Electricity - Some sunny numbers for fun

Elendur

Gamer and mathematician
Feb 27, 2012
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I'm eating lunch right now and want to play with some numbers.

EIA - Electricity Data
Gives:
11.92 Cents per Kilowatthour for a residential april, this year.

Solar Panels From 58¢/Watt, World's Lowest Price.
Gives:
68 Cents per Watt

(Note that these sites were chosen because they had the numbers I was looking for in a easy to spot place, not because they have good numbers)

List of countries by electricity consumption - Wikipedia, the free encyclopedia
Gives:
1402 watts per person

So. For the 'math' now ;)

To cover the average energy usage of an US citizen you'd need to spend:
1402*0,68 = 953,36 dollars

Assuming that we get nothing for half the time (due to night, clouds etc) and that we have four months (i.e. 1/3 of the year) at half capacity (due to winter) and that we're aiming to produce the entire demand at its minimum capacity:
((953,36*2)*2) = 3813,44 dollars

But of course we'd need to store the energy so that we still can deliver during the night and the cloudy days.
That'd be around:
1402*12 = 16824 WattHours = 16,824 Kilowatthours

Ok, so I'm a bit stumped to search for good, easy to read, batteries that aren't designed for car usage... But I'll list some of my results:
New solar battery technology offers household power at 2.5c per kWh
Gives:
2.5c per kWh

DailyTech - Envia Creates $125 Per Kilowatt-Hour EV Battery, Could Usher in More Affordable EVs
Gives:
125 dollars per kilowatt-hour

Electric Car Battery Cost
Gives:
375 dollars per kilowatt-hour

So obviously there's a huge difference here. I'll take the highest one.

We then have:
16,824*375 = 6309 dollars

So, in total:
3813,44+6309 = 10'122,44 dollars
to produce electricity to cover your lowest production and store energy as well.

We'll need an inverter to take care of the energy, so that we can connect it to the grid.
At the best we'll produce:
1402*4 = 5608 watts
(since we've covered the worst case of 1/4 output)

I'll search for 6kW. This was another part that I didn't find so easily. Though I'll list three results:
Grid tie power inverter 1000W-6000W, View grid tie inverter, Srups Product Details from Shenzhen Sunray Power Co., Ltd. on Alibaba.com
Gives:
100 - 500 dollars

6000W DC to AC Pure Sine Wave Power Inverter
Gives:
945 dollars

Ring 6000W 12V Inverter : Inverters : Maplin Electronics
Gives:
700 dollars

Again, I'll go with the highest. This gives us a new total:
10'122,44+945 = 11'067,44 dollars

So. How long before one'd go even? Assuming one'd be paid ziltch for when one exceeds ones production (those dirty companies, I knew it!).

Remember you had:
11.92 Cents per Kilowatthour
1402 watts per person

Since you'd be producing that much, you'd earn:
1,402*0,1192 = 0,1671184 dollars / hour

So. Last calculation.
11'067,44 / 0,1671184 = 66225,15 hours
(rounded up)

That is:
66225,15 / 24 / 365,25 = 7,6 years
(rounded up)

You'd break even, at the very latest, after 7,6 years (of course, I've also assumed that the solar panels degrade is negligible). After that, you're only in the plus.

Of course, I chose only the worst things so we can safely assume that the average person easily could trim off from that result. Also, I guarantee that someone who knows what he/she 's talking about can give better deals (and possibly tips about tax reductions etc) than those I've found.

Cheers :D

Edit: Changed a sentence.

Edit 2: Or if you want to skip the batteries:
4758,44 dollars breaking even after 3,3 years.

;)
 
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