The main factor in the amount of power used by the iPad is the screen’s brightness. As I slid from the lowest to highest settings the meter would move from 1.8 watts to 5+ watts. So if you’re looking to extend your battery life the brightness is going to be the biggest factor. You can plan on the battery lasting much longer at night or in a dark room that you would using it outdoors (although the iPad’s glare is just awful outdoors so I don’t see many people doing that).

Processing seems to be a much bigger deal on the iPod as it has a much smaller screen (so it’s not as big of a factor) and a much smaller battery so the one or two watts more for heavy processing really takes a toll on an iPod where it’s not a big deal really for the iPad.

So how much power does an iPad use?

Seven watts is probably the most your iPad is ever going to consume (although I’d like to see an app that will challenge that). If you’re wanting to preserve battery you’ll just need to turn down the brightness. You could turn of things like Wi-Fi & Bluetooth but from my tests these only moved the meter 1 to 2 watts which is a big deal if you have them of for 8 hours, but if you’re trying to save a little so you turn them off for a half hour you’re not really going to be making a big difference in battery life.

There is good reason to be prepared. Disasters do happen, but the fact is with companies like solutions from science out there it’s not true that the more money you spend results in you being more prepared. So when searching for a solar backup system realize that you can save yourself a whole lot of money by buying the individual components. And be aware that there are companies out their looking to scam you to get Rich while making a so-so product.

The purpose of this post is to illustrate how a homemade solar backup compares with the cost of the flagship “solution from science” solar backup from MySolarBackup. The cost for that system is $1,797.00 plus “only” $150.00 Here’s the rough price list for MY SOLAR BACKUP that has the same specs:

To be fair these systems are different. The main loss with the homemade solar backup would be that you wouldn’t have the terribly overpriced all-in-one battery & inverter. You can always go to Walmart and get 2 $8 crates: one to store a battery and the other for your charge controller and inverter. There are better things you can do as well to organize your solar backup, but if you’re looking to go real cheap crates will provide the same amount of energy and functionality from your system. The other difference is that solutions from science provides a 50 ft cord. The one I found was a 12 FT extension cord rather than 50 ft. cord but you can always connect 5 cords together for a price of $145 shipped. Chances are you won’t need more than 12 ft. Not to mention your solar backup system is actually more efficient with shorter connections. You loose a lot more energy with extension cords when you’re dealing with a direct current system.

Battery

The battery is the most important part of your solar backup. I was surprised to see that this system offered only a 51 AH battery. The battery in the solar backup from solutions from science is a SLA (sealed lead acid) battery. SLA’s are the most common in small systems because they have the cheapest upfront cost per AH. You can get a 100+ AH Deep cycle battery from a local store for under $100. So with the money you save you could get 10x the battery storage.

LED Light Strips

First, you’ll need some LED light strips. These aren’t the most efficient LED’s on the market but they’re the cheapest and most convenient we’ve found for cabinet lighting.

Power Supply

LEDs operate on direct current, these specifically operate on 12V DC- the same as your automobile. If you remove the 12V power port from this power supply you’ll have a perfect power supply for your cabinet lighting system.

Dimmer

You may want to adjust the brightness of your cabinet lighting system, especially if you can do it for around $5. You can do it with this dimmer.

A few things to keep in mind

Adding the lights are easy. The LED strips have adhesive on one side that allow them to easily stick to your cabinets. One side of the lights has raw wires that can easily attach to your power supply. The other end has an adapter that easily fits onto most plugin 12v power supplies. You may want shorter strips and you can do that by cutting the lights wherever there are 2 solder tabs. When you attach the lights to your cabinet you’ll want to put put them closer to the front of the cabinet, unlike the photo below.

With the lights closer to the front of the cabinet you’ll be sure that they won’t be visible from a lower line of sight, like when people are sitting down.

The 3 mile trip took 2.25 AH or 95 Watt hours of energy- Just about everything my solar panels generated within a day. So with my current setup commuting to work on solar power isn’t 100% feasible but more like 50% feasible on pure solar power. It works well for me however, because I plug into the wall at work giving allowing me to charge at home using 100% solar power only having only one 50 watt solar panel.

There’s quite a bit to take into consideration when looking at how much energy is use commuting to work on solar power. Your speed has a lot to do with it. Just like any other vehicle, the more you push the limits of your vehicle the more inefficient it becomes.

Here’s a bit of what I learned from my first couple of weeks commuting to work on solar power:
 

What uses energy on my Macbook?

A couple watts for your LED backlit display few more for ports if you’re iPod’s plugged in or your using an external drive, little bit more to keep your hard disk spinning. What really uses the most energy and creates the most heat on your Macbook is the processor. And the amount of energy it uses depends on how much work it’s doing. So just surfing the web, using an external monitor and external drive I sit at about 35 watts (not including the power the external monitor uses). If I put in a movie to rip for my ipod the processor starts working, my fan turns up and I’m at 60 watts.

It’s nice to know what’s you do on your computer to use the most amount of energy. Just like everything else you do in your house, once you know what’s using energy unnecessarily you can start saving.  It’s also important to know that not all computer are created equally. The computer I ran these tests on is an ’08 Macbook pro. If I was to sit and browse the web on my iPad it’s more around 10 watts of energy. If you’d like to know how much a specific computer or device cost you can always buy me one and I’ll test it for you. Or, a cheaper solution, you can always purchase a Kill-A-Watt device on your own! I’d love to hear your findings!

The main selling point for us was that the green slim projector doesn’t use a bulb, but uses an LED laser hybrid light source rated at 20,000 hours. We bought the pk-10 a few years back and it only had an output of 10 lumens. It’s refreshing to have the output of 2,000 lumens.

With the high output came the surprise of high amounts of heat. The laser must push the majority of the light. The fan can be annoying if the movie was silent but we typically don’t have a hard time covering up the noise.

The zoom and auto keystone adjustment have been helpful features. All in all we’ve been vey happy with it.

I’ve actually yet to monitor my panels reading peak power. They’ve reached about 90% of their maximum output in cool weather in direct sunlight. In cloudy weather (Rainy days) expect outputs around 5%.

Another important element of getting efficiency or peak power from your panels is to run your system at a higher voltage like 24 volts rather than 12 volts. Using the higher voltage results in less energy loss as it travels through wires routed to your batteries or inverters. To save even more energy from escaping the wire, keep connections short; DC power dissipates quickly as heat with long wires unlike AV power, that’s one of the benefits of panels with inverters built in.

It doesn’t have to be that hard! The terminal at the center of the holder is positive and the circle outside is negative. All I have to do is use a couple alligator clips and it is it’s own charging cartridge!