Solar-powered 'guiltless green' home theater system makes your Wall-E Blu-ray very happy
By Ross Miller 
posted Apr 18th 2009 11:42AM
posted Apr 18th 2009 11:42AM
posted Apr 18th 2009 11:42AM
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anyone have a rough estimate of how much a solar setup like that would cost to put up (not counting all the home theater stuff, just the panels)?
it seems like a pretty great way to save power, but i'm guessing it's pretty expensive...
You'd be looking at aprox $1,500-1,800 per panel, plus installation.
depends a lot on where you live.
stupid nano solar needs to go public with their $1/watt...
oh wowee...so how does the guy estimate that they'd pay themselves off in 4 years?
would that even be a good estimate if these panels were hooked up to your whole house?
Estimates for paying off solar panel installations are based on things like federal tax credits and the fact that you're paying the electric company less. In addition to not using power from the electric company, many of these systems are built to actually send unused power back into the grid...which makes your electricity meter run backwards.
John C.
You can buy the panels he's installed (the Sharp 175) for $757 each.
http://www.altersystems.com/catalog/sharp-175-watt-solar-panel-p-46.html
I ran the numbers for my house. In phoenix, with tax credits, etc the payback is 4 years for a 7.9 kW system. (SRP is my electric company). Plug them in to excel... your mileage may vary
Avg hours insolation (kW per m2 per day): 6.58
cost per kWh (SRP): $0.11
SRP Rebate per system watt: $3.00
Federal tax credit: 30.00%
State tax credit (up to $1000): 25.00%
Average monthly usage (kWh): 2,000
7.9 kW system cost : $40,000
cost per watt (gross): $5.06
SRP Rebate: $23,700.00
Fed tax credit: $7,110.00
State tax credit: $1,000
Total rebates and credits: $31,810.00
Net system cost: $8,190.00
Net cost per watt: $1.04
Average generated solar kWh per year: 18,976
Current average kWh hour consumption per year: 24,000
Current SRP year: $2,544.00
Solar savings year: $2,011.40
SRP AFTER Solar: $532.60
Savings percentage: 79.06%
Payback calculations
Net system cost: $8,190.00
Annual savings: $2,011.40
Payback years : 4
CraigJ:
So if you take that out a little further, what will your net profit be on the array, say at 10 years from install and at 25 years (the average warranty period for panels), taking into account your state's historical annual electrical rate increase?
My very quick and dirty estimate has it at about $13,000 at year 10 and $45,000 at year 25.
Sounds like you'd have to be a fool not to have a grid-tie solar array in Phoenix. My 10kw array, with 25kw battery, in Seattle has a hard payback of right around 13 years. Although considering the reduction in company down time (due to that battery backup) it's already more than paid for itself. Been working great for the past 2 years.
Yeah, and that is at current rates. electricity here is fairly cheap at .11 per kWh. If that goes to .15 or higher it's even more attractive. I suspect that with cap and trade, if that ever becomes law, that rates will HAVE to go up because most of the electricity comes from coal, oil, and natural gas.
extended figures:
savings after 5 years 10,057.02
savings after 10 years 20,114.04
savings after 15 years 30,171.06
savings after 20 years 40,228.08
If electricity goes to .15 kWh:
The payback is 3 years and
savings after 5 years 14,231.63
savings after 10 years 28,463.26
savings after 15 years 42,694.90
savings after 20 years 56,926.53
you always produce wasted heat with your electronics.
You need to discount those cash flows for inflation and the opportunity cost of investing elsewhere. 20 years from now, $1 is only wirth $0.12 if you're discounting at 10%, and that's pretty conservative.
Funny, I don't feel guilty at all for my home theater system. In fact, I feel pretty proud that I earned the money to buy it all.
700 watts per hour??
watts is already a time derivative...
I was thinking the same exact thing. At least the CEO of LG Energy solutions used Watts in the right way when he talked about the amount of power produced. The executive director of HTSA though is a moron if he and his writers can't even manage to do a stupid commercial and be correct. Makes me a bit disappointed when he has a job and so many others do not.
Ok there seems to be some confusion. No, power (W) measured on it's own is not time-derivative. However, that doesn't make the HTSA guy in the video right. The guy from LG plainly said 700W, which would mean they output 700W continuously, and at 120V that means there's a constant 5.8A being pushed through that home theater from each solar panel.
Watts per hour (W/h) doesn't make sense - if a device is constantly dissipating 1W, how much power is it dissipating per hour? There's no answer to that - the only way to measure it is by saying it is dissipating 1W for an hour, which would be 1 watt hour (Wh). If you look outside on your power meter it will probably say kVAh (kilo volt-amp hours) which is almost the same as KWh (kilo watt hours... actually some meters may even say kWh).
Dan is correct. Watts are not a time derivation. E x I = P ; or voltage x current = power (Watts)
At 700 Watts, that means during the 4 hour day (from the video) that these will provide 2,800 watt hours (2,800 Wh) or 2.8 kWh per day or about 80 kWh per month. (http://en.wikipedia.org/wiki/Watt-hour)
Most peoples electric bills are in kWh, and the average house uses several hundred kWh a month. I average about 1,600 kWh per month. Where I live a 700 watt system would cost about $6,000 before rebates (http://shop.solardirect.com). A kWh hour cost me $.1084, so if these produce 80kWh per month as quoted, they would save me $8.67 a month, or $104 a year and would take approximately 57 years to pay back.
It isn't about economic feasibility, its about forcing being 'green' down the throats of everyone, despite the cost.
CraigJ:
According to Glikes, the solar array cost $5,800, including installation. 30% of that will be paid back by a federal tax credit (-$1740), another 35% from a state tax credit (-$2030), bringing it's total cost to $2,030. He will also earn incentives from the utility, which bring the payback time to 3 years. Not exactly the 57 years you claim.
http://www.electronichouse.com/article/solar_panels_power_home_theater/C201
That was the raw numbers without credits. I did the research. See my reply to the first post.
I love how you left out the [shitty] cable manufacturer.
Good job!
Which begs the question, Shouldn't the Home Theater Specialists of America (HTSA) executive director know better than do use those cables?
do = to, hey engadget when can we edit our own comments?
I think aviating Sinuae are higher up the priorities list.
where did you see the cable manufacturer? I watched the video but i guess i missed it.
@alexmueller No, it does not beg the question. Begging the question is a logical fallacy where one assumes what they are trying to prove. Not your intended meaning of "begs to have the question asked." You could have used "Makes you wonder," or "One would assume," etc. I am sorry to pick on you, but this mistake is made too often and it makes me cringe every time.
http://begthequestion.info/
Very cool!!!
"with the best high definition equipment", what a joke....
100 inches..mines bigger :P
That's what s.....DAAAAAAMN!!!!1111
We don't have the same definition for "best high definition equipment", but i'd like watch some movie/series in this room
Watts is not a time derivative. Watts are the product of volts and amperes, no time measurement whatsoever. Go back to school.
what do you think an ampere is? go back to school
http://en.wikipedia.org/wiki/Ampere
hahaha owned.
A Watt is a Joule per time unit. The confusion comes in when people try to think about watt-hours. A kilowatt-hour is the amount of energy used by a kilowatt over the course of an hour. It comes out to 3.6 MegaJoules. 1000W*3600s=1000(J/s)*3600s=3.6MJ
Life would be so much easier if we used Joules to figure out how much electricity we need to pay for.
http://en.wikipedia.org/wiki/Watt#Confusion_of_watts_and_watt-hours
ugh, my brain hurts!!
Watts are the product of volts and amperes, and amperes are coulombs per second. That's where watts being joules *per second* comes from
At night time, Bob was a lonely man.
"Daddy, can we watch Madagascar tonight?"
"I tell ya what. I'll set our alarms for 6:47 am and we'll watch it then!"
Best Faith Hill music video...ever.
probably meant 700 Watt-hours
my guess that they can pay back in 4 years is that i believe they said the solar only powers that theater room. so they only watch a movie a day, the rest of the energy they'd sell back...
now if they were trying to power their whole home, that'd be another story..
The current that one volt can send through one ohm. You're confused.
you're terrible at science.
ampere is a derivative of time
http://en.wikipedia.org/wiki/Ampere#Definition
volt is a derivative of time
http://en.wikipedia.org/wiki/Volt#Definition
ohm is a derivative of time
http://en.wikipedia.org/wiki/Ohm#Definition
and....
watt is a derivative of time
http://en.wikipedia.org/wiki/Watt
1 W = (1V x 1 A)
= 1 J/s....
you were both right. They probably meant, 700W is created in one hour of sunlight exposure
1 watt = 1 joule / second
1 ampere = 1 coulomb / second
1 volt = 1 joule / coulomb
hence
watt = ampere * volt = (coulomb / second) * (joule / coulomb) = joule / second
the solar panels generate 700 Watts when exposed to sunlight. that is POWER
they generate 700 Watt * hours that is ENERGY
Watt per hour is nonsense in this case.
get it?
*** they generate 700 Watt * hours when the sun is shining for one hour.
Saying "Watts per hour" is like saying "MPH per hour," i.e. it makes no sense unless you're talking about acceleration.