You might have spent too much on the array. Most people target a 10-15 year payback period. But benchmarking it on December/January production is also likely

You might have spent too much on the array. Most people target a 10-15 year payback period. But benchmarking it on December/January production is also likely to blow up your projections as you noted. If you're net zero in the middle of winter you're probably going to be positive in the summer unless you live in a very hot climate. IMHO sizing an array to be net positive over the course of a year is probably a mistake, as this draws the ire of your power company and they'll probably screw you on overproduction. If you're planning to buy an electric car or something in the near future then it might not be a problem, but generally the best plan is to buy for about 100% of your total yearly usage. Solar panel production typically decreases by 2% during the first year of operation (0.5% every subsequent year) so you'll be slightly net negative which keeps you on good terms with the power company. One nice thing with the panels is that they effectively lock in your power rate at whatever you paid. You won't get burned by ever increasing power rates. It's a hedge against future rate hikes.