1-group

Per Brewing group you can make max around 30 double espresso shots per hour (that's a lot!).  A boiler size around 5 liters with 1 steam wand gives you the power to steam max 30 latte beverages with a size of 16 ounces per hour. Those machines are perfect for:

Gourmet bakeries, ice cream shops, convenience stores, book stores, ice cream shops, trailer and trucks if the coffees are not the main business