New solar power plant produces temperatures of 1500º C

Solar and wind power are very clean , renewable energy sources , and increasingly inexpensive but have an energy storage problem.

The batteries required to store that energy require rare earth metals, which are messy to extract and increasingly in demand. Hydro power is great but can have negative impacts on the river ecosystem. Nuclear is still a tough sell.

A renewable energy technology called Heliogen has a new approach to an existing model that may just accomplish the latter with a giant, extremely precise magnifying glass and some really hot rocks.

Essentially a lot of mirrors arranged in a circle reflecting sunlight at an elevated target, concentrated solar power heat that target, which could be water, molten salt, or even something solid, to very high temperatures.

Heliogen's current test refinery has 400 mirrors, known as heliostats. Its operation has produced temperatures as high as 1500º C.

By keeping the mirrors on target, the greatest amount of sunlight possible is focused on the target, creating more heat than was previously possible.

Unlike solar panels, this project does not use the photovoltaic effect to turn sunlight directly into electricity. This project is about generating heat. This heat can then be used to produce electricity.

If not used immediately, the heat energy can also be stored in plain old rocks, which can stay hot for days or even up to a week in a properly insulated storage unit.