400 Watt Solar enough?

[SJ-Chris]

Originally Posted by crb478

Now I plan to have a TV installed that will be watched about 8 or so hours a week during football season, some LED lights that will run about 4 hours a day, and two boats with 3 12 volt batteries total that will have a trickle charge applied when they are parked.

The requirement for this above is VERY SMALL. (Primarily/mostly(?) TV watching during the day when most football games are played).


Keep in mind: The typical usage for this scenario will have a STARTING point of any 12v batteries fully charge including the ones in the two boats. When the OP goes down to watch TV during the day, 200w of solar should be more than enough to run the TV and keep the 12v batteries 100% charged. So during the daylight, he will effectively be drawing 0AH from his batteries and 200w of solar panels will be providing all of his power needs through his charge controller.


If he's watching a night game, the TV and lights will finally start drawing from his 12v batteries probably at 4-10 amps depending. 4 hours of nighttime TV/lights will use 16-40AH from his battery bank. Two 6v GC batteries will give him 210AH total capacity which would be enough to sustain several/many days in a row without ANY charging (But that doesn't seem to be how he will use it, and he mentioned lots and lots of sunshine).


Summary:

- The minimum you could likely get away with is one 12v Marine/RV deep cycle battery and 100w of solar. Probably would be enough.

- A very comfortable system that would give you a lot of additional capacity/buffer would be two 6v GC batteries and 200w of solar.
- Adding batteries (more capacity) in the future is simple, but you won't likely need to. Adding solar in parallel (more capacity) in the future is simple (as long as your charge controller can handle additional amps), but you won't likely need to.


Warning....solar is addictive.



Enjoy!
Chris

[hclarkx]

I'd need to know more. Some football fans want a 50" or larger screen. I don't do football, but if I did I'd probably move my 55" Plasma down to my man cave and buy new for the bricks. It supposedly takes 400W though I've never measured it. Hopefully the OP is using a smaller and more efficient (newer).

How long does a football game last? Three hours?

When is the football season. IIRC it's in fall/winter. Solar production in winter in Denver is almost exactly half what it is in summer.

The op mentioned a 1500W inverter. That worries me a bit. Could portend considerable energy usage ..... which often grows over time.

As I mentioned before, inclement weather ride-through might be important to the OP. Though maybe not, maybe he can charge all week and use the energy only on the Saturday game day? That makes battery capacity more important than solar capacity.

A Denver 400W array at 20 degree slope and 20 degrees off of dead south will average 122 Watthours per day in December. I'm not sure what 6 on 12 slope means. If that is 6" over 12 feet, that's way less than 20 degrees slope and less than 122 Wh per day average (a higher angle is better in winter). In fact a 10 degree slope will produce 20% less than a 20 degree slope in December in Denver.

Take the effect of LA charge profile and losses into account, and about 40% of that 122 Watthours is either not usable or goes up in heat rather than reaching the load. That means about 72 Watthours of usable per day energy.

We definitely need more information. And it's definitely best to leave room for expansion!!

[crb478]

Originally Posted by hclarkx

I'd need to know more. Some football fans want a 50" or larger screen. I don't do football, but if I did I'd probably move my 55" Plasma down to my man cave and buy new for the bricks. It supposedly takes 400W though I've never measured it. Hopefully the OP is using a smaller and more efficient (newer).

How long does a football game last? Three hours?

When is the football season. IIRC it's in fall/winter. Solar production in winter in Denver is almost exactly half what it is in summer.

The op mentioned a 1500W inverter. That worries me a bit. Could portend considerable energy usage ..... which often grows over time.

As I mentioned before, inclement weather ride-through might be important to the OP. Though maybe not, maybe he can charge all week and use the energy only on the Saturday game day? That makes battery capacity more important than solar capacity.

A Denver 400W array at 20 degree slope and 20 degrees off of dead south will average 122 Watthours per day in December. I'm not sure what 6 on 12 slope means. If that is 6" over 12 feet, that's way less than 20 degrees slope and less than 122 Wh per day average (a higher angle is better in winter). In fact a 10 degree slope will produce 20% less than a 20 degree slope in December in Denver.

Take the effect of LA charge profile and losses into account, and about 40% of that 122 Watthours is either not usable or goes up in heat rather than reaching the load. That means about 72 Watthours of usable per day energy.

We definitely need more information. And it's definitely best to leave room for expansion!!

OK figure no bigger than a 50 inch TV, probably a 40 or 32 inch as I have limited room on the fingers, but can mount it over the center area where the boat will live. Figure 4 hours for most games, and mostly sunny warm days in the Fall or early winter. I can watch inside during not so nice weather. This is also Denver NC, not Colorado.
The 1500 watt inverter is just to have the power to keep up with everything and expand.
A 6/12 pitch rises 6 inches for every 12 inches it moves horizontally. I will probably also make the mount longer on one side so I actually face due south, but will keep it on the 6/12 pitch for the tilt.

This will have 5 to 6 days to charge usually, and then I will watch a game in the nicer weather. If it is getting rainy or cold, well its just 100 yards away to my house. Just trying to spend more time outside watching the games that I will be watching anyway.

Thanks everyone for all your insight.

[hclarkx]

Originally Posted by crb478

OK figure no bigger than a 50 inch TV, probably a 40 or 32 inch as I have limited room on the fingers, but can mount it over the center area where the boat will live. Figure 4 hours for most games, and mostly sunny warm days in the Fall or early winter. I can watch inside during not so nice weather. This is also Denver NC, not Colorado.
The 1500 watt inverter is just to have the power to keep up with everything and expand.
A 6/12 pitch rises 6 inches for every 12 inches it moves horizontally. I will probably also make the mount longer on one side so I actually face due south, but will keep it on the 6/12 pitch for the tilt.

This will have 5 to 6 days to charge usually, and then I will watch a game in the nicer weather. If it is getting rainy or cold, well its just 100 yards away to my house. Just trying to spend more time outside watching the games that I will be watching anyway.

Thanks everyone for all your insight.

Cool. So a 30 degree pitch in Denver NC. The results from PVWatts are in the table below. NOTE that I went bonkers with a number from the wrong column when I came up with 120 Wh. I was rushing to get out the door. See the right column below for the right answer. About 39 kWh per month in December .... or about 1.25 kWh per day from 400 Watts facing south at a 30 degree angle. That makes more sense. And, that's in December, the least sunny month of the year in Denver, NC.

According to this web site a 50" modern TV will take around 100 Watts more or less. https://screentvx.com/how-much-power...ch-led-tv-use/

So maybe 300 Watthours plus 15% for the inverter ...... 350 Watthours. That's about 28 Ah using 12.3 volts. Roughly a quarter of the capacity of even a smallish pair of 6V LA batteries.

And with an average 1.25 kWh per day, it will take a very rainy week to not get the battery back to 100% between weekends.

Long story short, those that said 400W will be fine were correct. !!

[crb478]

I know this is old, but for a follow up.

I installed 400 watts of solar panels with a 40 amp charge controller, and a 1000 watt continuous 2000 watt surge pure sine wave inverter. I have 6 - 12 volt led lights under the roof, and two more 12 volt led lights in the eves shinning down on the water. I also have two 235 amp hour 6 volt batteries. I wired in four 120 volt outlets, and installed a 32 inch Hiesence Roku tv that was given to me. I have a Center console boat with a built in charger that charger 2 - 12 volt batteries, and a Pontoon that used a trickle charger for a single 12 volt battery.
I also have a 110 volt 15 amp water pump wire in and a 110 volt air pump that was used to raise a boat lift, but now blows up lake flotation toys.

The results! The 400 watts of solar, 1000 watt inverter, and 2 6 volt batteries will easily power the TV and charge both boat batteries. They will run the air pump, but not well. The 1000 watt inverter will not run the water pump at all.

So since it is already on two separate circuits I have ordered a cheap 5000 watt modified sine wave inverter for the water pump and the air pump which are both on that circuit. I plan to piggy back it with the pure sine wave inverter and turn it on only when I need water or air.

I would like to thanks everyone that offered me advise on how to get this set up. It works great, I can leave the lights on all night with little battery drainage , and keeping the boat batteries fully charged is not a issue. The TV draws at most 20 watts , and often it uses 0 watts since the sun provides enough energy to power the TV. This has given me another room to enjoy! Total cost was about 700 dollars which was cheaper than trenching in wire form the house 100 yards down to the lake.