Switching To Solar Power, One Year Later

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.

Comments

Industy Standard Warranties

[spun]

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.

Re:Return on investment

[rs79]

" 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

[crmarvin42]

IIRC from the 6 month write up, he splurged and got the pricier (i.e. longer lasting) panels because he was getting either a grant or tax break from California for putting the panels in.

Re:Return on investment

[dgatwood]

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:Energy prices are unstable

[j79zlr]

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. Out of a little more than 4,000,000 MWH of electricity generated, about 65,000 MWH came from petroleum.

I'm in my 5th year and have statistics

[skidisk]

I deployed solar panels when I replaced my roof in 2004; the total out of pocket cost after state rebates and federal and state taxes was $14,612. The system generates about 15 KwH on a good day; I live in a tract home in Mountain View, CA. So far, the panels have generated 19,225 KwH, which reduced my energy bill by $10,392 as of May, 2009. I've not seen the expected degradation in the power production, but it's difficult to measure due to changes in the weather -- it's entirely possible that 2004-2005 were cloudier than 2007-2008, or something like that. In any event, the system has delivered between 3819 and 3930 KwH every year. I'm extraordinarily happy with the way this has worked out.

Re:Return on investment

[Space cowboy]

Panels generally last 25 years at which time they're at 80% of their initial efficiency.

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:

• The cost of electricity is only going up. If you graph it over time, it's been steadily increasing for the last 10 years or so in my area (Bay area, CA)
• You put yourself on the 'expensive electricity in the day, cheap electricity at night' and get a meter that sells your over-production back to the utility
• It puts a significant value on the house should you want to sell it, because the new owner gets to spend less per month on electricity.
• Your state will give you a chunk of change back (I got $15k or so) if you invest in solar power for your house
• You'll also get a 30% tax credit (ie: taken off your tax bill, not off your earnings-before-tax) if you go solar this year. Last year it was capped at $2k, so I lost out on ~$20k. Oh well.
• The more electricity you use, the more expensive each unit becomes. The cost of the top 50% of my electricity-use per month was costing 2x as much as the bottom 50% because prices are tiered. If you can get yourself out of that top-tier, it can really be worth it.

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:Return on investment

[Zalbik]

Doesn't sound to me like an obvious win for solar power

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:No, he's NOT saving money

[jonbryce]

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:A ten year ROI?

[dwywit]

Quality solar PV (such as mine from BP Australia) are warranted for 20 years. The terms of the warranty regarding output are basically: no less than 80% of rated output for said 20 year period. There's no cheap way - you pay big $$$ upfront for quality panels, and they'll last a long time - excepting severe accidents, of course.

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.