Vertically-oriented wind turbine and improved wind shield

A vertical-axis wind turbine comprising:

• a plurality of blades rotating axially about a substantially vertical shaft;
• an arcuate wind shield adapted to shield convexly-facing blades on a windward surface of the turbine against contact with oncoming airflow, the wind shield comprising:
• an arcuate inner surface spaced away from the blades;
• an arcuate scoop arching outwardly from the arcuate inner surface, the arcuate scoop angling forward of a forward edge of the arcuate inner surface, the arcuate inner surface and the arcuate scoop forming a wind channel terminating at one or more ejection ports positioned behind a concave face of the blades, the ejection ports adapted to redirect airflow forced into the open scoop to the concave face of the blades;
• wherein the wind shield affixes to the vertical shaft such that the wind shield may rotate axially about the shaft only in one of a clockwise or counterclockwise direction about the vertical shaft.