To: Bearcatbob who wrote (15556 ) 12/20/2009 9:55:27 AM From: Eric Read Replies (1) | Respond to of 86356 Bob, Sorry that I didn't answer your question on ROI last night. On that island where there is no utility virtually everyone years ago used to have generators as their main source for electricity. To have power 24/7 they had to run continuously. This is very expensive! So by the early 90's PV costs had dropped and the electronics necessary to convert DC into AC became available, especially sine wave inverters. The state of the art up till then was modified square wave. As a result folks started to compliment their generators with small solar PV systems. This allowed folks to turn off their generators at night and have enough power stored in batteries to run a refrigerator, lights and some small appliances till the next morning or for a few days depending on how big their array and batteries are. Suddenly folks realized they were saving a lot of money on diesel and propane not to mention wearing out their generator. Our neighbors behind our house on the island lived there year round and went through over 2000 gallons of propane a year, Remember that the fuel has to be delivered by barge so there is an extra fee per gallon. Last year it amounted to a price of about $3.50 a gallon. In the summer of 2008 it was $4.75! So my neighbors behind me had to have their generator rebuilt about every two years since it ran almost 24 hours a day. Expensive. No one on the island uses diesel anymore mainly because propane has a very long shelf life. As some of you boaters know diesel does not store very long before it starts to break down. Propane doesn't have that problem. Meanwhile my house runs totally on solar. No moving parts to wear out, no expensive propane, no noise, no smelly exhaust and smoke. Power available 24/7/365. That can't be said for the utility served islands! They lose power an average of 3 times a year with the average outage lasting 4 hours, occurring mostly in the winter. So when I penciled in all of the costs I figured that the PV system would pay for itself in about 8 years. Remember my house runs 24/7 with a refrigerator and separate freezer running all of the time along with some other small drains when I'm away. I couldn't run the house with a generator if I was not there! It is just not reliable enough. My other home down here in the Seattle area will be converted over to solar. PV panel prices dropped 50% last year alone. Much cheaper today vs what it cost in 1991 when my home up on the island was built. There are a thousands of folks around the country who have stand alone off grid PV systems, especially those that are more than half a mile off a road served by utilities. When you figure out how much it costs you to hook up to a utility putting up poles, wire ect it actually is cheaper to put in your own off grid system. If anyone is interested in learning more about running your house off grid I highly recommend this magazine. It has a wealth of information.homepower.com