Solar System 7 light-years away. Compared to many other planetary systems, the Solar System stands out in lacking planets interior to the orbit of Mercury. The known Solar System also lacks super-Earths (Planet Nine could be a super-Earth beyond the known Solar System). Uncommonly, it has only small rocky planets and large gas giants; elsewhere planets of intermediate size are typical—both rocky and gas—so there is no "gap" as seen between the size of Earth and of Neptune (with a radius 3.8 times as large). Also, these super-Earths have closer orbits than Mercury. This led to hypothesis that all planetary systems start
Solar power in Maryland of S.B. 791, solar hot water systems. Solar hot water systems have a 5 SREC limit. The passage of H.B. 1187, also on May 22, 2012, accelerates the state's Renewable Energy Portfolio Standard with a target of 20% by 2020, of which 2% must be solar. Currently, there is no limit on the system size for a photovoltaic system. In the state of Maryland, one SREC is equal to one MWh of electricity production, and is redeemable for three years. As of January 2017, an SREC is valued at $18, and if the RPS is not increased is expected to