Running in Parallel Utility Electrity with RE

Guest wrote: "Is it possible to run in parallel utility electricity at your home with Renewable Energy(RE), (eg solar power) for the purpose of reducing the rising electricity costs?. Say, for example to reduce the cost to 50%. But you don't intend to sell back the energy produced!If so,how the system configuration will be?."

Yes, it is possible. And, I assume from the way you've stated the question you don't want a connection to the utility?

In that case, you need to make an arrangement to switch loads between the utility and your renewable energy source, using either a manual or automatic means of switching. (I mean, worst case, you add additional distribution circuits for the renewable source, and then, while it is generating, unplug loads from the utility source and plug them into the renewable source.)

Will you have batteries to try to make the renewable source available 24/7? In that case, some loads could be switched permanently to the renewable source.

In general, I'd try to pick heavy loads, and loads that could be "scheduled" to be used while power is available--some ideas:

* if you have electric hot water heat (I hope you don't--more effective would be to use solar thermal power to heat hot water), but just to use it as an example, heat your water only while the renewable source is available--schedule showers, laundry, etc. to suit those times (hot water doesn't heat (or cool) instantly, so you might heat the hot water in the afternoon, then shower and do laundry in the evening--but you might still have enough hot water for showers in the morning--maybe even add an extra well insulated holding tank)

* similarly, I'd consider running things like a freezer (maybe a refrigerator, also) at a slightly lower temperature than you're used to, but only running it while the renewable source is available)

As another alternative, you could have a connection to the utility (although my understanding is they tend to be expensive, with all the regulator required safety equipment, and try to balance out the size of your renewable source to balance out (on a monthly / billing period basis) your electricity usage so on a net monthly (or daily, or whatever) basis, you supply the electricity you need and no more (even though you draw their electricity when your renewable source is not available, and they use your electricity when it is).

That is probably not easy as the seasons change.

My understanding is that some utilities can't (or don't attempt to) monitor and bill based on such differences, but just on the net power use during a given billing period. Of course, expect that to change if utilities recognize some additional revenue they could pick up...)

Hope that helps, and I'd like to hear more, especially if you follow through with your project.