https://www.scientificamerican.com/article/hawaii-wants-to-lead-the-renewable-revolution/

David Bissell’s Toyota Tundra crunches to a stop in the reddish dirt and gravel road as the first heads appear in the grass. A few sheep come into view, but, startled by the trucks, they skitter away through the unruly vegetation surrounding a network of solar panels. After a few moments, they calm and return to work, munching away on the island’s ever-present guinea grass.

These are the ovine foot soldiers in one of the most ambitious renewable energy revolutions in the United States. The Lawa‘i solar and energy storage project on the island of Kauai employs 300 sheep to keep the invasive guinea grass from engulfing the solar panels that supply 11% of the island’s electricity. This project is on the leading edge of a statewide effort to achieve 100% renewable energy by the year 2045.