Determining what power one item uses....

[Liamm_1]

A good solution for reducing usage is by using solar modules coupled with (Enphase) microinverters. You can start with just 1 module and microinverter. For instance, 1 240W module and a microinverter will probably generate over 1KWH per day using a grid tied system. (rough estimate)
Module = ~$400
Microinverter = ~$300
Plus mounting, breaker, wires, conduit, etc.
Add when you want, as many as you want (up to 15 I believe)

Whereas "Chance favors the prepared mind", it would be interesting to know what latitude one would put up only one solar panel with a microinverter and not put a storage device in place to hold energy when the sun is NOT shining. Up here that is quite a large portion of the day. Where do you suggest doing this?

My apologies for omitting the fact that this simple setup is for a grid tied system. The grid (your utility) acts as your storage device. During sunny days, when your solar modules are producing electricity, whatever is not needed to power things during the day, the surplus is sent back into the grid, i.e. your meter runs backwards.
For an off the grid system, yes of course there would need to be a battery storage system. And you would also more than likely need a substantially larger system than one module. The great thing about the microinverter technology is that a person could start small, say 1 module, and over time build it up as needed, or as is affordable.
With traditional inverter technology that is not as feasible, since the (expensive) inverters need to be sized properly for the entire system.

 

[Icu4dzs]

Just in case anyone is interested in this concept, I would recommend this link:

http://www.wholesalesolar.com/produ...older/m190-enphase-energy-micro-inverter.html

The enphase inverter Liamm talks about is discounted to $175 righ now. Might be a good price considering his last post indicated a much higher cost.
As things get a little less expensive, this will become the wave of the future. Right now, all these components are very expensive.
My HYBRID system has a Whisper 500 which can produce up to 3000 watts and 16 PV's which each produce 170 watts. Even during the time since I bought my system, the panels have become improved almost daily.

I was very intimidated at first when thinking about installing the PV's on one of my sheds (a quonset style building made of steel) but since doing it, I am convinced that I would love to cover that building with the panels and maybe even my house despite the fact that the roof faces east/west rather than to the south.

As I said, it really wasn't that difficult to install so I'd recommend it to anyone with a reasonable amount of tools/skill.

As for the power needs determination, I sent away for a "WATTS UP" meter. I have been going around the house and checking the items that are "critical" that need to be sent to a different box from my system.

Here is some information as to process.

Sizing your back-up system is the first step. To establish your critical electrical load, decide what items you want backed up and how long they'll need to run while the power is out. *(or which ones you want to run "off grid")

Most appliances have nameplate ratings marked with Amps, Volts and Watts. Remember amps (A) x volts (V) = watts (W). Multiply the watts used times the number of hours the appliances will run. For more accurate measurements of your power use per appliance, you can use a meter to gauge your actual electrical use in watts. (I use the WATTS UP meter for this)

Be conservative with the number of appliances you back up. Draining batteries completely of their power will ruin them. ALoad Evaluation Worksheet and Battery Sizing Worksheet may be useful to you.

How a Back-up System Works
When you decide which electrical loads are critical to power during a blackout, a critical load sub-panel is separated out. Circuits feeding the refrigerator, lighting circuits and any other necessary loads are pulled from the main breaker panel into the isolated sub panel. This sub panel can be located next to your main panel, attached to it by PVC, or a metal chase nipple.

Next, a 240-volt circuit in the main panel is routed to feed the back-up, allowing the batteries to stay charged at all times. Power is then routed through the inverter to the critical panel, allowing those loads to run continuously. In the event of a blackout or brownout, the back-up system will take over in less than one third of a second. Note: It is possible to wire and program your backup system to take advantage of your existing solar panels for assured power during extended blackouts.



Best to all,
Trim sends