Solar Panel for Scoreboard - Contractor Talk - Professional Construction and Remodeling Forum

Mitch M · 10-25-2009, 07:48 AM

I have a client who wants me to move a scoreboard from top of the field house to the deep left field. Power is presently available at the field house but it is not available where they want to move it. It has been suggested to use a solar panel. The board only draws .6 amps and the actual use is wireless.

How can I incorporate a solar panel with this project? What size? The board could be left on for several hours if they have several games. Of course, a backup is that they take a small generator down there and plug it in.

SLSTech · 10-25-2009, 08:22 AM

I can't tell you what size, but can you run the scoreboard off of batteries & an inverter - use the solar to charge the batteries. That would beat the generator & it won't be affected by clouds, bad gasoline, or a game that runs a little late into the evening

Mitch M · 10-25-2009, 12:02 PM

I figured that was the case. What size do you recommend? Northern has some for 7 watts right on up. I have attached picture of the scoreboard as well as the details.

SLSTech · 10-25-2009, 12:54 PM

Sorry, but I just don't know - a trickle charger for the battery may be enough - depending on the batteries, use, etc...

The amps to watts calculation is a 75 watt panel, but they rarely deliver that much power & might need to be doubled - hopefully someone that deals with Solar Power will stop by shortly

Static Design · 01-22-2010, 10:10 PM

You can build your own panels, they normally put out .5 V or 1.7watts per 3"x6" solar cell. Build your panel to whatever demand you need or build 2 of them, I would just use a battery bank with an inverter if the thing is only pulling 72 watts during operation.

griz · 01-22-2010, 11:21 PM

Call Electro Mech & ask them about a solution. They are a very reputable company and will probably be more than willing to help.

saveonsolar · 01-23-2010, 05:50 AM

Static,
you ever tied making a solar panel?
a lot harder than you think..
why even input that comment.
just say i know nothing.

OK
Now you need to find out what your load is.
I saw that slstech suggested a trickle charge to a battery,
maybe change the lights to DC,
That might be the answer

Static Design · 01-23-2010, 10:29 AM

Quote:

Originally Posted by saveonsolar

Static,
you ever tied making a solar panel?
a lot harder than you think..
why even input that comment.
just say i know nothing.

OK
Now you need to find out what your load is.
I saw that slstech suggested a trickle charge to a battery,
maybe change the lights to DC,
That might be the answer

A monkey can solder with tabbing wire and bus wire. It's not that hard, I can actually do more complicated things such as ecu and tv repair also.

But that's enough about me, the guy already knows his load look at his pic. He would need something greater then 72 watts, you should never question my ability until I give you a reason.

saveonsolar · 01-24-2010, 02:33 AM

wow,
Ok Now i am impressed...
OK what was i thinking.
OK thats right, your average Joe can put together a working module.
common

dextercath96 · 01-24-2010, 09:08 PM

Nice Solar Panel on Dashboard. I like it. Why don't you try Solar Power Generator on dashboard?

naptown CR · 01-24-2010, 09:31 PM

Just a little background
This is what I do for a living although mostly grid tied.
The unit is obviously used for baseball.
Is the field used for night games?
How often is the field used Weekends, daily?
The sign is in use for an average of how many hours a day during daylight hours?
The sign uses .6 amps at 120 volts
that equals 72 watts per hour
You will need a minimum of a 100 watt inverter. Xantrex makes reasonably good ones. This will both convert the battery to AC but will control charge on the battery.
A 100 AH deep cycle battery at 12 volts will provide about 600 watts per discharge ( You want to limit discharge to no more than 50% to extend batery life.)
The inverter will eat about 10% of the available power in losses.
That leaves you with 540 watt hours or 9 hours of sign use per charge.
If you add a solar panel and charge controller I would add no more than 75 watts of solar panel. this should provide more than enough for daily use of the sign.

Static Design · 01-27-2010, 02:43 PM

This is for saveonsolar

Sco · 01-27-2010, 03:11 PM

Question..Do I understand that that the data from the scoring booth to the board is done wireless. The scoreboard was previously mounted close to the scoring both so I'm sure it transmitted information just fine. Is the scoreboard designed to transmit across the field? If it wont transmit information that far all this solar talk may be for no reason if a conduit has to be installed to carry data to the scoreboard. I don't have an opinion, just food for thought.

dextercath96 · 01-31-2010, 09:27 PM

I also want to contribute a solar power generator for your scoreboard. Can you help me in building up a solar power generator? Your comments and suggestions are much appreciated.Thank you.

newenergy · 02-02-2010, 03:57 PM

Quote:

Originally Posted by naptown CR

Just a little background
This is what I do for a living although mostly grid tied.
The unit is obviously used for baseball.
Is the field used for night games?
How often is the field used Weekends, daily?
The sign is in use for an average of how many hours a day during daylight hours?
The sign uses .6 amps at 120 volts
that equals 72 watts per hour
You will need a minimum of a 100 watt inverter. Xantrex makes reasonably good ones. This will both convert the battery to AC but will control charge on the battery.
A 100 AH deep cycle battery at 12 volts will provide about 600 watts per discharge ( You want to limit discharge to no more than 50% to extend batery life.)
The inverter will eat about 10% of the available power in losses.
That leaves you with 540 watt hours or 9 hours of sign use per charge.
If you add a solar panel and charge controller I would add no more than 75 watts of solar panel. this should provide more than enough for daily use of the sign.

If he's going to possibly need 600 watt-hours of energy from the battery for one day's use (could be on for several hours), and if it might be used the next day he'll need to generate those 600 watt-hours that day to charge the battery or something close to it.

When is the system used? If it's the summer only, you'll be getting a lot more sun, but in the winter you might only get 3 solar hours or so in NC. So in that case you'd need 200 watts of solar to get 600 watt-hours of energy during that day.

Might not be sunny that day though, so you really might want to double the amount of battery so that you have longer to charge and maybe go with 300 watts of solar as well, so it charges better when it's cloudy.

Or, maybe you only use the field in the summer and the weather is usually good, and a generator is feasible. In that case a smaller system might be fine, but I'd still have at least a 300 watt inverter or so, so that you can add to it later if you need to.

Sco · 02-02-2010, 05:42 PM

I have read all these post and I am a little amazed that another electrician hasn't chimed in. All these parts and pieces and inverters and generators, sheesh, I'm suprised that someone hasn't come up with the hourly fuel consumption of a honda 5 hp 1500kw generator so you know how much gas the client needs to bring to the baseball field. While I believe that solar has its place to me this isn't one of those places. Mitch you are a general contractor who I'm sure knows an electrical contractor who would love to have this job. Give him a call and sell this client some pipe and wire. The client will end up with a far more reliable product and you and the electrician will make some money. My problem with the solar here is that there is no line voltage to back up the scoreboard if the solar system quits working because of one of the many components have failed. I know that I wouldnt want to get a call on a cloudy saturday morning or on a tuesday night with the client telling me that all the scoreboard just went out. I am an electrical contractor so obviously I am slightly biased but I do know that pipe and wire is a tried and true technology and that simpler is better, there are no moving parts to crap out in the middle of the 4th inning. (I guess we could bring out the generator but theres no gas in the gas can...lol)

newenergy · 02-02-2010, 08:32 PM

There are no moving parts for the solar either. It's reliable enough for a lot of sensitive and important uses. In this case the only question is how much bad weather you are willing to plan for. If the scoreboard is important enough you can install a solar system that will be as reliable as grid power.

naptown CR · 02-02-2010, 08:48 PM

Quote:

Originally Posted by newenergy

If he's going to possibly need 600 watt-hours of energy from the battery for one day's use (could be on for several hours), and if it might be used the next day he'll need to generate those 600 watt-hours that day to charge the battery or something close to it.

When is the system used? If it's the summer only, you'll be getting a lot more sun, but in the winter you might only get 3 solar hours or so in NC. So in that case you'd need 200 watts of solar to get 600 watt-hours of energy during that day.

Might not be sunny that day though, so you really might want to double the amount of battery so that you have longer to charge and maybe go with 300 watts of solar as well, so it charges better when it's cloudy.

Or, maybe you only use the field in the summer and the weather is usually good, and a generator is feasible. In that case a smaller system might be fine, but I'd still have at least a 300 watt inverter or so, so that you can add to it later if you need to.

take another look at the scoreboard
It is a baseball scoreboard so will only be used during the spring and summer probably for little league.
A larger inverter will only create more losses in the inverter and lead to more battery drain.
The reality is if there are 2 games a day at three hours each and the sign is fully lit up ( ratings plates are usually stated at maximum draw) this is only 432 watts + 10% for inverter losses = 477 watts. the battery in my example was rated for 100 Amp hours. I speced it for a 50% discharge which is how I came up with the 600 watts. There is still battery left after the 600 watts. Even on a cloudy day the panel will produce some power even though it will not be at full power. Remember Baseball is usually not played in the rain.

newenergy · 02-02-2010, 09:34 PM

Yeah, I put in some caveats 'cause it might have just been summer baseball, but maybe they play late fall/early spring too and long overcast/cloudy days as well. But, like I was saying it also depends on how important it is and whether you can back it up if necessary. Maybe somewhere in the middle, but a 300W inverter is still pretty small and I think I'd go for that an allow the possibility of adding another module/battery later if necessary.

protechplumbing · 02-04-2010, 11:53 PM

It's not a can it be done thing, it's a how much are you willing to spend thing.

To build something as reliable as grid power would cost $1500-$2000 just in materials.