Ok, this is almost 7 years later... No one seems to have solved the problem as of yet. It is a recurring problem, but what everybody seems to fail to notice is that any business that uses a lot of electricity would still need the financial records to be kept. That means that several different customers would have to deposit money into your bank, pay with credit cards and so on. This would have to be done in a very smart way, because when we cheat, we all tend to do it with similar patterns, which are easily recognizable by forensic accountants. So it would also have to be a cash intensive/only business. Foot traffic doesn't really matter, since if the power consumption is justified, you'd first have to have irregularities in your books for anybody to physically come and check. You could keep your shop closed 24/7.