Thermodynamics 101

[Shurp]

If a sun lamp uses as much power as 9 heaters, it should create as much heat as 9 heaters, right?

Our greenhouses should need air conditioning even on ice sheets!

[LordMunchkin]

If a sun lamp uses as much power as 9 heaters, it should create as much heat as 9 heaters, right?

Our greenhouses should need air conditioning even on ice sheets!

If it was creating as much as 9 heaters and providing all that light, wouldn't it be creating more energy than it receives? 

[Trylobyte]

Light is energy too. 

[Thyme]

That depends, if you don't grow something, the light gets transformed into heat.
If you grow something, some of the energy gets stored in your plants, which could be used to produce chemfuel, which can be used in fueled generators (well, no, but I made a mod, basically a single line of code, bla bla, let's say it can) to power heaters or more sunlamps.

Here comes the fun part: Growing rice in hydroponics, turning it into chemfuel, burning it in fueled generators to power a sunlamp & those hydroponics (& heaters) will give you excess rice. Or excess power. Conservation of energy does not exist in RimWorld!

tl;dr
A solar panel captures sunlight and generates electricity from that energy. If you use that to power some heaters, a room the size of a solar panel should heat up exactly as much as the open area ("unroofed"). It gets fiery temperatures instead, which shouldn't be possible with the conservation of energy.

[milon]

The difference comes from the inefficiency of our colonists' ability to create very bright light sufficient for growing

[Hans Lemurson]

The difference comes from the inefficiency of our colonists' ability to create very bright light sufficient for growing

INefficiency?  Every power system in the game is ridiculously efficient!  1600 watts providing enough light to grow a whole field of crops?  My toaster-oven uses 1100 Watts to toast my bread (although only for a brief time). 

1600 watts using modern LED lamps will illuminate only ~50 square feet of crops (according to stats I read about growing cannabis smokeleaf indoors), and 1 tile in rimworld is closer to 10 square feet.

The heaters though...that's where the real craziness comes from.   175 Watts and you can make a whole room warm?  Gimme a break.  1750 watts irl will power a hair dryer.  Heat is incredibly energy-intensive to create, but is produced trivially in RimWorld.

Burning wood in a Fueled Generator to power a Heater will create more heat than burning the wood directly in a campfire.

[travin]

If a sun lamp uses as much power as 9 heaters, it should create as much heat as 9 heaters, right?

No. Equal electrical input does equal heat output, unless devices are 100% efficient at performing whatever task. Only a variable percentage would be converted to heat. For example, a copper wire coil of a motor will produce a different level of heat than a Nichrome coil of a heater, based on efficiency of that device and material the electricity is traveling through.

While on the subject, the coolers should produce roughly the same amount of heating (when reversed) as they do cooling, just like in real life. However, currently, they don't.

[Catastrophy]

Hey, show some respect for a particle emitter that emits stuff at the speed of light!

[Hans Lemurson]

If a sun lamp uses as much power as 9 heaters, it should create as much heat as 9 heaters, right?

No. Equal electrical input does equal heat output, unless devices are 100% efficient at performing whatever task. Only a variable percentage would be converted to heat. For example, a copper wire coil of a motor will produce a different level of heat than a Nichrome coil of a heater, based on efficiency of that device and material the electricity is traveling through.

While on the subject, the coolers should produce roughly the same amount of heating (when reversed) as they do cooling, just like in real life. However, currently, they don't.

That's actually not true.  Creating heat is nearly always 100% efficient.  Heat is actually what most devices try to avoid creating, because that is what cuts their efficiency.  When a device suffers from energy inefficiency, then a portion of the energy input for the device is turned into heat, rather than the useful work that was intended. 

If you're trying to create heat, then your efficiency will be 100%.  The only thing that would bring down the efficiency is transmission losses to your device, which in truth just amount to heat being made elsewhere.

As for Air Conditioners, because it is impossible to create a 100% efficient heat-pump, some of the energy used to move heat from the inside to the outside gets converted into heat itself.  The total heat coming out of a Refrigeration Unit will actually exceed the heat being removed from its cooler.  If you feed an ACs hot stream back into the same room it's cooling, what you have created is a heater.

[Shurp]

Exactly.  *all* the energy which is not stored in some fashion becomes heat.  I was assuming the sun lamp was a monster incandescent bulb which throws off far more heat than light... but the earlier poster was correct that any energy absorbed and stored by the plants as they grow would not become heat.

Since no heat is generated by the lamp *or* the plants we have to assume 100% efficiency... a fantastic LED emitting nothing but light, and genetically engineered crops that absorb every single photon and converts it to cellulose.  Wow!

And yeah, the wattages don't make much sense unless you multiply them by at least 10.

[Hans Lemurson]

I think that the only reasonable explanation for the facts before us is that the plants on the RimWorlds must just be freakishly hyper-efficient at photosynthesis.  Trees reaching full maturity in 2 seasons?  Feeding a colonist on a 15 tiles of land?

The output from the Solar and Wind power are roughly correct for the dimensions depicted, so no problems there.

[Thyme]

Assuming 1 tile equals 1m² and perfect weather (sunny but not hot) and a 20% efficiency (and of course a star that represents our sun) a solar panel should have an output of 3.2kW. Many ifs, but that's what 16m² can do here on earth. Those are rather nice conditions I think, so the 1.7kW are ok.

A fueled generator consumes 22 wood/day, which is, using the ingame values, 8.8kg wood. Oak wood has a caloric value of 4,2kWh/kg* which should be 1,54kW when burnt in 24h. Given a ~66% efficiency (rather high for such a small generator) 1kW output is ok. Didn't expect that tbh, but 8.8kg wood/day is a better candle light.

The most interesting part of all this is, for me, not the violation of conservation of energy (it's a game/simulation after all), but that the greenhouse temperature should be lower when plants are grown compared to not growing plants. All the energy absorbed from the rice plants should make a good cooler actually.


*what a weird unit that is. such things happen when morons try to enter the fields of physics.

[mrm]

Solar panels calculation is good, IRL sun drops 1KW on 1m2 in summer, so its 200W/m2 with 20% (this is really the upper limit) efficiency. In winter its around 130W on 1m2, so its 26W/m2 with 20% efficiency, but should be more because efficiency is better in cold. And opposite. Efficiency drops when panels are very hot (heat wave should affect this), but 1700W is pretty ok.

I don't like how batteries behave. Battery efficiency is only 50%, why? It should be much more. IRL they have around 90% charging efficiency and around 90% discharge efficiency. Not batteries itself, but circuits used to convert energy. And they charging too slow also.

And for the solar lamps. Regular incandescent bulb have very poor efficiency, only 2-5% of the power is converted into light. Lets say its 5%. 95% is heat. 95% of 1600W lamp should produce 1520W of heat, which is equal around 8.68 x 175W heaters (heaters are 100% efficient). Well, plans are not taking 100% of this 5% energy, a lot of the light hit the walls and stuff and its converted into heat anyway.

Ok, if our sun lamp is LED, which is 10-15% efficient (lets say 15), it steel produces 1360W of heat which is around 7.77 x 175 heaters.

Ok, ok, if its even some magic rimworld technology 50% efficient, it steel produces 800W of heat which is 4.57 x 175 heaters. So why i have to use at least 4 heaters to heat up my indoor farm so it wont froze in the winter?

And one more thing. Efficiency of solar panel is 20% at best, efficiency of sun lamp is 15% at best, so theoretically 1KW/m2 from sun can be transformed into 30W/m2 inside the farm. But it game, we can take light from 16m2 and transform it into the same amount of light for 29m2. And we have left 100W extra. So this technology must be very advanced, if it has over 180% efficiency

[Hans Lemurson]

Assuming the Sun Lamp is 100% efficient, each of the 100 tiles it illuminates with "bright light" should be receiving 16W/m².  That's about 1/20th what you need to grow smokeleaf indoors.

Lolz.  People already complain about Sun Lamps being such power-hogs.  Imagine if they actually used 32,000 Watts! 

I wouldn't use the 175 watt heaters as a "reasonable example" of anything, though.  Multiply the wattage by 10 and now you're in the range of "Portable Space Heaters".

I wonder how miserable it would be to try to play a mod with "Realistic Power Consumption" that got everything obeying the conservation of energy.

[SpaceDorf]

Well maybe, the Sun Lamps are actually that.

Instead of a tiny black hole, you have a tiny, tiny sun in a containment field.
The Sun creates light and heat, and the power requirements are to keep the containment field stable

add radiation filters and other techno-babble to the power requirements to explain where the excessive extra amount of energy goes that such a thing should create