110v to 12v conversion questions

Who told you that. Grid tied systems work between 300 to 600 volts DC. Very small battery systems can be 12 volts DC, but that is pretty much for toys and RV's. Any serious application is going to be 24 and 48 volt battery using an inverter to convert to 240/120 Volts AC.

Hi Jon and Welcome to Solar Panel Talk

I think that you will find the number of 12 volt items are diminishing and mostly reside in the RV & automobile equipment users.

Lately more and more electronics (cell phones, iPads, cameras) run and charge using a USB connection or 5v power supply. Even the cell phone charging cable used in a car plugs into the 12 volt outlet but generates 5 volts going to the phone.

What might be an energy savings is not having to invert from the DC voltage generated by a solar panel to run an AC voltage device. You can store that DC energy in a high voltage system and easily convert it to a lower DC voltage to meet the need of the electronic device.

@ Sunking:
48v sounds familiar, I must have forgotten or misunderstood what was being explained to me at the time. Mostly what I remembered was something along the lines of using 12v LED lighting as opposed to converting to 110v to use LED lightbulbs that fit into conventional sockets.
This led me to wonder what else I could power in a similar fashion to avoid having to convert. I'm not sure on the specifics of the energy loss due to conversion, but I figured it was worth looking into.
This system will not be grid tied.

@Suneagle:
Could you describe the high voltage system to me in more detail, or point me to resources so I can study it further? My knowledge of electronic systems is fairly limited at this point, but I'm trying learn as much as I can.

What is your application. Your application dictates what you use.

What I am trying to do is prevent you from making a huge mistake we see a lot here. People taking there homes off grid and trying to use 12 volt battery systems to power Kw sized inverters to run home items and appliances at 120 volts. Those fools are throwing away a lot of money and taking extreme risk of burning their homes to the ground. Don't join that crowd.

You charge a 48volt battery system and then use a DC to DC converter to lower the 48v to the specific DC voltage to run your electronics. This eliminates the DC to AC to DC middle man.

But before you go out and build a 48volt battery system you really need to know how many watt hours you will be using a day to run your electronics. Once you know that you can start designing the battery system and pv panel wattage to charge it.

@Sunking and Suneagle:
I'm going to discuss in greater detail the equipment available to me as well as research the types of electronics expected to be used this weekend. I will get back to you both with more information then.
I'm turning a 16'x20' storage barn into an art studio. My step-dad is well versed in electronics and has done quite a bit of work setting up a PV system for his RV. I'll be using some equipment he purchased for his home, but due to beuracratic complications in setting up a grid-tied PV system where he lives, he would rather I use them for this project rather than sell them or hold onto them indefinitely.
I will have 10 PV panels at my disposal, though they are in two sets. A group of 6 that are the same and a group of 4 that are the same. Unfortunately the two sets seem to be incompatible, so we are looking into working around that. I'll have access to a 5500 watt inverter.
I would like to be able to have lights, a TV and a computer, (probably a laptop) as well as small A/c unit and a small fridge. Likely a microwave or something as well.
I'll have more specific information soon.

Thank you,
Jon

Most of those loads are AC and will require a DC to AC inverter. When you determine what those loads take to run in Watts and how many hours a day each will run will be the begining of determining the battery system you will need. When you get more information on those solar panels let us know what their nameplate information is such as: wattage, Vmp, Voc, Imp and Isc. That will help determine which (if any) can be used for your system.

Last little bit of information. Building any type of solar battery off grid system will cost 5 to 10 times to generate a kWh as compared to purchasing it from your utility. So if that 16x20 shed can get utility power then that would be the less expensive way to go.

I have 6 Evergreen 195W panels


4 Evergreen 115w panels
And a Trace Engineering SW5548 inverter.

We are currently trying to cut the inverter out of te equation by using DC only devices and appliances, and the only thing we haven't figured out how to convert is my TV. It's a Vizio P502ui-b1e.
I'm pretty sure it has a transformer, but it seems to be integrated into one of the TV's boards and I don't know if we can bypass it. If anyone knows of a way to do that, it would be awesome.

We don't use too much power in the place.
Strips of LED lighting. Not sure how much we'll use just yet.
TV at 153w
Mini PC at 65w
Small stereo system at 10w
Laptop at 45w
The big ones will be a fridge, microwave and (hopefully) an A/C system (San Antonio is hot 9 months out of the year.)
Been looking into those things and all are available in DC, but I haven't made a choice just yet. If anyone has advice in those areas it would be greatly appreciated.

I'm also pretty sure we are going to need more panels, if we are ever going to power an A/C.

The shed cannot be hooked up to a utility pole.
Any advice on what we should do would be helpful.

I see a couple issues.

First I am not sure how easy it will be to use both those 195watt panels and 115watt panels since they will probably have very different Vmp ratings.

Next before we can size your battery system you need to determine how many hours a day each of those loads will be running, such as LED xx watts for 6 hours, TV @ 153watts for 4 hours, etc. Once you have those figures you add them all up to estimate your daily watt hour usage. I will tell you the items like the fridge, microwave and A/C system are usually rated very high wattage and even if you use them for a short period it will require you to build a very large battery system.

I think I mentioned in the initial post that the two types of solar panels were not compatible with each other. We were thinking of setting up two systems, essentially running the lighting off of the 4 smaller panels, and then setting up the rest on the other panels.
I'll try to work out usage and get back to you.