It seems like we should be able to make a solar cell light enough to cover the top of an airship and use electric power. Most solar aircraft don't make sense b

It seems like we should be able to make a solar cell light enough to cover the top of an airship and use electric power. Most solar aircraft don't make sense because there isn't enough surface area to get a minimum amount of power to keep the aircraft aloft. Airships don't have this problem. The issues are weight and expense and being limited to operating only during the day. Cloud cover isn't a huge issue, you can rise above it.