So we've briefly covered some basic ideas about the cost of solar kit installations that tie into the local electric grid and sell unused power to the utility at wholesale prices. They are game changing home modifications, with major long term implications about what it means to own a home. But, maybe you aren't able to spend tens of thousands of dollars all at once, but you still want to get started doing a conversion a little bit at a time. In that case we'll start exploring alternative energy options that are completely separate from the electric grid.

These closed loop systems can be used to power specific devices or a small separate circuit in your household and are far more affordable than traditional grid tie kits. They scale down more easily, and for the DIY enthusiast, these systems are almost all entry level hands on installations. Non-grid tied systems are usually best suited for particular applications like hot water heaters, cell phone/mp3 player recharger's, AC/Heating unit boosters. But with a little ingenuity the systems can be expanded with battery packs and DC/AC inverters to power specific appliances that see infrequent, high wattage short term use, or long term low power use, like microwave ovens, laundry driers, dish washers, blenders, coffee machines, fans, radios, etc... In fact, you can slowly scale up a non-grid tie system until all your household needs are met and the grid is just there for backup.

So assuming that you want to try out a small entry level project, let's look at the personal electronics recharging station. This may only save you a few dollars worth of grid electricity a month, but it's a start and you achieve the added benefit of being able to recharge your device during brownouts, blackouts or natural, or otherwise, disasters. To keep things simple we'll start with a USB recharging station so we have consistent standard to work with and cheap off the shelf connectors.

A USB recharging station has simple power needs, 5 volts of DC power with no more than a .25 volt fluctuation positively or negatively(5V±5%), with a starting at 100 milliamperes current starting which can go up to 500mA upon request of the device. There is also a charging specification that allows plugged in devices to pull up to 1.5A upon request. This may sound a bit intimidating but we're going to use an off the shelf hub, so you don't need to worry about most of it. There are also two ways of doing this, one is to power the hub directly from a stepped down solar panel, or the way we'll be demonstrating here, charge a small battery from a solar panel and run the hub from the battery.

The battery buffered option allows us to charge appliances overnight which is consistent with how I charge my appliances, which when given the option you should always go with the system that is provides the lowest habitual barrier to break. There is no sense in investing in systems that you'll have to jump through hoops to use, because chances are they will simply not be used.

So here is our basic shopping list:

• $125.03 Bundle deal through Amazon.com

  • $29.99, Sunforce 60012 7 Amp Charge Controller

  • $129.99, Sunforce 50032 15 Watt Solar Battery Charger

• $17.99, Targus 4 Port USB hub with 5V, 2.6A additional power input

• $62.00, Deep Cycle Wheel Chair Batter 12v 18A.

• $23.75, 12 volt to 1.5, 3, 4.5, 5, 6, 7.5, 9 Volt DC/DC Converter (Adjustable Regulator)

• $8.00, Barrel and Audio power connector assortment )

• $2.95, Double Throw Knife Switch

• $10.00 Rated Wiring(...)

Total Parts $249.72

I won't be providing a step by step breakdown of how to do this project as I've been advised against it for legal reasons(maybe if and when this site generates enough revenue for legal insurance). But it boils down to wiring up the solar panel to the charger to the battery. Then installing the switch to change the circuit from the solar ---> battery, to battery ---> converter for charging. And wiring the DC/DC converter to the switch, and the converter plugs into the USB hub.

Your primary concerns, besides not shocking yourself, should be to make sure the solar panel lines up with the average solar apex of the southern sky(in the US), and that your contacts are all protected from corrosion due to moisture exposure. The battery should also be stored in a cool place, with some sort of acid spill protection.

But still, we're only going to save a very small amount of energy monthly with this system. Using the “off the shelf” adjustable converter also means we can plug in a much wider variety of equipment, therefore get a little more use out of our system. Using back of the napkin math, I calculate that just using the USB hub to charge a bunch of little electronics every night will realistically max out at about 100watt/hours, or about 3 cents a night worth of electricity, so over the course of the next 10 years assuming conservatively that the average cost of grid electricity will only rise by a penny a kw/h a year(it's more likely that it will rise faster than that), the system will have paid for itself in about 9.7 years. If the market values of domestic coal increase with the projected increase in import demand of other nations, then the system will pay for itself much, much faster. But that is too speculative, 9.7 years, that's what can reasonably be projected from aggressive use.

Being green sometimes doesn't seem like it's worth the effort, does it?

Before we make that dreary conclusion lets go back and look at what potential benefits we derive from changing our living space from a constant consumer to a producer. You can charge your personal electronics without adding to the global air/carbon mix. In the event of brownout or blackout you can still use your personal electronics. If a catastrophic event wipes out the grid for a short or long period of time, you will still have access to your personal electronics to help maintain comfort and possibly basic services. Not bad, not bad at all for $250.

This project is nearly as small as you can possibly make it, and it's cheap enough that most people in the US can scrap together the money to build the system if they really want to. And like all off the grid energy systems, it scales up beautifully. So when you want to add your microwave to the system, you simply invest in more solar panels and more batteries, upgrade the switching and your there. And with some creative work some of the major drawbacks and money sinks to the system can be overcome, but we'll cover more of that later. For now, there you have it, an entry level off the grid solar system.