2023  By  Kaitlyn Ramirez,  Tessa Weiss,  Thomas Kirk,  Chathurika Gamage                                    The Myth: Scaling green hydrogen will severely impact global freshwater supply because it uses far more water than other hydrogen or equivalent energy production processes. The Reality: The additional draw on the world’s water supply from producing the green hydrogen needed for a 1.5°C-aligned future will be minimal. To produce the same amount of energy, green hydrogen often consumes less water than fossil fuel-based hydrogen or some types of electricity generation. However, this does not negate the imperative that green hydrogen developers prioritize efficient process design and consider local water availability in project planning. In areas of water scarcity, consideration of alternative sources such as treated wastewater or desalinated sea water can minimize freshwater reliance.Scaling up clean energy technologies without infringing on water access is essential in ensuring real and lasting solutions to the climate crisis.Green hydrogen has made a splash for its role in addressing the 30 percent of global emissions from industries that haveno alternativesfor decarbonization, making it essential to consider this technology’s impacts on water supply. Distilling Green Hydrogen’s Water Consumption Down to the Kilogram- Green hydrogen, made by separating the H2 from H2O with renewables-powered electricity in a unit called an electrolyzer, consumes a similar amount of water to other processes used to produce hydrogen. All methods of producing hydrogen require water, and green hydrogen does not consume a significantly greater amount than its alternatives. Inefficient designs such as evaporative cooling systems may exceed this range, but those systems are uncommon, especially at large scales of production. Green hydrogen’s cumulative 20-30 L/kg of water consumption is on par with or even less than the 20 to 40 L/kg of water required for fossil-based hydrogen production pathways, as seen in Exhibit 1. Zooming out beyond the bounds of the hydrogen production plant, the source of electricity and/or natural gas could add “embodied” water consumption to all hydrogen pathways. Electricity generation- for use to power the fossil-based hydrogen plant or split water via electrolysis can have a range of water requirements depending on the source. Green hydrogen’s reliance on renewables minimizes additional water consumption. Fossil fuel power generation requires a substantial amount of water for temperature regulation, and as such, electricity drawing from the grid which includes sources like coal or gas will see a greater amount of water consumption than electricity largely sourced from solar or wind.                           https://rmi.org/hydrogen-reality-check-distilling-green-hydrogens-water-consumption/    

Geothermal energy is poised for a big breakout “An engineering problem that, when solved, solves energy.”   After many years of failure to launch, new companies and technologies have brought geothermal out of its doldrums, to the point that it may finally be ready to scale up and become a major player in clean energy. In fact, if it's more enthusiastic backers are correct, geothermal may hold the key to making 100 percent clean electricity available to everyone in the world. And as a bonus, it’s an opportunity for the struggling oil and gas industry to put its capital and skills to work on something that won’t degrade the planet. Vik Rao, former chief technology officer at Halliburton, the oil field service giant, recently told the geothermal blog Heat Beat, “geothermal is no longer a niche play. It’s scalable, potentially in a highly material way. Scalability gets the attention of the [oil services] industry.”In this post, I’m going to cover technologies meant to mine heat deep from the Earth, which can then be used as direct heat for communities, to generate electricity, or to do both through “cogeneration” of heat and electricity. (Note that ground-source heat pumps, which take advantage of steady shallow-earth temperatures to heat buildings or groups of buildings, are sometimes included among geothermal technologies, but I’m going to leave them aside for a separate post.) Before we get to the technologies, though, let’s take a quick look at geothermal energy itself. The ARPA-E project AltaRock Energy estimates that “just 0.1% of the heat content of Earth could supply humanity’s total energy needs for 2 million years.” There’s enough energy in the Earth’s crust, just a few miles down, to power all of human civilization for generations to come. All we have to do is tap into it. Tapping into it, though, turns out to be pretty tricky. The easiest way to do so is to make direct use of the heat where it breaks the surface, in hot springs, geysers, and fumaroles (steam vents near volcanic activity). The warm water can be used for bathing or washing, and the heat for cooking. Using geothermal energy this way has been around since the earliest humans, going back at least to the Middle Paleolithic. Slightly more sophisticated is tapping into naturally occurring reservoirs of geothermal heat close to the surface to heat buildings. After that came digging deeper and using the heat to generate electricity. The first commercial geothermal power plant in the US was opened in 1960 in the Geysers, California; there are more than 60 operating in the US today. The technology for accessing deep geothermal is developing at a dizzying pace these days. Let’s take a look at its basic forms, from established to experimental. Once it reaches the surface, geothermal energy is used for a wide variety of purposes, mainly because there are many different ways to use heat. Depending on how hot the resource is, it can be exploited by numerous industries. Virtually any level of heat can be used directly, to run fisheries or greenhouses, to dry cement, or (the really hot stuff) to make hydrogen. Flash plants require heat of at least 200°C. The newer, “binary” plants run fluids from the ground past a heat exchanger and then use the heat to flash steam (meaning the underground water isn’t boiled directly and there’s no air or water pollution). Binary plants can generate electricity from around 100°C up. Getting the heat to the surface is the trick. For that purpose, it’s useful to think of geothermal energy technology as falling into four broad categories.......there's much more so read on      https://www.vox.com/energy-and-environment/2020/10/21/21515461/renewable-energy-geothermal-egs-ags-supercritical