Solar Lighting in Shed

[scottydel]

HI,

What are the basic requirements I need to install solar lighting in my shed, maybe a radio as well? I will probably use this light with the radio an average of one hour a day (that's probably on the high end). I could possibly want to charge a cell phone as well.

Solar Panels
Controller Box
Batteries
Outlets? (not necessary but might be nice)
Inverter?

If anyone has any recommendations (books or kits) on getting started, much appreciated. I am an electrical engineering school drop out, the link between Amps, Watts, current, totally eludes me. Speak in simple terms if you can

Thanks,

Scott

[SunEagle]

Hello scottydel and welcome to Solar Panel Talk

I am sure some of the members would be happy to help you but first you have to determine what do you really want.

In your first sentence you went from just a light (wattage unknown) and radio (also wattage unknown) to be used for an hour. Then you added charging a cell phone (again wattage unknown). Followed by that you mentioned Outlets for what other appliances?

So coming back to you. What is your expected daily watt hour usage and approximately where do you live. From that information a solar/battery system can be sized. Otherwise I will say the first, second and maybe the third design will not be large enough for what you really want to power. So help us help you. Thanks

[Logan5]

I assume you want a nice bright work lamp over a bench. I generally use two E-26 90deg. 12v 9 watt LED bulbs in a ceramic T-post fixture, one 2200K and the other 5500K plus With seperate dimmers the mix gives the perfect Light color for all of my projects and hobbies. so that's 18 watts and I have a radiator fan for ventilation wile soldering let's say it's 20 watts. so that's 38 watts. So you run these devices for one hour and your watt hours is 38. I would also use a 110 AH lead acid battery to 50% is 55AH = 660 watt hours minus 1 hour of operation leaves plenty to spare for multipliable days of clouds. In the past I have used florescent tubes with special 12 or 24 volt ballast. If you keep everything close together you can keep it simple w/o any need for an inverter.

[scottydel]

Thanks for the feedback. Wattage unknown is right. I honestly don't know. I would say a light bright enough to illuminate a workbench after sunset, as Logan5 suggested. The radio would be small, nothing too powerful, a radio about the size of an NFL football. The cell phone would be a standard (?) cell phone charger. The outlets would be for the light, radio and charger, no new appliances in mind.

I live in Ohio, so not exactly a solar mecca but I'm not looking for a ton of use either, I don't think.

I'll take some guesses, but I'm really just guessing here, any help appreciated.

Lighting - 20 watts
Radio - 30 watts (I'm just assuming a radio has more pull than LED or fluorescent bulbs)
Charger - 10 watts (again just assuming this is lower than lighting)

In my experience (software) estimates are usually doubled to be safe. So I might need 120 watt hours a day? Does that sound right for minor use in a shed? Assuming 120 is the number, tell me what system and devices you think would suffice.

Logan5, why no inverter if everything is close together? Remember I'm an electrical engineer dropout so simple terms!

[Logan5]

in my case batteries are under my bench, light is on the bench and the fan pulls air under back of bench and outside. all are DC native devices and no inverter is needed. Inverters are inefficient. If you need occasional AC power get a small bench top inverter maybe 150 to 300 watts. However if you shop around you may find your needed devices in a DC version. In my case I use a 12v solder iron, but still sometimes need an AC powered solder gun.

[PNjunction]

You don't need solar at all.

Given your requirements, just pick up your common jumpstarter with a radio built in. There are quite a few different brands. Heed their charging instructions in the manual, which most consumers disregard and wonder why they either fried the box, or sulfated it with undercharging. Get a new one, not some crusty old one where people have played around with it.

Most come with "msw" inverters, which are fine for ac-led driven lighting, which you can get at the grocery store now.

Consider a GE or Osram type typical 100 watt "equivalent" led bulb (soft white or daylight - your choice) running 15 watts. How long could you run that light from the inverter from the typical 18ah internal agm battery before reaching 50% DOD?

9ah / 1.5a = 6 hours. Way more than you require, and plenty enough for cellphone charging. Modern units tend to have usb ports that are higher powered than in years past (like 2A usb ports vs the old 500ma ports, which may not work with your phone nicely)

Ideally, once could piece this all together from the best of componentry, but at this level, the cost and convenience make it a commodity item you'll probably like for your needs.

[LucMan]

Here's what I use for lighting in my barn.
2-40 watt 115v florescent lighting fixtures
1-60 watt drop light
1-Cobra 400 watt inverter with 5v usb and 2-115v ac outlets
1- 100 watt 12v solar panel
1-Morningstar 12v x 4.5 amp Sun Guard charge controller
1-old car battery
In use for 6-7 years on 2 old reject batteries, supplying light for 30 minutes or more. Plus 24/7 12v power to my wireless security camera.
If you use LED lighting and a good deep cycle battery you should have no problems with lighting for a couple of hours before the inverter kicks out on low voltage.

[PNjunction]

If you use LED lighting and a good deep cycle battery you should have no problems with lighting for a couple of hours before the inverter kicks out on low voltage.

Just be careful with that statement - relying on the inverter to kick out on low voltage with a good deep cycle battery is a recipe for turning it into one of your rejects pretty quickly - since at the relatively low currents we use for lighting, the dead-man lvd kickout is 100% DOD for the most part.

Far better when starting new is to calculate / measure your power draw over time, and make sure it doesn't exceed 50% DOD, or even better, less.