The best power plant in numbers [UP TO DATE 1.2]

A conprehensive guide on the electric power plants available in the base game Cities Skylines II
** TLDR in the last section **

Preface

Allright, le me preface this by saying i don't play Cities Skylines to "win the game". For me it's just a canvas where i can do what i enjoy or what feels fulfilling. So i totally get that you don't place an asset or a service because you have to but also because it feels like that's the right thing to plop in that space. It creates an atmosphere and we don't care if it should or shouldn't be there, or is not the most optimized way to do things. We just have a vision and yours might be a hell made of black smokes, one running on renewables only, or a city that's massively subsidised and doesn't give a flying crap about what's financially wise.
But sometimes, you gotta do what's best, and with the massive shift that Cities Skylines II is compared to its predecessor, i think a lot of people just have outdated beliefs. And some of us like to play through the milestone and optimise, at least at the beginning.

All tests made under 1.2 build as of December 25th 2024



For my calcs, i've assumed water costs of around 0.3 per cubic metre, since that seem to be the lowest rate you can get ingame with the Advanced Pump Station and Sewage Outlet.
Garbage was included assuming the garbage accumulation stat listed in the wiki is up to date AND equal to a monthly garbage production. I've used a price of 55/ton of garbage processed as this seems to be the lowest you can get through the Incineration plant with the extra furnace.

Of course the different types of pollution, the size or the workforce needs can't be analyzed from a mathematics standpoint, but those factors will play a role depending on the shape of your build. So don't overlook them.


The second column is the most important one, giving you an overview of the overall upkeep per MW needed for any power plant with or without any relevant upgrades. "Comfort" upgrades are listed but since they won't improve the overall efficiency of the plant, they haven't been included in overall solutions. You can of course still pick them in order to reduce pollution or other things.
The second most important column is probably the fourth, "Upfront cost", it represents the amount of money you need to build the plant or the upgrades initially.

Starting a city : electricity on a budget

Early game


Placing a transformer station and importing what little electricity your city needed was the way to go in the past. However, you must consider the fact you can sell electricity for 2'500/MW, while importing it seems to be costing a lot more in 1.2 (prices seem to be changing a lot, but usually upward of 9'000/MW for buying). It used to be 5'000/MW.

So basically any power plant producing for less than 2'500/MW can make you money. This is the case for a number of plants, however early on, the Wind Turbine is your best bet, as long as you can max out its output (5 MW or very close to it). They don't make a lot of electricity, but it's more than enough for an new city, the capital cost is low enough, and you can upgrade them with the Advanced Rotor System in order to boost their efficiency as well as overall production. They can also be placed anywhere you need power, saving you money in network costs.

Keep in mind the transformer station has a pretty hefty upkeep, so it might be a good idea to save it for the first few months. Once you have about 60'000 in electric upkeep, it might be time to use the transforming station and sell the excess power you have.

If the capital cost (ie the amount of money you need to get going) scares you, keep in mind a Wind Turbine that you build just to generate and sell electricity will be profitable within 5 months (4.5 months if you add the Advanced Rotor System). Considering you'll be playing for a few years at least, it shouldn't be a problem.

Wind Turbine
Footprint : 3x3 cells
Workforce : none
Upfront cost (base / upgraded) : 25'000 / 40'000
Maximum output (base / upgraded) :
5 MW / 7.5 MW
Upkeep w/o water nor garbage (base / upgraded) : 7'500 / 10'000
Ground / Air / Noise pollution : - / - / 20'000




As long as you can maintain more than 60% efficiency (ie more than 3MW when you place it down), you'll be able to make money out of it by exporting the electricity. Pretty decent for a clean source of energy ! Just place them wherever there's already some noise : industries, highways, infrastructures, etc.
The Advanced Rotor System is the best upgrade by far as it lowers the overall upkeep/MW. The other upgrades are all ok, since they don't increase the upkeep, but they don't provide as much benefit. If you go with the solar panels, it is highly recommended to add batteries to your grid so you can flatten the curve. Unless you just want to sell that electricty outside, in which case your revenue will just shift depending on the cycle.

Small coal power plant
Footprint : 14x16
Workforce : educated (24%/9)
Upfront cost : 100'000
Maximum output : 20 MW
Upkeep w/o water or garbage : 71'300
Ground / Air / Noise pollution :
30'000 / 30'000 / 30'000




The worst option in the game by far. It produces a lot of pollution, relies on coal that you need to dig out or import, and has an overall cost per MW so ridiculous that you'll be better off importing electricity from another town. I can only see this being an option for maps without an outside electric connection or to roleplay a developing country.

Getting serious : your first "real" power plant

Depending on your playstyle, this might be the first power plant you invest in, the earlier options being so lame. All 3 are big and reliable power plants, the difference lies in the details.

Gas power plant
Footprint : 27x38 cells
Workforce : Well educated (25%/25)
Upfront cost (base / upgraded) : 650'000 / 950'000
Maximum output (base / upgraded) :
250 MW
Upkeep w/o water nor garbage (base / upgraded) : 510'000 / 592'000
Ground / Air / Noise pollution :
10'000 / 10'000 (5'000) / 10'000



Cheapest to build, but most expensive to run out of the 3 “Tier 2”. It’s also the least polluting and its air pollution can be further reduced with the upgraded filters. From a financial standpoint, the consumption or turbine upgrades do not make sense, either taken on their own or added together. It will always net you a worse upkeep per MW.

Coal power plant
Footprint : 50x39 cells
Workforce : Well educated (25%/35)
Upfront cost (base / upgraded) : 1'000'00 / 1'750'000
Maximum output (base / upgraded) :
300 MW / 400 MW
Upkeep w/o water nor garbage (base / upgraded) : 594'000 / 764'200
Ground / Air / Noise pollution :
100'000 / 100'000 (50'000) / 100'000



It’s big, dirty, but powerful. Best output out of the 3 “Tier 2” plants. Although it should be said the only upgrade that increases its output is not really worth it (high cost to build and maintain) so it should only be done for space reasons. But if you stay at 300 MW, there’s no real incentive to go the coal way as the other plants can achieve the same output with much less downsides. The upgrade for its resource consumption is barely worth it since it will allow you to save 7500/month on the base plant (so you’ll need almost 3 years to make your money back). It’s slightly better with the 2nd turbine but still yields a worst cost/month per MW than the base plant and that furnace will still require 9 months to get your money back. That being said, this is purely theorical as right now, they don’t seem to work : the amount of fuel you burn remains the same with or without the upgrade.

Note : In both Gas and Coal instances i have used import prices (or so it seems). It's unclear (to me at least) how the production of said fuels in your city would affect the runnning costs of the power plants. However, it is likely that those materials would be further transformed in your city if they weren't used to power it up, and so the deficit would probably be the same or even greater.

Geothermal
Footprint : 44x35 cells
Workforce : Well educated (24%/17)
Upfront cost (base / upgraded) : 750'000 / 1'375'000
Maximum output (base / upgraded) :
150 MW / 300 MW
Upkeep w/o water nor garbage (base / upgraded) : 296'700 / 489'100
Ground / Air / Noise pollution :
15'000 / 15'000 / 15'000



Although the game UI states the Geothermal plant is “somewhat” expensive to maintain, it’s actually the cheapest of the “Tier 2” power plants, and second only to the NPP overall. The Coal power plant is not too far behind but is still more expensive, pollutes way more, and require resources (so there’s a risk of shutdown). The only real drawback in my eyes is the lack of freedom of placement, since you need groundwater deposits. But these seems pretty common on the vanilla maps so far. It might not be realistic though and I could see custom maps where such ground deposits are few and far between (and possibly being your only access to clean water) in which case the geothermal might not be as good.

The last stage : no more air nor ground pollution

Nuclear Power Plant
Footprint : 72x41 cells
Workforce : Highly Educated (25%/75)
Upfront cost : 5'000'000
Maximum output : 750 MW
Upkeep w/o water nor garbage : 1'220'000
Ground / Air / Noise pollution : - / - / 150'000





On paper, the Nuclear Power Plant (NPP) is the better option even if it costs a fortune upfront, is ginormous and requires a considerable workforce. Usually its upkeep is what tilts the scale. However, 400 000 m3 of water is nothing to sniff at. In fact, assuming the most favorable rates, it will cost you around 120k/month to provide clean water and sewage for your NPP. While the water upkeep for most plants is around 2-4% of their total upkeep, it raises to 11% on the NPP !

That being said, the NPP still is the best option overall and should be the most profitable option after around 8 to 15 months (time needed to offset the huge upfront cost). But you’ll need to pay attention to that water cost because I’ve used the cheapest price per m3 (sewage outlet + advanced pumping station). If you run less ideals plants it will cost you even more and possibly offset the gains of the NPP. You'll also need to make sure your workforce is plentiful before you decide to build a NPP.

Solar Power Plant
Footprint : 36x70 cells
Workforce : Well educated (25%/8)
Upfront cost (base / upgraded) : 1'500'000 / 2'100'000
Maximum output (base / upgraded) :
100 MW / 150 MW (values halved to account for the solar uptime)
Upkeep w/o water nor garbage (base / upgraded) : 220'000 / 290'000
Ground / Air / Noise pollution : - / - / 36'000

So what about the Solar Power Plant (SPP) you ask ? Well I don’t have accurate enough data on the sunlight and the solar panel output because CO seems to have implemented a fairly initricate system depending on the hemisphere, time of day and the latitude of the map. It's not even as simple as having 100% efficiency or 0% depending if it's day or night. Sometimes you'll be at 80% during the day, probably because of clouds or the sun's position on the horizon or in relation with the surroundings, which is very realistic indeed. For this reason nobody can tell how much power your SPP is going to produce. However, we can easily assume around a 50% sun uptime as a best case scenario.
First of all, this means you need to cut in half any power output rating the game gives you. So the big SPP would give you 200 MW during daytime, and 0MW during nighttime, which equates to roughly 100MW on average over several months (I can only assume winter and summer hit differently on the efficiency).

Secondly, you’ll need a way to fulfill your electricity needs during this downtime unless you want to resort to importing. Enter the batteries. The SPP itself has an integrated battery of 50MWh and 15 MW output. Notice the lame output. 50 MWh at 15 MW means around 3.3 hours of power. After which your city will run dark. You can upgrade this further with an added backup battery rated at 50 MWh and 50 MW. Or you can make use of the standalone emergency battery station (EBS for short) rated at 500 MWh and 200 MW. While it’s quite a bit bigger, it can be placed anywhere and is much cheaper than the SPP upgrade. If you’re going for capacity, you’ll need 10 upgraded batteries from the plant, for a whopping 274'000/month in upkeep whereas the standalone version will set you back only 115700/month. If output is your main goal then you’ll require 4 upgraded batteries and the upkeep would be barely lower (109'600/month vs 115'700/month), but with a storage capacity 20% lower. Even the upfront cost doesn’t make much sense. It would be 3x and 1.2x more expensive respectively.


The only time I could see the upgraded battery be of any use is when you don’t have huge electricity needs and so the standalone EBS would be oversized compared to your only SPP. Also having a much bigger battery capacity than needed is always preferable to account for lack of sun in winter and allow some leftover power to recharge the battery during daytime.

Let’s make some assumptions. I’d say you won’t unlock or use the SPP until you need 150 MW or more. So let’s say you build 2 of those (rating of 300 MW, effective power generation of 150 MW) and have an EBS alongside those. The upfront cost is 3.15 millions and the upkeep ticks in at 660 000/month. For 150 MW as I said. That makes it 4'333/month/MW.
However you’re fully independent, don’t rely on raw ressources, don’t pollute the ground or the air and you can split your power plants and batteries so your grid doesn’t show any bottleneck. Scaled up on a big city and scattered around the map, this could offer a good protection against natural disasters too. But overall, it probably adds too much complexity and should be kept for realism and variety.

What about the damn dam ?

The dam is obviously excluded here because there are an infinite number of dams and so it’s very hard to analyze. But most likely it would be the best solution overall. Its upkeep seems to remain constant (87'500/month) no matter its size, the latter only influencing the building cost. So as long as you’re able to make 35 MW out of your dam it’s a win. At 75 MW it already is the cheapest source of electricity, excluding building costs.
For context, a massive dam in the game can easily generate 1'500 MW of clean electricity, making it the cheapest source of electricity by far at around 58/month per MW (compared to at least 1'300 for anything else)

Footprint : -
Workforce : Well educated (22%/4)
Upfront cost : 1'575'000 at least
Maximum output : upwards of 1'500 MW
Upkeep w/o water nor garbage (base / upgraded) : 87.5K
Ground / Air / Noise pollution : - / - / 50'000

Keep in mind however it will take a very long time to fill the reservoir if your dam is large enough. The one you see, made on the northern side of the map Mountain Village (after the two rivers merge), took a good 9 months to be fully operational. It didn’t yield more than a MW for the first 8 months. So if you ever go the dam route, plan ahead, not only for the change in topography (don’t drown your city in the reservoir) but also because it shouldn’t be the answer to an immediate problem but rather a long term goal that’s running in the background.

TLDR

Tier 1 (~Milestone 0-4)
At the very beginning, it would be ideal to place wind turbines. If that's not possible, then i would avoid the small coal power plant.

Tier 2 (~Milestone 5-12)
Overall, Geothermal is the best option and can be kept even through endgame as it’s not much worse than the more advanced options. Not a lot of pollution, no resources to import, and cheap overall. It only requires groundwater but that should be easy enough to come by. The 2 upgrades are worth doing (additional turbine and binary cycle) but keep in mind they'll require more educated workforce, which can be an issue early on.
The 2 other big plants are not as competitive, although the big coal power plant can be decent (cost-wise) if you add the second turbine. The gas power plant is an in-between, with significantly reduced pollution. Both can be placed anywhere but require constant influx of goods.


Tier 3 (~Milestone 12+)
Nuclear is the endgame and is the best solution overall. Can be placed anywhere, produces a ton of energy and all of that with no air nor ground pollution. After 8 to 15 months it’s the cheapest plant despite the high starting capital involved. Be wary of it’s water consumption though.Note that a bunch of wind turbine can be even cheaper to use over a long period, thanks to their lack of workforce, water or garbage needs. But you'll need 75 of them just to make as much power as the NPP, so probably not very practical.
Due to its battery need, solar will never be the answer, but i have to admit it looks good !

Upgrades worth getting
The only upgrades worth doing from a cost standpoint : wind turbine rotors, geothermal turbine & binary, solar tracking, coal turbine. The cost of any other one is hard to justify and should be kept for realism/variety/space constraints purposes.
Note that the reduction in resources consumption (advanced furnace on coal and gas plants) do not work as far as i could tell. You'll still need your ton of oil and 150 tons of coal monthly no matter what. I have however simulated numbers where it works, just to be on the safe side. Hopefully it will get fixed at some point.

[Aieonae]

Yup this guide is very comprehensive in calculation.

[Ben]

@macluk In my last update, i worked out the workforce cost in the upkeep, so any per MW price is including those

[macluk]

All fine, but the real cost is when employment is added. That is a massive black hole in any guide I've found so far - including wiki pages. Massive unknown that eats into budget unexpectedly.

[Aieonae]

Thanks for the update. Interesting.

Since recently I am still looking into ways to making fuel power plants viable using proper logistics. I had look into both Coal and Gas and actually favor gas power plants as mentioned in prior comments in both footprint and flexibility. the primary viable consideration for fueled power plants to be viable was unsurprisingly simple, just go with the additional turbine and nothing else*.

[Aieonae]

On local fuel source indeed it would somewhat** reduce the import price depending on the proximity of local production of resource netting storage. But overtime the city needs would take priority over the resource like coal and petrochemical causing the city to import the fuel directly, this is actually exacerbated over time especially the game deals with non renewable resources. in turn it making coal power particularly less attractive as time move on. its approximate nett income while having full fuel import is slightly beyond double that gas power full power export.

[Aieonae]

Also I am not too sure if we should embrace buggy power sources like solar power(it does not work at night even with upgrades) and Hydroelectric(the game speed affects the output efficiency) other than for aesthetics purposes.

*Observed these upgrades are seriously overrated as in operation they are horribly overpriced.

**Observed Coal price reduction can go from import 300k to around local 70K~140k, while Gas goes from import 145k to local 93k,

[Ben]

There we go, guide is updated with 1.2 data. It looked like a huge overhaul, but it's more about details than overall rebalancing. There are a few outliers though, namely wind turbines and small coal plant.

[Aieonae]

Merry Xmas and keep up the great work!

[Ben]

You're right. Haven't been able to play the game that much since the big update, but i plan on doing so soon with the new DLCs. I'll update that guide around Xmas hopefully.

[Aieonae]

Thank you for your insights and analysis.

I see they had normalizes power plants profitability by a fair bit since I last observed, the metrics might be the same the breakdown on accountable might actually defer, in short it's no longer that profitable to run just a nuclear power plant like when it was first release. But it's still remain pretty much the only one that can provide at 2 full 400MWw HV export without much consideration. It's still a point to strive towards upfront.