[seahorse2]

I hope people here who understand solar systems can give me an opinion about this grid tie system, which markets itself for know-nothings like me that can barely hang a blind. Its supposed to be a "ready" system, meaning even a novice like me can easily bolt it to the roof and simply call an electrician to do the electrical connection.

Here's a link to the system:

Grid tie "ready solar"

If you have any alternative suggestions, please let me know as well as the pros and cons of the alternative.

Thanks

[dunewalker]

At a quick glance, it appears to be missing some critical components, like an inverter to change DC current to grid-compatible AC of a higher voltage (maybe I missed it). That's an expensive item right there. Also, what's the point of going grid-tied with no battery bank? Grid power is presently inexpensive, certainly cheaper than this set-up will ever repay on investment. If the grid is up, you've got power. If the grid goes down, you're out of power even with all this stuff.

Btw, that site seems to have a glitch in it--the 2nd time I opened it a warning popped up and it shut down.

[Hermes]

To my mind a grid-tie system isn't really a collapse-prep system. You may know this already.... but to make sure it's clear for you and others who may be reading:

A grid tie system is appropriate for someone who wants to help out the existing grid by feeding electricity into it, and to essentially "lock in" their electric bill for the next 20 years or so at a fixed rate.

Now if you think the grid is going to be up for 20 years then to my mind this does indeed make sense.

I happen to think it's going down pretty shortly myself.

When the grid goes down you're going to have solar panels on the roof... but won't be able to store their energy in batteries, plus a host of other details I'm not 100% clear on yet, but understand to be a headache post-collapse with a grid-tie system.

An off-grid system is more collapse-prep, with a battery bank that you're charging up via the solar panels. Or one step better is an off-grid system that you can charge up FROM the grid while it's still around. This means that you can squeeze some extra years out of your batteries potentially by periodically topping them off from the grid and therefore keep them in better shape.

I forget the term for a system like that... "grid interactive" maybe?

The whole solar energy thing is a big freakin' mess. I salute anyone who can successfully get a system up and running.

[mos6507]

And why not use cheap petroleum (propane, gasoline diesel, etc.)as backup when the grid goes down?

Um, maybe, uh, because of this?

[dunewalker]

Each panel has a "micro inverter" associated with it. They claim that shading therefore on one panel does not affect total output. Also the output from each panel (and the entire system) is an AC line voltage and is just plugged into your circuit box.

Isn't the theory behind grid-tie that you sell expensive electricity to the power company during the day when you need less, and buy it back at night when it is cheap? You become a provider? Then later, when TSHTF, you buy batteries and a charger.

And why not use cheap petroleum (propane, gasoline diesel, etc.)as backup when the grid goes down?

Ok, I did miss seeing that mini-inverters are included in the package. Btw, still can't get the site to stay open--hope it's not my computer with the problem. Yes, you're correct on the theory of selling power, etc and in cases of temporary grid failure, like storms, it would be feasible to just run a generator on propane, diesel or gasoline. Like hermes says, a good idea if there will be grid power for the next 20 years. But of course we here know otherwise. If I were seahorse I'd pass on this package and consider investing in an off-grid package that also connects to the grid. You can have a solar technician install the whole thing but you have to have a commitment to learning how to operate it or you're wasting your money.

[cephalotus]

no technical data sheets for modules and converter and 9000US$ for 1kWp ?

Sounds like a very bad deal to me.

Here you pay around 3500€ for 1kWp, but you can get excellent modules with data sheets, converters with efficiency of 96%+ and aluminium + stainless steel mounting system that will survive storms for that money.

a data sheet for a module could look like this:
http://www.sanyo-solar.eu/uploads/media ... screen.pdf

for a converter like this:
http://download.sma.de/smaprosa/dateien ... 082118.pdf

(those components are similar to the components that are mounted on my paarnets house, see avaar. Even in cloudy Germany you get >1100kWh for 1kWp in a year.
A few years ago the typical energy production would haven been around 900kWh for 1 kWp.

[mos6507]

And why not use cheap petroleum (propane, gasoline diesel, etc.)as backup when the grid goes down?

Um, maybe, uh, because of this?

The article on electric cars?

Must I be blunt? Preparing for fossil fuels running out by building an off-grid system and then backing it up with a generator that runs on fossil fuels is the pinnacle of stupidity. Sometimes I wonder whether anybody is even prepping for peak oil anymore or it's all about Great Depression 2.0 or Yellowstone Caldera????

[cephalotus]

Must I be blunt? Preparing for fossil fuels running out by building an off-grid system and then backing it up with a generator that runs on fossil fuels is the pinnacle of stupidity. Sometimes I wonder whether anybody is even prepping for peak oil anymore or it's all about Great Depression 2.0 or Yellowstone Caldera????

this is off topic, but I don't see independant systems as the solution to peak oil, energy reduction within a society that works well is the best solution imho. So -I- do believe that photovoltaic systems connected to the grid are way better to fight peak oil than off grid systems with batteries.

[mos6507]

Propane and propane generators will lasts for years. Even in a fast collapse I bet I can still get propane for back up.

You can hoard it now if you like. I wouldn't count on a steady supply down the road. If you don't think it will get that bad, fine. I don't think you'll be able to go out and buy batteries when TSHTF either.

For the record, I think things getting that bad are probably far enough down the road that it's not a grave concern. I am not as much a hard doomer as I let on. But if you want to think ahead, you will want to have these backups in place sometime between now and before TS actually HTF. Waiting until there are zombies in the streets is too late.

I am an EXPERT

Oh really? How many TEOTWAWKIs have you gone through?

[dunewalker]

...while you may be preparing for the zombie-doomer collapse (are you really? preparing?), I am living in the real world where I am completing a passive-solar homestead and considering pv to generate some electricity. It is a costly complicated design process.

What i am struggling with is this: Do I invest in costly batteries for storage (How many? For the entire house, all the circuits? Or just one sub-circuit?), or just rely on the grid for storage? This is actually a very relevant question, OUT HERE IN THE REAL WORLD.

Propane and propane generators will lasts for years. Even in a fast collapse I bet I can still get propane for back up.

mos6507, There are technical subtleties here. Difficult decisions in a real world. You're lecturing me like I'm a newbie? I'm not anybody. I am an EXPERT

pstarr, you're still imagining what your "real world" is going to look like. Meanwhile, my "real world" consists of off-grid power and has for several years. My total investment for shelter, power and heat in 2002 dollars was less than $12,000, not including the cost of the land. But it does include the house (self-constructed) as well as the off-grid system, no stupid intertie link to the past. If you're considering investing $100,000 in shelter plus electricity, you're not living in the real world that we are entering as we type. Better go back to the drawing board there. Btw, this system permits pumping all necessary water, internet connection and desktop computer, table saw, skil saw, washing machine, electric drills, all house lights, vcr, etc. What more does a person need?

[dunewalker]

I guess we live in different worlds then

Yes, we do, at least for now, but they are converging worlds, for better or for worse.

[seahorse]

Dunewalker,

What type of off-grid system do you have? Can you tell me how much power it produces? What kind of panels, inverters, batters etc? and how many of each? How much costs in today's dollars? Reputable places you've used to buy the components?

Is your system running your refrigerator?

In November, my house used about 1.8kw.

My initial idea was to have a grid tie system to offset some of our power usage, obviously during the day when we use the most and especially in the summer (with three kids home from school). I thought this would be a lot cheaper and simpler than an off-grid system.

[dunewalker]

Dunewalker,

What type of off-grid system do you have? Can you tell me how much power it produces? What kind of panels, inverters, batters etc? and how many of each? How much costs in today's dollars? Reputable places you've used to buy the components?

Is your system running your refrigerator?

In November, my house used about 1.8kw.

My initial idea was to have a grid tie system to offset some of our power usage, obviously during the day when we use the most and especially in the summer (with three kids home from school). I thought this would be a lot cheaper and simpler than an off-grid system.

seahorse, I'll give a quick rundown on the conponents:

620 watts of photovoltaic panels
8-L16H Trojan lead-acid batteries
C-40 Xantrex controller
1524DR Xantrex inverter
Air-X 400 watt windmill (Southwest Windpower)
fuses, breakers, wires, cables
hand-built manual tracker for panels

estimated cost of everything at today's prices: $8,000-10,000?
good source, where I've bought most of this stuff:

Backwoods Solar

On good long summer days the system produces between 2-3 kwh/day
(btw, you said you used 1.8kw in Nov.--is that per day or what-sounds low)

I have a little 6 cu. ft. electric refrigerator, but unplug it during winter & use a pantry screened to the outside.

Now, if you had a system like this, you could also, with additional equipment (which I'm not familiar with) do a grid-tie arrangement and have the best of both worlds.

edited to add h to kw--kwh/day ie, 500 watts production for 6 hours would make 3kwh/day

[Frank]

Seahorse: your units of consumption don't make sense. kw is power, kwh (kilowatt-hours) is energy. If you consume 10 kwh/day of energy and the sun shines x-# of hours per day average in your location (let's say 5 hours average) then you can calculate how many panels you need (2kw worth in this case.)

Having batteries in the basement or wherever will provide local storage and lots of folks do this for either philosophical or practical reasons (ex. if it's going to take $25K to run utility poles onto your land and you can pre-buy your electricity for the next 30 years for the same $25K it makes sense to do it!)

Batteries however are expensive and have limitations. You might have to maintain them, replace them every 5-8 years (depending on chemistry) and respect their limitations. Every time you cycle them you eat into their life expectancy.

Using the grid as a battery (grid-tied) saves upfront money but means you won't have power during outages. Can you live with that? How reliable is the grid in your area? etc. etc.

[rdsaltpower]

I have a small 580w solar system at home. I charge 10 deep cycle batteries with them and convert to ac into the house. I also have a small 4.5hp diesel gen. coupled to an alternator as backup to this system. My panels have been snow and ice covered for the last three days and last evening I lost grid power for 4 hours. My batteries were down so I had to run the gen. for a while. Luckily I have a wood burner w/blower and was able to run it and two compact flo. lamps till bedtime. I am thinking about adding another panel soon since the price has come down. I also thought about doing a grid tie but no nothing about the cost and hoops to jump through for the grid operator. Anyone have any cost figures on inverters and disconnects etc. required for this purpose?