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Switching To Solar Power — Six Months Later 591

Posted by CmdrTaco
from the it-burns-my-eyes dept.
ThinSkin writes "Slashdot readers may remember an article regarding ExtremeTech's Loyd Case's experiences with solar power for the home after one month of usage. During that time six months ago, it sure seemed like a great deal, but the tables have turned significantly once winter approached. While it's no surprise solar power generation is expected to dwindle during the winter, Loyd compares solar power data of the last six months to determine if solar power is still worth the time and money."
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Switching To Solar Power — Six Months Later

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  • $400 a month? (Score:5, Interesting)

    by Gothmolly (148874) on Wednesday January 14, 2009 @10:19AM (#26448781)

    Who the hell uses that much electric power?

    • by Anonymous Coward on Wednesday January 14, 2009 @10:23AM (#26448837)

      You ask how he uses $400 a month in electricity? His tech is EXTREME!

    • by Andy Dodd (701)

      California residents... Cal is notorious for having very expensive electricity.

      • Re: (Score:3, Informative)

        by HardCase (14757)

        In his case, the math says $0.27 per KWh. The national average for September from the Department of Energy was $0.1194. Looks like location is his problem, although the DoE reports that California's average was $0.1459 per KWh. Are there enough taxes to raise that by 66%?

        Lucky me, I live in Idaho. 7 cents per KWh. I whine when the power bill hits $100 in the summer.

    • Re:$400 a month? (Score:5, Interesting)

      by je ne sais quoi (987177) on Wednesday January 14, 2009 @10:31AM (#26448985)
      Look at the kWh, he's using 1,635kWh per month. While it is high, it's not surprising if his house is especially large and he has a heat-pump. Those things are notoriously inefficient if the temperature drops below 40 degrees F. It getting that cold should be rare in silicon valley, but it does happen.

      What I found interesting was that, while December was bad for solar power, he says:

      My total power consumption cost for the last six months is $389.39--less than my utility bill for January, 2008.

      Basically, his solar power does what it's supposed to more often than not. But then again, we've always known that about solar power, the big problem with solar is the large up-front capital cost of installing it.

      (Or other strange things, like my mother just moved into a retirement community and her housing rules say solar panels are not allowed because they're unsightly, but directTV antennas and satellite dishes are just fine. One must have priorities I suppose. Television is obviously more important than renewable energy.)

      • Re: (Score:3, Informative)

        by maxume (22995)

        The dishes are allowed because federal law says that they have to be:

        http://www.fcc.gov/mb/facts/otard.html [fcc.gov]

        Given time and lower installation costs, I would imagine that similar legislation will be applied to solar cells.

      • Re:$400 a month? (Score:5, Interesting)

        by Andy Dodd (701) <.ude.llenroc. .ta. .7dta.> on Wednesday January 14, 2009 @10:54AM (#26449425) Homepage

        "but directTV antennas and satellite dishes are just fine"

        After a couple of legal battles, there are some federal laws that say that banning antennas and dishes in a housing development is not permitted. Many developments try to do it anyway but you can fight it if you know the right laws.

      • Re:$400 a month? (Score:5, Interesting)

        by Joe Snipe (224958) on Wednesday January 14, 2009 @10:55AM (#26449459) Homepage Journal

        Dishes are allowed because someone paid the FCC to enforce the right to install one. If you can come up with a solar panel that generates ad based revenues and is steeped with kickbacks and non-compete contracts, someone will pay the FCC to enforce the right to install those on your moms roof too.

        • Re:$400 a month? (Score:5, Interesting)

          by MBGMorden (803437) on Wednesday January 14, 2009 @10:57AM (#26449517)

          It's not just being paid off - external television antennas were part of those laws too.

          The whole thing is disgusting to me though. We're not living in any semblance of a free country when your neighbors can tell you what things you can and can't have on your property simply because they don't look pretty.

          • Re:$400 a month? (Score:4, Insightful)

            by inviolet (797804) <slashdot AT ideasmatter DOT org> on Wednesday January 14, 2009 @11:43AM (#26450441) Journal

            The whole thing is disgusting to me though. We're not living in any semblance of a free country when your neighbors can tell you what things you can and can't have on your property simply because they don't look pretty.

            If you equate 'free' with "allowed to create negative externalities", then yes, we are not living in any semblance of a free country. But your lost externality is a necessary part of preventing all those other externalities that you would hate, such as loud music.

            That said, I agree that 'prettiness' is a difficult externality to quantify, and enforcement of non-quantifiable things is perilous.

          • Re: (Score:3, Insightful)

            We're not living in any semblance of a free country when your neighbors ...

            We have a free society. That is, society is free to do whatever it wants, including taking away rights from individual members of that society. Our society is free, but individuals within that society are not.

          • Re: (Score:3, Insightful)

            by CodeBuster (516420)

            We're not living in any semblance of a free country when your neighbors can tell you what things you can and can't have on your property simply because they don't look pretty.

            You could always put up the solar panels anyway and then publish their fight to get your 'unsightly' solar panels taken down in your blog and on the local news. Sometimes a little public shame can go a long way towards changing people's attitudes and positions. Nobody likes to be the 'bad guy' in a public news story.

      • Re:$400 a month? (Score:5, Informative)

        by Muad'Dave (255648) on Wednesday January 14, 2009 @10:56AM (#26449469) Homepage
        Restrictions on the installation of DirectTV and other satellite dishes are explicitly preempted by FCC regulation [fcc.gov] in the US.
    • Re:$400 a month? (Score:5, Informative)

      by dfdashh (1060546) on Wednesday January 14, 2009 @10:33AM (#26449039)
      Here's why, from his initial article [extremetech.com]:

      Our power usage is unusually high for a typical, four person nuclear family. A big part of that is because I have a PC lab and network in the basement. Both my wife and I work out of the house much of the time, with her time almost 100% in the home office. Plus, we have two teenage girls and a pretty beefy HDTV and home audio setup in the family room.

    • Re:$400 a month? (Score:4, Interesting)

      by SBrach (1073190) on Wednesday January 14, 2009 @10:37AM (#26449111)
      Anyone in the southwest running a 3-6 ton heatpump in the summer when it is over 100F and the winter when it is below 40F. My house is 1400 sq. ft. and even though I have one of the cheapest electricity rates in the country (APS combined advantage 7am-12pm)I still pay $250-350/mo. during the summer. So far my bills for Nov. and Dec. have only been around $150/mo but I also have a load controller on my house which many people say cuts their bills in half. Basically I set a maximum demand limit in kW's and the unit prevents either my A/C, dryer, and/or hot water heater from running if need be to stay under that limit depending on the priority set for each appliance. Currently I have it set at 2.0kW but during the summer it needs to be above 5.5 for the A/C to run enough to keep the house cool. The unit does not restrict anything during off peak hours.
    • Re: (Score:3, Insightful)

      by Lumpy (12016)

      Let alone the man did it half assed.

      I used to have a solar home. Step 1 is knowing your EXACT load before you start.

      Step 2 is to understand the solar rating for your location, then cut it by 1/4 and use that number.

      The man did neither. he should have a 35-50% excess for summer and have a 10-20% lacking in winter. Supplement that with a single decent wind generator and your intertie.

      Finally your biggest step to solar is you REDUCE YOUR CONSUMPTION. We bought all low energy appliances and got rid of silly

      • Re:$400 a month? (Score:4, Insightful)

        by drunkennewfiemidget (712572) on Wednesday January 14, 2009 @11:00AM (#26449565) Homepage

        It's a half assed install that was doomed from day one, and now he's bitching about it.

        Of course, technology marches on, and there will no doubt, with higher efficiency panels available at lower prices in the coming years. Alas, that's the price one pays for being an early adopter. But when I look at my power bill, I still have a nice, warm feeling inside.

        ... he is?

      • Re:$400 a month? (Score:5, Informative)

        by MoonBuggy (611105) on Wednesday January 14, 2009 @11:37AM (#26450295) Journal

        Firstly, he's not bitching about it. To quote TFA:

        But Is It Really Worth It?
        For a variety of reasons: cost, that "green" feeling, and the idea that I have an asset that generates income on my roof, I personally think it's worth it. Overall, the system has been operating smoothly.

        Secondly, if you look at the article [extremetech.com] he wrote when the system was installed, you'll see that he looked into a variety of options and chose the one that he felt fitted his situation best. It is estimated to pay for itself within 10 years, which seems perfectly sensible to me - as he points out, he's pumping money into an asset that increases the value of his house rather than simply giving it away to the electrical company.

        I don't see how it's half-assed, it's working perfectly well, it appears cost-effective so far and he says he's happy with it. You don't seem to be trolling, I don't think, but your post just fails to make sense.

      • Re: (Score:3, Informative)

        by radl33t (900691)
        You shouldn't be so critical. His experience will be more typical of future solar converts than your know-it-all solution. One of the main problems is that solar energy will necessarily have to respond to the twisted and misinformed attitudes of most people... Relatively speaking this guy seems on the ball... Besides your answer is just as half-assed when compared to a number of other 'superior' methods.
    • Re:$400 a month? (Score:4, Informative)

      by winkydink (650484) * <sv.dude@gmail.com> on Wednesday January 14, 2009 @10:56AM (#26449485) Homepage Journal

      He is a PG&E customer in Northern California. That's how he spends $400 a month on electricity.

      PG&E = Pricks Grabbing Everything

    • by afabbro (33948) on Wednesday January 14, 2009 @11:03AM (#26449611) Homepage

      Who the hell uses that much electric power?

      His other hobby is recycling aluminum.

    • Re: (Score:3, Informative)

      by tweek (18111)

      Read the article a little more closely. He isn't a standard run-of-the-mill electricity consumer. He runs benchmarks on hardware from his home requiring multiple pcs running at full bore (I'm inferring the last part based on experience in the load testing arena). Additionally, he DOES live in CA so he probably runs the AC more than someone who lives in MI.

      If you look at my power bill, you might say the same thing. I have running at home right now, the following:

      - Dell M1710 laptop
      - Dual-CPU Opteron workstat

  • by Carik (205890) on Wednesday January 14, 2009 @10:27AM (#26448911)

    There's an important step that this guy missed: cutting consumption. I have a roughly 3000 square foot house, and the most I've used since August '07 is 700kWh in a month... and that was a month when I had visitors for basically the whole month, so we used a lot more power. My average is around 500.

    Now... we don't know how big this guy's house is, or how many people live there. But really... 1,635kWh? That seems pretty excessive for any reasonable house. Maybe if he's got a bunch of servers on all the time, and has electric heat, and lives in a cold climate, but it still seems high.

    • Insightful (Score:3, Interesting)

      by Kupfernigk (1190345)
      Yes, he spent $36000 up front on the system, which means that even with 25 year life on the panels an eventual payback is uncertain. He must surely also know that in a few years those same panels will probably cost no more than half that, so he has heavy depreciation to contend with. Of course people do waste money on big toys- I plead guilty myself - but you don't get much actual enjoyment out of a solar panel.

      I don't know about the position in the US, but in Europe there is a market in energy efficient ap

      • Re:Insightful (Score:5, Insightful)

        by QuantumRiff (120817) on Wednesday January 14, 2009 @10:52AM (#26449391)

        Yes the panels will drop in cost, but you are forgetting that Electric bills are going to go UP in price over the same time. 10 years from now, he can generate the same amount of power, and save more money than he does today.

        Of course, those that wait will have a MUCH quicker payback, since their equipment goes down in cost, and rates go up. But then again, you probably don't own a computer, do you? Cause there is always one that is faster/cheaper coming in another few months. Sometimes you just gotta jump in.

  • ROI? (Score:3, Interesting)

    by RyanSpade (820527) on Wednesday January 14, 2009 @10:32AM (#26449005) Homepage

    Why didn't this follow up article include a Return on Investment number? It would be nice if he would have included the cost of the install and compare it to the difference in his electric bills. I'm curious to see how long it will take the install to pay for itself.

    • Re:ROI? (Score:5, Funny)

      by lucifuge31337 (529072) <daryl AT introspect DOT net> on Wednesday January 14, 2009 @10:47AM (#26449293) Homepage

      Why didn't this follow up article include a Return on Investment number?

      For the same reason that you NEVER EVER add up your receipts when you are restoring a car. It is sure to make you cry.

    • by clonan (64380) on Wednesday January 14, 2009 @10:57AM (#26449519)

      I went back to his original article (the instalation). He said the estimate is that his anual utility bill will drop from 4400 a year to 1100 a year.

      So I made a few assumptions.

      #1-his power use will not increase. Not really likely but a future increase shouldn't change the ROI on his current investment.

      #2-Utilities will just keep pace with inflation (assumed 2%)...power costs will stay porportinally expensive in the future. This is probably not ture as power prices tend to increase slightly faster than inflation. So this assumption will tend to increase the ROI.

      #3-I assume he is financing it through his mortgage at about 5%

      Therefore when I calculate out to 25 years I find that he would spend about $141,000 in power over the 25 years without slar. With Solar he would spend $35,233.

      The Payoff date comes at about 12.5 years.

  • by RichMan (8097) on Wednesday January 14, 2009 @10:36AM (#26449097)

    Who ever installed the panels mounted them directly flat on the roof. That is bad.

    They need to be angled for the best sun during the time the power need is greatest. Ideally they would be adjustable semi-annually/quarterly/monthly for the best angle. And if fixed would be biased toward the point of worst number of sun days and power need.

    Doing a suboptimal installation and not accounting for sun angle is not a good installation and should be perform at a fraction of potential output.

  • by Maxo-Texas (864189) on Wednesday January 14, 2009 @12:01PM (#26450859)

    A lot of it would be gone.

    You can count on the returns for solar.

    You can pretty much count on electric rates rising in the future.

  • No single solution (Score:3, Interesting)

    by AviLazar (741826) on Wednesday January 14, 2009 @12:25PM (#26451415) Journal
    People talk about single solutions but that is not the answer. It will be a blended solution. It will be a combination of solar, natural gas, wind, water, AND nuclear. In Israel, ever since I can remember (80s) each house/condo has solar panels to help heat water tanks...which are also sitting under the sun. Wind turbines are in various areas (Atlantic City NJ has about 5 or 6 MAJOR wind mills). Water turbines can work well. In California they created these water turbines that are hidden into the cliffsides. So when surf hits it water is sent up (and back down) to generate electricity.

    But all of those will not be enough. We also need to supplant that with natural gas and nuclear energy. We also need to find ways to recycle spent nuclear fuel and convert it to useful energy...put it this way if that spent fuel is SO radioactive (meaning having lots of energy) then we could harnass it - we just don't know how (i think).

    Until we get warp power - a blended solution will be needed - but it can work.
  • by ducomputergeek (595742) on Wednesday January 14, 2009 @12:51PM (#26451997)

    And that's in the winter. It's a lot more in the summer because of AC. Granted our building faces south and in the winter time gets a lot of solar time when the sun is out.
    Granted we're a business and we run several servers in house 24x7 for development, testing, and backup and about 25 PC's.

    We put up as much solar as we could given our amount of roof space last October. We've seen our electric bill go down to around $700 - $900 per month. It's basically cut our bill in half. Now we had the cash on hand to invest in the technology, plus there were some tax write offs that made it advantageous to do so before December of 2008.

    But we viewed it as a wise investment that freed up over $1000 a month in cash flow. That's about a $1000 per month we can spend on additional development. It doesn't sound like much, but it was enough to offer 2 paid internships this spring semester at the local university.

    Will the investment still take 5 - 7 years to pay for itself? In raw dollars, yes. But there are intangibles as far as I'm concerned. We've found two really good interns for this spring semester. Just over winter break they were able to take a piece of one project and get it to a working beta. It was the final piece of the puzzle to finishing that product that is now on the market and we've already got 20 installs lined up totaling about 1/3rd the cost of the solar panels.

    Granted, we knew what our limits were. We did it not to be green and save money. The cash was either going to be given out as dividends (we are employee owned) and taxed or retained as earnings and taxed.

  • by Doc Ruby (173196) on Wednesday January 14, 2009 @01:08PM (#26452329) Homepage Journal

    That article has a lot of consumption and billing numbers for each of utility and homegrown power, but it's hard to get exact performance comparisons because the numbers don't exactly measure the same things. There is no exact start and end date, just month names, and approximate mentions of offsets into them, not lining up generation and billing dates in either the solar generation half-year or the time before drawing from only the utility. And practically no data on income from overgenerating, selling back to utility or grid.

    But there is enough data to make rough comparisons. They say [extremetech.com] their January/utility bill was $446, but their December bills are the highest (all of which extra usage was billed in the highest rate, 300% of the base rate). So let's say their average bill used to be $450:mo, or $5600 annually. However, they said [extremetech.com] up front that their annual bill is about $4400. We'll take the average of $5400. Now their July-December/solar bill is $389.39. Even if we call that $400, and so their annual/solar bill is $800, they're saving $4600 a year. They paid [extremetech.com] about $55,000 before rebates, about $37,000 after all rebates. Their utility bill savings pays off their installation investment in $37,000 / $4600 = 8.04 years. Pessimistically, they should be paid off in 9 years.

    These systems have a minimum lifetime of 30 years (if you don't invest in an upgrade during that time). Even if energy rates stay the same in those 30 years (probably not, probably higher), that $4600 for 21 more years is $96,600, or 2.6x the installation cost. Total return is $133,600 on $37,000 investment, so 3600% Return on Investment over 30 years. If you invested that money in a compound interest account (either savings or some investment with an average annual return reinvested), you'd have to get 15.43% annual compound interest to turn $37K into $136K in 30 years. Conversely, if you took out a 30 year mortgage on your home at today's average rate of 5.63%, you'd net 9.8% benefit. Which means that it's worth mortgaging (part of) your home to invest in these, with a fraction of your old utility bills paid as mortgage interest, and getting $78K more ("profit", really utilities savings) after 30 years, with no out of pocket.

    That could be even better than they say. Their reasons [extremetech.com] for failing to maximize their roof generating area don't seem compelling: "it would get a little crowded up there". Other than access to the panels for cleaning, who cares how crowded it is? It looks like they could double their area. Which would give them closer to zero Winter bills, but overkill in Summer that exceeds what's left (if any) during Winter, which exceeds their "zero annual bill" maximum for reselling overgeneration to the utility at retail rates. So probably about 1.5x the area would give them Summer overgeneration that would equal their Winter utility draw, netting zero bills. It's got to cost less than 1.5x to install just more area, because labor and shared components (especially the inverter that sells power back to the utility) are a substantial cost that doesn't increase at all at that rate. Say it costs 1.2x, or $44,400, but they save the full $5400 annually. That's still about the same time in payback (about 2% longer), but 3.7x the return. And the "green feeling" is complete.

    • Re: (Score:3, Informative)

      by NereusRen (811533)

      Total return is $133,600 on $37,000 investment, so 3600% Return on Investment over 30 years.

      I assume this was a typo for 360%. Of course, calculating total return like that is a pretty horrible way to measure whether a long-term investment is worth it. A better way is this method:

      If you invested that money in a compound interest account (either savings or some investment with an average annual return reinvested), you'd have to get 15.43% annual compound interest to turn $37K into $136K in 30 years.

      But you messed it up somehow... by a LOT. The actual number is slightly under 4.4%. You can verify it like so: since you gain 4.4% compounded each year, calculate $37k * (1.044) * (1.044) ..., 30 times, for a total of $37k * (1.044^30), which is about $134k.

      Still, 4.4% isn't bad. Good luck earning that on rolling CDs, eve

  • by Doc Ruby (173196) on Wednesday January 14, 2009 @04:05PM (#26455381) Homepage Journal

    Solar PV is a good replacement for utility electricity, as this article demonstrates.

    Solar heating of water is supposed to be even more economical. The equipment is cheaper (basically a black pipe looped across area), and captures a lot more than 20% of the sun's power in the heated water. The only problem is that the extra power not consumed by using the hot water (washing or heating the building's air) is lost, dissipated through the system, or discharged when it exceeds even the water tank's heat storage capacity. But the tank can be made very large, and its heat can be converted to electricity (inefficiently, but better than losing it). You don't get to send unlimited surplus power back to a "bottomless reservoir" like the surplus PV electric to the utility, but some large tank should be sufficient to store all the extra heat. And perhaps store some extra PV power beyond what the electric utility will stop taking when the net annual utility consumption reaches zero. Elevating the water stores energy at close to 90% efficiency (the multiplied efficiencies of the elevating electric pump and the electric turbine in the downpipe).

    It seems that there's a compelling case for installing both, and using a large tank as storage that increases the total efficiency substantially beyond the basic operating parameters. Which sounds like it's even better than the 3-4x+ 30 year ROI from just the PV demonstrated in the article.

  • by niktemadur (793971) on Wednesday January 14, 2009 @06:34PM (#26457943)

    I remember reading about solar shingles a few years ago, how it was supposed to be the next wave of solar power for the home, the price was lower for installation, etc. I did read that they were a bit less efficient, but you were able to cover a much larger area of your roof for the price, thereby more than offsetting the disadvantages.

    Fast forward to today, everywhere I look people are still installing solar panels and I haven't seen a single new article, blog or discussion about solar shingles. Was the technology flawed?

    I'd love some feedback on this, because there's a possibility I might build a home in the foreseeable future, and I'm definitely intending on going solar for both electricity and water, maybe even a heat pump. Proper insulation is a given, energy efficiency appliances, passive solar design. I'd love to shoot the works on this project.

We warn the reader in advance that the proof presented here depends on a clever but highly unmotivated trick. -- Howard Anton, "Elementary Linear Algebra"

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