I'm getting ready to go on to a net metering system, but it will likely be almost a month before I can give you any kind of information about how it's working.

I live in Hawaii, and the "hurricane proof" foundation they're making for the array is enormous. One of my future neighbors asked if it was the pool.

I'm not concerned if I ever could end up off grid completely, though. The house is designed to meet the needs of my growing disabled daughter, and what was important for me was to ensure a non-stop supply of power within the house.

I've also got propane for cooking, the fireplace and the dryer, and solar hot water.

Hope this is some sort of help!
Summer

I would be real surprised if you can do an adequate off-grid solar power system (DIY) for $15K, unless you're planning on going to incredible lengths for electrical conservation.

I recommend taking a real hard look at your numbers before proceeding along that path.

I have been looking around and have talked to a couple of folks. 15K seems very likely.

Here is just an example, http://www.backwoodssolar.com/

I have priced this system out from less expensive sites and can get the equipment for under 12K. That is for over 1000 watts solar, a 12.5Kw propane generator, 2 3000+ watt invertors, a powercenter, and batteries.

Perhaps I am wrong, as I am just digging into this. A friend of a family member did a small off grid full time cabin for under 8K.

Yah, you might be able to get a system based around 1000 watts of panels for that. Depending on where you are, in the winter that will get you about 2 kWH per day after losses in the system, maybe inching up towards 3 kWH per day. If that'll run your house, then you're fine.

Around here, that'll barely keep the computers running, let alone run the house.

Be aware also that solar power from an off-grid system isn't "free." If you are using less than what the panels are putting out at the time, you can consider that power to be "free." Anything that goes through the batteries, whether at night or during peak loads during the day, will cost you around $0.25-$0.50 per kWH in wear-and-tear on the batteries. Which is a lot more than what the utility company will charge you.

Solarpowered, can you explain the wear-n-tear on the batteries. I was lead to believe well taken care of batteries should last 10-15 years. Is this not the case?

My cousin did this when they built their dream home (1,500 square feet) out in the country. They used a combination of propane (refrigerator, hot water, clothes dryer and back up heating systerm), solar panels, and wood-burning furnace. They had thought they would stay there forever, but then had to move after only a few years. They had to bring in electricity to their property to sell their home as no one wanted to buy it without it being on the grid. I know they had to expand their solar power system to get adequate electricity, and their electrical needs were pretty minimal, but don't remember the details. You may want to put in some propane lights as a back up too.

Hi Mike!

We considered it breifly but then decided to bite the bullet and go with the electrical company. We're still fighting to have our poles installed and it's costing us a lot to do it. We ended up having to dig our own holes due to our soil type too :/

Still, it's closer to $10,000 compared to your $20,000 so we decided to do it. There's a certain appeal to being off the grid for some of us. If you think you want that then do your research well and go for it.

I doubt if you can be competitive in costs with your local utility over time. The installation cost may seem high for service, but most companies will install services for free so I am curious if that you are soo remote that they do not stand to benefit from your installation. Also your daily cost of power production will be extremly high compaired to your utilties cost, not to mention your maintenance and repair cost of your generation source be it solar or gas generator. Just to give you an idea, my utility charges .08 cents per KWh in the summer and .06 per KWH in the winter. So if you are already thinking of .35-.50 per KWh your are way over what my utility charges. Energy is one of those things that cost's you daily and over time the cheapest form of it is best. You may want to suppliment your daily usage with one of the solar generators you are speaking of, but not as your primary source of power in my opinion.

Still wondering where the .35-.50 per KWh comes from? IF that is the case then yeah, it makes no sense.

PV solar is not cost-efficient.

Don't get me wrong. I spent 100K installing a 10kW net-metered system with a battery backup on my new house, which (though large) was designed to be very energy-efficient - super-insulated, passive solar design, ultra-high efficiency heat pumps, etc. But even with such a huge system I don't expect it to generate all of my electrical needs. Even when it's running right, which it isn't most of the time - we've had several parts replaced under warranty already which has resulted in significant downtime in the 2 months I've been on line.

You do it because (1) it's the right thing to do and you can afford the cost, or (2) because you have no other alternatives. Not to save money.

The solar hot water for the pool is another story, though - what an awesome thing! Cheap and reliable.

Hi Mike,
Where are you located? I'm in the Mountains East of San Diego, and I am planning to do the same thing. In fact, I just took the first baby step in that direction by purchasing the first of 4 Outback inverters for the system. I'm going to steal a couple of solar panels off of my motorhome to start out.

As with you, the power company wants to charge me an arm and a leg to bring the electricity about 1/4 mile. I'm an Electrical Engineer and a tree hugger, so this is right up my alley.

I don't expect to be able to do the whole thing for the $20k I'm saving from the power company, but I won't have any power poles anywhere near my property, and I'll have power during those frequent times when the local grid goes down. I'll be doing some solar and also experimenting with wind power. I'll be designing and building my own hvac system including heat pumps and shallow pipe geothermal etc. etc.

For me it is as much of a hobby as a means of powering my (yet to be built) house. Also with global warming and fossil fuel shortages, I think the day will come when my system actually saves me money.

As for the battery thing, it's real, but it isn't as bad as the numbers quoted by SolarPowered. I too would like to see some explanation from him. Also, if you are in an area where some wind production is practical, that can greatly reduce your battery needs, as the wind often blows more at night than during the day. Conservation, with modern types of lighting etc. also plays a part.

And, finally, solar prices will almost certainly come down some in the next few years. Depending on your timing etc. it might make sense to start out small with the solar and make up for it with the propane generator for a few years. Then bulk up your Solar once the costs come down some. With so many new technologies and so many companies building up factories right now, it almost has to get cheaper.

cheers,
jp

Just to fill in the missing data on battery storage, I think I may now understand the numbers that "SolarPowered" presented. They are accurate, in terms of the numbers and the math, but don't represent the situation correctly.

Let's say you needed about twelve killowatts of energy storage (a modest amount, but certainly possible with a small amount of conservation).

Surrette 6CS-17PS Battery
546 Amp-Hours, 6 Volt DC
Regular price: $992.00
Sale price: $791.76, 4/$3,120.00

Let's round this off and say 500 amp hours at 6 volts times 4 batteries =
$3000/500 * 6 * 4 = $0.25 per killowatt hour of storage. So the total cost of your storage for the ten to fifteen years that you will get out of these industrial quality batteries is 25 cents per killowatt hour...per day, times 10 years...

So in actual fact, since you will be putting 12 KW-hours of energy into and out of the batteries many times during those ten years. Each killowatt-hour only costs about .25/365*10, or about 0.007 cents per killowatt hour.

So, while it is a significant cost in setting up your solar power system, it is not, contrary to solar Powered, going to make it impossible for you to make your own energy cheaper than the power company can.

I think $30K is a more realistic number for an off grid system for a whole normal sized house. If we take off the $20k we don't have to pay the electric company to string a wire to our property, we are looking to generate more than $10K worth of energy in the same time we would pay that much in monthly bills. Using very round numbers, let's say a typical monthly electric bill might be $100. At that rate, our power is free after the first 8 years.

So the $20k we're not paying the electric company doesn't pay for our whole system, but it reduces our payback time from an impractical 24 years to just 8 years. Since the solar panels and many other parts of the system are expected to last twice that long, I think it's a pretty fair bet that the system will save money in the very long run.

That, coupled with the fact that you get to send your favorite obscene gesture in the general direction of "Big Power", and operate your home with a near zero CO2 output and you are free of concern over power outages and rising costs...I would say it is a no-brainer.

If you don't have the big up-front cost to connect, it could easily go the other way though.

jp

Or you could co-exist with the power co. and get the solar setup where during the day the meter runs backwards,at night forward and you are either credited or pay depending on your consumption. Whole house set up averages 15k.

Good to see your still around, jeff. Hope all is well with your project.

jeff,

thanks a ton for the info. I am located in Burney, CA. It is a small logging town an hour NE of Redding. We are around 3500ft in elevation. I have 2.5 acres, almost on top of a hill, with great exposure to the South, East, and West.

Your #'s are similar to what I have run. I have heard that a diesel generator would be a better bet in the long run over propane? Any input on that?

You will be running 4 invertors? How many Watts each? I would like to hear more about what you are planning on setting up.

I still have 2 major hurdles to cross, being insurance and mortgage. Do you have any insight? My mortgage broker says I can definately get a loan, but it may not be as good as interest rate. She is doing more research. I have not heard back from state farm yet.

I will admit, I am very new to this and need to learn a lot more. Life has become very busy these days. I am a teacher and school starts tomorrow. We also may get our permits this week (keeping my fingures crossed!!!!).

sierraeast - I would not mind being hooked up and run net metering. It is a cost issue though and if I do hook-up with PG&E, there will not be much money left over for solar/wind.

Hi Mike,
I'm using Outback inverters. They are very easy to build up over time. One will give me 3.5KW of 120V power. I can then add one more to get 6KW, and that can come in the form of single phase 240V to handle welders and big honking shop tools. I can then add up to two more to the panel as needed for more power. (see OutbackPower.com)

Propane is more convenient in that you will likely have heat and hot water and cooking from propane. I would only suggest a propane generator if you expect most of your energy to come from solar/wind. A diesel generator will run a lot more hours with less maintenance than propane. Propane genny is more like a backup/unusually cloudy weather/unusually large power use type genny rather than one you intend to run for several hours a day.

As for mortgage and insurance, I haven't looked into that. Insurance I'll have to look into eventually, but as for mortgage, I have a small one on my land, and I am paying for stuff as I go on the construction. Working about 80 hours a week. My goal is an off the grid property that is completely paid for. Monthly bills? We don't need no stinkin bills! :)

best of luck to you in your endeavors,
jp

P.S. Hi Sierra - good to see you still kicking around here.

Talked to my insurance agent (State Farm) today. They said they do not ask nor care where or how I get my power.

I have also found that there are mortgage companies that specialize in off-grid homes. My mortgage broker believes that it will not be a problem getting a mortgage through a conventional mortgage company, but she is checking into it further.

So we are getting there!

Hi Mike,
From what I've heard, just being in the "outback" can sometimes create a problem with insurance. This is mostly just because it can take longer for the fire trucks to get there in an emergency. Where I am, there is also the simple fact that the area has been in an ongoing drought for many years now and fire has become a big problem. For me it might be a bit better, since my property was in a fire a few years ago, so much of the fuel got used up.

As for mortgage, I don't think on/off grid is an issue, but often DIY/be your own GC is an issue. This is one of the more convincing arguments in favor of using a service like "Ubuildit". It can make it easier to get a loan if you have the help of a company that has been through the process many times.

best,
jp

Sorry I haven't replied to the (far) above questions--I just noticed that this thread picked back up after it died for several days.

On the subject of the cost of batteries:

Jeff did the appropriate calculation, except for a couple substantial errors. There first is a factor of 1,000--he calculated watt-hours, not kilowatt-hours. That brings his 0.007 cents per kWh (which was actually cents per Wh) to 7 cents per kWh.

The second error is much smaller--a 10-year lifetime for the batteries is based on something closer to a 50% charge/discharge range, not the nearly 100% he figured on. If you run 100% charge/discharge, the batteries won't last long at all. That brings the calculated cost to around 14 cents per kWh.

In practice, it turns out that the batteries don't really do quite as well as the spec sheet says they should. Home Power magazine a few years ago looked at what people were getting in actual running systems, and, IIRC, people were typically seeing 25-50 cents per kWh for the total battery cost, over the life of the battery.

You can look at it this way: A good set of batteries will run you around $10,000. If they last 10 years, that's $1,000 a year, or about $80 a month, for a lot less electricty than the 30-40 kWh per day you can get from your utility for $80 a month.

Something people often overlook in "payback time" is cost of funds. If your solar power system costs you $30,000, that money either has to be borrowed from a lender, or taken from investments that could be giving you a return on investment. If you use 10% as a round number for cost of funds, that system is costing you $3,000 a year in cost of funds before you even start to get into "payback" of the principal.

There is no way anybody in the U.S. with a $30,000 solar power system is offsetting $3,000 a year, or $250 a month, in electricity costs. (Unless there is some huge surcharge for some reason.) That's around 100 kWh per day, which is far, far more than you're going to get out of a $30,000 solar power system.

(This calculation is, of course, improved somewhat if the rest of us are forced to pay for part of your system. (I.e., government subsidies.))

soloar-powered:
"Jeff did the appropriate calculation, except for a couple substantial errors. There first is a factor of 1,000--he calculated watt-hours, not kilowatt-hours. That brings his 0.007 cents per kWh (which was actually cents per Wh) to 7 cents per kWh."

jp --> blush. He's right. When I saw the .25 come up on the calculator, I said to myself "Ah hah!".

With tail between legs, I must still mention that solar-powered managed to leave out the $20,000 that Mike and I will each save by not paying the electric company to bring their ugly poles and wires to our houses. As I mentioned in my earlier assessment, that $20k makes all the difference.

jp