Switching To Solar Power, One Year Later 541
ThinSkin writes "Slashdot readers may recall Loyd Case's series of articles illustrating his experiences after switching to solar power for his family home. Loyd shared his one month update, a six month update, and now finally concludes his series after one year of solar power. Despite the $38,000 initial cost for the setup, Loyd is very optimistic after a $3,000 savings in one year, meaning that in about 12 years he will break even — though he suspects ten years is a better estimate considering other factors. Other reasons such as feeling 'green,' increasing the property value of his house, and the 'spousal acceptance factor' all support Loyd's decision on why he'd do it all over again if he had to." The article is spread annoyingly over multiple pages, like everything at the site, and the print version omits the graphs.
Re:Solar panel longevity (Score:2, Informative)
So maybe it'll pay for itself in 12 years, but how long before those panels need to be replaced? That's what we really need to know in order to decide if he's actually saving money.
Well if you want to be a financial stickler, you might want to factor in the standard rate of inflation if it's going to be 12 years. The funny thing is that inflation has been going down in the past three months according to this site [inflationdata.com]. But you need to remember the pert formula and assume that most of the time you're looking at an average of what about 3% inflation per year? On your original investment of $3800, right? So that's like a 42% increase in the value of that 2008 money assuming inflation continues at an expected yearly rate and a bank will give you that return.
Industy Standard Warranties (Score:5, Informative)
Most manufacturers guarantee that their panels will give at least 90% of peak power at ten years, and 80% of power at 25 years. Yes, he's saving money.
SunRun (Score:3, Informative)
Affordable solar for little money down [sunrunhome.com]
If you live in CA, MA, or AZ, and have a roof with decent sun exposure, please check SunRun out.
I've got nothing to do with them; I just think they have a winning method of making the cash flow of solar very attractive.
Re:Return on investment (Score:4, Informative)
" Despite the $38,000 initial cost for the setup, Loyd is very optimistic after a $3,000 savings in one year, meaning that in about 12 years"
Might want to look up the lifespan of solar cells.
"Cost of Solar Panels ...
Solar panels have an effective lifespan of about 20 to 25 years, and their value and wattage output decrease steadily over time. The solar cell that has
www.solarpanelinfo.com/solar-panels/solar-panel-cost.php "
I have them too, but to be rigorous one needs to take their lifespan into consideration.
Re:Return on investment (Score:5, Informative)
Re:Price of certainty. (Score:2, Informative)
Electric companies shouldn't be directly linked to Gulf politics. Most of the electricity in the U.S. is produced by coal, natural gas, nuclear, and hydroelectric energy sources according to the Department of Energy. Petroleum makes up only 1.3% of U.S. electricity production. http://www.eia.doe.gov/cneaf/electricity/epm/epm_sum.html [doe.gov]
Your point is a good one though, that energy prices will most likely go up per kWh.
Re:Return on investment (Score:5, Informative)
With the exception of the part where you said their output decreases over time, that's simply not true. Most of the current generation of solar panels guarantee a minimum of 80-85% output after 25-30 years, depending on manufacturer. That's in the warranty for the panels. If they fall below that level within 25-30 years, you get new panels. The effective lifespan before they produce no power at all is probably 100+ years, though most people would replace them with more efficient panels well before that time....
Re:Going green takes some green. (Score:2, Informative)
Check into your state and local programs. I live in Texas and there are some very significant incentives available. I copied this from http://www.solarpowerrocks.com/texas/ [solarpowerrocks.com]
EXAMPLE 3kW SYSTEM HOME INSTALL IN AUSTIN TEXAS
So, if you were to install a 3 kW system that would be about $27,000 ($9.00/Watt x 3,000 Watts). In this example youâ(TM)d be in line to receive the maximum incentive of $13,500. The Fed offers a 30% incentive in the form of a tax credit with no cap. Assuming you have the tax liability, youâ(TM)re in line to deduct another $8,100 (30% x $27,000). Now, youâ(TM)re at a net cost after year 1 of $5,400. This is a lot more palatable. Just think, this energy upgrade is also property tax exempt and youâ(TM)ll realize an immediate property value increase of 20 times your annual electricity bill savings. In this example, a 3kW system will increase your property value by about $9,600 ($40/mo savings x 12 = $480; $480 x 20 years = $9,600).
Re:Energy prices are unstable (Score:5, Informative)
But there's no hard guarantee. Sure there is. Go read up on Peak Oil. Then go read what anybody's doing about it. (Hint: Apart from mostly singular projects like the one in TFA, mostly jack shit.) Electricity prices will go up.
Except for the fact that only around 1.5% of the US electricity generation comes from the use of oil. Take a look here: Net Generation by Energy Source by Type of Producer [doe.gov]. Out of a little more than 4,000,000 MWH of electricity generated, about 65,000 MWH came from petroleum.
Re:Return on investment (Score:3, Informative)
According to it's decreased output overtime? ...... and you expect zero output after 50 years
Check out a typical actual warranty for a kyocera module:
http://www.kyocerasolar.com/pdf/specsheets/kc_warraty.pdf [kyocerasolar.com]
They guarantee 90% at 20 years since manufacture, or 80% at 20 years after sale date (from reseller or whatever)
So, at about 30 grand, at least for the first 20 years, it loses about $150 of output per year.
Basically decreased output is no longer economically relevant compared to disaster type problems. Now that we get "100 year floods" every year for the past 4 years, the house will rot out from underneath. Or a 'nado will blow it away. Or X percent of homes burn down per century, so in twenty years across millions of homes you'd lose X*20/100 percent due to fire vaporizing the entire structure including panels. Insurance for theft. Hail destroys the entire roof including the panels (note that panels are actually tougher than "old" asphalt shingles)
I'm in my 5th year and have statistics (Score:5, Informative)
Re:Return on investment (Score:5, Informative)
I spent $78k (with no loan, so no extra payback) putting solar panels on my house late last year. My highest bill (August last year) was ~$1000 and I was averaging ~$700/month over the year; my May bill this year was $49. I estimate payback for my system to be ~10 years or so. There's a few things to consider if you're thinking of doing it yourself:
We use a lot of electricity. This is a nice, green way to offset that and still have the toys I like (heated swimming pool, air-conditioning, pond in the back yard, server-room in the garage,...). Example: last month (1st May -> 31st May), the power production (I have the monitoring system all set up :) was 1,260 kWH. That matches nicely with our average 40 kWH/day with air-conditioning on. And if it's not being soaked up by your solar panels, it's just warming the roof and causing your air-con to go into overdrive... :)
:)
The payback calculation is pretty easy. Maintenance is essentially zero, so total cost including permits, installation, etc. was ($78k - $2k - $15k) = $61k. Savings per year are ~$6000. Payback in ~10 years, assuming electricity costs are static (unlikely) and after that it's all gravy
Simon
Re:A ten year ROI? (Score:2, Informative)
That somebody would brave a risky expensive project with not-too-golden financial rewards over such time is commendable, especially in the not-exactly-guaranteed chance that it works as planned over a decade.
Re:Solar panel longevity (Score:3, Informative)
Learn to read. His cells are warranted for 30 years with a guarantee that they will output 80% of rated at hat power. This 50% drop in 10 years was never true. You are also not factoring in the almost assured rise in electrical costs.
Re:Return on investment (Score:5, Informative)
It is an obvious win, because you are failing to compound the savings.
He can invest the savings on electricity each year and substantially increase his ROR.
The IRR formula does NOT account for the potential re-investment of interim cash flows.
Re:Price of certainty. (Score:3, Informative)
The hookups should disconnect from the grid when the grid is down. It is silly to turn off your power when the grid is down, rather than just run it separately. Then, once the grid is back up, connect them together again. Oh, and all electrical workers are aware of this, and all electric lines are treated as hot. Yes, treating a hot line as hot is less safe than treating a dark line as hot, but it isn't like the unsuspecting electrical workers are grabbing them with their bare hands and getting fried.
Re:No, he's NOT saving money (Score:5, Informative)
The last 70 years or so ago takes you from just after the wall street crash. That's probably not the most representative time frame. If you had invested just before the wall street crash, your investment would still have underperformed compared to a cash investment after all this time.
Re:No, he's NOT saving money (Score:3, Informative)
It took until 1954 for the stock market to recover to its 1929 peak.
Re:Still not practicle (Score:2, Informative)
My fridge, TV, laptop and external monitor were the big devices running when I ran out and timed my power meter (I wanted to catch the fridge while the compressor was on, so I only timed it for 1/5 of a revolution, so these numbers are probably only decent).
Anyway, it turns out they were drawing a total of less than 350 watts (my meter has a Kh of 7.2 and 1/5 of a turn took 16 seconds, making one revolution 80 seconds; (3600 * 7.2) / 80 = 324.
If your refrigerator averages 900 watts, freaking replace it.
Re:Price of certainty. (Score:2, Informative)
Um, no, not really. There's no reason to stop producing power when the grid goes down. You, however really do have to have an automated Transfer Switch (these are sometimes integrated into the inverter with a solar system) with any on-line power system, so that when the grid goes down, you stop powering the GRID. You can do whatever you want with power you are generating inside your home, which if the power goes out when it's sunny, or if you have a battery system, or a generator, feeding the inverter, should be plenty to run your fridge, and maybe a few lights, even if you are producing less than you need to run everything. This is vastly under-appreciated I think, in terms of the value it adds to your home.
Re:Price of certainty. (Score:3, Informative)
I'm not sure how you got modded "Interesting" since your main point "Sync'd" is incorrect.
Apparently they didn't explain the function of a transfer panel at your alternative energy show. A transfer panel will decouple your home energy generation system from the grid in the event of utility power failure.
Some panels do this automatically and others are manual. Either way a solution exists and is commonly used for just the situation you're describing. Also, AFAIK almost every municipalities electrical code requires the installation of these when you install your own power generation capability.
Also even if he doesn't have batteries he can always reduce demand to equal his output and have SOME of his stuff going. Maybe he has to turn off the home LAN/WLAN, his big screen TV and not run the dryer or microwave but it's almost certainly possible for him to stay at or below his generation capacity unless it's the dead of the night.
Re:A ten year ROI? (Score:4, Informative)
I'm in a situation where I'm not looking for ROI - I'm off-grid, and getting the mains connected has been quoted at AUD$33,000 PLUS tree-clearing costs. My latest upgrade (new 1320ah battery bank, 6x165w panels, regulator, frames & installation) cost AUD$23,000. It was subsidised at 50% so we only paid AUD$11,500, but even if it wasn't, it's still cheaper than getting the mains on.
Re:Solar panel longevity (Score:2, Informative)
Like everything else, you get what you pay for.
Re:SOLAR PANELS ARE CHEAP AND EASY TO REPLACE!! (Score:3, Informative)
Also I don't think the electrical safety laws apply to 12V installations - that's how I would wire things up. There is a lot of lighting and appliances designed to run off 12V and not need an inverter, you might just have to hunt around at places that fit out boats etc.
Re:Price of certainty. (Score:3, Informative)
It would be really easy for you to be trying to draw 4kW while your system could only make 3kW, which would probably result in relatively nasty results.
Haven't you heard? They've got these new-fangled current-limiting devices. I heard a wizard -- I mean, an electrician -- talking about them the other day. I think he called them "fuses." He also said something about working on a new invention called a "circuit breaker," but he wouldn't tell me what it was supposed to do.
*ahem*
We could even get fancy, and build a device that automatically breaks the circuit when the voltage drops too low (which is really just a simple way of measuring current availability vs. usage). The cheapshit inverter in my work truck does this nicely. It'd even be fairly simple: Power goes out on a nice sunny day, PV system can't keep up with the load, and drops out. Mr. Homeowner then simply turns off the electric drier, tells the kids not to use the microwave and the TV at the same time, and pushes the reset button. If load gets to high (and voltage drops sufficiently), it cuts out again.
I do question the utility of such a system, on the basis that I've only experienced meaningful power outages during occasions when it is decidedly NOT nice OR sunny. And if it goes out during the day, who cares anyway? You've still got light. *shrug*