1999 was a good year for solar generation. We ended up with a 352 kWh surplus. We generated more power in 1999 from our PV array than in 1998, but by living in the house full-time we increased our power usage somewhat.
Here are the results for 1998 which I've broken into months. The monthly PV output reflects the amount of sun harvested by the PV panels.
The array generated 4.246 megawatt hours of electricity for the year, even though June and November were particularly cloudy months. We "imported" 2.417 MWhrs of power from Central Maine and "exported" 3.008 MWhrs to the grid. Annually, we generated 591 kWh more than we used.
While the bill has been figured on a monthly basis these past few years, starting in 2000 the bill will be annualized - excess production from one month will be added to the following until a final 12-month net is determined. As I can see from these figures, we'll owe nothing for electricity - just a small hookup charge which has yet to be determined. As part of the new net billing rule, any excess will be give back to the utility at no cost and any deficit will be paid at the retail rate (currently 12 cents/kWh - but that will be less with deregulation as well).