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Consider the following setup:

  • Solar panel (0.5 m2 / 12V / 100W)
  • Solar inverter (12 volts DC → 120 volts AC)
  • LED TV (32" / 55 watts)
  • no batteries / no grid-tie

Assume the solar panel is receiving sufficient insolation (positioned in direct sunlight at midday in the summer) would it be possible to turn on and use the TV in this configuration?

What happens in low-sun and no-sun scenarios? If a cloud temporarily passed in front of the sun, would the inverter detect a low voltage scenario and shut itself off? And would it resume working once full sun exposure was regained? (Assume the TV is configured to turn itself back on after a power outage.)

Are any components in this system at risk of getting damaged? It seems like frequent low-power scenarios might be bad for the inverter.


I've been wondering about this for so long and this question inspired me to ask here.

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    You need to make sure the TV is happy to lose power random and will recover. I would not be surprised if it failed unexpectedly from that treatment. If the TV has a DC power brick you would be better off using a DC-DC converter. But you'll be much better off with even a small Lithium battery to cover the brief periods when solatr output fluctuates
    – Móż
    Sep 2 at 22:07
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the short answer to your question is yes, that type of inverter does exist, they are very rare. The Delta model H6 (Thailand) is one example. A battery less grid tie inverter that is also advertised as a backup inverter for power outages, up to its full rated 6kw output, provided the solar array is sized for the load and in direct sun, no clouds. This unit also costs much less than similar sized grid tie units and has a full 1 month warranty, you can derive your own conclusions from that. Most battery less models that had backup capabilities are not on the market long because as your question states,are components in the system at risk of damage? Yes. There are a number of grid tie battery bank models that operate as backup power as well with proven track records. Our Trace (Xantrex now) SW-4024 is one example, it’s been running non stop at our property for over 20 years now.

It’s worth mentioning that a battery bank can be expensive, or cheap. We use 4 Trojan T-105 golf cart batteries for ours, so for a few hundred dollars we have reliable grid tie solar and solar/battery backup. The components never seem to have any trouble going from one mode to another and back again, mainly because the inverter has two fairly solid voltages to anchor to, 24 VDC batteries, and 120 VAC grid to synchronize with. Either one is sufficient, but the batteries are required in either mode, and any available solar power is simply dumped into the homes existing AC wiring. In most cases when our power goes out here, we are not aware of it until a neighbor calls and asks if we have power, because they don’t.

The few batteryless, grid tie/backup power inverters that are available are purely computer generated sine waves driven entirely by the variable output of your array, which accounts for why most companies making them stop making them after a time, or offer short warranty periods. A battery based grid tie “hybrid” unit has a much higher incidence of reliability.

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  • +1. Is this the inverter you're talking about? The ebay description says "We've recently found that this inverter can support up to 6kW of power when used off-grid with no battery bank attached." I'd be highly skeptical of this claim, especially since nothing in the manual indicates this is true.
    – LShaver
    Sep 3 at 2:57
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    Good point, I would be skeptical as well, and no the manual does not mention such a feature. The Sunny Boy 3800 TL-US does provide such a feature, up to 1500 watts with solar only, but for the cost you can get a battery based unit like the Xantrex SW3024, and batteries for less money, then you have full wattage available at night as well. I personally can’t see the point in the batteryless setup from a users standpoint, even a stray passing cloud would shut your loads down momentarily.
    – Rudydoo
    Sep 3 at 8:48

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