Buoyancy
One of the main questions is: What happens if the BILS is heated up. Densitiy will increase, buoyancy will induce uplifting forces. What is going to happen really?
-> We are working on it.....
To make the BILS floating or even sinking when hot, three options were investgated
- Fix it on the ground
- Add weight to the whole contruction
- Use salinated water
If you have other good ideas: Please let us know
Saline water
One option to reduce buoyancy when heating up the BILS is the use of saline water. The density of seawater is higher than for lake water. Hence by using saline water it is possible to hide the BILS even when hot.
The maximum required salinity to keep a BILS under water is in the range 6% when using NaCl. This is more than the mediterranean sea which is in the range fo 3.8%. Of course the required amount of salt is depending on the lake temperature and the temperature in the storage. This is a problem that needs a solution. Good ideas?
The calculations and the experiments show however that this is an option that must be considered.