Jeffry Gitter of Belle Harbor once had a big monthly electric bill. An amount of nearly $400 was not uncommon. Lately, that has changed. It has changed because Gitter’s home now has 43 solar panels on the roof. So, instead of getting a bill from the Long Island Power Authority, or LIPA, Gitter has been getting a regular credit on his statement, with last month’s credit close to $200, thanks to Go Solar/Green NY of Hollis, the premier installer of solar power systems in the Rockaways.