Solar hourglass

The architect Santiago Muros Cortés made an interesting plan. This is something both useful and beautiful : a solar powerplant with the shape of an hourglass, a monument of modern architecture.


I Technical characteristics
II Development of the concept

I Technical characteristics

This is a solar powerplant. It makes a clean and renewable electricity with an estimated output of 6.2MW. As a point of reference, some people agree with the idea that each person needs on average 1kW of electricity.

The solar hourglass focuses light coming from the Sun by the use of mirrors. The rays come onto a cone-shaped mirror at the center, that reflects the light as a strong beam down to the other part of the hourglass.


This ray heats KNO3, it’s a chemical salt. This salt melts and we use it to activate a steam machine.

What happens in detail with the steam machine ? Water gets heat from the molten salt, becomes steam, activates a turbine. After this, the turbine activates a generator, that makes electricity.

This kind of system is called Concentrated Solar Power (CSP). It doesn’t work when there are clouds, but it is possible to store the energy.

II Development of the concept

A solar hourglass needs to be close to equator, for two reasons. First, because the sky is less cloudy. Second, because the angle of the Sun in the sky is closer from the vertical, the zenith.

Actually, the beam going down may burn the eyes. We won’t force people to wear sunglasses, so a protection around the beam may help a lot to protect our eyes.

Personally, I don’t see why a solar hourglass should be suspended. Why not use columns, like a traditional hourglass ?

A traditional hourglass made of metal.

If a monument can help the cause of political ecology, this is worth the effort.

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