Can You Start Out Small?

System

Years ago I bought some solar plates on an impulse buy but they're still sitting in my garage.

But my question is can you start out small, say 1000 W home system, and save electricity, or is that like spitting into the wind, relative to any inverter that I might have? In other words how much power do you need to generate, say I use 3 kW, before I can reduce my electric bill by 10%?

Thanks.
Curious Chris

nigtomdaw

Re: Can You Start Out Small?

Bit more info Chris I assume your looking at Grid Tie ?

For saving money on your electric , conservation is king , ie reducing you electricity consumption comes in at pole postion.

Insulation of your home from excess heat / cold.
Installing energy star appliances, CFLs Led Lighting.
Using Nature for drying clothes
Even installing a Domestic Solar Hot Water System.

All have better payback returns before PV solar even thinks of putting in a qualifying lap.

Sos for the NASCAR slant to the post

BB.

Re: Can You Start Out Small?

Chris,

Where are you at? Solar is highly dependent on location... You will get more sun/power per $$ spent in the American Southwest vs Michigan.

How much electricity do you use per month? Do you use electric heat/cooking/etc. or gas/propane? Do you have A/C? Are your winter or summer electric bills high? How much do you pay ($/kWhr) for electricity? Does your utility support Grid Tied connected solar power--and what kind of plan/requirements do they have?

As Nigel says--conservation is the first place you should spend your money. It is almost always cheaper to spend the cash on conservation vs trying to generate replacement power.

And usually it is a better investment (energy efficiency/insulation/remodeling improves the price of your home--adding a grid tied system does not, usually, add near as much to your home's value).

-Bill

System2

Re: Can You Start Out Small?

We live in SE Michigan. We have good windows, siding and new furnace.

I've given up on conservation because my wife, and family, seem genetically incapable of turning off electrics when they're done. :grr

We have a 40x4 ft strip of yard that receives a lot of sun and would be perfect to experiment - we don't garden much.

I am under the impression that an inverter acts like an diode and if you don't have enough current, then no current will flow. Is this true?

Curious Chris

BB.

Re: Can You Start Out Small?

A grid tied inverter is pretty much automatic (as far as you are concerned). Simply connect the solar panels to the input and the GT Inverter's output to your Breaker Box--and it will, very efficiently, move the solar panel's DC power into your 240 VAC breaker box.

Depending on your home's load, the energy will either slow down, or even reverse your utility meter's logging of kWhrs.

The details are more complex... Basically, if this is your first solar PV GT install--you need a professional to assist/turn-key install. It is basic construction and electrical work--but you need to know what you are doing (and typically building permits and Utility Approval) for a safe and legal installation.

Conservation is still a very reasonable goal... You can get a kill-a-watt meter (less than $30) for measuring your plug-in loads (fridge, freezer, computers, TV, stereos, etc.) and see how much they cost you (on and in standby).

To see how much power you can get from a GT solar installation--you can use the PV Watts Website to estimate your monthly/yearly power collection. Assume 3.5 kWatts of solar panels (~$20,000 very rough guess after Federal and local rebates/credits), fixed mount, Grand Rapids MI, defaults:

[FONT=Fixedsys]Results

Month
Solar Radiation (kWh/m2/day)
AC Energy (kWh per month)
Energy Value ($ @ 8.3 ¢/kWh)

1      2.66          231        19.17   
2      3.57          280        23.24   
3      4.39          370        30.71   
4      5.09          399        33.12   
5      5.54          433        35.94   
6      5.79          425        35.27   
7      5.80          431        35.77   
8      5.48          414        34.36   
9      4.67          350        29.05   
10     3.76          300        24.90   
11     2.43          189        15.69   
12     2.15          182        15.11   
======================================
Year   4.28 hrs sun  4002 kwhr/yr $332.17 per yr    [/FONT]

Just to give you a rough idea on the equivalent $/kWhr cost for GT system in Grand Rapids--assuming a 20 yr payback:

$20,000+$3,000 maintenance reserve / (20yr*4,002kWhrperyr) = $0.29 per kWhr (very rough estimate)

Right now, you are probably paying less than $0.10 per kWhr...

In the end, it is always much cheaper to conserve than it is to generate the power (but divorce is more expensive yet--so there is a limit on consevation )

-Bill

System2

Re: Can You Start Out Small?

Thanks Bill. This is exactly what I wanted to know.

Curious Chris

BB.

Re: Can You Start Out Small?

I should add that my 3.5 kW array (3kW rated system) takes up roughly 280 square feet.

40x4=160 sq.ft.

So your available area is a bit smaller.

-Bill