Found out that bulk of Sao Miguel’s power comes from geothermal energy. Those pipes – I assume – are carrying hot water. One thing I could not figure out is the weird shape of the pipe. At one time, I came close to the pipes and saw a dirt road run under one of those “gates”. But that cannot be the purpose. If you carefully look, there are those “gate” structures horizontally too.

Do you think this could be to allow for expansion due to temperature fluctuations?