I know you don’t want to hear it, but forget about the solar panels my man. It’s not going to work and it isn’t going to be worth it. You can charge the battery from the grid a thousand times for the cost of the solar panel. And that’s excluding all the other extra components you’d need to include if you want solar charging. Plus all of the time you have to put into it.

But if you just want to do it for shits and giggles, just go look up a panel that fits your size and other specs. The watt peak is right there in the specs.

Alright, now we get to the real question, that’s something we can help with.

How big is this robot going to be? Because to tell you the truth: solar panels kind of suck. If the angle isn’t perfect and you don’t have a lot of square meter, the output is terrible. That means putting them on mobile things is kind of hard. There usually isn’t a lot of surface area available and almost always the angle to the sun is going to be terrible. And keep in mind they don’t work in the shade. So inside won’t work, in between buildings won’t work, under some trees won’t work, a bit of clouds and it won’t work etc. So you need a big ass battery onboard to buffer energy, so the robot can charge up in the sun and then run on battery power the rest of the time. Then we get to weight, those regular 400Wp panels you were calculating with are regular roof panels. Those have a aluminum frame, plastic back and glass front. They are around 120x180 cm and pretty heavy. They are also sturdy but can break easily since they are made of glass. For mobile applications you need to look at RV panels. Those are usually flexible, rugged and much lighter. The spec you are looking for is Watt peak. That gives you the amount of watt the panel produces in perfect conditions. You can then calculate the losses you get in your situation because it won’t be perfect. The batteries used in combination with solar are normally lithium iron phosphate. These can store huge amounts of energy and are very safe. Plus they last a long time and can do a lot of cycles. However they are very heavy and to get enough energy storage you need a big ass battery. They are also very expensive. For robots you are probably going to want lithium ion instead. These are cheaper, lighter and can still store a lot of energy. However they are very dangerous to work with and wear out faster. In a mobile application to prevent losses you also don’t want an inverter that converts stuff from DC coming from the panels to AC. It’s a lot better to stay at DC all the time, for example 24V. That way conversion losses are kept to a minimum. But you’d still want a good inverter with builtin battery charger, as the voltage coming out of solar panels fluctuates a lot. Just connecting them directly to batteries is a really bad idea. Solar panels also don’t like it if you draw as much current as possible, that ruins their efficiency. Because of how they work, there is a sweet spot in the voltage and current. Be sure to get an inverter that takes this into account (keyword mppt).

Take a look at something like this panel:

https://www.amazon.com/Flexible-Monocrystalline-Semi-Flexible-Trailer-Surfaces/dp/B0BQ1Y8JMH

If you get three of these you can get something going. If you do it right you can get about 100W of energy under perfect sunny conditions with 3 of these panels combined. That isn’t a lot of energy.

That’s why you don’t really see solar panels on anything mobile, it really kinda sucks. My advice for solar power robots: put a solar installation on the roof, put all of the energy generated over a year into the grid and simply charge the batteries for the robot from the grid. This way you can’t just charge when there is sun and if there is sun and you don’t need to charge the energy isn’t wasted. And being on the roof they are sure to be at a better angle and without any obstructions. They can also be as big as the roof, which helps a lot. This is what we do with electric cars and it seems to be the most efficient we can get.

You aren’t posting correct information, you are making assumptions that are unwarranted and therefor claim stuff that simply isn’t true. Most things aren’t true or false in an absolute way when it comes to complex systems, they are only true under specific conditions or when taking into account certain assumptions. Often it’s easy to generalize and handwave away small details, because they don’t matter for the end result we are going for. But you then can’t say this is a fact and works in all cases, sometimes the details matter a lot.

When it comes to solar installations, those are very complex things. That’s why you only find the resources you found, they are meant to convey a specific understanding of a complex system as it applies to the general audience. For example how many panels should I get, or how much money will I save on my energy bill if I get solar. If you go into the nitty gritty of solar installations it gets complex super fast and small details can matter a whole lot.

For example I have a micro-inverter system where each inverter doesn’t take full advantage of the capabilities of my panels. However due to my location and the angle of my panels, the panels don’t reach that peak capability for almost all of the year. Maybe in perfect conditions on a couple of days a year in the middle of the day, I go over the peak. I could change the angle, but that means more ballast is required for the bigger wind profile, which means I need a structural calculation done which costs money. So I opted to go for cheaper inverters, saving something like $300 on the whole installation, but that means I miss out on about $100 over the lifetime of the system in generated energy. Since that’s a nett positive of $200, that’s what I went with. I could have optimized a bit more to make use of the low-end of the solar output better if I went with a single inverter system instead of the micro-inverters, but that means a large device in a place that was inconvenient and the pricing calculation was tight.

The reason you aren’t getting a straight answer is because it appears to be a XY problem situation (https://en.wikipedia.org/wiki/XY_problem). You are asking for something that doesn’t really make a lot of sense to ask. So it’s likely you are actually trying to figure out something else, have come to the conclusion this is the information you need and thus asked the question. However that conclusion probably wasn’t correct, as the question doesn’t make sense. So it would be really helpful if you ask the initial question you are trying to figure out and let people help with that instead.

When talking solar it would also really help if you state where about you are located on the planet and if you feel like sharing which country, as each country has very different ways of structuring the pricing of energy and that matters a lot when it comes to solar.

Check out this: https://globalsolaratlas.info/map

Be sure to check out the details, it has the exact specs for your location.

I did a calculation for a 20kWh battery for my installation, which would cost me about 18k to purchase and setup. I can do a lot of the work myself, so the equipment costs are the bulk of the price. Figuring a prediction in the price of energy, my usage pattern and a lifetime of 15 years for the batteries, it figured out to be not worth it.

In winter where I live I’m totally fucked, there is basically no sun at all and it’s cold AF so energy usage is highest. Any battery would be empty within days and not really able to charge it because the little bit of solar that might be available is used right away in heating. So it would be down to spring and fall where there is still some sun and also some request for energy.

You can’t convert the kWh to W, that’s not how it works. The amount of sunlight is highly variable during the day and the way the sunslight gets converted into usable energy differs a lot depending on the installation.

Normally those calculators assume you can connect the solar installation to the grid and use the grid as a buffer. So when there is sun and you’re not using it, you deliver the power back to the grid. And when there is no sun, you get your power from the grid. When there is a little sun, or you’re using a lot, you use some energy from the solar panels and some from the grid.

It starts getting complicated depending on how your local grid works. Often supplying back energy to the grid means the power provider credits you a certain amount. Depending on your contract, this might be a day price or even hourly. Or it may be a fixed price. This often means you pay a lot more using power from the grid then you get back pushing power back into the grid. So you need to think more in terms of money and using the energy in a way that’s cheapest.

If you are thinking about an off grid installation, the amount of power is almost always dependent on your equipment and not so much the solar panels. For example you can charge up a large bank of batteries from the sun during say a week. Then when fully charged, you can draw huge amounts of power from them till the bank is empty. But depending on the batteries used and the inverter used to convert DC into AC, the amount of amps it can push can be limited.

When thinking of something simple like a use case where you directly use the DC from the solar panel, the panel specs always include the Wp value. You can use that to calculate the exact amount depending on your location, time of day and angle of the panel. Weather services these days also include a watt per square meter of solar energy for different locations, which is useful. And keep in mind it only works when it’s sunny, with clouds the output drops a lot.

I’ve seen huge swings in my pv installation year on year. So it isn’t a sure thing how much energy you get from the sun.

Yeah I used these in my manual mill converted to do power drive and some basic CNC stuff. They are excellent and have a lot of torque, but they are also very slow. Especially with the amount of step down gearing in a manual mill, the end result isn’t very fast. But I don’t really care, I’m usually not in a rush to do anything.

I’m sorry, I’m just insecure because I’m a small boi myself with a 8D shaft

Compensating for something are we? /s

I know enough about these kinds of optics to be firmly in the valley of despair on the dunning kruger graph. It’s super complicated and well beyond my understanding.

The silver ones, I believe they are some form of silver coated silicon. But they are highly specialized with several coatings that improve the performance and longevity in different ways. They also come with very clear instructions to clean them as little as possible, as that can ruin the coatings. So I try to optimize my dust extraction when cutting anything that puts sticky stuff in the air.

Flat enough? Sure

Useful? Not really, they are optimized for a whole different wavelength. If I look in my CO2 laser machines mirrors everything looks grey/washed out. They are highly reflective for waves in the 10060nm range, but aren’t as reflective in other parts of the em spectrum.

so I can retire.

So you can become homeless you mean :p

One thing I’ve also noticed is people doing code reviews using ai to pad their stats or think they are helping out. At best it’s stating the obvious, wasting resources to point out what doesn’t need pointing out. At worst it’s a giant waste of time based on total bullshit the ai made up.

I kinda understand why people would think LLMs are able to generate and evaluate code. Because they throw simple example problems at them and they solve them without much issue. Sometimes they make obvious mistakes, but these are easily corrected. This makes people think LLMs are basically able to code, if it can solve even some harder example problems, surely they are at least as good as beginner programmers right? No, wrong actually. The reason the LLM can solve the example problem, is because that example (or a variation) was contained within its training data. It knows the answer not by deduction or by reason, it knows the answer by memorization. Once you start actually programming in the real world, it’s nothing like the examples. You need to account for an existing code base, with existing rules, standards and limitations. You need to evaluate which solution out of your toolbox to apply. Need to consider the big picture as well as small details. You need to think of the next guy working with the code, because more often than not, that next guy is you. LLMs crumble in a situation like this, they don’t know about all the unspoken things, they haven’t trained on the code base you are working with.

There’s a book I’m fond of called Patterns of Enterprise Application Architecture by Martin Fowler. I always used to joke it contained the answer to any problem a software engineer ever comes across. The only trick is to choose the correct answer. LLMs are like this, they have all these patterns memorized and choose which answer best fits the question. But it doesn’t understand why, what the upsides and downsides are for your specific situation. What the implications of the selected answer are going forward. Or why this pattern over another. When the LLM answers you can often prompt it to produce an answer with a completely different pattern applied. In my opinion it’s barely more useful than the book and in many ways much worse.

Yes.

Even in a unjust world mob justice isn’t justice. This means a mob deciding someone is guilty and acting out punishment is unjust. But also a mob deciding a crime should go unpunished is unjust.

There’s plenty wrong with how insurance works and plenty wrong with the justice system. But instead of giving up, we should be trying to fix these issues. It’s all to easy to give in to our basic instincts and point to someone to blame. We punish them instead of fixing the issues. Killing one ceo might feel good, but it doesn’t really change the big picture and in fact constitutes layer upon layer of failure. We should be better than that. History is full of people (singular and groups) being used as a scape goat to deflect and feel like something is being done, whilst in fact not actually fixing anything and just feeding hate.

Also in a capitalist world, the people with the most money have the most power. If we collectively decide it’s open warfare, purge style distopia, they are going to have the upper hand. So purely from a self interest point of view, it would be better to work on fixing shit instead of reverting to monke.

Because it’s broad blanket statements that boil down to: “Just do better”.

I have had some experience working with logistical processes for example. They always have their flaws, but trying to improve them beyond some point quickly becomes impossible. It’s easy to make big gains at first, but once you get into the weeds more and more small issues start popping up. It gets to the point solving these issues is more trouble than it’s worth.

So when the thing says we need to reduce food waste by having better logistics for example, I call bullshit. Modern logistical processes are often at the max of what’s possible. And we saw with covid how fragile those processes are. We’ve sacrificed flexibility for efficiency and as the world became weird for a while, the whole thing crumbled and still hasn’t fully recovered.

15C while I’m away, 17C while I’m in. Gas is expensive and my home isn’t that well insulated. I just put on a warm vest and it’s fine by me.

Can someone explain the joke to the Europeans? We don’t have either of those and I have no idea what this means. I know Best Buy is a electronics store and Home Depot is a hardware store, but I have no idea what the parking lots have to do with it. In Europe it’s more common for shops to be all close together with a shared parking lot in between.

I’ll post and respond all day, but if nobody is interacting, it’s going to stay quiet.

Well I just wanted to respond because I’m also trying to comment as much as I can and even post every now and again. But the issue I’ve seen is Lemmy draws a certain kind of person, which means a lot of like minded people in the comments. I see your response here, read it, like it and then think: “Yes I agree, nothing to add”. So I don’t respond, which makes it feel pretty quiet.

Another thing I’ve seen is not a lot of people even bother opening posts, they just scroll through the feed, get their dopamine and that’s it.

What are you talking about? Java runs on millions of devices!