Prosecutors say the group, linked to far-right and anti-Covid movements, were planning to destroy power stations to cause a nationwide blackout.
They also wanted to kidnap Germany’s health minister, who backed the country’s strict coronavirus controls.
The group are due before a judge on Thursday.
A fifth suspect remains at large.
In total, investigators have identified 12 people they believe were connected to the group, which used the Telegram messaging app to communicate.
According to TV news programme Report Mainz, the group wanted to attack substations and power lines, destroying the country’s energy infrastructure.
In a statement, the prosecutors office said the aim was to cause a long-lasting nationwide power failure “intended to cause conditions similar to civil war and ultimately to overthrow the democratic system in Germany”.
Two of the suspects are believed to have been planning an attack on Health Minister Karl Lauterbach.
Mr Lauterbach said the plot showed that coronavirus protests had become radicalised, and promised that his work would not be affected.
The group were arrested in a series of raids on Wednesday, with police also seizing numerous guns including a Kalashnikov.
They also found gold bars and cash in euros and foreign currency totalling almost €20,000 (£16,600; $21,800).
The group, aged 41 to 55, are accused of preparing a serious act of violence that endangers the state and of violating a weapons control act.
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