Hawaiian Electric Co. is asking its Oahu customers conserve electricity use tonight.

HECO said there has been an “unexpected partial loss of output from several generating units, in addition to several units being offline for maintenance.”

HECO said it expects to have enough generating capacity to meet the demands during peak evening hours of 5 p.m. to 8 p.m., but by the public’s conservation efforts it can meet the demand.

In its news release late this afternoon, HECO said the need was prompted by humid weather, driving demand for electricity, but followed with the above explanation of loss of output.

HECO has also asked larger commercial customers to voluntarily reduce their electricity usage.

The general public can help reduce use by turning off or reduce use of lights and air conditioners, delaying hot showers, laundry and dishwashing and minimizing cooking until after 8 p.m., HECO suggests.