Energy production is one of the defining problems of our time. As global demand and consumption rise with population growth and economic development,
so do emissions, resource waste, and health hazards. We are in a time of transition from polluting, wasteful, and dangerous ways of generating energy
towards technology that is safer and decreases the strain on non-renewable resources. As some of the greatest impacts and threats come from climate change,
there is an urgency to the issue of energy transition like no other.
Building capacity in alternative energy sectors takes time and large investments. The transition to other sources has to be financially feasible, as well
as timely to prevent further damage from pollution. How can the mix of electricity generation technology change, based on both cost and pollution? This Systems
in Focus model analyses how capacity can be developed in different energy sectors over time.
This Systems in Focus model takes a look at Sustainable Fishing. In theory, Sustainable Fishing is achieved when fish are caught at a
rate which does not cause a decline in the overall fish population. In practice, sustainable fishing can be very difficult to achieve.
Fishing areas are within the commons, which encourages greater investment in ships when there is demand. More importantly, we can never
really know the population of the given fishery and therefore whether it is in danger of being fished out. This model explores the
trade-offs between investing in more ships to catch more fish and the long-term viability of the fishery.
The modern assembly line is one of the greatest and now most common manufacturing process concepts in history. It was created to save
time and money, and to increase the overall quality of the output. By mechanically moving parts in a line through a factory to different
work stations, a product can systematically be built up piece by piece, while decreasing time spent moving parts. This process was
perfected and used most famously by Henry Ford in the 1920s.
In this simple example, we have modeled the basics of a bottling plant. Before we can model the process however, we need to consider
the supplies required to create the final product, in this case, water. A bottling plant requires a constant supply of purified water.
It is usually run through three sets of filters that remove smaller and smaller particles before being sterilized.
The bottling side starts with bottles that have either been shipped in (glass) or are blown into the proper shape from small stubs of
plastic. Glass bottles are placed on a disk-shaped hopper while plastic bottles are often dumped into an open box hopper. The hopper
feeds a machine known as an unscrambler, which puts the bottles onto a conveyor belt in single file. From there, the bottles are
quickly rinsed to ensure cleanliness, filled with water, and capped.
The bottles are then inspected for stray particles inside and some bottles are rejected. Since filling made the bottles wet, they
are blown dry before labels are affixed to them. At this point, any labels that need to be printed onto the bottle are added.
Finally, bottles are grouped and packed into containers. In the case of water, the package gets shrink-wrapped.
The package of water is now ready to ship!
The video above shows a waterfall in a serene setting. A lot is happening behind the scenes to create this picturesque vista.
Rainfall on land creates runoff and therefore stream flow. Some of this runoff is absorbed into the soil. Some of that flows
beneath the ground to the stream and some returns to the air through evapotranspiration. Another part of it
percolates further down through the soil layers to become part of the groundwater, which provides a base level flow for the
stream. Using Stella Professional, we are able to draw a map that corresponds closely to the physical world and then simulate
that map to see what happens. This both increases our understanding of how this system works and allows us to experiment with
different policies that might lead to alternate, more desirable outcomes.