Austria typically employs two separate meters and a radioteleswitch rather than dual tariff meters. Makes for quite a chunky meter enclosure...
Some areas traditionally have water heaters (150l and up) on the night meter, there the night meter is usually single phase with a separate RCD and 16 amp breaker. Night storage space heating usually gets a 3x35A service but I don't think a system like that has been installed anywhere during the last 30 years. They were insanely popular during the late 1960s and 1970s though, particularly in new construction. Now people have a huge problem upgrading to any other heat source since these houses don't even have a chimney (and burners vented straight through the wall are illegal at least in Vienna).
My family considers buying a house with a night tariff hot water tank and the first thing we are going to do is throw it out.
Reason: we need to put in a central heating system anyway (right now the house has individual coal stoves supplemented by plug connected oil filled electric radiators), so the initial investment is more or less covered by the central heating, practically giving us a free new hot water source. The meter is 40 Euro/quarter, taking it out would thus save 120 Euro a year. Besides, even with the soaring prices gas is still considerably cheaper than even night tariff electricity here.
