Spend money on the roof installing solar panels?

Thank You for taking the time again Freddy and answering some of my questions, you really have me thinking about it now ! The wife and I are alot like you and your wife, i usally buy a car used and keep it for as long as i can, usally get 200,000 mile out of a car. Now if you were to sell your house that surley ( The Electric Bill Part ) would add more to the house value and really be a good selling point because as we know that electric cost is only going to go up higher in the future. I'am paying about half of what my monthly house payment used to be when i first built the house ( back in 1976 ) in electric right now. A few more years and i'll be paying ( just for electric ) what my house used to cost me a month. I hope i said that right I'am really thinking,,,, thats kinda scary !!!!!

samhill wrote:when the grid goes down can you still basically shut off the feed to the grid & run your own house if the sun is out?

With my system, from a scientific, technical standpoint, yes, but in reality, no. You see, the inverters that change the DC into 240 volts AC and connect to the grid are constantly "sniffing the grid". When they sense the grid is down in a couple of milliseconds they shut the inverters off. When the grid comes back up, they sniff the grid for five full minutes. Once they determine the grid is up and stable they allow the inverters to go back to work. So, in order for me to disconnect from the grid and have my panels power my house, I'd have to have some way of tricking the inverters into thinking they were connected to the grid and also it would require a bank of batteries. You can NOT simply run AC things direct from solar panels and an inverter. Think about it....if you have no batteries, & you have somehow tricked the system into making power and you are running the fridge and watching TV. Then a cloud covers the panels for 10 seconds. What happens? You see it can not work without batteries. Much, much simpler and cheaper to have a generator.

That being said.... there is a company that does make a combo unit. It will allow you to have batteries and connect to the grid. It charges the batteries first, then the remaining goes to the grid for credit. I did not go that direction for several reasons. One, it's old technology and not all that dependable. Also I did not want the added expense and maintenance of batteries, and the inverters I have are approximately 11% more efficient than the combo type systems. I have "Micro inverters". I have 30 panels and 30 inverters. Each panel is it's own separate system. Other systems have "central inverters". All the panels are connected to make one one system. If a shadow covers one panel, ALL panels drop their output to that of the lowest panel. If I have a shadow cover one panel, the other 29 still put out full power. That's most of the 11% difference.

Electricity rates keep going up, but sunshine doesn't!

PS: Today was a bitter cold but very sunny day. It proved to be the record day for 2012, and only 7 KWHs away from the all time record. We use 20-25 KWHs a day. Today we made 40.4. I expect before this August we will break the all time record.

Thanks for the explanation Freddy, sounds like you did your homework. If I could only get the state to start harvesting some trees I have 60ft. of South facing roof but I know it will never happen.

You around the park and campgrounds sam? We go up to the lake alot in the summer,used to have a camper and pontoon boat up there

I'm right up against the park lands on the Pa./Ohio line, nothing south of me for a half mi. except trees & then the lake. The pines were planted by the CCC folks & are at least 60ft. high., they do an excellent job of blocking the sun & my garage is only a few ft. from them so no solar for me.

That would be paridise !! Except in the winter months

Freddy thanks for sharing the details of your system, pretty neat how quickly the payback period of things can change. I have a couple questions for you, what was your average annual usage prior to your system install and what do you think your annual production will end up as on average? How close is this to your initial estimate before deciding to take the plunge?

I didn't realize how the credit system actually worked, any idea on how many gal gasoline you could save per year if all your credits were used on electric vehicle charging? My guess is the payback is too long today and the credit surplus is small in comparison to gal gasoline used on an equivalent energy basis, but I'd be curious to know how expensive gas would have to get before you see a payback in the 5 yr time frame.

qbwebb wrote:what was your average annual usage prior to your system install and what do you think your annual production will end up as on average

I dollars we average about $145 a month. (That may seem high, but I work at home...sewing machines, printers, air compressors, welders) I designed the system to exactly produce what we use. Of course it will vary from year to year, and as time goes on the panels produce less and less. These first years I trust it may produce extra. At year 25 when it's only making 85% output, well, perhaps 25 yrs from now I won't be doing so much work. We realize that when we have one of "those" summers that it rains all the time we may run short. Other years we may run over. Whatever will be will be!

I know one person that overbuilt his system and then bought a Chevy Volt. It's working for him. I personally don't think an electric car is all that hot an idea in the northern states. It takes a lot of energy to heat a vehicle. But, as a novelty I did build an electric motorcycle and have fun "riding for free". I'm not sure how much gas would have to get to before things made sense, but I do know that at today's prices all electric cars cost way more per mile if you run them out long enough to buy new batteries.

I know one person that overbuilt his system and then bought a Chevy Volt. It's working for him.

Does he work at the WH balancing the budget.

Electric cars are like anything else, they have their place just like the hy-breds if you need a highway driver then it's not the car for you. Heck I'm about 25Miles from the nearest Walmart, by the time my wife would load that little bugger & head back she would be running out of juice.

Yeah I just ran some rough numbers, assuming you pay nothing for the extra capacity to generate the credits you need to charge your car for free, I commute about 7k miles/yr and consume about 233 gal/gas to commute w/ a 30 mpg vehicle. At $10/gal gas & say 25k to obtain a Nissan leaf its almost 11 years not including replacing the batteries. I'm sure you can easily do a more detailed analysis with battery data for %capacity vs. charge cycles and a tax break but its prob not even worth doing the math again until gas is $10/gal.

Unless I'm mistaken a chevy volt is close to forty grand,with a 40mpg new dodge duster? that is about 18k tax etc included that leaves a lot of money for gas,at 5 bucks a gallon about 160000 miles worth,electric car battery would be replaced long before then at huge cost.Use the electricity for the household,payback will be much sooner and the car will be more useful.Didn't Obama recently have a huge import tax put on chinese solar cells because they beat the pants off solyndra cells and helped contribute to their demise? Now we'll all pay more for greener energy cause they couldn't handle the competition.For household power when the grid goes down a generator is an effective alternative,mine will run the (coal)Pioneer,water pump,lights,fridge,oil burner if necessary,hot water heater if I turn the water pump off long enough to heat a tank of water.Beats sitting in the cold and dark.

My Uncle has a similar set up to Freddy but he uses wind power. It is tied to the grid in the same way and gets the same kw credits. It really is a good deal because when he is kicking power out on the grid, he is getting paid in what essentially is a retail pay for what should be wholesale pay.

That is the good news...

The bad news is, at his age, (70) he will never live long enough to ever recoup his investment. His windmill cost $17,000 and saves him about $65 per month. At that rate he will pay off the windmill in 21 years...at which point the windmill will be junk and need to be replaced. It really is not worth it, and that is his words, not mine.

The sad truth is, IF he had spent $17,000 on buying new, higher efficient appliances, and installed green switches in his home to kill phantom kilowatts, he would have had a greater return on his money. Most of us are in this boat. The problem is, having a windmill is far more interesting then having a little green switch in your hallway, and having a refrigerator that looks like any other refrigerator...even if it is more efficient, is kind of boring.

But solar power in Maine is actually a bright spot. A neighbor has solar panels and like Freddy, he thinks he will get a return on investment in just a few years as well. He does not say that about his windmill or his geothermal heat pump though.

I love coming onto this site to live and learn about many things. When I bought my beat up golf cart with new batteries a leaflet from US batteries explained about extending battery life. Once a day is minimum, once a golf round is better and recharging every hole is best. The more you keep it charged the more cycles you get out of it and they give a cute little graph. Sure seems to me you have to keep those suckers charged.

If your always charging it and never driving it they will probably last a long time. Not a very efficient use of your money as it costs something to charge it. Of course a "free" solar or wind system would be....not free.
When you are young, you can't afford to do this. That is the only way to get ahead of the costs providing the system lasts long enough. I know people on their second windmills. $$$$$$ There is no free ride, only hope for it.

Kevin