standeven

I've worked with hydrogen (H2) quite a bit recently. Embrittlement and leakage are easy to work around, but here are the pain points I've seen:

1. H2 is still expensive. Most fuel cells require very pure H2 (five nines; 99.999%), or else it can damage the internal membrane. This pure H2 is not very affordable outside of a limited number of fuelling stations.

2. The rules around H2 use and transportation are still fuzzy. Despite being around for so long, regulations are still lacking or unclear.

3. H2 is light weight but takes up a lot of volume, limiting the usefulness of small-scale applications. Compressing it to liquid takes a lot of energy.

4. Fire/explosion risks, as you mentioned.

5. Fuel cells are expensive. If you look at financial statements for most fuel cell companies, they are selling them at a loss, meaning most fuel cells sold today are subsidized by government grants and investors.

6. The oil/gas industry is still pushing "grey" and "blue" hydrogen, which uses natural gas and emits carbon to produce H2.

I think H2 will play an important role, especially in decarbonizing steel making and large transportation applications, but people need to be aware of the limitations and longer timelines required for widespread adoption of green H2.

Here’s the only terrible use case I’ve found; my Samsung washer and dryer now interrupt movies on my Samsung TV to let me know when they complete a cycle.

I can provide many sources for each point, let me know if there's a specific one that you find questionable.

I've been on several frack sites. On one, it was literally raining oil and chem on everything as they were wirelining. I'll take the windmill thanks.

...and also requires uranium mining and risks nuclear weapons proliferation. I prefer solar and wind.

I worked in oil/gas for a long time. In addition to "windmills are killing all the birds", here are a few of the top green energy lies I've heard:

1. Solar panels are toxic, require more energy to produce than they generate, and can't be recycled.

2. EV's are worse for the environment than ICE vehicles.

3. Lithium mining is worse than oil/gas drilling.

4. Solar/wind prices are skyrocketing and everyone is abandoning solar/wind.

5. Solar/wind can't work because they're too intermittent.

6. Climate change isn't real OR climate change is real but natural and unstoppable OR climate change is helpful to the planet (these opposing beliefs are often repeated back to back)

One way to measure this is energy stored on energy invested (ESOEI). It answers how much energy is stored over the lifetime of the device compared to the energy required to build it. Lithium batteries come in at around 32.

This isn't bad, but pumped hydro is way better (704). And both options are way better than the ongoing drilling and mining and combusting required for fossil fuels.

Isn’t approval expected and already priced in? The hackers should have announced it wasn’t approved, maybe then the price would have moved more than 3%.

Do you have any evidence that bridges, planes, trains, etc are failing at a higher rate?

I suspect you have it backwards, and these events are less frequent than ever which is what makes them newsworthy.

I realized Boeing sucks during the C-Series fiasco.

https://en.m.wikipedia.org/wiki/CSeries_dumping_petition_by_...

Yeah, we’d have to include display quality, battery life, etc. to get a really fair comparison.

Does Apple not usually have the best performance / price? Looking at M- and A- series chip benchmarks, Apple is way ahead of the competition.

Bearing and windage losses scale down drastically with lower speeds, so only slightly worse than other flywheel systems. They are best for daily cycles or multiple-daily cycles. Things like load shifting, peak shaving, frequency regulation, etc. They are not well suited for storage beyond a few days.

Waiting for patents to file before public disclosure of the tech, but I can give you a basic overview. We use mass instead of speed to store energy. This is slightly less efficient but way less expensive; speed requires magnetic bearings and operating in a vacuum and many other expensive design constraints. Other flywheels operate in the 7500 - 100k RPM range, and we spin at 2000.

A buried flywheel storage system would accomplish this, they're just prohibitively expensive at the moment. Vehicle-to-grid will be big once it catches on and consumers get over the idea of adding cycles to their vehicle batteries.

Wind often increases when solar energy decreases and vice versa, which is why they are deployed together when possible.

Here's the storage solution project I'm working on: https://vortical.io

Flywheel storage (which is not new), but we sacrifice some efficiency and energy density so we can do it for cheap.

Yes, storage is the bottleneck that not many people talk about. The transition to renewable energy is still young and already we're seeing negative spot prices. My company is working on affordable, lithium-free storage for the grid to address this.

This works, but it requires a lot of complexity, consumer buy-in, the willingness to add extra charge cycles (and degradation) to vehicle batteries, etc.

It’s easier to add a bunch of grid-scale storage, but more expensive.

I think both solutions will scale alongside solar/wind adoption.

49710 chains

Codesys 3.5 with a license. Git functionality is built right in, it’s fantastic.

Controls programming always feels 20 years out of date. 10 years ago I was excited to move projects from ladder to structured text. This year I’m excited to finally use git to manage a PLC code base.

In a few years, this will switch.

I regularly work with mobile machinery that was primarily diesel powered, but which is now switching to electric power. The new electrical equipment is far more reliable than the diesel and hydraulic systems they replace, but there are more design issues out of the gate; the engineers are still learning about battery cooling systems, motor sizing, etc.

Once the knowledge and experience gap closes, the superior reliability of moving electrons instead of pistons and belts and gears will be clear.

I mean, it's true - the most disruptive and destructive part of fracking is the work on the surface, like the clearing for drill pads and access roads and water works. That said, you can't frack without these.

No, stationary only. It’s modular, so you can combine as many as you need for grid-scale storage.

Physics work, but cost has historically been the issue. My current project involves driving down the cost to make extremely affordable 50 kWh flywheel modules.

My company is working on this right now. We are early/stealth but moving towards a pilot project and acquiring IP.

Placeholder site: vortical.io

I just downloaded the Google app for iOS and this feature was missing until I force-closed and reopened it. Then it appeared.

Hydrogen could be very useful for CO2-free iron smelting, powering cargo ships, and many other use cases. The problem is getting it - cheap green hydrogen requires excess green power, something we don’t have yet.

HN believes it because it's true. Your link (to a twitter post) says nothing to the contrary.

"People infected with COVID-19 before receiving a vaccine were 11 times more at risk for developing myocarditis within 28 days of testing positive for the virus. But that risk was cut in half if a person was infected after receiving at least one dose of a COVID-19 vaccine."

https://www.heart.org/en/news/2022/08/22/covid-19-infection-...

"Risk of incident myocarditis is more than seven times higher in persons who were infected with the SARS-CoV-2 than in those who received the COVID-19 vaccines"

https://www.frontiersin.org/articles/10.3389/fcvm.2022.95131...

"The incidences of myopericarditis after mRNA COVID-19 vaccination among adolescents aged 12–17 years were very rare; they were not higher than other important reference incidences."

https://www.sciencedirect.com/science/article/pii/S0264410X2...