WARNING!
Local electrical inspectors and many electrical contractors in North America are still unfamiliar with off-grid systems: it is wise to consult an expert before committing to a system.
A Word About Safety
Installation must be correctly and safely performed. Although your renewable energy system is fun and very cool, it is not a toy: fire or electrocution can result if your installation procedures are careless.
Some electrical contractors and local inspection authorities remain uneducated about renewable systems, even making comments like: "Those systems wouldn't even operate a toaster - it's a waste of time". The last laugh goes to the system owner enjoying his morning toast but it is important to remember that these systems and the related technology are not commonly understood. Verify your installer's credentials.
A renewable energy system operates like a standard electrical power station. Regardless of the size, you can get seriously injured or even killed by an inverter or battery bank in the same way as sticking your fingers in a grid-connected electrical socket. Be careful.
Electrical Codes and Regulatory Issues
North America's local electrical safety inspection authorities issue work permits before installation can begin. They will also review the finished work according to state or national standards. Make sure you leave all wiring uncovered for the inspection process (including trenches).
In the US, the National Electrical Code is used to oversee all aspects of electrical wiring and battery, wind turbine and PV array installation. Canada has the Canadian Electrical Code for similar purposes. You can read the National Electrical Code documents in every version from the original 1897 version (seriously!) right up to the upcoming 2014 edition by visiting the NFPA Code 70 page .
Both countries' codes comprise Part 1 Installation Codes used to regulate electrical interconnection and distribution to/from commercial, industrial and residential buildings. Your home's internal wiring is also dealt with directly by these codes.
Most system owners think that the codes do not apply to them once they have a renewable energy system, but that's not correct. Barring a few exceptions, PV and wind system installations need to comply with the appropriate code's requirements. Article 690 was included in the NEC in 1984 for PV system installations.