• Hawaiian electricity load peaks in the early morning around 6:30 AM with its least requirements between midnight and 5:00 AM (see chart but note the 24-hour day).
• After midnight HECO orders H-Power and wind power producers to reduce output so that HECO can maintain the minimum output they need to keep their reheat type steam turbines running.
• Wind energy blows stronger overnight, when the demand for electricity is lowest, while solar energy, weather permitting, assists ONLY with the daytime load.
More information may be found at the Hawaiian Electric website.
Alan points out that the electric car, whether pure or hybrid is rapidly taking over the automobile world. Owners typically charge their cars at night and can be easily scheduled to charge from midnight to 4:00 AM. Most cars charging on a 240v system take from 2 to 4 hours to recharge.
The marginal increase in electrical power needed for the rail system, which is scheduled to run from 4:00 AM to Midnight will come from existing oil fired generators consuming imported oil. During early morning hours the marginal increase needed for electric car battery charging will come from H-Power municipal waste and wind power.
In short, during the rush hours rail transit will be using electricity generated primarily by oil-fired turbines. Electric cars on the other hand will be using electricity from batteries that have been charged from power generated earlier in the day from wind turbines and H-power. You may draw your own conclusions as to which transportation system is preferable for the environment.