The amount involved is minuscule, as is the quantity of electricity needed to keep the filter charged (a small solar panel would be sufficient to supply it).

银的使用量非常小，与维持滤水器运转所需电量（一小块太阳能电池板就足够了）一般。

There aren't many feasible ways to store large quantities of electricity, so for the most part, the supply and demand have to be matched simultaneously.

储存大量电力的可行方法并不多，因此在大多数情况下， 供应和需求必须同时匹配。