Portable Tailgating Solar System - newbie questions

[sunthas]

I'm looking to get started in solar and I came up with a project I thought would be fun and also provide some value.

I'd like to start with simple parameters and then build from there.

I want to power a TV and a satellite box. Since I'll be using this for tailgating at football games and all the games are at Noon (for simplicity) I don't need battery power or any other system. Assume I always park in the sun too.

Solar Panel (I'm thinking 300W) - no greater than 8'x4' in size.
power inverter - I'm sure I could find a way to rig my satellite box and TV for DC since this is what they likely use internally, but for simplicity I figure start with the power inverter, plus if I've got watts to spare I can plug in cell phone chargers or whatever.

Which panel and inverter should I buy and what is the best place to buy them from.

thanks in advance for the help.

[Sunking]

Got bad news for you. Batteries are required, no way around it. If you did this would just be for show as the solar is not needed, all you need is a properly sized battery that can be charged by the vehicle. A 300 watt panel requires a 120 pound battery which is more than required to do what you want. All you need is a good AHM 12 volt battery like an Optima Yellow Top and an inverter. You can charge it at home, or use a Battery Isolator and charge it from the vehicle alternator while you are driving. A Yellow Top will last many hours, all day with no problem between charges.

If you want you can put up a Faux Panel with some wires going somewhere to impress people, but it has no purpose.

[sunthas]

Got bad news for you. Batteries are required, no way around it. If you did this would just be for show as the solar is not needed, all you need is a properly sized battery that can be charged by the vehicle. A 300 watt panel requires a 120 pound battery which is more than required to do what you want. All you need is a good AHM 12 volt battery like an Optima Yellow Top and an inverter. You can charge it at home, or use a Battery Isolator and charge it from the vehicle alternator while you are driving. A Yellow Top will last many hours, all day with no problem between charges.

If you want you can put up a Faux Panel with some wires going somewhere to impress people, but it has no purpose.

Thanks for the input. Can you clarify (or point me in the right direction) of why a battery is required? I like the idea of doing it without a solar panel, even though that doesn't lead the direction I want, but I'm missing a key piece of knowledge (obviously).

[SunEagle]

Thanks for the input. Can you clarify (or point me in the right direction) of why a battery is required? I like the idea of doing it without a solar panel, even though that doesn't lead the direction I want, but I'm missing a key piece of knowledge (obviously).

The simple answer is that the equipment you want to power requires consistent amount of electricity. The output from a solar panel is not consistent and will usually fall below the require voltage your equipment needs to run. Using a battery to run that equipment will give you consistent power.

If you want to add a solar panel you will just be spending a lot of money for no really good reason. It will cost you much less to recharge your battery from either a charger plugged into your house receptacle or from the power of your vehicle alternator.

[sunthas]

The simple answer is that the equipment you want to power requires consistent amount of electricity. The output from a solar panel is not consistent and will usually fall below the require voltage your equipment needs to run. Using a battery to run that equipment will give you consistent power.

If you want to add a solar panel you will just be spending a lot of money for no really good reason. It will cost you much less to recharge your battery from either a charger plugged into your house receptacle or from the power of your vehicle alternator.

thanks, so in order for this to make sense we'd have to change the parameters.

Longer term I was thinking that it would be great to have an emergency system powered by solar to use (instead of generators) in case the grid went down like after Hurricane Sandy. But it sounds like such a system would require batteries to really function and that kind of changes the usefulness of an emergency system if you have to have a bank of batteries just to make sure you can keep your food from spoiling.

[SunEagle]

thanks, so in order for this to make sense we'd have to change the parameters.

Longer term I was thinking that it would be great to have an emergency system powered by solar to use (instead of generators) in case the grid went down like after Hurricane Sandy. But it sounds like such a system would require batteries to really function and that kind of changes the usefulness of an emergency system if you have to have a bank of batteries just to make sure you can keep your food from spoiling.

If you only want to keep a small refrigerator running during a power outage then you can build yourself a solar emergency power system. It still will require solar panels, battery chargers, batteries and an inverter to convert the battery DC voltage to AC to run your frig.

Just try to keep the electrical load small and not a big 20 cubic foot cooler because that requires a whole lot of batteries.

But you still have to understand that it will be much cheaper to have a gasoline, propane or diesel generator as the emergency backup then solar. The cost to own and maintain your batteries would pay for a very large propane generator and a 100 gallon tank. Best bang for your buck.

[Sunking]

Thanks for the input. Can you clarify (or point me in the right direction) of why a battery is required? I like the idea of doing it without a solar panel, even though that doesn't lead the direction I want, but I'm missing a key piece of knowledge (obviously).

Technical answer is a solar panel is a current source, an dnot a voltage source like a battery which the inverter needs.