Power generation using closed-loop water recirculation
nevroticlime (contact me on Discord for info or feedback)
26/10/2021
This paper will present a way to use water
wheels to produce power by making water flow in
a closed loop. The setup requires a set of water
pumps and water dumps, as well as haulers to
improve the efficiency of the system. The paper
will show that, even though the prototype uses
beaver-power, it does so in a more efficient way
than beaver-operated power wheels.
1
Introduction
Water wheels in Timberborn are 2x3 buildings
that produce power at a constant 180hp as long
as they have flowing water underneath them.
They are a handy power production system, but
as they require flowing water, they cannot work
in a dry season, when water flow does not happen naturally. They can be made to work even
during a dry season using a reservoir and one
or more floodgates to artificially produce a current. This method, however, requires a large
reservoir, taking up valuable space, and a lot of
micro-managing. Moreover, it is limited by the
size of the reservoir: a larger reservoir will keep
the wheels spinning for longer, but it will also
take a longer time to re-fill during the wet season, a process that diverts water flow away from
other uses (including spinning the wheels!)
What this paper presents is instead a way to
make the water flow in a loop, thus generating
power, at least in theory, infinitely. This setup is
more reliable than wind turbines (since its power
output is constant), more resource-efficient than
engines (since it only consumes a few units of
water per day), and more beaver-efficient than
power wheels (since its ratio of power produced
Figure 1: Prototype (complete view)
per beaver employed is higher).
2
Prototype description
Figure 1 shows a complete view of the prototype:
it is built on levees, with platforms and stairs
connecting the different levels. Figure 2 better
shows the three sections: the injector, the plant,
and the collector. All three are better explained
below.
2.1
Injector
This section contains 8 water dumps, placed so
that they discharge water directly into a 2-wide
canal. Each water dump takes 10 in-game seconds to output three units of water: in contrast,
a water pump takes a little over 3 in-game seconds to collect one unit of water; meaning water pumps (see subsection 2.3) and water dumps
1
The plant is, in theory, infinitely scalable: one
can lengthen each individual row, or add more
rows, or both. As the system becomes larger,
evaporation losses will increase accordingly, and
the system’s transient (the time it takes from
start of work hours to full power) will also increase dramatically. This prototype aims for a
comparatively small power output, but larger
ones can in theory be built with little trouble.
2.3
This section is a 1-wide canal containing 8 water pumps: once water has flown through the
plant, it drops down one more time and pools
into the collector, where water pumps suck it
up and allow haulers to transport it back to the
water dumps in the injector. Each water pump
is placed so that only its pumping part is over
water, the rest being over levees and platforms,
making the canal the smallest possible.
The prototype’s design, with free drops in the
plant and a collector that is as small as possible,
aims at minimizing evaporation losses. During
working hours, water flows through all three sections, for a total of 98 exposed water tiles, or
4.70 water/day (water evaporation rate: 0.048
water/tile/day). However, when not in working
hours, beavers don’t pump any water and, given
that all drops are free, water all flows downstream and collects in the last section (hence the
name, “collector”), which is just 9 tiles. Thus,
assuming 16-hour working days, the actual evaporation loss of the system is 3.28 water/day, a
30% improvement. For reference, as mentioned
in subsection 2.1, 3 units of water is what a water pump produces in 10 seconds of work time,
thus it is a very small number indeed.
Figure 2: Prototype sections: injector (green),
plant (orange), collector (magenta)
Figure 3: Detail of the drop between the two
rows: notice how the path is free, blocking no
water
should be used in a 1:1 ratio.
2.2
Collector
Plant
This section contains two rows of 5 water wheels
each. The water from the injector flows through
the top row, then drops 1 tile and turns 180 degrees to flow through the bottom row. The water
wheels are placed two tiles away from the turn
in both rows: the space allows the flow to regularize and provides a more even power delivery.
The drop is free, i.e. it is not obstructed by a
dam piece (figure 3): this is a small optimization
that provides more even power delivery, and will
also have an important benefit described in subsection 2.3.
2.4
Complementary structures
Included in the design itself are the power shafts
that bring power down all the way to ground
level, as well as a large water tank and a hauling post. The large water tank holds more than
enough water to start the system from scratch
(a dry start requires about 150 units of water),
2
and haulers improve the efficiency of the wa- Working hours Energy produced [khpD/beaver]
Power wheel
Prototype
ter dumps and water pumps by automatically
1
1
N.A.
transporting water up without interrupting op4
4
1.38
erations. During testing, a full complement of 10
8
8
6.92
haulers was sufficient to keep the system running
12
12
12.46
at full capacity with a little margin, but more
16
18.00
16
might be needed depending on the specific sys20
23.54
20
tem (especially the length of the paths). During
24
24
29.08
testing, the large water tank (and no other building) was prioritized by haulers. Also, the protoTable 1: Energy produced by the two methods
type ran in a separate district where haulers had
for a different amount of working hours (assumno other jobs but carry water.
ing no power produced during transient)
3
4
Prototype operation
The prototype takes approximately 60 in-game
seconds from the start of the working day to
achieve full power, which is about the time the
water takes to flow all the way to the collector: this seems to be due to the way Timberborn’s water mechanics handle transient flows.
In those 60 seconds, power slowly climbs from
0 to 1800hp, more or less linearly. After reaching steady-state, the prototype produces 1800hp
constantly. A more compact version of the prototype is possible using 7 or even just 6 water dumps (and decreasing water pumps accordingly), but the resulting output is less ideal, with
several water wheels blocking frequently and not
providing power to their full potential.
The prototype employs 26 beavers: 8 each
in water dumps and water pumps, plus 10
in the hauling post.
This tallies up to
69.23hp/beaver, which is 38% better than the
power wheel’s 50hp/beaver. A more reasonable estimate should account for the 60-second
delayed start: taking that into consideration,
and assuming 16-hour working days, the prototype produces 468khpD (kilo-horsepower-day),
or 18khpD/beaver1 ; while a power wheel produces 16khpD/beaver. Increasing the length of
working days improves this metric even more, as
shown in table 1.
Conclusions and future
improvements
This paper has shown that it is possible to build
a functioning closed-cycle water flow system that
is able to generate power from water wheels.
Moreover, it demonstrated that, even at prototype scale, this new power generation technique
is more efficient than its most direct competitor,
beaver-operated power wheels. Given that even
this small system requires a large amount of resources to be built and 26 beavers to operate,
this is definitely a late-game build. However, it
might be very useful for situations such as lategame hard mode in which wet seasons are short
and far-between and there is a need for alternative power generation methods.
Future tests should explore how the system scales, by building larger prototypes with
larger power outputs. Even the current system
could possibly be improved further by shortening paths, reducing exposed water tiles and experimenting with variations on the design.
Finally, this project gives some insight into
Timberborn’s water dynamics and into why,
specifically, the developers could be holding back
on adding proper pumps and aqueducts into the
game: generating infinite power could be much
easier with pumps that are able to create uninterrupted, looping canals. Therefore, it cannot
1
These figures do not account for power produced in be ruled out that this type of build might be
the transient: the actual figures might be better by up patched out of existence in future updates.
to 10%
3
5
Appendix: guide for build recreation
Figure 4: Level 1
Figure 5: Level 2
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Figure 6: Level 3
Figure 7: Level 4
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Figure 8: Level 5
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