I have been a bit quiet here. Let me explain what I have been doing.

I realized that I tend to be full of ideas (as opposed to what some others think I am full of) but some never reach the light of day. Others get explained in email to an assortment of people. Still others get turned into a completed project but with no available information about it.

When designing an electrical system for your home or business, you need to do a budget. That is, how much energy you will need and when you need it. Don't get scared off—this doesn't need to be any more complicated that doing a grocery budget.

While the focus of this article is for off-grid systems, you really need this even if you are connected to the grid.

That's an example. Feel free to substitute bread machine, coffee maker, hair dryer, crock pot, or a host of other things—given the choice. This is something that all too often is ignored and the result can be either needing more PV panels or running your generator.

The answer, assuming your primary energy source is solar, is "when the sun is out". Easy answer but you need to understand why.

A battery is not 100% efficient. That is, the amount of energy you have to put into a battery to recharge it is more than the amount of energy you took out.

I have been writing a lot of off-grid articles, partly inspired by questions on http://www.NicaLiving.com, partly by having a book half-done on the subject. I will continue to write them but if there is something specific you would like to see covered, let me know. That will help me prioritize what I will be covering.

While most of my off-grid articles have been about producing electricity, an area where you can make big energy savings on the cheap is using solar energy to heat water. It's not new, it doesn't have to be high tech and it works.

There are lots of reasons why being off-grid makes sense. Here are some thoughts to help you make that decision.

What if there is no choice?

The first and most obvious is that you may not have a choice or even if you do have a choice, the initial investment for a grid connection may be more than for a system to allow you to be off-grid. Where I currently live extending the grid would have cost about $17,000. My PV solar system cost $12,000.

A common question is whether to focus on 12 volt (or other low DC voltages) for running things or just invert to 120 volts AC and run everything off AC. There is no right answer but there are some considerations.

The first is where you are starting and where you see the future of your system. If, for example, you have an existing 120VAC system (either grid connected or just things you run off a generator), 120VAC is more likely the right answer. On the other hand, if you are just starting, 12VDC is probably the best choice.

While lights tend to be on the low-power end of what you may be running, they also tend to be used for more time. Thus, saving energy on lighting can have a big impact on total power requirements.

The good news is that LED lighting is efficient and becoming inexpensive. A few years ago you couldn't find much that would serve as useful home lighting but today you can and at fairly reasonable prices. The trick is to shop carefully.

If you have an off-grid system, take a look at what is available to run on 12 volts.

Efficiency in off-grid systems tends to be overlooked as often as safety. The end result is that all too often you are surprised when your system does not perform as well as you calculated. This post offers some clues to help you right-size your system.

These same losses/inefficiencies can exist in grid-connected electrical systems as well. They are just less likely to be noticed because the are represented as an increment in your electric bill rather than a dead battery.

• Batteries are not 100% efficient at storing energy and delivering it later.

Probably the most neglected part of a system design is safety. Programmers put off documentation and home electricians put off safety.