High-Level Project Summary
We developed a sand battery that will collect the silicon from the sand dunes on Venus. To power the lander for 60 days, we also developed a generator of wind turbines to harness the kinetic energy from the strong winds on this hot planet.
Link to Final Project
Link to Project "Demo"
Detailed Project Description
Our Project
We plan to store energy using a silica based thermal battery. Due to silica's high specific heat capacity and melting point, it has the innate ability to store large amounts of thermal energy. The silica required for our battery already exists in the sand dunes on the Venusian surface, so a large system will not be required on our payload, increasing efficiency of the mission.
The Math
To solve for the required amount of sand, we inputted our values for specific heat and change in temperature of silica (accounting for the increased surface temperature of Venus and the melting point of Venusian sand) into the equation for heat transfer and solved for mass with respect to Q, or thermal energy transfer. Because Q could be represented as the definite integral of power, we replaced it with one, accounting for the 60 day bounds. We then solved the integral assuming the mission requires 100 watts of power (which is upwards for a lander) and simplified the equation to arrive at the mass of Venusian sand required for our system. Finally, we utilized the high density of silica to solve for volume. Because of the uniquely high density of silica, large masses of it can be spaced in relatively tight volumes, allowing for an efficient repository.
The Engineering
With a given value for sand volume, we can now move to the rest of the system. Our energy is collected via a wind turbine attached to the top of the repository, utilizing the powerful winds of Venus. Using the principle of Joule heating, the electricity generated by the turbine will be used to heat the sand in the lower half of the insulated repository. Once the energy is required for withdrawal, a protected valve will open on the ceiling of the sand chamber, allowing the heat to transfer to an upper chamber containing a vat of water. The amount of water in this chamber was calculated in a similar way as the silica calculations, accounting for the different specific heat and boiling/melting points of water. The heated water will turn a steam powered generator, converting the energy back into usable electricity.
Space Agency Data
We used NASA's Magellan Fact Sheet to learn more about the surface of Venus, specifically its dust, sand, and winds. This knowledge helped us to research more Venus's winds, ultimately inspiring us to use a wind turbine on our energy storage unit.
Hackathon Journey
We learned how to work as a team and bring our ideas together. My team was excited to solve this challenge because Venus is a "cool" planet. We talked through ideas of using large-scale rubber bands to store energy, but ultimately landed on using sand as our battery. NASA Space Apps Challenge was a fun project that brought together the GIGABand, which is one of the greatest things we could ask for. We would like to thank our GIGAFriends and Uncle Wally, who prepared us for this exact moment.
References
https://nssdc.gsfc.nasa.gov/planetary/factsheet.html
https://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.html
https://phys.org/news/2022-05-venus-pluto-sand-dunes-clues.html
Tags
#venus #energy #sandbattery #energystorer