How I do power grids: No overloads

[Zarquan]

When some people make grids, they often just hope that overloads don't happen or they run dedicated wires all the way from their spine to their power hungry buildings.  I don't like doing this, and instead have a 3-tier design that is relatively easy to create and understand, especially with the new power wire colors.

Tier 1:  Power spine  (Heavi-watt)

• My Tier 1 grid contains my generators and my smart batteries.  It connects to my Tier 2 grids using two small power transformers.  

Tier 2:  Power limited power distribution (Green conductive)

• My Tier 2 grids are an intermediate wire between my Tier 1 grid and my actual buildings.  It is provided with only 2000 kW, so it can not deliver more power than that. 
• It gets its power from the Tier 1 grid and has numerous transformers of whatever kind you want to my Tier 3 grids. 
• No batteries are allowed on this grid.
• This grid never overloads, but it does saturate.  If it is constantly at 2 kW, then you need another tier 2 grid.  You can use automation to detect if this is happening too much. 
  • But, as long as you on average spend less power than 2 kW, then you will be fine.  Power spikes are no problem.
• This grid can be normal wire instead of conductive, but then you only give it 1 small transformer.
• You can put consumers on this grid if you want.

Tier 3:  Consumer-limited power usage

• My Tier 3 grids are the final destination for my power.  It gets its power from either Tier 2 or Tier 1 grids, but normally Tier 2.  The Tier 3 grid can take input from multiple Tier 2 grids/ 
• These grids can and must have batteries.  They can be any kind of battery, but you might want a smart battery so you can have automation to detect brownouts.
• These grids must not have more than the capacity of their wiring.
• If the tier 3 grid is critical enough, you can put emergency generators on them, but it should be unnecessary.

Here is a picture of a build I can do with this:

In this picture, I have one conductive wire managing two metal refineries, a rock crusher, an aquatuner designed for running a deep freezer, and several small buildings.  I also added automation to let me know if my metal refineries are actually draining the battery so I will know if I need more storage.  The theory, which I have put in to practice in my bases, is that if your metal refineries are being used by dupes with levels in machinery, they can't run all the time due to coolant flow.  If your dupes have enough levels, then even if they are solely dedicated to running the refineries, they will have significant periods of time where the metal refinery is idle.  And deep freezer aquatuners barely ever run, maybe a few seconds every few cycles, so they are barely a power draw.

By building your grids like this, you only have to worry about averages, not about peaks.  An aquatuner that runs 2% of the time is no longer a beefy 1200 W load that you have to worry about for your Tier 2 grid, but instead a measly 24 W load on average that you barely need to be concerned about.  This is true as long as your Tier 3 grids have enough battery storage to let them run through their peak power period.

This theory can work in the real world too, and often does.  My gaming laptop CAN use USB-PD to charge, but it can only take so many watts.  That means that if I am doing a large job, like hitting the GPU and CPU with a large rendering task, it will draw power from the wall AND the battery, as it does not have enough power from the wall to run the job.  This is fine as long as (1) your wall + battery can provide enough power, (2) you have enough battery to supplement the peak power draw, and (3) you have enough time between peaks to recharge the battery (i.e. the average power draw is less than the power delivery).  The same holds true with my grid design.  You can do this with an entire house in theory if you have a backup battery, where you have moments where you draw more amps than your circuit breaker allows because some of that is coming from a battery.  The actual power grid is like a Tier 1 grid, my USB cable is like a Tier 2 grid, and my computer and its peripherals are like a Tier 3 grid.

 

On top of this, there is also a benefit of storing power.  If you have things like steam turbines that have to run to keep a volcano cool or solar panels that just generate power for free or a natural gas geyser whose storage is full and might as well be burned but don't want to waste the power on full batteries, I designed what I call a Tier 0 grid.  This grid acts like a consumer to the Tier 1 grid if the grid is almost full and like a generator if it is empty and is full of batteries, so the Tier 0 grid acts like a giant backup battery. 

Tier 0: Excess Energy Storage:

What I do is I put two arrays of transformers, one for charging the Tier 0 grid and one for discharging it back in to the Tier 1 grid.  These transformers are on automation to make it so they don't run at the same time: 

1. If the grid is approaching full (say, 98%), the transformers to the Tier 0 grid turn on and dump power on to the Tier 0 grid. This is achieved by using a smart battery with a NOT gate on it.  I like setting this battery to 98-95.
2. If the grid is needing power (say, below 90%), then you turn on the on the transformers from the Tier 0 grid by attaching them straight to a smart battery like a generator.  I like setting mine to 94-90, then setting all my other generators below 90%.

Here's a couple pictures of that:

Spoiler

 

If you want to be fancy, you can actually use the same transformers for both directions using the Power Shutoff.
 

Spoiler

 

 

Edited April 23 by Zarquan

[bobthedog]

You have some interesting applications here. I particularly liked the use of shutoffs to switch the direction transformers send power, even if it was included almost as an afterthought. 

I like your idea of using transformers to send power over long distances using thin cables (your T2 grids), but I don't think I would have much use for it. I tend to build most of my stuff close to the "main spine" anyway, so adding an intermediate power grid would not be that useful. Though I can see the benefit of separating things like a deep freezer AT into a T3 grid.

 

[Zarquan]

7 hours ago, bobthedog said:

I like your idea of using transformers to send power over long distances using thin cables (your T2 grids), but I don't think I would have much use for it. I tend to build most of my stuff close to the "main spine" anyway, so adding an intermediate power grid would not be that useful. Though I can see the benefit of separating things like a deep freezer AT into a T3 grid.

 

Question:  Do you build things near your spine because it's convenient, as you don't have to run as many long wires, or for other reasons?

I find using T2 grids for inside a base is great because it can greatly decrease the number of wires.  Most rec room buildings have huge peak power draw, but are only used a fraction of the time, so you could have one or two wires in to there to power all those buildings despite their high peak power draw.

Edited April 12 by Zarquan

[ghkbrew]

Great explanation.  I've settled on a lot of the same tricks (except the using shutoffs to switch transformer direction on battery sub-nets.  That's genius!).

In practice though, I rarely use T3 grids.  I mostly stick to a single T1 spine, with everything powered by T2 grids directly.  The main exception is early game: I set up a very small T1 grid in the room with my generators and everything else on a couple 1kW T2 grids.  Which works great until you want to run a metal refinery (1.2kW > 1kW). So it gets a heavy watt wire T3 grid with ~3 large batteries, enough to run at least one batch of ore before the batteries are drained. 

The other trick that might be useful to mention is using small gauge wires to bring power from distant power sources to your T1 grid.  You can have, e.g., steam turbines on volcano tamers output onto a 1kW and bridge the power onto the T1 spine with a transformer.  It saves you making huge runs of heavy wire to add a single intermittent turbine to your power system.

[Zarquan]

5 hours ago, ghkbrew said:

Great explanation.  I've settled on a lot of the same tricks (except the using shutoffs to switch transformer direction on battery sub-nets.  That's genius!).

In practice though, I rarely use T3 grids.  I mostly stick to a single T1 spine, with everything powered by T2 grids directly.  The main exception is early game: I set up a very small T1 grid in the room with my generators and everything else on a couple 1kW T2 grids.  Which works great until you want to run a metal refinery (1.2kW > 1kW). So it gets a heavy watt wire T3 grid with ~3 large batteries, enough to run at least one batch of ore before the batteries are drained. 

The other trick that might be useful to mention is using small gauge wires to bring power from distant power sources to your T1 grid.  You can have, e.g., steam turbines on volcano tamers output onto a 1kW and bridge the power onto the T1 spine with a transformer.  It saves you making huge runs of heavy wire to add a single intermittent turbine to your power system.

The issue with hooking things up to the T2 grids is that your buildings will be interrupted if your peak power draw attempts to exceeds 2 kW.  That's why the T3 grids are so great.  My peak power deaw can be as high as I want as long as I have the storage on my T3 grids to cover it and my average power draw is less than 2 kW.  Although, as far as I can tell, buildings appear to have higher power priority than transformers, soma few buildings on them shouldn't be a problem. 

The idea of running a cable from a steam turbine off to a T1 grid is a good one.  I've done that a few times.

Edited April 13 by Zarquan

[ghkbrew]

5 hours ago, Zarquan said:

Although, as far as I can tell, buildings appear to have higher power priority than transformers, soma few buildings on them shouldn't be a problem. 

Last I knew buildings, including transformers, had priority based on build order, with older buildings getting power first.  Though, I've never tested extensively.

[Zarquan]

2 hours ago, ghkbrew said:

Last I knew buildings, including transformers, had priority based on build order, with older buildings getting power first.  Though, I've never tested extensively.

I think that transformers are lower priority, but we can test that.

Here, I have a picture of a pre-built setup:

If the transformer gets priority for power over all newer buildings, no newer buildings should get power until the jumbo battery is charged, as the transformer is older than it and it is consuming the full 1 kW input.

The light has power.  I think that means that the light has priority over the transformer.

[bobthedog]

On 4/12/2026 at 8:08 PM, Zarquan said:

Question:  Do you build things near your spine because it's convenient, as you don't have to run as many long wires, or for other reasons?

Both to save on materials (no need to run pipes, wires etc.), and to reduce travel time for stuff that needs dupe labor.

[KittenIsAGeek]

This is pretty good.  Initially I set up some simple grid to run the early basic things.  Later, once I've developed a stable source of fuel, I'll build a generator room using heavi-watt wire and put a couple of large transformers on it.  My base design usually puts a 2-high "maintenance floor" every three or four "main" floors.  I can then run a single regular wire from the generator room to this floor, and where necessary set up a switched-mode power supply to run things nearby.   

Another great way to do things is to use the power packs from the Bionics set.  Build some recharging stations near your generators, then a bunch of rechargeable power packs.  If you need power in an awkward place, build a couple compact dischargers or a large one and set it to use the rechargables only.  You can use Flydo's with door permissions or cargo rails to automate things.