I don't know how old the meter needs to be to spin backwards...not just the little rotor, but even the numbers...I would presume that electric companies safeguarded against that a long time ago...I think making an old meter go backwards could be done without pushing electricity back...but just using magnets on the outside...
In any case, the best thing is to talk to your power company...the new meters are unidirectional and so it would need to be replaced with one that can do what is called net-metering, it effectively has two meters in it...one to measure energy in one direction and the other in the other direction...when you get your bill, they list both numbers, substract them and charge you only for the net consumption.
If you over-produce, the bill will probably show a credit...they are not going to bother to send you a check every month...they figure the weather will eventually catch up with you and will end up consuming more than producing...unless you have a huge farm.
Oh, one more thing...whenever there is an outage on the grid...I think you also need to make sure your system stops pushing electricity into the grid by automatically disabling the inverter...the electric company wants this assurance so that when their workers are out there fixing stuff do not get electrocuted because of your system.