Re: Planning South America Off-Grid Installation. Some questions.
With amorphous panels--typically they are about 1/2 as efficient as mono/poly crystalline panels--so you need ~2x the square meter area for the same amount of power.
Originally Posted by Galecra
Personally, I am not a big fan of amorphous/plastic/flexible panels unless you have a real reason for them--perhaps yours is a good reason (shipping size/costs).
While I am not sure that the UniSolar (and others) will last as long as glass panels--given that my own "Grade A" glass panels from a reputable mfg. needed to be replaced in about 5 years--I will not make any predictions for you.
You can get good (expensive) MSW inverters too--or stick with cheap and locally available that meet your needs. For a off-grid live/work situation (9+ months a year), spending money on "good inverters" with remote heads, various power saving/monitoring features are pretty nice to have.
Regarding the inverters, do you know the PowerBright brand? They do make 12VDC-230VAC converters modified sine waive at a good price. I'm thinking on getting one Morningstar 220VAC inverter for the regular loads <300W , and another bigger and cheaper PowerBright to connect the heavier loads...
Also, as most of our loads (laptops, chargers, etc) have international adapters which run with 120VAC or 230VAC, I'm thinking getting a 12VDC-120VAC inverter is also a good choice, and then I can buy here a transformer 120VAC-220VAC for the few loads that must run with 220VAC..
However, by the time you pack them for Argentina (or buy local)--They simply may not be worth it for you.
Regarding using a transformer--I would suggest avoiding using them, if possible. Transformers are not usually very good for use on MSW inverters (lots of losses) and even on TSW inverters, you may end up with 5% or more in losses.
Certainly will not hurt to try--but measure your DC power into the inverter and see if you can tolerate any additional power usage/losses by using these guys (and, for example, you may find that "search mode" will not work with a transformer on the AC output).
Tough question to answer. In general, low voltage disconnects have limited current support (~8-30 amps depending on manufacturer and model).
Directly connected to DC I would have the water pump, and maybe a couple of lights... how would I connect them?, just directly to the battery (I don't think it would be a good idea)? or do I need some sort of controller or voltage regulator between? That's what I meant in my previous message on using the load control outputs of the charge controller to connect the water pump..
And, measuring battery bank voltage to estimate state of charge is not very accurate. Plus you have more voltage drop through the extra hardware and wiring.
Is this going to be an unattended system/pumping at times and you need to protect the battery bank?
Setting up a system for unattended operation can get complex and expensive.
If you/family are always going to be there--then you can cycle pump power as needed and save the money/complexity.
20x BP 4175B panels (replacement) + Xantrex GT 3.3 inverter for 3kW Grid Tied system + Honda eu2000i Inverter/Generator for emergency backup.