Balloon power sources with a buoyancy trade-off

A non-transitory computer readable medium having stored therein instructions executable by a computing device to cause the computing device to perform functions comprising:

• causing a balloon to operate in a first altitude-control mode, wherein the balloon comprises an envelope, a high-pressure storage chamber, and a solar power system;
• while the balloon is operating in the first altitude-control mode:
• operating the solar power system to generate power for the balloon;
• determining that the balloon should move in a first horizontal direction;
• determining that wind at a lower altitude corresponds to the first horizontal direction;
• in response to determining that wind at the lower altitude corresponds to the first horizontal direction, determining that the balloon should move to the lower altitude;
• and
• responsively using at least some of the power generated by the solar power system to move gas from the envelope to the high-pressure storage chamber such that the buoyancy of the balloon decreases;
• causing the balloon to operate in a second altitude-control mode;
• and
• while the balloon is operating in the second altitude-control mode, determining that the balloon should move to a higher altitude and responsively moving gas from the high-pressure storage chamber to the envelope such that the buoyancy of the balloon increases.

A balloon comprising:

• a solar power system configured to generate power for a balloon, wherein the balloon comprises an envelope and a high-pressure storage chamber;
• and
• a control system that is configured to cause the balloon to operate in at least a first altitude-control mode and a second altitude-control mode;
• wherein, during operation in the first altitude-control mode, the control system is configured to:
• operate the solar power system to generate power for the balloon;
• determine that the balloon should move in a first horizontal direction;
• determine that wind at a lower altitude corresponds to the first horizontal direction
• in response to the determination that wind at the lower altitude corresponds to the first horizontal direction, determine that the balloon should move to the lower altitude;
• and
• responsively use at least some of the power generated by the solar power system to move gas from the envelope to the high-pressure storage chamber such that the buoyancy of the balloon decreases;
• wherein, during operation in the first altitude-control mode, the control system is configured to determine that the balloon should move to a higher altitude and responsively move gas from the high-pressure storage chamber to the envelope such that the buoyancy of the balloon increases.

A computer-implemented method comprising:

• causing a balloon to operate in a first altitude-control mode, wherein the balloon comprises an envelope, a high-pressure storage chamber, and a solar power system;
• while the balloon is operating in the first altitude-control mode:
• operating the solar power system to generate power for the balloon;
• determining that the balloon should move in a first horizontal direction;
• determining that wind at a lower altitude corresponds to the first horizontal direction;
• in response to determining that wind at the lower altitude corresponds to the first horizontal direction, determining that the balloon should move to the lower altitude;
• and
• responsively using at least some of the power generated by the solar power system to move gas from the envelope to the high-pressure storage chamber;
• causing the balloon to operate in a second altitude-control mode;
• and
• while the balloon is operating in the second altitude-control mode, determining that the balloon should move to a higher altitude and responsively moving gas from the high-pressure storage chamber to the envelope.