141–150 of 343 posts
But it's still just a battery, and needs to be charged from the electric power grid (by using the electricity to separate hydrogen from water), just like any other battery would.
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Many of the things you're saying aren't correct, see my other comment (sibling to yours) for references. Nuclear is not cheap compared to photovoltaics, wind and hydro. Since the former two are bursty, overcapacity in them leads to cheap excess energy at times, which needs to be stored. Which storage method is the best depends on multiple factors, particularly on the duration of storage, capacity required and frequen…
> Many of the things you're saying aren't correct, see my other comment (sibling to yours) for references. I really wish that I was wrong instead of just semi-accurate and sloppy. > Nuclear is not cheap compared to photovoltaics, wind and hydro. The price of nuclear power is dominated by regulation. Running the power plant is quite cheap. The real cost is satisfying regulation and getting rid of the nuclear waste. If…
I've been diving into this literature a bit recently, and it's been mostly encouraging. Affordable clean energy is realistic. Clean energy sources are typically the cheapest sources of energy [0]. The intermittent production issue is solvable: At ~150 $/kWh storage, a combination of storage and renewables is the cheapest energy source 95% of the time [1]. The cost of different energy storage methods is coming down ex…
I've read about a couple of solar projects that projected x/kWh and turned out to be much worse in production. Pakistan's big deployment is one example, it was planned to be 100MW but only produced 18MW. Mostly because they didn't factor in the dust that would cover the panels, keeping them clean was very expensive (I'm curious how this applies to other proposed desert deployments). Nor factoring in the typical malai…
With some basic equipment like rolling carts with sprayers and squeegees on extension sticks, how many individual 72-cell sized panels (1.99 x 0.99 meter size) can one person clean in one day? Multiply by probably 4 to 6 full time staff positions.
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I like this diagram from Volkswagen visualizing the energy loss at every step for hydrogen versus BEV: https://images.hgmsites.net/lrg/hydrogen-vs-electric--volksw... This image (don't know the source), which includes oil and coal, is also a good visualization: https://i.imgur.com/Wuhnlvu.png Even simpler: https://pbs.twimg.com/media/DPkaz0nX4AAcr_v.jpg
I would like to have seen more elaboration on transmission losses in the power grid. For example, if we imagine solar cells in Sahara generating energy for Europe, is power grid transmission feasible or does hydrogen look better in comparison?
Hydrogen is sexy but alcohol matches our existing context better. Small-scale alcohol fuel production integrated into regenerative agriculture farms is different from mass ethanol production. You can ferment anything that has starch or sugar, the leftovers from the distillation can be composted or fed to livestock. Most existing internal combustion engines can be modified to use alcohol fuel. And it's carbon-neutral.
Feedstock is the problem here: there's simply not enough net primary productivity on the planet, and humans already appropriate ~20%. There are some marginal gains possible, but on the order of single-digit percentages of present fossil fuel consumption. Maybe low double-digits. The US had a largely biofuel based transport system in 1900. Horses consumed 20% of all US grain production, the population was under 100m,…
The key is that you're producing the alcohol as part of an integrated system of production that mimics Nature. You have a farm that requires no inputs (of fertilizer, and in some cases no irrigation) that produces multiple crops per year. ("Syntropic" agriculture, "Permaculture", food forests) You can grow sugar beets, yams, sugar cane, or starchy plants such as potatoes, certain kinds of reeds, tubers, etc. directly for fermentation, or use scrap fruit from the orchards, etc. Literally anything that has starch or sugar can be used as a feedstock. Scrap dough from a (doughnut) bakery.
The leftovers from the fermentation and distillation aren't wasted: you feed them to livestock. Because it's a yeast culture there's more protein in it now than it had before.
So your farm produces fruits and veggies, meat, and alcohol fuel.
(I'm getting all this from http://alcoholcanbeagas.com/sitemap )
Hydrogen has an efficiency problem. You need to convert other forms of energy to hydrogen at a loss. Then you need to store it and transport it, which is costly and may impose quite some energy cost for cooling or compression. Then you need to convert it back to electricity, also at a loss. If you start at electricity, the electrical grid and batteries would be much more efficient. If you start at oil or gas, you cou…
Electricity has a transmission problem though - there are some parts of the world with lots of clean energy, which we can't fully take advantage of because we can't transport electricity that far. Hydrogen allows us to use that clean energy to power cars in other parts of the world, since you can produce hydrogen in those places and then ship it to places without much clean energy. Also you can presumably stop and st…
http://large.stanford.edu/courses/2010/ph240/harting1/
Appearances is that losses in transmission lines are a few percent per 1000km. Across the US is about 4000km so you'd lose a little under 20%.
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I've read about a couple of solar projects that projected x/kWh and turned out to be much worse in production. Pakistan's big deployment is one example, it was planned to be 100MW but only produced 18MW. Mostly because they didn't factor in the dust that would cover the panels, keeping them clean was very expensive (I'm curious how this applies to other proposed desert deployments). Nor factoring in the typical malai…
Solyndra's failure had nothing to do with technology at all. They failed because Chinese manufacturers undercut them in price , quite severely. Allegations of dumping (or fraud, on the other side) notwithstanding, what this says is that solar is actually much cheaper and more readily available than Solyndra's investors expected. And that's sort of the opposite of your point, no? Similarly the Tesla plant is doing exa…
Ordinary 60 or 72-cell panels are DEAD SIMPLE in their construction. It's a sandwich of a backing material, encapsulation for the cells and soldering, glass in front, with an aluminum frame and a junction box on the rear.
Solyndra "panels" are fragile, hard to transport, hard to mount, everything about them was a pain in the ass.
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I've read about a couple of solar projects that projected x/kWh and turned out to be much worse in production. Pakistan's big deployment is one example, it was planned to be 100MW but only produced 18MW. Mostly because they didn't factor in the dust that would cover the panels, keeping them clean was very expensive (I'm curious how this applies to other proposed desert deployments). Nor factoring in the typical malai…
Solyndra's failure had nothing to do with technology at all. They failed because Chinese manufacturers undercut them in price , quite severely. Allegations of dumping (or fraud, on the other side) notwithstanding, what this says is that solar is actually much cheaper and more readily available than Solyndra's investors expected. And that's sort of the opposite of your point, no? Similarly the Tesla plant is doing exa…
Earlier quoted context omitted.
> It also has a tendency to leak. But I mean, that has to be a limitation of current technology, right? There has to be engineering solutions that we can devise to make it as safe statistically as for example gasoline transport?
No, it's not just a matter of technology, or at least not in ways that are readily addressable. Hydrogen molecules are so small that the simply pass through solid matter as if it were loose-weave cloth. Worse, it embrittles most metals. And the leaked gas, especially if in an enclosed space, is flammable or explosive over a very wide range of concentrations. Long-term storage, transport, and use, at scale, is hugely…