Directly using PV panel (without batteries/inverter)

[lkruper]

I received my 200w solar kit today. Just for experimenting. I can't afford batteries now. I might try connecting the panel/s directly to a dc water heater element, set in a metal 5 gal bucket full of water. Just have to find the correct heating element for my system. Doing this just for residual heat. Getting cold here and I don't have the energy to build a big can collector system. My little one pumps out good heat at 120f. Not enough. Do you have any recommendations on a cheap battery? Maybe a 12v 150ah. I've researched and can't afford it right now. there was an old ups from work i was going to play with but that is gone now. When it stops raining here I have to trim 3 silver maples that block a lot of sun.

UPS batteries are not designed for cycling, but if free perhaps worth it for experimentation. I recently tried to survey a lot of batteries for cents / kWh and Costco 6v batteries came out at about 11 cents / kWH but you would need two of them at $84 each + 15 core to get to 12 v and that would be 207AH. The Costco Marine battery would be less expensive for $79 plus $15 core but that would be only 70 AH. That is, if, your Costco has the same Interstate flooded lead acids that mine do. Not as good as Trojan, but much less expensive for learning on.

[SunEagle]

I received my 200w solar kit today. Just for experimenting. I can't afford batteries now. I might try connecting the panel/s directly to a dc water heater element, set in a metal 5 gal bucket full of water. Just have to find the correct heating element for my system. Doing this just for residual heat. Getting cold here and I don't have the energy to build a big can collector system. My little one pumps out good heat at 120f. Not enough. Do you have any recommendations on a cheap battery? Maybe a 12v 150ah. I've researched and can't afford it right now. there was an old ups from work i was going to play with but that is gone now. When it stops raining here I have to trim 3 silver maples that block a lot of sun.

I am not sure what you are trying to accomplish with solar. If you can't afford batteries and the amount of sunlight is limited due to trees and rain why would you spend anything on solar panels?

Also using solar to power a heating element is pretty much a waste of time and money.

So what are your plans for solar?

[gfry2267]

I received my 200w solar kit today. Just for experimenting. I can't afford batteries now. I might try connecting the panel/s directly to a dc water heater element, set in a metal 5 gal bucket full of water. Just have to find the correct heating element for my system. Doing this just for residual heat. Getting cold here and I don't have the energy to build a big can collector system. My little one pumps out good heat at 120f. Not enough. Do you have any recommendations on a cheap battery? Maybe a 12v 150ah. I've researched and can't afford it right now. there was an old ups from work i was going to play with but that is gone now. When it stops raining here I have to trim 3 silver maples that block a lot of sun.

[SunEagle]

Hey guys,
i want to know if can can directly hook up some load (like LED) to PV panels directly, (Of course voltage/power ratings are almost equal).
ie- no intermediate device connected .. wires from PV panels connected across LED strip (12V).
Will it work ? if so what about stability?


honestly speaking i'm quite new to practical solar applications. but detailed electronic explanations are welcome.
Also please do suggest some books/sources to deeply understand PV panels output,

You may already understand the issue. Due to the way a pv panel generates power it is due to the "lack" of stability that makes it unwise to just wire one directly to a dc load.

Not only are you fighting the issue of a voltage the panel generates being higher compared to what load 12v DC load is expecting, but the panel amp output will change as the sunlight hitting the panel changes.

To combat the voltage difference you need to install a device to regulate the voltage to the load. But you still do not have a guarantee the panel will produce enough power to keep the load working.

While batteries are expensive IMO they are a better investment to provide a stable voltage and amp source to safely run a DC load. The only place I might wire a small wattage panel directly to a load would be to use the panel as a trickle charger for a battery.

There is a "Solar for Dummies" book that can be downloaded for free. That book might provide some more details on how a pv panel works and what are the best path to use them.

[TyrionLannister]

Hey guys,
i want to know if can can directly hook up some load (like LED) to PV panels directly, (Of course voltage/power ratings are almost equal).
ie- no intermediate device connected .. wires from PV panels connected across LED strip (12V).
Will it work ? if so what about stability?


honestly speaking i'm quite new to practical solar applications. but detailed electronic explanations are welcome.
Also please do suggest some books/sources to deeply understand PV panels output,