Energy sorce and storage | Solar Panels On Venu

The Energy Source

Our idea consists of a powered aircraft harvesting solar energy in the upper reaches of Venus atmosphere, using high temperature solar arrays, and storing this energy in on-board high rechargeable batteries.

The incoming solar radiation at the top of Venus’s atmosphere is about twice that of the Earth. Using solar power might seem like a good solution, but the thick acid clouds would absorb most of the sunlight, and only ten percent of it would reach the surface.

We propose a solution already used before:

The basic idea is transferring this energy by power beaming, from an atmospheric platform to the lander energy storage. This is how it works: the aerial, balloon- like platform would charge its molten salt electrolyte batteries above the clouds, and then a transmitter on board would beam power (via electromagnetic energy) to the receiver on the surface. The beams would then be converted to electrical current with a rectifying antenna (made of high temperature materials and using high temperature silicon carbide diodes). This approach is said to significantly lengthen the time the craft would survive on Venus.

WHY THE AERIAL STATION HAS TO MOVE:

However, there is one problem. The microwave beams would not penetrate through the thick clouds and would be absorbed. For the transmitter energy to reach the rover, the aerial platform should move up and down: collecting solar power above the clouds, and then descending to transmit it to the rover’s
batteries.

We proposed a solution using the sulfuric acid abundant in the atmosphere to allow the aerial platform to move up and down.

HOW WATER VAPOUR IS MADE:

Sulfuric acid in the atmosphere is collected through a high surface area mesh. Nevertheless, the concentration of sulfuric acid is extremely low, so a very large surface area of the net or a long time would be required to collect enough acid.

The sulfuric acid would then be decomposed into water and sulfur trioxide. This process takes place above 100’C

(temperature of Venus is sufficient) and does not require a catalyst.

The water vapor made would be used to fill the balloon when it has to ascend. Water vapor is less dense than
Venus’s atmosphere, so the balloon will rise. To descend, the water vapor will be stored in a cooling
tank, where it can be condensed.

The Energy Storage

Although the main energy would come from the solar panels on the aerial station, primary batteries would be needed to generate energy at high levels of activity.

Characteristics of battery suitable for Venus:
- High-capacity anode (lithium alloys)
- High energy cathode (metal di/trisulfides, halides, and other materials)
- Molten salt electrolyte with low vapor pressure
- Separators that minimize self-discharge (magnesium oxide, aluminum oxide, lithium oxide)

The molten salt battery will withstand high temperatures and has a high specific power and energy density.

The sodium–sulfur battery (NaS battery), along with the related lithium–sulfur battery employs cheap and abundant electrode materials. It was the first alkali-metal commercial battery. It used liquid sulfur for the positive electrode and a ceramic tube of beta-alumina solid electrolyte (BASE). Insulator corrosion was a problem because they gradually became conductive, and the self-discharge rate increased.

Because of their high specific power, NaS batteries have been proposed for space applications. An NaS battery for space use was successfully tested on the Space Shuttle mission STS-87 in 1997, but the batteries have not been used operationally in space. NaS batteries have been proposed for use in the high-temperature environment of Venus.

Another idea is coating the battery with aerogel. Aerogels are a broad category of solid, porous materials that display an amazing range of extreme material properties. Most notably aerogels are notable for their extraordinarily low densities. An aerogel is essentially the intact, dry, low-density, porous, solid framework of a gel that has been separated from its liquid component, which occupies the majority of the gel's volume. The aerogel insulation can withstand temperatures of 600 degrees Celsius!

PRECAUTIONS:

One way to in protect the system and battery from Venus' high temperature, an insulation of aerogel is going to be used as previously mentioned in detail above. Vacuum pockets can also be useful in insulation (heat doesn't transfer through vacuum).
To prevent crunching under high pressure, the Rover and balloon have to be made from hard material with high melting points such as steel.
The mass that would be able to withstand such high pressures is impractical, therefore the electronics should be pressurized from the inside. A useful approach would be to transport the pressuring gas as a liquid, so when the spacecraft enters the atmosphere of Venus, the gas will vaporize and enable the electronics to withstand the high pressure.