• 2 Posts
  • 108 Comments
Joined 1 year ago
cake
Cake day: June 11th, 2023

help-circle
  • While the article takes no solid position about the benefits and harms of alleviating global warming with solar geoengineering, it does correctly point out that discussion and governance of the subject is lacking.

    Some hypothetical examples:

    Case A:

    • a coastal country experiences increased storm surges, a large percentage of its population stands at risk, it perceives climate change as an existential risk
    • this country decides to engage in solar geoengieering to cool the planet, however its neigbours on higher ground don’t perceive a risk from warming, instead they fear that wind patterns could change and deprive them of rainfall
    • they accuse each other of violating each other’s rights, start a trade dispute and eventually make war

    Case B:

    • lots of people are convinced that efforts to control climate change by reducing carbon output have failed
    • they decide to go for solar geoengineering, but the predicted impact on food production is -10%
    • this affects the poorest of people most adversely, but there is no compensation mechanism
    • cooling the planet succeeds, but results in outbreaks of famine

    Case C:

    • lots of people are convinced that efforts to reduce emissions have failed
    • solar geoengineering allows to cool the planet to pre-industrial levels
    • does incentive to reduce emissions disappear now?
    • if the cooling effect is terminated, extremely fast warming may now happen

    Myself, I perceive this as a last resort. If reasonable measures don’t save the day, this is one of the less reasonable measures that could buy time. I would like people to research this, so that capability would exist. But I would not be easily convinced of the necessity of taking action, as long as alternatives remain.



  • Machinery comes is varying width. I would guess a farmer needs to decide at some point - is the priority using a 10-meter wide tool, or is it OK to settle with a 6-meter tool, or even a smaller one.

    Basing on that, they’ll decide what the clearance between rows of panels should be. From an energy installation viewpoint, the shadow of one row should not cover another row during normal operating conditions. Assuming sun at 30 degrees elevation (“September on latitude 60”), the shadow of a fence that’s 1.2 meters tall will be about 1.75 * 1.2 = 2.1 m long. So from an energy generation viewpoint, one can pack things more densely than makes sense for farming.


  • Also, costing €623,000 over three years sounds rather expensive for just 100m

    It’s hugely expensive, but I expect most of the cost to be in the wagon that lays panels down and picks them up - and could hopefully service a big stretch of railway (if it works). That kind of systems will cost a pretty big penny.

    I doubt if this project will “fly”, however. A totally horizontal solar panel at ground level is a far cry from producing energy efficiently.





  • The proliferation of a new technology typically doesn’t start from poor people.

    It starts from fanatics first. I built my first EV. It was crap, I cut it apart and sold the metal (environmental footprint: awful). Then I built my second EV. It drove around 10 000 km, but had to be retired due to metal fatigue (enviromental footprint: neutral at best, lesson learned: big).

    I bought my third EV on a crashed vehicle auction. New front axle, stretching the frame back to correct dimensions… I drive it every day, but it’s a crap car that I’d not recommend to my worst enemy. :) Environmental footprint: positive, I can produce fuel for myself from April to October. But if the same vehicle would be used by someone who doesn’t produce (or buy) renewable power, the footprint would be less positive.

    Anticipating the demise of my factory-made electric microcar, I am however building another EV. Again the footprint is negative, but I need information about how to easily manufacture one, and obtaining information has a cost in resources. :(

    Meanwhile, of course, truly rich folks buy fancy and electronics-laden self-driving EVs which some then proceed to crash or mishandle due to lack of clue. People are like that and it will stick out in statistics.

    IMHO: if they hadn’t bought an EV, they’d have bought another kind of status symbol and would have used it even more wastefully. What matters more is what the average person can and will do. And how do we influence the auto makers to produce less resource-intensive vehicles?


  • I have a solar panel that died. A piece or plywood flung by a storm went right through it, leaving a 30 cm “wound”.

    Well, to be honest, it’s alive, just weaker - the panel remains suitable for pumping water on the field during muddy season. I wouldn’t take a good panel to such a bad place, but this panel, I have no worries about.

    As for what happens when they really, really die - they get disassembled. The aluminum frame gets taken off and goes into metal recycling. Junction boxes go to where plastic goes - not a nice place. The glass and doped silicon go into a crushing mill, after which they get separated. The glass is easy to recycle, but the doped silicon is difficult to refine again to such a purity, so it likely won’t become a solar panel. But it’s a very small fraction of the panel’s mass.




  • instead of powering the heat pump from the wall, the heat pump can be connected directly to a PV

    I have no experience with this exact combination. I know that “batteryless” inverters exist, but most of them are on-grid inverters. In that scenario, all that matters is monitoring your production: if you don’t want grid energy, you only run your system when your PV produces enough.

    Another type of batteryless inverters are “pump inverters”. Farmers seem to like them for pumping water from wells into water towers. A pump inverter can be configured to run at 50 Hz (or 60 Hz for North Americans) and 230…240 V (or 110 V for North Americans) alright, but it is not designed to power electronic devices, but dumb agricultural motors. There is considerable risk involved with powering a heat pump from a pump inverter, unless you find an exceptionally simple and dumb heat pump with very limited or resilient steering electronics.

    Efficiency losses are small anyway, but mostly happen during battery storage or when voltage needs to rise or drop considerably (e.g. a transition of 700 -> 24 V or 24 -> 240 V would cause a small efficiency loss).

    I’ve heard that a PV can directly power a compressor

    This seems unlikely as the compressor would have to be a brushed DC motor. That kind of motors don’t last long, they wear out their brushes. Long-lasting motors are brushless, and those generally cannot be run on DC power. For example, a “brushless DC” motor is essentially a three-phased AC motor, just its controller (full of smartness and MOSFET transistors) accepts DC input.

    If you have a good technical overview of your heat pump system, maybe you can locate a point where regulated DC can be fed into the system, but that would be hacking. Alternatively, maybe a niche market already exists for DC-powered heat pumps, e.g. for caravans, trucks or ships? But on niche markets, prices typically aren’t good for you. :(


  • it would (as far as i understand with high school chemistry) be strictly more efficient to electrolyse rust directly

    I’m not a chemist either, but I do know a bit of chemistry.

    Typically, you need a solution of NaOH (sodium hydroxide) to directly reduce iron oxide in an electrolysis cell. If your iron oxide contains impurities, those may react with NaOH and ruin the fun. Also, if you have exposure to CO2, your NaOH will gradually degrade, producing NaHCO3 and losing potency.

    My impression: wet electrolysis is great for making high purity iron, but it would be hard to make it work for energy storage.


  • Yep, indeed, I’m already discovering differences too. :) A good document for techies to read seems to be here.

    https://reticulum.network/manual/understanding.html

    I also think I see a problem on the horizon: announce traffic volume. According to this description, it seems that Reticulum tries to forward all announces to every transport node (router). In a small network, that’s OK. In a big network, this can become a challenge (disclaimer: I’ve participated in building I2P, but ages ago, but I still remember some stuff well enough to predict where a problem might pop up). Maintenance of the routing table / network database / <other term for a similar thing> is among the biggest challenges when things get intercontinental.


  • Interesting project, thank you for introducing. :)

    I haven’t tested anything, but only checked their specs (sadly I didn’t find out how they manage without a distributed hashtable).

    Reticulum does not use source addresses. No packets transmitted include information about the address, place, machine or person they originated from.

    Sounds like mix networks like I2P and (to a lesser degree, since its role is proxying out to the Internet) like TOR. Mix networks send traffic using the Internet, so the bottom protocol layers (TCP and UDP) use IP addresses. Higher protocol layers (end to end messages) use cryptographic identifiers.

    There is no central control over the address space in Reticulum. Anyone can allocate as many addresses as they need, when they need them.

    Sounds like TOR and I2P, but people’s convenience (easily resolving a name to an address) has created centralized resources on these nets, and will likely create similar resources on any network. An important matter is whether the central name resolver can retroactively revoke a name (in I2P for example, a name that has been already distributed is irrevocable, but you can refuse to distribute it to new nodes).

    Reticulum ensures end-to-end connectivity. Newly generated addresses become globally reachable in a matter of seconds to a few minutes.

    The same as aforementioned mix networks, but neither of them claims operability at 5 bits per second. Generally, a megabit connection is advised to meaninfully run a mix network, because you’re not expected to freeload, but help mix traffic for others (this is how the anonymity arises).

    Addresses are self-sovereign and portable. Once an address has been created, it can be moved physically to another place in the network, and continue to be reachable.

    True for TOR and I2P. The address is a public key. You can move the machine with the private key anywhere, it will build a tunnel to accept incoming traffic at some other node.

    All communication is secured with strong, modern encryption by default.

    As it should.

    All encryption keys are ephemeral, and communication offers forward secrecy by default.

    In mix networks, the keys used as endpoint addresses are not ephemeral, but permanent. I’m not sure if I should take this statement at face value. If Alice wants to speak to Bob tomorrow, some identifier of Bob must not be ephemeral.

    It is not possible to establish unencrypted links in Reticulum networks.

    Same for mix networks.

    It is not possible to send unencrypted packets to any destinations in the network.

    Same.

    Destinations receiving unencrypted packets will drop them as invalid.

    Same.

    P.S.

    I also checked their interface list and it looks reasonable. Dropping an idea too: an interface for WiFi cards in monitor/inject mode might help some people. If the tool gets popular, I’m sure someone will build it. :)



  • As an anarchist who would welcome other anarchists - sadly, I doubt if that’s a reliable recipe to stop climate change.

    Limiting (hopefully stopping) climate change can be done under almost any political system… except perhaps dictatorial petro-states. However, it takes years of work to tranform the economy. Transport, heating, food production - many things must change. Perhaps the simplest individual choices are:

    • going vegetarian (vegan if one knows enough to do the trick)
    • avoidance of using fossil fueled personal vehicles
    • improving home energy efficiency (especially in terms of heating)
    • avoidance of air travel
    • avoidance of heavy goods delivered from distant lands

    The rest - creating infrastructure to produce energy cleanly and store sufficient quantities - are typically societal choices.

    As for corals - I would start by preserving their biodiversity, sampling the genes of all coral and coral-related species and growing many of them in human-made habitats. If we’re about to cause their extinction, it’s our obligation to provide them life support until the environment has been fixed.

    Also, I would consider genetically engineering corals to tolerate higher temperatures. Since I understand that this is their critical weakness, providing a solution could save ecosystems. If a solution is feasible, that is.

    Corals reproduce sexually so a useful gene obtained from who knows where would spread among them (but slowly - because typical colonies grow bigger asexually). Also, I would keep in mind that this could have side effects.

    As for tempeature - it will be rising for some time before things can be stopped. Short of geoengineering, nothing to be done but reduce emissions, adapt, and help others adapt. The predictable outcome - it will get worse for a long while before it starts getting any better.



  • The article is mostly correct. :)

    Notes: out of the three, Latvia has serious energy storage - a 4 billion cubic meter (at normal pressure) underground gas store, sufficient to carry all three countries over the winter. So far, it’s filled with fossil natural gas - but some day it could be filled with synthesized methane.

    As a backup option, Estonia has oil shale - probably the worst fuel on Earth, so the price of emitting CO2 keeps those plants out of the energy market during summer. During winter, they come online though.

    As for solar, we aren’t planning to rely much on that. Solar capacity has of course skyrocketed, but only because it’s very easy to install. For me, it provices a nice way to charge my car from April to October. But at latitudes 55 to 60, days are really very short in midwinter, so wind and waste wood are the likely candidates in future - after oil shale leaves the scene, but before synthetic gas becomes feasible.

    Regarding pumped hydro - it can stabilize a day, but can’t stabilize a week or month. Lithuania has a biggish (~10 GWh) pumped storage facility. The rest of Baltics don’t have suitable terrain. Estonia has limestone banks, but they’re under various forms of protection and even if one built a lot of pumped hydro, the low elevation difference (up to 50 meters) means one couldn’t support the electric grid through more than a few days.

    Regarding hydrogen - maybe. But hydrogen is difficult to store, so I’m betting on wind, and on sourcing technology from Germany to produce synthetic methane from excess power during summer, and pumping it to Latvia for storage.

    Finally - connecting to the continental EU power grid allows importing energy when local wind isn’t strong enough, and exporting any surplus. So far, all three countries are still in the ex-Soviet synchronization area (common with Russia and Belarus, but with no trade, just synchronization), and thus unable to connect with the EU synchronization area. Local power companies have been building synchronous compensators (devices that steer grid frequency) for the past 2 years to drop this dependency.

    If things go as planned, Baltic countries will sever those connections and join the EU grid via Poland in winter 2025. Undersea cables already go from Estonia to Finland and Lithuania to Sweden, but in the current political conditions, I don’t think anyone counts of them for sure (a Chinese-owned but Russian-crewed ship broke the Estonia-Finland gas pipeline last autumn when dragging its anchor during a storm - it’s still unsure if the damage was accidental or not).