Japanese power companies are worried about the impact on the grid during an extended 10-day holiday starting in late April. The period is longer than usual this year due to an Imperial succession.
The large number of businesses on break could lead to oversupply and blackouts, so firms are getting ready.
Energy venture Enechange and solar-power company Looop will try encouraging consumers to shift their electricity use to the daytime. The abundance of solar power means that is when there will be the biggest chance of oversupply.
CEO of Enechange, Yohei Kiguchi said, " When the sun shines, we can use electricity. If it is cloudy, we should try to use less. Solar power generation has spread to such an extent that we have to change our habits."
The campaign comes as power companies in western Japan might cut back on solar-energy production during the holidays.
Looop will notify customers if this is expected to happen. The firm also plans to give gift certificates to those who shift their power use during these times. The companies say the campaign will start on April 19 and last for a month.