In some cases, hydropower is growing as a backup power supply for wind and solar power.

在某些地区，水电项目是作为风力发电和太阳能发电项目的后备手段。

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When bus gets into trouble, it can perform the function of automatic switching to backup power supply.

当母线出现故障（过压或欠压）时，能够完成两组母线的自动投切，即备自投的功能。

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As backup power supply of the DC system, the residual capacity of battery effected safe operation of DC system directly when ac power failure occurs.

蓄电池作为直流系统交流停电时的后备电源，其剩余容量直接影响了直流系统的安全运行。

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Phone service from cable companies is also dependent on power, but most companies supply backup batteries to power the phones for some hours in an outage.

WSJ: Phone companies prepare for storm power outages

The reserve power category includes backup batteries and related products that provide a continuous supply of direct current (DC) during power outages.

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