Re: Smoke and mirrors, or the real deal?

The vendor you linked is a snake oil saleman. While power factor correction capacitors can save demand charges for industrial/commercial customers (IF the customer is billed based on kVA demand and not kW demand), this vendor is claiming that installing one of their units on a residential service will save "10-25%". Residential customers are invariably billed based on kWh only, so the power factor of the load is immaterial and there are no savings to be had.

To the original post, the question to be asked is: "Am I billed on kW demand or kVA demand?" It is best to ask your utility, if your bill is not clear. If you are billed on kVA demand, then, in order to understand how much savings are available, you need to find out the power factor at your peak load. If someone wants to sell you capacitors to correct your power factor, then they should be able to measure your power factor, recommend a properly sized system, and predict your monthly savings. Someone who can do this is NOT a snake oil salesman. If you are billed on kW demand, there's no advantage to installing capacitors.