this post was submitted on 01 Mar 2024
289 points (97.1% liked)

News

23665 readers
5190 users here now

Welcome to the News community!

Rules:

1. Be civil


Attack the argument, not the person. No racism/sexism/bigotry. Good faith argumentation only. This includes accusing another user of being a bot or paid actor. Trolling is uncivil and is grounds for removal and/or a community ban. Do not respond to rule-breaking content; report it and move on.


2. All posts should contain a source (url) that is as reliable and unbiased as possible and must only contain one link.


Obvious right or left wing sources will be removed at the mods discretion. We have an actively updated blocklist, which you can see here: https://lemmy.world/post/2246130 if you feel like any website is missing, contact the mods. Supporting links can be added in comments or posted seperately but not to the post body.


3. No bots, spam or self-promotion.


Only approved bots, which follow the guidelines for bots set by the instance, are allowed.


4. Post titles should be the same as the article used as source.


Posts which titles don’t match the source won’t be removed, but the autoMod will notify you, and if your title misrepresents the original article, the post will be deleted. If the site changed their headline, the bot might still contact you, just ignore it, we won’t delete your post.


5. Only recent news is allowed.


Posts must be news from the most recent 30 days.


6. All posts must be news articles.


No opinion pieces, Listicles, editorials or celebrity gossip is allowed. All posts will be judged on a case-by-case basis.


7. No duplicate posts.


If a source you used was already posted by someone else, the autoMod will leave a message. Please remove your post if the autoMod is correct. If the post that matches your post is very old, we refer you to rule 5.


8. Misinformation is prohibited.


Misinformation / propaganda is strictly prohibited. Any comment or post containing or linking to misinformation will be removed. If you feel that your post has been removed in error, credible sources must be provided.


9. No link shorteners.


The auto mod will contact you if a link shortener is detected, please delete your post if they are right.


10. Don't copy entire article in your post body


For copyright reasons, you are not allowed to copy an entire article into your post body. This is an instance wide rule, that is strictly enforced in this community.

founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
[–] dual_sport_dork 5 points 10 months ago* (last edited 10 months ago) (1 children)

RITEGs ... Their energy conversion is very very low.

Yeah, no kidding. These will never be viable for personal vehicular applications because they are A) by necessity incredibly heavy, large, and expensive with the casings, shielding, heat exchangers, etc. required, and B) can't produce enough energy to meaningfully propel something the size of a car any useful distance in any realistic time frame. A 1500 kilogram unit the size of a refrigerator only generates ~35 watts. That's not enough to do anything with, from a transportation perspective. There is no "new technology" that's going to get around this, either. Isotope half lives are what they are. The decay heat is what it is. The temperature differentials that you can safely maintain in a consumer environment can only be so large. That's physics.

You'd literally be better off with a $200 worth of solar panels from Harbor Freight to recharge your EV. And yes, that includes taking into account that solar panels don't work at night.

That, and you'd never get any random member of the public to willingly park anything that is known to contain radioactive isotopes in their own back yard. Radiophobia would ensure that such a proposal would be completely dead on arrival. People are already deathly frightened enough of radioisotopes existing in tightly regulated, very competently run nuclear power plants.

[–] [email protected] 1 points 9 months ago

I'd happily have a RITEG buried in my back yard to sustain my base load from my house. Using geothermal cooling for the unit seems like a good idea, and it would be underground where nobody can fuck with it.

RITEG research and use hasn't stopped, but most of the terrestrial units have been long decommissioned. The most recent example of note was the MMRTG unit used in curiosity (now on Mars), which is 45 KG and can produce 110W of output. The most notable terrestrial examples were the IEU units used by the Soviets for light houses, weighing upwards of 2-3 tones and producing less than 120W at their peak, mostly fueled by strontium 90 (the MMRTG uses plutonium 238). The only modern RTG for terrestrial use is the Sentinel units used for monitoring stations in the arctic by America, which top out under 60W and weigh more than a ton, closer to 2 ton. There are others but information is limited.

A lot of weight is due to the fuel (which is classified as a "heavy metal") and the casing, which on earth is more robust than you would need in space, since it's feasible that people would be nearby the unit for extended periods of time and any breach could be fatal.

Even with the weight, if we're effectively burying it in a yard, deep enough to take advantage of geothermal cooling, then weight isn't really a problem. Even size isn't a problem since it can be the size of a large consumer vehicle and most homeowners have more than enough land to accommodate that... With little more than an access hatch for inspections and maintenance, it would be a viable option to contribute to offsetting the base load of your home. Even a 100W unit would trim about 2.4kWh from a household electricity bill per day for something like 100 years. That's in the ballpark of 8.5 GWh over the lifetime of the unit before the fuel needs to be replaced (based on the half life of the material. Strontium 90 would need to be refueled every 40-50 years or so).

I'm not saying it's a fix to the problem by any stretch, but it could trim about 1/4 of electricity costs per home, based on an average consumption of around 10 kWh per day.

This is why I like RTGs, they're stable and long lasting, relatively safe (unless the housing/shielding fails) and solid state with basically no maintenance.

I'm a fan of the idea, but I'm not going to say it's a one stop fix, nor do I think the regulatory people will green light any implementation of such a system for home use, ever. Nor do I think that even if such a solution were to be given approval, that the general public would ever accept it being installed "in [their] back yard" either literally or figuratively.

You're right that a pair of 200W panels and a small battery system would have a similar effect (at least until the batteries needed replacing... or simply grid tie it), and as long as you can average ~2 kWh/day of generation, you'd be fine... You might need 4-5 panels to get the same daily output, but a system like that is probably still less than $1000, and will probably last ~20 years. So to make it economically viable such a system would need to cost the consumer less than ~$5000 or so before it becomes a better option.

I'm still a fan of the technology, and I find it immensely interesting, but I try to keep my expectations realistic. Due to the excessive weight of a terrestrial RTG, it's not viable for a vehicle, but wouldn't it be cool to have a car that charges itself all the time no matter where you park it or whether it's in the sun or not?

I think that would be cool.