FYI Basic Solar Kit from Costco

mena661 wrote:
Guys remember there is a $355 2000W PSW inverter included in that price too. This isn't really all that bad of a deal.

If a person bought two of these kits could they parallel the inverters?
Easy to see that I'm in the dark when it comes to Solar Electricity.

Running the inverter at full output of 2000W would require a 200 amp battery draw. If this would be a 24/7 situation, you will need that shed stacked with batteries and more modules to deal with the daily use, in the neighborhood of 5K AH. The wiring bill will be a face-slapper, too.

Here's the thing though, you won't be drawing 2000W 24/7. My house doesn't use that much power 24/7 and we are electrical pigs.

FWIW, I run a small 120V dorm fridge in my rig using a 235W module and 300 AH of storage. The fridge draws 80W when running and normal duty cycle is 1/4 -> 1/5, depending on ambient and use. A larger double door fridge will draw 1KW, daily. about 100 AH. The costco kit is rated to charge back 100AH and you'll need enough battery storage to make it through days of less sun. If you wish to use more devices, you'll need more module and more storage.

Here is a Downloadable spread sheet calculator that will tune you in to use and storage numbers.

The 2Kw PSW inverter only sweetens the deal if that is what you want. To me it is just an extra cost.

Hi,

No, you can not parallel (or stack) all but the most expensive inverters.


If you had a 50 amp RV you could power "both legs" of the unit, if you had two inverters.

Horizon170 wrote:


If a person bought two of these kits could they parallel the inverters?

Horizon170 wrote:

QUESTION--------for home use how big a battery bank should one have?

Recommended bank size is 6-10 days of your average daily energy draw multiplied by 2. Because you want the bank to be at least 50% full after 6-10 days of zero solar charging, ex. snowstorm or heavy rain.

This is - for homes. RV users rarely carry more than 4-5 days energy supply.

Horizon170 wrote:
.. building that could be used for battery storage and the building is 10' X 20' and half (20' X approx 6.5') the gable roof is facing SSW or almost due South

I don't mind the expense but want a big bang for the buck, so to speak.
There are several other things the wonderful FREE Sunlight can help us with like water heating, even cooking with the right salvageable items.

You will need a big building if you expect any heat-related appliances like a water heater. I do not know if WHs are sold as 120v units. Were I in your shoes, I'd be expecting to install at least 16 batteries.

I have 8 in my RV, and 800w of solar, 2kw inverter, but, I don't run the refer, or water heater, or cook with electric. It's usually overkill, but, if it weren't for those stinkin' cloudy days, I wouldn't need that much. It's very comfortable.

House power needs are generally much larger, assuming you want next-to-grid comfort.

mena661 wrote:
Guys remember there is a $355 2000W PSW inverter included in that price too. This isn't really all that bad of a deal.

If somebody is going to need a 2000W inverter, then they are going to need more than 400W solar. Or they will have to run a generator regularly. In such a scenario solar becomes sort of crutches to support a generator - or vice versa. There's gotta be a better way.

Almot wrote:
If somebody is going to need a 2000W inverter, then they are going to need more than 400W solar. Or they will have to run a generator regularly. In such a scenario solar becomes sort of crutches to support a generator - or vice versa. There's gotta be a better way.

For a house, oh yeah. For a RV, depends.

2oldman wrote:

Horizon170 wrote:
There are several other things the wonderful FREE Sunlight can help us with like water heating, even cooking with the right salvageable items.

You will need a big building if you expect any heat-related appliances like a water heater. I do not know if WHs are sold as 120v units.

Horizon170 said "sunlight", this doesn't always mean "solar electrical energy". There are other ways of solar heating. Rooftop solar water heaters on homes (not on RVs unless the rig is not movable) are VERY common where I spend winters lately. It works very well, the smallest model is enough to make a hot water for 2 people for shower and everything else. This "hot" becomes "warm" when it's cloudy but still in upper 60s. The only time when I needed to use propane for shower was early in the morning.

I still prefer propane for cooking, and guys on the camp with more solar wattage than me and with the same "solar only" approach also prefer propane. Microwave or induction plate increase daily energy draw too much, you can use them but carefully.

FYI, solar hot water heating is now required by code on Oahu, HI. The electric rates are unbelievable.

A 2000W inverter may not be overkill for an RV'er that wants to run a refrigerator, you have to have enough power to get past the lock rotor draw. It would be in the range of occasional microwave use, too. The Xantrex Prowatt 1800W inverter draws .8 amps at idle. A Prowatt 900W draws .6 amps.