Q: Is there a fee to use the GRU calculator tool?
A: No. The GRU calculator tool is available for use to the public and is free of any charge.
Q: Is the tool certified by GRU?
A: No. The tool does not have any GRU oversight and is not certified by GRU. The tool is strictly independent of any agency and only servers the needs of those whose utility bill is based on the performance of their electricity meter.
Q: Is the tool accurate?
A: The accuracy of the tool is based on the same formula GRU uses to determine your bill. The formula is fixed and GRU shares that formula with anyone who request it. The formula is applied to your total kilowatt-hours. The dials on your meter indicate your kilowatt usage. Therefore, if you use the tool, it is up to you to read your meter correctly to ensure the formula gets applied against accurate information. If applied against accurate information, the tool is as accurate as the GRU billing department.
Q: Why use the tool?
A: Good question. The two most important reasons for using the tool are auditing and awareness.
Auditing: Electricity meters like any other mechanical device can be defective. I'm sure GRU will gladly replace any defective meter it finds. The problem is GRU doesn't really look for defective meters. How can they since most meters don't just out right die. Defective meters tend to fail intermittently. Therefore, if you don't detect your defective meter it will most likely never get replaced.
awareness: Having your electric bill be a surprise to you each month is not the best way to manage your finances. Most bills (rent,auto,loans) are of the static or fixed amount variety. Light bills can deviate wildly from month to month based on externalities like weather conditions. If you are on a tight budget, the tool can help you manage how you use electricity and prepare you for the outcome well before your billing statement is released.
Q: What is the best way to use the tool?
A: The most effective way to use the tool is to enter your meter readings daily. Doing so allows you to develop a traceable usage pattern. The more usage data you have on your meter the easier it is to spot malfunctions, audit your usage and make usage adjustments.
If your meter suffers from large intermittent jumps at times, you will be able to isolate the problem and report it. (An example would be if your average daily KWh usage is 60KWh but one day your reading suddenly jumps to 200KWh without you doing anything differently usage wise.)
Q: What if I can't read my meter everyday?
A: Not reading your meter on a regular basis lessens the chance of finding a faulty meter. One of the core functions of the tool is to isolate malfunctioning meters but it can do far more than that.
The tool also has ancillary uses such as being an accounting tool to tabulate how much is owed for electricity and taxes for a given period of time. (Good for short term rentals) Remember, important historical data can be gathered and be very insightful even if you are limited to reading your meter only once a week.
Q: Can the tool help me lower my utility bill?
A: Many users who were experiencing extremely high electric bills were able to see how much electricity they were using per day by taking daily readings of their meter. This caused them to note the difference in daily cost when they did things like changed the thermostat settings. When they experimented with what the daily cost would be if they set their thermostat at 78 degrees compared to a setting of 76 on consecutive hot summer days, they could see the difference they would be charged by GRU for those days. The tool helped them see that a monthly utility bill is a series of daily usage bills that they can control by making simple daily conservation choices like changing their thermostat.

Q: How often can I enter my meter data?
A: The tool is very flexible in that you can enter data at any time and as often as you like. If you are concerned about the amount of electricity being used each hour you can do hourly inputs to track your amount owed by the hour. Most users don't have time to track by the hour but if you require high intensity usage like mining bitcoin requires, then you will be very interested in hourly cost of electricity.
Q: Can the tool be configured to read my meter automatically?
A: No, I'm afraid not.
Q: If I take a picture of my meter everyday can I upload it into the tool?
A: That is currently not a feature of the tool but we are toying with the idea.