this post was submitted on 03 Sep 2023
53 points (76.2% liked)
Videos
14343 readers
182 users here now
For sharing interesting videos from around the Web!
Rules
- Videos only
- Follow the global Mastodon.World rules and the Lemmy.World TOS while posting and commenting.
- Don't be a jerk
- No advertising
- No political videos, post those to [email protected] instead.
- Avoid clickbait titles. (Tip: Use dearrow)
- Link directly to the video source and not for example an embedded video in an article or tracked sharing link.
- Duplicate posts may be removed
Note: bans may apply to both [email protected] and [email protected]
founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
The problem here is round trip efficiency.
Using a battery to store solar power is about 95% efficient. A small amount of energy is lost to heat when charging and discharging.
Using hydrogen as energy storage is about 30% efficient. A small amount of energy is lost when making the hydrogen, but a large amount is lost when converting it back to electricity.
Unfortunately this isn't even a solvable problem. The fundamental limit of efficiency due hydrogen to electricity is about 50%. Physics and entropy prevent it from being any higher.
Burning hydrogen for heat is about 100% efficient, but heat pumps (running from electricity) can be over 600% efficient. Heat pumps get the extra efficiency by moving heat rather than creating heat directly.
If you wanted to use hydrogen from electrolysis, we would need 3 to 6 times as many solar panels than if we just used batteries.
Hydrogen can be clean, but it's rarely the best option.
Agreed. But in cases where a large amount of energy is needed on one tank/charge (large freight haulers, long-distance busses, trains, etc.) hydrogen might be a good alternative to petrol while we work on improving battery capacity and recharge times.
You're never going to see 95% efficiency doing that. You'll realistically lose around 20% or so from things like parasitic losses, AC-DC conversions, transmission losses, etc. And that's ignoring the energy needed to make the battery in the first.
That's completely wrong. An electrolyzer is an electrochemical system. It has about the same level of efficiency as charging a battery. People are just regurgigating BEV propaganda here.
In reality, hydrogen is far more scalable than batteries. What people don't realize is that you will fail to capture all of your renewable energy with batteries. You end up with a lot of curtailed power. You actually have to use hydrogen for this, and in fact you'll have fewer solar panels in the long run.