Selling Power

System

My system was installed 3 days ago and something has me confused. I have a 5.4kW hybrid system with 16-305amp hour batteries. Right now I producing about 4.8kW and selling 3.0kW. My readings have been that way for about an hour. My question, if I am selling that much power to the grid, and only using 0.7kW, how come the numbers on my meter are still going up about 1 every hour. I am only running 1 light and 1 computer, trying to get the number to go down. My system includes 30-180 watt Evergreen panels, 2 GVFX 3648 Outback Inverters, 2 MX60 Controllers, a Mate System controller and the 16 Sun Xtender AGM Baterries. The utilty company has not been out to change the meter so I am thinking that may have something to do with.

BB.

Re: Selling Power

Dean,

It is a bit difficult for me to understand your question/statement...

I am assuming that your numbers (4.8kW, 3.0kW, 0.7kW) are actual numbers that you have measured with your system's monitors.

Your question is why is your electric meter numbers still going up (i.e., charging you for power)?

One possibility, the electric companies realized years ago that some people where going to connect grid tied power systems to their homes/businesses and start "selling" power back to the utility at "retail price" (i.e., just start turning the meter backwards).

So, some utilities bought/modified their meters so that A) they don't turn backwards) or , does not matter which way the power was going (to/from grid), the utility was only going to "Charge" for the power (i.e., you use 3kW of power or generate 3kW of power--the meter was only going spin one direction--the direction where the utility was going to get paid).

So--if your utility still needs to change to your new "Net Meter", it is possible that your current meter does not turn backwards and you are actually getting charged for putting 3kW of power on the grid (I don't know your utility--so this is just a guess).

If, you are getting charged for powering the grid, you might be better off prohibiting the "selling of power" until your meter has been changed out.

Just as an FYI--PG&E in California was notorious for messing up the first month's bill for people who had installed solar panels.

In my case, it took about 1-2 weeks for my meter to be changed out. Well, it was the end of summer so my meter had actually spun "backwards" for the first week of my billing plan. Guy changed my meter, wrote down the numbers, and chucked the meter into the back of his truck.

My next month bill (which had never been more than $20-$30 per month) was $900 for 1.5 weeks of power! Needless to say, my wife was not too excited with our electric bill (or me) now that we had solar. And, of course, the utility could not find our old meter to confirm the readings were wrong.

My theory was that we had generated about 100 kWhr during that time (ran the meter backwards). The billing computer "knew" that power meters do not spin backwards and therefore assumed that my number was recorded wrong. So, the computer just added 1, 10, 100, 1,000 etc. (at each digit), until it got a net negative number and sent me the bill.

The utility never admitted the problem but, after a couple of months, zeroed out the balance and went on with our net metering plan.

So, check your meter and see if the rotor (or LCD "rotor") direction of spin, and copy down some some numbers to see what is happening. You can do it during the day, and at night to check direction. And don't let your system run up your last "normal" bill.

-Bill

System2

Re: Selling Power

Thanks BB. After reading your reply, I did some research on my meter. Even though the digital squares are moving backwards, the meter does not count backwards. Technically the utility company is getting fed free power until they swap out my meter. I will be sure to keep records of my meter readings so the same thing doesn't happen to me. Thanks for the reply!!

BB.

Re: Selling Power

Dean,

Worst yet, you are being charged real $$$$ for the "privilege" of providing the utility with "free power" (perhaps $0.30, or more, per hour the sun is shining)...

Your bill will be much less for now if you either turn on every load in your home to burn off that 3kW of power, or simply turn the "sell power" off (or even your solar array off) until the meter is replaced.

Don't know about your power usage and rates--in California our rates are 3-5x higher as we "use" more power.

-Bill

PS: Or just "run off grid" mode for your system... Sounds like you have more than enough power right now to do this (or just run--off grid--during the day to prevent the meter from charging you for feeding the grid).

System2

Re: Selling Power

I was told by my contractor not to run my system until my meter was changed out. They said it could not tell wheather the current was going into the house or going out so you are getting charged for the power you are sending to the grid. It only reads the pulses of energy it does not know which way it is going. It was hard for me to wait the week before my meter was changed out.