sizing equipment

[georgerc]

I don't care much for a generator, I have one and hate to run it, it bothers me, I can do without power if I have to, if that was the solution I could care less for solar or wind period,

My bill really isn't worth talking about, whatever I may end up spending on RE would cover my bill for a long while, the whole apeal for RE is to have my own supply, ID rather not bother with any of it if I'm still dependant on the grid

I'll have a look at SMA, thx senij

[SunEagle]

I don't care much for a generator, I have one and hate to run it, it bothers me, I can do without power if I have to, if that was the solution I could care less for solar or wind period,

My bill really isn't worth talking about, whatever I may end up spending on RE would cover my bill for a long while, the whole apeal for RE is to have my own supply, ID rather not bother with any of it if I'm still dependant on the grid

I'll have a look at SMA, thx senij

If you don't want to be dependent on the grid or a generator yet still want power you will be spending a lot of money. That would be a choice you have to make. At least with a grid tie system you get to use RE as well as using the POCO as your battery which is much cheaper then you owning a battery.

Most people do not like to spend a lot of money on a solar pv system only to have it shut down if the grid fails. Life sucks but that is the way it is.

At least now with the newer technology you can get some usage out of your solar panels during the few hours of the day with the SMA secure power option. I just wouldn't rely on that power if there are clouds or rain.

If you don't like a generator then I guess your choice would be sitting in the dark or by the light of a small LED lamp. Again that is your decision to make.

[georgerc]

That's pretty much it, sometimes it's about what you want, and for me that is the whole apeeal of RE, my bill is pretty low to begin with, dodo all this just to lower it some more doesn't interest me, I might as well just stay plugged in and don't bother,

I only plan on a few hours of battery backup, part of the reason why I'm lookin into windmills, my area seems to have wind when there's no sun

[Mike90250]

There are all sorts of generators, quiet, noisy, small, large. The EU 7000i is one I'm starting to look at.

[georgerc]

There's just something fundamentally wrong in my opinion running a generator, while your array sits idle because the grid is out

I wouldn't even bother with RE that be the case, just pay my bill and run the Genny as needed, but that's just me

[joerossjr]

Wait. Are you guys telling me that if you have "grid tied" panels, that you can't disconnect from the grid when it's down and you can not power your house at all during the day? That can't be right.

[sensij]

Wait. Are you guys telling me that if you have "grid tied" panels, that you can't disconnect from the grid when it's down and you can not power your house at all during the day? That can't be right.

There is "hybrid" equipment available to transition on-grid and off-grid (battery supported) use when the grid goes down. It is more expensive. SMA's TL inverters offer battery-free power when the grid goes down, but with strict operating limitations.

[J.P.M.]

Wait. Are you guys telling me that if you have "grid tied" panels, that you can't disconnect from the grid when it's down and you can not power your house at all during the day? That can't be right.

For the right amount of money, most anything is possible. But, since the usual and common goal with most residential PV is to do thinks in such a way that they are cost effective, while being grid tied and up during a power outage is possible, it's not cost effective and therefore not often done. So, at this time for some limited, quasi off grid power, see Sensij's ref. to SMA -TL inverter. Elsewise, open your wallet.

[SunEagle]

Wait. Are you guys telling me that if you have "grid tied" panels, that you can't disconnect from the grid when it's down and you can not power your house at all during the day? That can't be right.

It may not be what you want to hear but unless you have an inverter that can operate without the grid working your pv system is dead in the water.

You would have to totally disconnect the panels from the grid tie inverter and connect them to an inverter/charger for a battery system. That is not easy or IMO worth the time.

Or you just get a hybrid inverter which has the ability to charge a battery when the grid is down or power the house when the grid is up.

[georgerc]

I seem to be a bit unconventional in almost everything I do and in this case I had my own system design in mind before I even looked into what most commercial systems are made of.

My whole concept was to size my RE wind and solar according to my needs and burn i t up as it's beeing made, I'm not your average demanding customer, I don't have to have full power available at all times or 2 weeks worth of battery backup

Since this is a new build and I am starting from scratch, I have considered a DC fridge for example and either run it on a timer, or an output sensing circuit, for me it doesn't have to be running 24/7 even considered converting the washing machine to DC and load it whenever but run it during peak production, I know this is not for everybody, most people want that light to come on at the flixk of a switch, I can wait until morning or light a candle, I thought I could size a battery bank just large enough to run a couple lights maybe the TV over night, provided there's no wind

[J.P.M.]

I seem to be a bit unconventional in almost everything I do and in this case I had my own system design in mind before I even looked into what most commercial systems are made of.

My whole concept was to size my RE wind and solar according to my needs and burn i t up as it's beeing made, I'm not your average demanding customer, I don't have to have full power available at all times or 2 weeks worth of battery backup

Since this is a new build and I am starting from scratch, I have considered a DC fridge for example and either run it on a timer, or an output sensing circuit, for me it doesn't have to be running 24/7 even considered converting the washing machine to DC and load it whenever but run it during peak production, I know this is not for everybody, most people want that light to come on at the flixk of a switch, I can wait until morning or light a candle, I thought I could size a battery bank just large enough to run a couple lights maybe the TV over night, provided there's no wind

If you've lived off grid, you know what you're going to find. If you have not, I might suggest trying it by camping out in the wilderness for about a year and in so doing see if you like the lifestyle adjustment. Seems that living off grid is not quite what the romantics and those with $$ to make off the public's ignorance would have us believe. Also, unless you have quite high sustained winds, unobstructed terrain and high turbine location, a wind energy conversion system will probably not be practical or cost effective.

[georgerc]

If it was easy, everybody else old do it, but that's beside the point.

So 48v is that the majic number? I suppose most of you don't have much experience in this department, any inverters I should look into? Besides SMA gridtie that was mentioned, preferred brands etc

What's the deal with the stacked inverters, where can I read more about that.

12 v inverters seem to be done a dozen, most 48v I've come across apear to be overkill for my needs at 8 kW , any suggestions besides batteryless grid tie I'm all ears

[ButchDeal]

If it was easy, everybody else old do it, but that's beside the point.

So 48v is that the majic number? I suppose most of you don't have much experience in this department, any inverters I should look into? Besides SMA gridtie that was mentioned, preferred brands etc

What's the deal with the stacked inverters, where can I read more about that.

12 v inverters seem to be done a dozen, most 48v I've come across apear to be overkill for my needs at 8 kW , any suggestions besides batteryless grid tie I'm all ears

48V for a bimodal or off grid.

SMA grid tie is a battery less system that has a solar only off grid mode of 2kw. it is more of a gemick than anything else but if it helps you sleep at night....

Stacked inverters is a feature of inverters usually reffering to off grid or bimodal that can stack or assist each other. two 3kw inverters to get 6kw of performance, or two 3kw 120V that stack to give you 3kw of 240 split.

OutBack has lots on stacking.

You think that a 48V system is overkill for an 8kw system. Then you have a hell of a lot to learn.
BTW of the people responding to you nearly all of them are very familiar with 48V systems.

[SunEagle]

If it was easy, everybody else old do it, but that's beside the point.

So 48v is that the majic number? I suppose most of you don't have much experience in this department, any inverters I should look into? Besides SMA gridtie that was mentioned, preferred brands etc

What's the deal with the stacked inverters, where can I read more about that.

12 v inverters seem to be done a dozen, most 48v I've come across apear to be overkill for my needs at 8 kW , any suggestions besides batteryless grid tie I'm all ears

The problem with 12volt inverters is that you can't get big kW rated ones because the amps it will draw on the DC side get to be very high requiring very big wires and the potential of fires.

Even trying to stack the inverters will not help much unless you can isolate each load to a specific inverter all connected to the same battery bank.

When you start to look at your larger loads it begins to make sense to go with a higher voltage battery system. That is where the 48volt value comes from. Unfortunately while you can find those inverters, they are not cheap or plentiful but still available if you check out the Quality manufacturers like Xantrex, Schneider, Samlex, to name a few.

[Mike90250]

Wait. Are you guys telling me that if you have "grid tied" panels, that you can't disconnect from the grid when it's down and you can not power your house at all during the day? That can't be right.

uh, yep. That's the short story. You could buy a $1500 high voltage MPPT charger, transfer switch, 2Kw 24v inverter and some batteries, build up a smallish 24V system that could run a fridge and some lights for the days you have sunshine. And water and maintain the batteries, ignore them and let them go flat, and you have dead batteries when the grid goes dead.

Regular Grid Tie inverters are not allowed to operate when the grid is down, to avoid frying linemen.