Projects:2019s1-192 Gravitational Energy Storage

The cost of extending conventional power grids makes it difficult to supply remote locations. There are established solutions, such as diesel-generators, but these are expensive, and are more suited to corporations, or large communities. There are low-cost solutions for small remote communities, in the third-world. These typically involve the use of batteries, but there are problems with batteries: they have finite lifetimes; they use chemicals that are scarce and toxic; they are difficult to repair (using simple tools); they suffer from internal leakage. There are solutions that have been used in remote communities (in Africa) where the storage is gravitational. Gravitational storage is much more convivial. Gravitational storage is very robust, with a long lifetime; it does not use exotic materials, it can be easily repaired using simple tools; there is no internal leakage. The main disadvantage of gravitational storage is low energy-density. It would take a very large mass, falling through a very large distance, to match a car-battery, for example. The loads have to be chosen appropriately, low-power LED lighting, for example. Also energy conversion has to be very efficient. In this project we will examine the possibility of using permanent-magnet synchronous machines, and power-electronics to efficiently store energy in gravitational form, and then to efficiently recover that energy at a later time. The plan is to design, build and test a small-scale solution, as a proof of concept.

Project Team

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Students

• Keilah David
• Kai Yang

Supervisor

• Andrew Allison

Introduction

Gravitational energy storage is that changing the height of the solid matter can be stored or released by a lifting system driven by an electric motor/generator. Compared with fossil fuels, this type of energy is more environmentally friendly. Gravitational storage is very rugged and has a long service life. It does not use special materials and can be easily repaired with simple tools. There is no internal leakage. There will be no other pollutants discharged at the same time. However, this system is not perfect. It needs heavy enough weight and enough height to get enough gravity potential to generate electricity for the motor. This means that the gravity energy storage system needs enough space to run.