It can power up to eight common homes.它可以给多达八个普通家庭提供电力.
= It can (supply) power (to) up to eight common homes.
= It can (supply) up to eight common homes (with) power.
固定搭配：supply A to B = supply B with A,意思都是“给B提供A”.
up to的意思是“直到...（如数量等）为止”.
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