Here's what this kind of system involves: two Xantrex 4,000-watt inverters stacked together and connected to twelve 300W solar panels. Four 1,270 amp-hour batteries were installed to provide close to 50 KWH of electrical storage.
The McVickers have a propane generator for battery charging and backup purposes. This provided them with the extra capacity to handle air conditioning and other large loads.
The electrical load could have probably been scaled down with judicious application of green design principles, eliminating the need for the propane backup, and making the house run completely on renewable energy. But this is an interesting example of how a modern house can be re-equipped for living off-grid on an island. For more information see: Home Power Magazine (PDF File)
[By Justin Thomas]