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Getting the Most Out of Your Green Buck?
batobin asks: "My dad is thinking of installing a solar photovoltaic system on the roof. After tax credits, it'll cost $12,000. In Santa Barbara, where we live, our power company grants credits when the meter runs backwards and saves the credits for 12 months, reducing our monthly power bills year round. If the contractor's math is correct, the amortization period (when our power bill savings equals the installation cost) is about 12 years. With environmental and geo-political concerns in mind, is this the best use of our money? Will reduced consumption translate into cleaner air / less dependence on fossil fuels? What other environmentally proactive investments could be made with 12 grand?"
Correct me if I'm wrong, but I looked into this about 4 years ago and things might have changed since then...
Doesn't it take more power to manufacture a solar panel than that solar panel will produce in it's lifetime? That was the primary factor in the expense of manufacturing of solar panels. So, by going solar you will save money over the years, especially when you take into account inflating energy prices. But better for the environment, not really. Possibly worse if you add in the industrial waste of the manufacturing process of the panels itself.
I'm not putting you down either. If I didn't live in perpetually cloudy western Washington, I'd have a roof of solar panels myself.
Replace your car with a diesel VW, and run BioDiesel. Producers of BioD get a tax credit for producing it, so it's competitively priced with regular dinosaur-diesel, and the slight decrease in BTUs of the fuel is mitigated by the more complete and more efficient combustion of said fuel, due to the higher cetane rating. Figure 45 mpg, and you get a real car, with a real stereo and trunk, no banks of potentially hazardous batteries to recycle in X years, and you're not sitting in the middle of a giant magnetic field while driving.
BioDiesel solves the chicken and egg problem, and its a fuel with similar energy density to petroleum fuels, unlike ethanol, or god forbid, hydrogen.
BioDiesel also comes close to closing the carbon cycle, since the carbon in the fuel came from the air to begin with. Because it doesn't come from the ground, there's no sulphur or metals in it.
I want to delete my account but Slashdot doesn't allow it.
You could buy $12K worth of pollution credits from these guys. This would likely result in a greater net reduction in pollution, but of course you don't get any financial return on investment.
"The dinosaurs died because they didn't have a space program." - Niven
There was just recently a "breakthrough" in solar photovoltaic techonology. You may want to wait a year or two and see if that technology pans out. If so, it would be a much cheaper solution.
And, your Dad won't be pissed when your neighbor buys a similar solar panel rig for 20% of what he paid.
Don't think that a small group of dedicated individuals can't change the world. It's the only thing that ever has.
I just got through reading a Wired story about new Rooftop Mirror Arrays available in the fall. Unfortunately, the story isn't avail on-line until July 11: http://www.wired.com/wired/ The Rooftop Solar Revolution Dotcom king Bill Gross wants to sell you a high-energy, low-cost solar concentrator that will fit on your roof. And overthrow the powers that be. I have no idea if this is applicable to you, but I thought you might enjoy the info.
Photovoltaic still isn't economical and really is not all that green either. There are better ways to be environmentally proactive.
Don't bother with photovolatic. Not yet. The manufacturing process is polluting and the ROI is not worth it.
I'm not sure if I'm reading it right, but according to this study (linked in someone's comment above in this thread, "Production photovoltaic module payback is significantly less than its expected lifetime."
You should donate that money to my "Pave The Earth" project. You see, once the entire earth has been paved, people will be able to drive in straight lines to their destinations. The fuel savings will be astronomical, pollution will drop dramatically, and everyone will be happier.
Slashdot - where whining about luck is the new way to make the world you want.
What are you using so much power for?
Temperature control (heating and cooling) can be better done through passive means, ie: insulation, shading, ventilation, low-e windows.
Use the kiss principle, don't buy electronic gismos for every little thing. Do more manually, the human body is designed to manipulate manual tools. Don't throw away the gifts that all those generations of evolution have given you.
Move to a tiny apartment within walking distance of jobs, schools, restaurants, bars, theaters. Lose the car. Shop less, live more.
PV is great for off-grid systems, it doesn't disrupt the local hydrology like a hydroelectric system, and it doesn't make any noise like a wind turbine. The energy per dollar is pretty poor, however.
You'd make a bigger dent in energy usage by putting solar water heaters on your own home and the homes of several friends. They have a much more direct energy cycle and a much shorter payback period, and they're just as silent and unobtrusive as photovoltaic.
Personally I hate fluorescent lights; they give me eyestrain and headaches, so I won't put them in all the fixtures in a room. If there's already daylight or incandescent light in a room, a CFL fixture works well as "fill-in" lighting, but never as the only source. YMMV.
Other important steps would be to consolidate servers (VMware can help) and put as much as possible onto low-power PCs. I can't find a good CPU comparison table of FLOPs per watt, but such data should be easy to compile.
I wonder about the embodied energy in LCD monitors, are they as expensive to produce, energy-wise, as photovoltaics? Large semiconductor devices of any sort are pretty tricky to manufacture. If anyone has this data, please link it.
You can go for a 'grid-interactive' system, which basically just has an inverter connected to both the solar panels and the grid. With grid interactive units, no batteries are needed, although there are disadvantages, chiefly that most grid-interactive systems shut off if there is no grid power.
:-)
Basically two operating modes:
Sunny day - the house gets its power from the solar panels, with any excess going 'into' the grid. You may get a cheque in the mail from your electricity provider for the power you send into the grid, you may not - it all depends. If you're at work 5 days a week and the house is basically empty, you should get some cash back, and with appropriately-sized panels, your power bill should zero out.
Rainy day and nighttime - the house gets its power from the grid, and your 20 grand's worth of panels sit useless on the roof, while your neighbours mock you
Grid-interactive's probably the way to go if your existing grid supply is reliable, and your provider has some environmental smarts about it.
You are in a twisty maze of processor lines, all alike.
There is a lot of hype here.
Grandparent is saying $12,000 is the subsidized price. The true cost is higher.
As far as we know, photo-voltaic systems are not "self-sustaining". That is, every kilowatt hour of energy your system produces in it's entire lifetime will not be more than the kilowatt hours that were used up to purify and crystallize the silicon, and make the PV system.
This is a myth. After two to four years, there is a net gain. (It also fails the sniff test: if the myth were true, they would have to sell them for less than it costs to make them.)
--MarkusQ
On the upside, you'll have some daytime electricity during power failures
This is not exactly true. if you're tied into the grid in such a way so that your meter spins backwards, if the power goes out, your solar will go into the grid but you won't be powering your house with the solar that you produce. The giant pull that then happens on your solar grid won't be able to support all your neighbors and such so your house will go out to.
I have solar on my house, a 4.5 kW system and its sure nice to have it, we used to pay about $250 a month in electrical bills, now we pay about $15 in a yearly bill(electricity only, not gas).
On top of that I guess I could also say that my dad sells solar panels for a living now, mostly doing big businesses and he's finding that a company who spends ~ $25,000 a month on electricity is jumping to solar as their bill drops to about $1,000 a month on solar. Its all something to think about. its worth it, plus you help the environment, and it gets paid off in about 3 years.