Does Tongwei photovoltaic panel need a battery

In cloud conditions, the panel output can be as low as 80%, meaning you will need a reliable battery system to hold energy stored for those days when the generation via solar isn't enough. [pdf]

Why can wind turbine blades kill birds

Scientists believe this disorienting visual phenomenon, known as motion smear, contributes to the collisions that kill an estimated 140,000 to 679,000 birds per year at wind farms in the United Sta. [pdf]
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