The ship starts with 999 energy, and this is gradually used up by operating the ship's systems. When the ship runs out of energy some systems become inactive, making refueling necessary. The current energy level is displayed on the helm, tactical and engineering screens.

Energy Production

The ship's energy can be restored in the following ways:

• Docking with a starbase restores the energy to full
• Colliding with an appropriate anomaly gives a large boost to energy. This can exceed the ship's starting energy of 1000.
• If engineering sets power to all systems to 0%, energy will recover slowly (at a rate of roughly 0.8 energy per second, regardless of difficulty level).
• Even with some systems set above 0%, a ship can regenerate energy as long as its rate of consumption (varies with difficulty) does not exceed its rate of production (low, fixed).
• If there is at least one homing torpedo in stores (unloaded), the Weapons officer can convert it to 100 energy by clicking the "Torp to Ene" button.
• Certain side missions given by ally ships and base stations can provide you with energy, similar to an anomaly.  
• IMPORTANT NOTE: If your ship's energy exceeds a threshold (4000 is the default - set via "overloadThreshold" in Artemis.ini), it can cause a thermal runaway that can destroy the ship!

Energy Consumption

All systems drain energy when their engineering power slider is set to more than 0%. This is true even if the system is not currently in use (eg. beams drain power even when they aren't firing, engines drain power even when you're not moving, etc).

The current power drain of each system is shown in brackets above the power slider. A drain of 100 seems to equate to roughly 2 energy per second.

The rate of power drain depends on the following factors:

• The higher the engineering power slider, the faster the energy drain
• Different systems drain energy at different rates, as follows. These numbers are multiplied by the base energy drain for the difficulty level.
• x3 - beams
• x1 - tubes
• x1 - sensors
• x2 - maneuver
• x4 - impulse
• x6 - warp
• x5 - front shld
• x5 - rear shld
• The above energy drain factors are defaults. They can be set to different values (between x1 and x10) in the server's artemis.ini file.
• Energy drain is multiplied by the ship's efficiency, which varies by ship class. A Light Cruiser, with an efficiency of 1.0, is considered the standard. By comparison, a Scout has an efficiency of 0.7, and thus uses only 70% of the energy of a Light Cruiser, while a Dreadnought has an efficiency of 1.2, and uses 120% of the energy.
• In addition to the above, the following activities drain energy:
• Firing beams
• Having the shields up
• Traveling at Warp. The higher the speed, the faster the energy drain.
• Using the Jump drive. The entire energy cost is spent all at once, at the beginning of the jump, and depends on the distance traversed.
• Creating a homing torpedo by clicking "Ene to Torp" from the Weapons station; this consumes 150 energy and produces 1 torpedo.
• A higher difficulty on the server settings screen leads to higher energy drain. The base energy drain for each level is:

The placement of coolant makes no difference to energy drain.

Activities that drain energy

Firing Beams:

Each beam fires costs an additional 2 energy per shot. This does not depend on damage done, so a Dreadnought's Beam Cannon uses as much energy to fire as its standard lower damage beams. However, a beam with a faster fire rate does use more energy over time, so the XImni Battleship's faster firing beams will drain the ship's energy much sooner.

Since the increasing the power setting of a Beam increases its fire rate, setting the Beams slider to 200% will not only drain more energy for the system, it will also increase the number of shots fired by the Beams, and thus the energy cost of those shots over time.

Using the Warp drive:

The formula for calculating the additional energy drain per second due to using the warp drive is:

     0.5 * (difficulty coefficient) * (shield coefficient) * (warp factor) * (warp factor) * (warp efficiency)

Where the difficulty coefficient is:

And the shield coefficient is:

This means that Warp 1 is the most energy efficient form of travel, as energy consumption increases by the square of the warp factor, using shields while warping uses 50% extra energy, and energy consumption increases linearly with difficulty level.

As with energy drain, each ship class has its own warp efficiency. A Scout will use about 70% of the energy of a Light Cruiser at Warp, and a Dreadnought will use 120% of the energy. A Scout is also faster than a Light Cruiser for the same Warp setting and energy cost, so it is even more efficient. Likewise, a Dreadnought moves slower than a Light Cruiser at the same Warp speed.

Using the Jump drive:

The formula for calculating the additional energy cost of using the Jump drive appears to be: (for each jump)

     0.9 * (4 + difficulty coefficient * 4) * (distance in km) * (jump efficiency)

Where the difficulty coefficient is the same as the table for Warp, above. The jump coefficient of 0.9 is modifiable in artemis.ini. Jump drive cost is not effected by shield coefficient, as the energy cost does not increase if shields are up. If there is not enough energy to travel the specified distance, the ship will Jump by the available amount of energy remaining, possibly ending up in a hazardous location.

Like Warp Drive, the energy cost of Jump does not depend on power put into the system, but unlike Warp, power level does not change how fast you go. Instead, it decreases the amount of time taken to warm up for the jump. Jump Drive power level also makes Combat Jump recharge faster. 

As with efficiency and warp efficiency, each class of ship has their own jump efficiency. Again, the TSN Light Cruiser is considered the standard, but the Scout has the same efficiency, giving it no additional range. The Ximni ships are actually more efficient with Jump drive than the TSN, with their Light Cruiser using 50% of the energy for the same jump, and their Scout a paltry 40%. The Scout's (and Ximni Scout's) high speed gives no advantage to Jump drive, as the ship does not traverse the space that was jumped.

In other words, Jump drive is very efficient for Ximni ships, and very inefficient for the TSN. The Pirates are sort of in the middle, their Longbow uses less energy for a jump than the TSN, but their Strongbow and Brigantine use way more. In general, Jump drive is more efficient for ships that are slower and have a lower top Warp speed, as Jump drive depends only on distance and not speed.

NOTE: As of Artemis 2.5, this energy cost value is not significant. Even a jump of 50 km does not cost more than 20 energy on difficulty 10. With numbers this small, it is not possible to see the effects of efficiency. Combat Jump still costs nothing. Jump efficiency also modifies the time taken to jump (but not the blackout time) so Ximni ships are able to jump faster than TSN ships. 

Running out of energy

When the ship runs out of energy, the following systems will become inactive:

• Beams
• Warp drive
• Jump drive 

The following systems continue to operate, albeit at a reduced level:

• Torpedoes
• Tactical
• Maneuvering
• Impulse
• Shields

Engineering settings can increase the efficiency of these systems even when the ship has 0 energy. Heat buildup is as normal, however.

Related pages

Engineering | Anomalies