This batch totals 10 575 Health points (https://wiki.factorio.com/Enemies#Biters), and requires 77 000 pollution to generate (https://wiki.factorio.com/Pollution#Native_life).
An unupgraded laser turret uses 800 kJ per shot and deal 20 damages.
(800 / 20) * (10 575 / 77 000) = 5.49 kJ/pp
(pp = pollution point)
What does this number means?
For example, if you let a burner mining drill run for one second, it will generate 10pp, which you will eventually have to pay 54,9kJ of electricity for in laser turrets. By comparison, the same burner drill will burn 300kJ of fuel by itself during the same second, which translates into 150kJ of electricity, if we want to keep things comparable. So that's a 36.6% energy penality.
For electric drill and pumpjack, the most polluting per J building in the game, that number raises to 54.9%, meaning when you think they consume 90kW, they actually cost you 1.38kW total.
For other building, use the table found in the wiki here :
https://wiki.factorio.com/Pollution#Pro ... Absorption
The column "Pollution per KW per game second (60 ticks)" also shows the Pollution per KJ if you change the unit, and multiplying the numbers in that column by 5.49kJ gives you the fraction of the power consumed by the machine that you'll have to pay in laser shots (multiply by 2 for burner mining drills and boilers).
Another example worth of notice is boiler : at 15% penality, it means that if you rely on steam power for a high pollution base (I don't know why you would do that, but hey), your steam plants effectively only produce 85% of what you think they produce.
That "Pollution per KW per game second (60 ticks)" column is what affects the pollution effect of production modules. So they directly increase the share of energy dedicated to laser shots.
Now this 5.49 kJ/pp is very pessimistic. Here are some reasons which makes it vary, most of them making it diminish :
- Evolution factor. At 1, the ratio HP/pp is very high, 0.137, very close to the 0.15 of behemoth. Big biters are under 0.1, and small and medium ones are at 0.75
- Techonlogy. At level 7 Laser Turret Damage technology, turret damages have tripled effectively dividing by three kJ/pp
- Laser turret drain. Not a cost per pp, and even tends to be negligible the more you use turrets, ie the more you pollute, but drain has to be weighted for bases at the frontier between low pollution and high pollution, because the alternative is non draining gun turrets with lower upfront cost, and possibly lower upkeep cost as well.
- Mixed defense. I have used Laser because that's the most common defense, being the simplest to setup and only requiring electricity. Gun turrets are about 10 times more energy efficient at their best but eat ores (and their best is normal ammo and uranium ammo with modules, so mid game piercing round kind of sucks compared to Laser), flame turrets and landmines are hard to evaluate.
TL;DR : you have to pay for the negative extarnality that represents pollution by killing biters and spitter. The price represent a non trivial fraction of your total energy consumption. From a few percents for most machines, about 35% for miners and pumpjack, ignoring Productivity modules (worsening) and defense technology (reducing pollution cost).
The figure I'd go by is 2kJ to 4kJ of laser turret shot per pollution point.