mcgivor ✭✭✭✭


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  • Re: I'm doing a simple solar setup, i need help on which cables to buy.

    Where to start?  Loads is the best starting point, let's assume the TV and the X Box use 200W and the fan is 100W, which is pretty high for a fan, but let's use that as a starting point.
    200×5= 1000Wh
    100×16= 1 600Wh
    Total 2 600Wh or 2.6Kwh

    The hours of daylight are not the hours of productive sun, in Puerto Rico the average is around 5.5 hours. Panels rarely produce the wattage they are rated at, 75% is a good rule of thumb, so the 400W array actually would produce 400 × .75 × 5.5 = 1.650 Kwh,  so well below the the load requirements. It gets worse, there are other losses, cable, battery, charge controller and inverter which have to be factored in. Realistically you would need about 10 100W panels to satisfy the load requirements. The battery situation is another story, if the loads are nighttime loads the battery must be large enough to support them, without dischargeing below 50%, but you wouldn't want to do that  because the next day may be cloudy, so the capacity must be large enough to compensate, 200Ah is nowhere near enough, about 4 times or 800 Ah would be more realistic, unless of course a generator is part of the picture. That TV, gaming  console and fan are becoming an expensive proposition, I would suggest getting a 12Vdc fan use what you have so you can sleep at night , get a pack of cards,  be creative  and wait until the grid is restored, because off grid is not as simple as it appears on the surface. 
  • Re: I have an opportunity to buy some panels that were removed...pls advise

    This is how I would handle the situation, it would seem obvious the owner has little interest in the equipment, a plus on your behalf, most panels would probably be fine, using the date of manufacture of the inverter as a guide to the age of the panels, 4 years is not old, take a $1000 in cash, smaller bills, make an offer without testing, cash in the hand is worth more than an offer without the carrot dangling in front of the seller, if it's really something you need/want don't hesitate, because someone else may come along and do exactly what I've described, money talks bullshit walks, as the saying goes. Yes SMA equipment is good, you might get lucky and it works, if not the value of the panels will absorb that, setting up, testing and contemplation may cost you the deal, the worst outcome would be a refusal or counter price, but the cash in hand works extremely well. Used to buy cars this way, there was no insurance, current  emissions test, so no test drive, just a driveway ornament that need to go, always be confident with a smile. Good luck. 
  • Re: Lithum, Battle Born battery, claims of peformamce and origin

    Yes they were forthcoming, responding to questions immediately, which is a good sign of customer service, although I don't have their batteries. It would seem they intend them to be drop in replacements for those who don't want the hassle of carefully monitoring voltage ballance and so forth. Glad you're happy with them and hopefully they give you good service, there seems to be many suppliers in China with similar configurations, been looking around for future consideration, seems lithium is the logical progression, but I'm more inclined to go the prysmatic cell route. One distinct advantage is lithium are less sensitive to temperatures above 25°C than L.A., where my batteries spend most of their time, they also don't need watering,  discharge range is another distinct advantage.
  • Re: Absorption cycle from grid

    Could you describe your system in more detail, as I'm reading grid and AC pass through in an off grid section. Is the reference to 25.8 amps actually voltage? Without details is a guessing game. Is this a grid tied battery backup system? 
  • Re: Puerto Rico's governor says 'let's talk' after Elon Musk says Tesla can rebuild the island's grid

    Batteries have a limited life expectancy, so like a drug dealer, get them hooked, creating a market for what it is you have to sell, good from a marketing point perspective , but seriously 3.41 million people on an off grid system is unrealistic. Of course with government incentives, tax right offs, for expenses disguised as charity, the honest tax payer will foot most of the bill, but won't benifit on the profit from  replacement batteries later down the road, even if the whole scheme were possible.
    edit.  The Australian project claims to  supply power to 30 000 homes, but read the fine print....30 000 homes for an hour during a sag in the grids ability to support the load, meanwhile the grid would be working at full capacity, things are not always what they appear.