solar power plant better than nuclear reactor

[Hellatze]

solar power are expensive, but infinite source, while uranium ore are scarce.

[hoho]

Yes, and?

Nuclear requires far less space and with enrichment, you'll have fuel for ages.

[AndrewIRL]

I thought this thread was about the critical resource nuclear consumes but solar doesn't : UPS.

According to Xterminator's video some people calculated a 7-8 UPS drop for a 10GW powerplant. The UPS cost of solar is 0 because there's no moving parts and the devs optimized it back in 0.13 or earlier, regardless of the number of panels.

https://youtu.be/epxHZC-DRk8?t=372

[BlakeMW]

Nuclear setups are a lot cheaper per MW in terms of iron/copper etc compared with solar/accu. Also, if you decide to not research nuclear power and instead invest that into solar, you only get about 30-40MW of solar/accu, so the threshold where a nuclear setup becomes cheaper in terms of iron etc is about 50MW - after that it's much cheaper.

The uranium is itself unusable for any other purpose*, so if you've already secured some against biter attack there is little cost involved in mining and utilizing it.

* Except for nukes. But for the cost of one atomic bomb, you can run a reactor for nearly 24 hours, so if you're setup to make atomic bombs you can definitely use nuclear power without feeling the uranium cost.

[Hellatze]

but to find the uranium ore itself are rare. unless i got big ass radar to find ones

[Ranakastrasz]

Once you can enrich uranium it is surprisingly long-lasting.

[BlakeMW]

but to find the uranium ore itself are rare. unless i got big ass radar to find ones

That depends on the map. But even in the worst case it's not bad. Even a single U-235 will make 10 Fuel Cells which will run a reactor for 33 minutes (or a 160MW reactor for 16 minutes). In principle a centrifuge fully supplied with ore will make enough U-235 to run a single reactor.

The basic ratio is:
~2 Electric Mining Drills -> 1 Centrifuge -> 1 Reactor

The most basic nuclear setup that makes sense produces 160MW, so would require 4 mining drills on uranium to run full time. But actually, it's a no-brainer to use prod3 modules when making fuel cells even if you temporarily borrow the modules from another assembler to make a batch of fuel cells. This increases the fuel cells by 40% and means you'd only need 3 mining drills on uranium to make 160MW continuously. That means you don't need a heap of uranium ore to run even quite a large factory on nuclear power. Enrichment greatly increases the ability of an ore patch to support reactors, but it does not tend to be very worth doing unless you're really going large-scale, as that 40 seed U235 could generate 160MW continuously for 16 hours.

[purdueme91]

The problem I have at the moment with nuclear is the 235/238 ratio. In my first playthrough my first patch of uranium only could fit 3 miners. With the processing ratio, I could not physically mine enough uranium ore fast enough to process to keep one nuclear reactor going. I was only getting 3-5 pieces of 235 from 10k ore so I shut the reactor down. My second patch was better in that I was able to up the mining speed to I think 150/minute. But I decided to get the Kovarex process and wait. And that took forever to get 40 pieces but then I was swimming in 235 after that.

I just think it is so unbalanced right now. I was so excited once I got the research to play with the reactors and never got much figured out before I shut it back down. Even though the 0.7% ratio is accurate they've taken liberties elsewhere already so maybe the ratio on a different planet is 5% or something. But then adjust the Kovarex input to be 200. Or introduce a breeder reactor that can use 238.

[Kametec]

When it was just steam vs solar (now it is solar vs steam-165 vs steam-500), I always went for steam for one reason: Pollution. I like to build large polluting power plants providing for large polluting factories. I never use efficiency modules, I always put production where applicable and speed otherwise. I like to watch world (or at least biters) burn.

Now I am torn inside. I like the performance of nuclear setup, but it is way too clean for my taste. Do nuclear reactors generate any pollution at all? When I tried nuclear reactor in sandbox mode, I didn't see the bright red pollution cloud which always accompanies rows of boilers.

[HurkWurk]

Pollution in 15 doesn't show by default, you have to select the pollution button on the world map screen

[netmand]

I use both. Neither is better from a general sense, more like one is more applicable in certain situations over the other, in terms of area, resources, power requirements, etc.

[Aeternus]

Chemical:
- Requires water
- Requires moderate amount of space
- Requires chemical fuels, most of which are derived from oil. These are essentially infinite since oil does not run out.
- Produces pollution
- Requires relatively small amounts of investment (boilers and steamengines are cheap, refineries and chem plants moderately expensive)
- Always on. No batteries needed.
- Fuel production can be significantly improved with modules
- Fuel consumption scales with power production.

Solar:
- Requires no water or fuel
- Requires a very high amount of space.
- Only generates power in daylight
- Requires a second powersource (generator or batteries) to supply power at night.
- Requires moderate amount of investment (moderate amounts of resources per solar plant, small amount per battery, but you need a lot of them)
- Does not pollute

Nuclear:
- Requires water (but less then chemical for the same power)
- Requires moderate amount of space
- Requires a high resource investment, both in the buildings and in research.
- Requires a high amount of time to get uranium mining, refining and Kovarex processing going. Significant power draw while this starts.
- Provides very high amounts of energy in a relatively small area.
- Limited pollution from producing nuclear fuel.
- Fuel production can be significantly improved with modules
- Constant fuel consumption in reactors. Can be remedied with some controls and steam storage.

Each of these has it's pro's and cons. There's no real "winner". With full production modules in the refining centrifuges, uranium mines and fuel production assemblers, you can produce a -lot- of fuel from very little actual uranium. Investing in Mining Productivity also helps a little. But the same holds for chemical fuel - even a single blue belt of solid fuel can supply up to 900MW electrical power generation from chemical boilers (taking into account the 50% efficiency). If you produce rocket fuel, then burn that, this raises to 4.5 GW for a single blue belt. That rivals most nuclear plants easily. Solar plants are just... large. A 4.5 GW solar plant I suspect would be at least 10 times as big as a chemical plant of the same power production. A nuclear plant would probably be roughly one fifth of the size.

[iceman_1212]

...
Solar:
...
- Requires moderate amount of investment (moderate amounts of resources per solar plant, small amount per battery, but you need a lot of them)
...
Nuclear:
...
- Requires a high resource investment, both in the buildings and in research
...

On a per watt basis, Nuclear is more affordable than solar, even after taking research costs into account. As we can see in the table below, once we've paid for the fixed cost of research, Nuclear is cheaper by far.



I'm on my first playthrough in which I used Nuclear for power. I first went up to ~200MW using steam, then went up to just over 2 GW using nuclear (16 reactors), and am now sitting at 10.5GW of capacity using solar (of which I'm using ~2/3rds). In retrospect, I was happy with when I switched from steam to nuclear but I probably switched to solar too early. If I could do it again, I would probably go up to ~5gw using nuclear as the massive amount of green circuits and copper required for solar panels represented a large opportunity cost in terms of modules.

As someone else mentioned, the biggest advantage of solar imo is the fact that it costs effectively 0 UPS in the extreme late game.

[Aeternus]

Not entirely. All those solar panels and accus themselves count as items. As long as you use bots to move things around (no belts - keep stuff stacked in chests as much as possible), I think it'd be fairly tight UPS wise between solar and nuclear.

As for the nuclear investment: I meant the initial investment for the first reactors, and centrifuges. It's a onetime cost but it is quite steep, a smaller factory isn't likely to be able to do so. Whereas a solar panel plant can be expanded and built gradually as need increases. I myself would still prefer solar - for the simple reason that it has no logistical needs once the solar plant is set up. It can never fail due to water or fuel shortages, so as long as you've got sufficient batteries, you've got a reliable (solar reliable? Yes solar is reliable) power generating option.

[iceman_1212]

Not entirely. All those solar panels and accus themselves count as items. As long as you use bots to move things around (no belts - keep stuff stacked in chests as much as possible), I think it'd be fairly tight UPS wise between solar and nuclear.

It is indeed a lot of entities but what we are concerned with is entity updates per tick. My understanding is that solar optimizations were made a few versions ago which dramatically reduce calcs per tick. From an old FFF (https://www.factorio.com/blog/post/fff-148):

Solar panels where grouped so regardless of how many you build the calculation is: N * light * power
Accumulators are grouped similar to solar panels

In a nuclear setup, the steam engines, pipe segments and storage tanks are all separate fluid boxes, each of which would require a separate calc per tick. (Incidentally, UPS is part of the reason that some streamers have elected to go for accumulator based fuel throttling with solar instead of relying on storage tanks.)

Maybe someone more familiar with this stuff can confirm re: solar UPS efficiency compared to nuclear?

[AcolyteOfRocket]

In the early stages of the game I am playing I overexpanded and ran out of power for my factory just as I had maxed the laser defence on the perimeter - the results were not pretty

I decided that I would make separate power for the production part of the factory, and for the defences, and make sure the defences were generously provisioned and reliable. As a result I use solar/battery with coal backup for defence and nuclear/solar(!) for production.

It is a bit more fiddly to set up, and you have to make sure that you don't cross connect the systems whenever you expand your factory, but the advantage of having two power systems is that I get more scope to play with them all - definitely the silver lining to the cloud of biters that set me on this path

[Methusalem]

Nuclear reactors are an incredibly efficient way to generate power, even early in the game. The trick is really to use steam tanks and circuit control to limit the fuel consumption.

My (still rather small) factory requires currently around 60 MW and uses the 2 reactor, 160 MW setup as main power supply. The steam is buffered in 50 tanks and fuel is only inserted into the reactors if the tanks drop below 2000 steam. Then it adds 5+1 Fuel Cells into each reactor, they have the next 20 minutes to fill all the tanks back up and stay idle while the tanks feed the turbines. The reactors only run around 30% of the time (this number will go up as the power demand for the base increases), which means a single U-235 can power the current base for more than 50 minutes.

[Selvek]

The problem I have at the moment with nuclear is the 235/238 ratio. In my first playthrough my first patch of uranium only could fit 3 miners. With the processing ratio, I could not physically mine enough uranium ore fast enough to process to keep one nuclear reactor going. I was only getting 3-5 pieces of 235 from 10k ore so I shut the reactor down. My second patch was better in that I was able to up the mining speed to I think 150/minute. But I decided to get the Kovarex process and wait. And that took forever to get 40 pieces but then I was swimming in 235 after that.

I just think it is so unbalanced right now. I was so excited once I got the research to play with the reactors and never got much figured out before I shut it back down. Even though the 0.7% ratio is accurate they've taken liberties elsewhere already so maybe the ratio on a different planet is 5% or something. But then adjust the Kovarex input to be 200. Or introduce a breeder reactor that can use 238.

Yeah it's really weird how they've done it. My suggestion - research uranium processing early, and just put uranium in chests for a while. Then, once you hit 40, you can rig the kovarex loop, build the power plant, and have virtually unlimited U235.

[BlakeMW]

Yeah it's really weird how they've done it. My suggestion - research uranium processing early, and just put uranium in chests for a while. Then, once you hit 40, you can rig the kovarex loop, build the power plant, and have virtually unlimited U235.

I used to think this way, but the thing is that each u-235 makes 10 fuel cells (or 14 with prod3) that will power a reactor for 33 minutes (46 minutes w/ prod3), so given you can run a reactor for damn near three quarters of an hour off of a single u-235 you just don't need to be making a heap of it - unless you want to use it to make nukes.

[AndrewIRL]

Yeah it's really weird how they've done it. My suggestion - research uranium processing early, and just put uranium in chests for a while. Then, once you hit 40, you can rig the kovarex loop, build the power plant, and have virtually unlimited U235.

I used to think this way, but the thing is that each u-235 makes 10 fuel cells (or 14 with prod3) that will power a reactor for 33 minutes (46 minutes w/ prod3), so given you can run a reactor for damn near three quarters of an hour off of a single u-235 you just don't need to be making a heap of it - unless you want to use it to make nukes.

Exactly.

If you want to run 2 nuclear plants you only need 1.5 centrifuges and 2.8 miners to feed them without productivity or speed modules.

Or look at it another way if you have 31 miners and 16 centrifuges you'll get Kovarex up and running in 1 hour. But if you were running two reactors the entire time they'll consume some U235, which delays your Kovarex start by only 9%. Instead of 3600 seconds to Kovarex you'll be waiting 3922 until start but you will have enjoyed an hour of fine nuclear power.

The ore difference is minimal 62752 ore required to get Koverex and power vs 57152 to just get Kovarex. So if you have only a 60K ore patch (accounting for the ~10% mining productivity you'll probably have by this point) then don't start nuclear power early. Wait until Kovarex is done.

Nuclear power start before Kovarex math