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Switching To Solar Power – One Month Later

Soulskill posted more than 5 years ago | from the bright-idea dept.

Power 730

ThinSkin writes "After an interesting article on solar panel installation for the home, Loyd Case at ExtremeTech has written a follow-up after about a month of normal use. Posting an $11.34 electric bill (roughly 3% of previous months), Loyd shares his experiences using solar power and how it can be fun for the geek, with computer monitoring services and power generation data. Of course, solar power isn't all fun and games, given the amount of required maintenance — even unpredictable maintenance, like wiping off accumulated ash from fires in Northern California."

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haha (-1, Offtopic)

Anonymous Coward | more than 5 years ago | (#24282217)

trix are for kids mutherfucker!

Re:haha (5, Insightful)

negRo_slim (636783) | more than 5 years ago | (#24282295)

trix are for kids mutherfucker!

That's right and responsible energy use is for adults. I like to see things like this, and as some might decry the amount of involvement one must provide to effectively commit to a project along similar lines. Though I personally think people (especially in the U.S.) could really benefit from having to be more involved in the production and usage of the energy they consume.

Re:haha (0)

TheSync (5291) | more than 6 years ago | (#24282587)

Though I personally think people (especially in the U.S.) could really benefit from having to be more involved in the production and usage of the energy they consume.

I prefer that people stick to doing what they do best and thus provide greater wealth to humanity through specialization (as mathematically proven by Ricardo [wikipedia.org] ).

Re:haha (3, Funny)

mrbluze (1034940) | more than 6 years ago | (#24282859)

I prefer that people stick to doing what they do best and thus provide greater wealth to humanity through specialization (as mathematically proven by Ricardo [wikipedia.org]).

You and every banker.

Insane energy usage. (5, Interesting)

SuperQ (431) | more than 6 years ago | (#24282915)

Yea, I was shocked at how much energy the family in this article uses. My GF and I average ~370kWh/month, 4,440kWh/year. We live in Mountain View, which is the next small city over from Sunnyvale. The family in this article is using 17,400kWh/year. If he expects a 20% drop in usage when the family becomes 2 people, that's still THREE TIMES what we use. I also have a home server and network.

My PC is running great on solar power ... (5, Funny)

krkhan (1071096) | more than 5 years ago | (#24282239)

... even though it was raining cats and dogs today. I'm still using it withou

Rookie mistake (4, Funny)

ciaohound (118419) | more than 6 years ago | (#24282865)

You forgot to engage the hydropower backup generator.

Why can't he sell it back? (5, Interesting)

deanoaz (843940) | more than 5 years ago | (#24282241)

According to the article California will not allow homeowners to sell more power back into the grid than they are buying. He doesn't say why. I don't understand the reasoning for such a restriction, since the possibility of selling more than you buy would encourage wider adoption.

Re:Why can't he sell it back? (5, Interesting)

Delwin (599872) | more than 6 years ago | (#24282313)

Because their billing structure would put the power company out of business if they allowed it.

Note that while can't go net negative for the year he can get to net 0. Also note that he's 'selling' back power to get to that net 0 at retail rates.

The places that allow you to go net negative buy your power back at wholesale rates, which is far lower. If you think about it when you sell power back to the power company you're not competing with the power company, you're competing with the power generators. Why should the power company give you an unfair advantage there?

Re:Why can't he sell it back? (4, Insightful)

shaitand (626655) | more than 6 years ago | (#24282443)

Simple fix, trade kwh for kwh until net zero is reached and then sell excess for wholesale. Of course you would do this on an estimated annual usage basis just like the 'budget' billing most power consumers have to prevent huge spikes in their bills during certain hot or cold months.

As for putting the power company out of business, I'm all for it. Whoever had the bright idea of privatizing a utility should be shot. Fundemental public services should not be privatized they should be public and operating in a fully transparent manner. Roads, Schools, Libraries, Utilities, and Health Care.

Re:Why can't he sell it back? (-1, Offtopic)

CensorshipDonkey (1108755) | more than 6 years ago | (#24282659)

Mod parent up, insightful stuff!

Re:Why can't he sell it back? (2, Insightful)

Anonymous Coward | more than 6 years ago | (#24282779)

expect the power company ensures that everyone has lights when possible. There is a lot of regulation there. The problem without that is that who is going to pay you back, who are you getting the power from, what prevents you from not giving power to some people. At the very least you have to have some organization there to paid and sell power.

Re:Why can't he sell it back? (3, Insightful)

Firethorn (177587) | more than 6 years ago | (#24282895)

My power company, like my phone company, is a coop. I'd like them to remain in business, thank you very much.

Then again, depending on your definition, a coop could be considered a 'public' company.

Re:Why can't he sell it back? (1)

crispytwo (1144275) | more than 6 years ago | (#24282973)

Fundemental public services should not be privatized they should be public and operating in a fully transparent manner. Roads, Schools, Libraries, Utilities, and Health Care.

hear hear!

Re:Why can't he sell it back? (5, Interesting)

Klaus_1250 (987230) | more than 6 years ago | (#24282515)

Why should the power company give you an unfair advantage there?

Lower costs for the power-company in terms of transmission and distribution of power (and related costs for that infrastructure). E.g. the power you produce can go right to your next door neighbor. Power from a power station usually has to travel quite a bit.

Re:Why can't he sell it back? (1)

CensorshipDonkey (1108755) | more than 6 years ago | (#24282705)

Good point!

Re:Why can't he sell it back? (0)

Anonymous Coward | more than 6 years ago | (#24282325)

Probably because he's getting retail rates for the extra power. Unless he has a large surplus, he's better off that way.

Re:Why can't he sell it back? (2, Informative)

negRo_slim (636783) | more than 6 years ago | (#24282333)

It's called Net Metering [wikipedia.org] you can check Google [google.com] for more information...

Re:Why can't he sell it back? (4, Informative)

dfsmith (960400) | more than 6 years ago | (#24282345)

It was arranged so that PG&E will never have to pay you money.

There is also a $5 "connection fee" each month, so your smallest possible annual bill will be about $50. I used to hit that with a 4kW array (minute-by-minute stats are available [dfsmith.net] ).

Re:Why can't he sell it back? (1, Troll)

nido (102070) | more than 6 years ago | (#24282637)

I don't understand the reasoning for such a restriction, since the possibility of selling more than you buy would encourage wider adoption.

This is the reason. There are three problems with individuals (citizens, if you prefer) persuing their own personal Energy Liberation. One is easily solvable; the other two are not.

Freedom from the electric company is one aspect of Liberation Theology; Valcent Products [valcent.net] ' technology offers the possibility of a BioDiesel Cooperative, where individuals could buy a "plastic bag" to hang at the local Algae Farm, completely cutting Wall Street out of the transportation energy marketplace. (There are other options coming down the pipe to cut Big Oil out of the picture -- I'm just listing this one because it's the most direct substitution I've yet heard about.)

  1. As the cost of energy plummets from the commodity rate (where you pay for every watt-hour/gallon consumed) to the ... investment level (where you pay once, and for irregular maintenance), individuals will have a lot more time on their hands... How will they spend their time, if they don't have to spend so much time to pay for energy (heating, light, transportation - I believe the statistic is 500 calories of energy to get 1 strawberry from California to New York in the winter)?
  2. Government revenues will fall like a rock. With people working less, income taxes receipts will fall like a brick. However will the government motivate us to slave away if we don't have to?

    Also, a good chunk (300 billion?) of federal revenue comes from leasing lands containing hydrocarbons to Wall Street. Once we've cut Wall Street out of the picture, there goes that honeypot. How will the U.S. Federal Government finance the interest on the money supply, much less station troops on bases and outposts in 100+ countries?

  3. Utility companies have traditionally paid good dividends. How will we support people whose incomes depend on those dividends? With significantly reduced cost of living, pensioners won't be a big problem. But private golf courses don't mow themselves...

I'm sure there are other problems with Energy Liberation, but these are just the three I've been thinking about...

Re:Why can't he sell it back? (1)

fred fleenblat (463628) | more than 6 years ago | (#24282679)

Obviously, the utility needs to make money, but a secondary consideration is that they don't want to encourage large numbers of people to send excess power back up the lines. Imagine a whole neighborhood of solar enthusiasts on a bright clear spring day (i.e. cool enough to not need a/c) pumping several thousand Amps backwards through the lines. The substations were not designed for this and could conceivably trip a breaker at best, catch fire and spew PCB's at worst.

And there is no way the utility will let you net meter more than your service amps (often in the range of 200) which comes out to a 24kw array. The install in the article was 1/4 of the way there which is not a huge margin of safety. A larger install and slightly more efficient panels (coming soon) would do it.

Re:Why can't he sell it back? (4, Insightful)

rcw-home (122017) | more than 6 years ago | (#24282923)

Imagine a whole neighborhood of solar enthusiasts on a bright clear spring day (i.e. cool enough to not need a/c) pumping several thousand Amps backwards through the lines. The substations were not designed for this and could conceivably trip a breaker at best, catch fire and spew PCB's at worst.

I think this is a long ways off, and I'd imagine that if this starts happening, they'd start installing more/bigger transmission infrastructure, rather than a voluntary-shutoff communications infrastructure. They may even increase their connection fees to do so. The power company wouldn't want all that power to go to waste.

And there is no way the utility will let you net meter more than your service amps (often in the range of 200) which comes out to a 24kw array.

Err, 240*200 = 48kW.

The install in the article was 1/4 of the way there which is not a huge margin of safety.

First off, if the solar constant [wikipedia.org] changes by a factor of 4, this guy's wiring is going to be the least of your trouble. Second, NEC ampacity standards are for tolerable voltage drop, not wire overheating. A 200A-rated line will actually carry a lot more than 200A. Third, many of the newer electrical panels have a main breaker that everything goes through. They are thermal, so they don't care which direction the electricity is going through them. If not, the inverter will usually have an output breaker of its own. Fourth, the house itself is consuming a good fraction of the power it's generating.

Wait to winter time when there is less sun to see. (3, Insightful)

Joe The Dragon (967727) | more than 5 years ago | (#24282247)

Wait to winter time when there is less sun to see how much you save at that time.

Re:Wait to winter time when there is less sun to s (1)

sholsinger (1131365) | more than 6 years ago | (#24282329)

Wait to winter time when there is less sun to see how much you save at that time.

In Alaska, maybe. I doubt that it will affect the California resident's generation ability.

Re:Wait to winter time when there is less sun to s (2, Insightful)

shaitand (626655) | more than 6 years ago | (#24282469)

It sure will. Even in California or here in Florida you have fewer hours of sun in the winter. Since most people on solar are trying to live on far less energy than a human needs to be comfortable in order to utilize technology that simply isn't cost effective yet, I have no doubt they will be borrowing from the grid in winter.

On the other hand, unlike the northern states, power usage in these places is also reduced. In warm climate areas you stay inside in the summer to avoid the weather rather than the winter.

Re:Wait to winter time when there is less sun to s (0)

Anonymous Coward | more than 6 years ago | (#24282669)

Yes, but how many hours of sunlight in Alaska in the summer, when most of the residents and tourists are there? Perhaps they can pipeline it down to rainy Seattle?

Re:Wait to winter time when there is less sun to s (3, Interesting)

tha_mink (518151) | more than 6 years ago | (#24282745)

It sure will. Even in California or here in Florida you have fewer hours of sun in the winter. Since most people on solar are trying to live on far less energy than a human needs to be comfortable in order to utilize technology that simply isn't cost effective yet, I have no doubt they will be borrowing from the grid in winter.

Of course, if you'd RTFA, you'd know that the author mentioned that and figured his overall power bill to go from $4000 to roughly $1000 yearly.

You'd also have known that he states his power usage is higher than your typical family home due to the fact that both he and his wife work from home, he's got two teenage daughters, a pc lab, and pretty hdtv setups around his house. (thus the $4000/yr electric bill in the first place)

If you wanted to be a crotchety bitch, which clearly you did, you would have mentioned that it'll take him roughly 11-15 years to recoup his investment of $40,000 for the equipment and setup. That's what I'd go with.

Re:Wait to winter time when there is less sun to s (1)

Narpak (961733) | more than 6 years ago | (#24282907)

If you wanted to be a crotchety bitch, which clearly you did, you would have mentioned that it'll take him roughly 11-15 years to recoup his investment of $40,000 for the equipment and setup. That's what I'd go with.

Unless of course the price of energy rises significantly, then he will probably "recoup his investment" quicker. Not to mention that he is less dependant on energy companies and that the effectiveness of solar panels is bound to increase. As mentioned in this earlier Slashdot post:
http://web.mit.edu/newsoffice/2008/solarcells-0710.html [mit.edu]
http://hardware.slashdot.org/article.pl?sid=08/07/11/2017237 [slashdot.org]

Even if solar panels only reduces your energy consumption during the summer; if everyone in a relevant area did this perhaps the general price of energy would drop; even during winter. Since the general consumption would be reduced.

Re:Wait to winter time when there is less sun to s (3, Informative)

Rei (128717) | more than 6 years ago | (#24282983)

Working against that, you need to amortize your capital costs and pay for maintenance. Still, in some parts of the country, solar can indeed give you a reasonable mortgage length and IRR [daughtersoftiresias.org]

Re:Wait to winter time when there is less sun to s (1)

mattack2 (1165421) | more than 6 years ago | (#24282899)

Not cost effective? He went from a $348 bill to a $11 bill.. It will go down in the winter of course, as you say. But it will "pay for itself" in a short period of time.

Re:Wait to winter time when there is less sun to s (2, Interesting)

RobinH (124750) | more than 6 years ago | (#24282359)

This is actually quite striking. I worked on a solar/wind project last year and the solar panel we were using was an 80W rated panel (normally provides a little over 60W in full sunlight at these latitudes), but I never realized how much your eyes compensate for the variation in illumination levels. When it was cloudy in the winter, even when you could see perfectly well and thought it was rather bright outside, the solar panel was only pumping out about 2 or 3 watts.

The idea is that it tends to be windy and sunny alternately, which is somewhat true, so they market wind and solar as a good combo, but the fact is the amount you have to spend to get the same power from wind is way more than the equivalent amount for solar, and trust me there are lots of times when it was calm and overcast for weeks.

Still I think the most economical setup would be to find a way to reduce the hardware as much as possible. Let's say you have air conditioning for instance. Take a solar panel, use it to charge a single 12V auto battery, and then use a voltage sensitive relay to turn on a surplus 12V marine air conditioner. Basically the solar charges up the battery. When there's enough power in there, the air conditioner kicks on and runs for 15 minutes or so and drains the charge out of the battery. The sunnier it is, the more the air conditioner runs, and that means your central air (powered by the grid) runs less. The benefit is that you don't need to fuss with inverters and big battery packs.

Re:Wait to winter time when there is less sun to s (1)

shaitand (626655) | more than 6 years ago | (#24282489)

That would be a nice idea if marine a/c units weren't ungodly expensive.

Re:Wait to winter time when there is less sun to s (1)

Joe The Dragon (967727) | more than 6 years ago | (#24282581)

There was this one guy who rigged up a window unit ac in his truck useing a 12Vdc to 120Vac inverter.

Re:Wait to winter time when there is less sun to s (1)

shaitand (626655) | more than 6 years ago | (#24282617)

a number of people do that here in florida if a hurricane knocks out power. A lot more plug A/C units into gas generators which are basically the same thing without the truck.

Re:Wait to winter time when there is less sun to s (1)

maxume (22995) | more than 6 years ago | (#24282935)

I think he means that the A/C was installed _in_ the truck, not hooked up to run off of power from the truck.

Re:Wait to winter time when there is less sun to s (0)

Anonymous Coward | more than 6 years ago | (#24282433)

As opposed to saving nothing at all??

Re:Wait to winter time when there is less sun to s (2, Interesting)

Anonymous Coward | more than 6 years ago | (#24282491)

Mod parent up! I am posting from a house with four 80W solar panels on a rainy day and the generator is on. If you want to go solar you need a lot of batteries and a lot of panels.
Of course, we don't have the convenience of mains power at all.

F.Y.I
Current usage is; 1 laptop (80W), 1 low power fridge (120W), 1 one modem (8W). Storage is 4 deep cycle batteries.

Re:Wait to winter time when there is less sun to s (0)

Anonymous Coward | more than 6 years ago | (#24282833)

What are you using for an ISP if you have no connections?

Winter MegaHurtz (0)

Anonymous Coward | more than 5 years ago | (#24282265)

I want to see what happens to usage in winter! When buns are a cold and Mhz use increases due to rainy days!

Re:Winter MegaHurtz (2, Funny)

smitty_one_each (243267) | more than 6 years ago | (#24282631)

It's OK, he has Three Dog Night on the iPod.

Not a month (4, Informative)

krkhan (1071096) | more than 5 years ago | (#24282297)

about a month of normal use. Posting an $11.34 electric bill

From TFA:

Additionally, I've received my first electric bill since the installation, although it's only for 19 days, not the usual 29 or 30.

Re:Not a month (1)

WindBourne (631190) | more than 6 years ago | (#24282339)

Ok, add an extra 30% to it. Gee, it is up $15.00. I will take a bill like that.

Re:Not a month (1)

Brain Damaged Bogan (1006835) | more than 6 years ago | (#24282427)

the summary never mentioned the time period of the bill... and you apparently stopped reading TFA after that paragraph... he estimated his monthly (30 day) bill to be about $16

Re:Not a month (1)

krkhan (1071096) | more than 6 years ago | (#24282497)

the summary never mentioned the time period of the bill... and you apparently stopped reading TFA after that paragraph... he estimated his monthly (30 day) bill to be about $16

For your later point, he did. For the former: RTFS and then RTPP.

Loyd Case at ExtremeTech has written a follow-up after about a month of normal use.

I just pointed out that he didn't use it for a month after-all. The estimate surely is handsome but that still doesn't vindicate the summary's inaccuracy.

That last paragraph says it all (3, Insightful)

WindBourne (631190) | more than 6 years ago | (#24282393)

money going towards assets rather than a simple debt. Would you rather own or rent?

Re:That last paragraph says it all (3, Informative)

raoulortega (306691) | more than 6 years ago | (#24282537)

Depends on how fast those assets depreciate, and the long-term maintenance costs.

Eh (5, Informative)

Reality Master 101 (179095) | more than 6 years ago | (#24282401)

So he saved about $330/month. It cost him $36K (which really cost $50K, but let's say). So it'll take 109 months to get back the money, or 9 years, not adjusting for inflation and investment opportunity cost. Let's say that brings it up to 12 years. Not including maintenance and repairs. It might even need complete replacement at that point. At 50K, which is the real cost, we're talking more like 16-18 years.

That's still a bit too long an investment for this to be really practical. Prices need to come down to about a four year payoff before I'd be really interested.

On another subject, I'm kind of glad to see someone who actually uses more electricity than I do. :)

Re:Eh (0)

Reality Master 101 (179095) | more than 6 years ago | (#24282523)

*sigh* Slashdot! Where doing math is considered trolling!

Re:Eh (1, Interesting)

liquidpele (663430) | more than 6 years ago | (#24282543)

Exactly. When I can get panels on my roof for under $5k I'll do it for sure (I'll consider it for under $10k), but until them it's just not practical for me - especially considering Atlanta is a lot more cloudy than California is in my opinion. Solar power is awesome, but no company has found a way to scale the manufacturing up enough yet.

Re:Eh (1)

tha_mink (518151) | more than 6 years ago | (#24282789)

Exactly. When I can get panels on my roof for under $5k I'll do it for sure (I'll consider it for under $10k), but until them it's just not practical for me - especially considering Atlanta is a lot more cloudy than California is in my opinion. Solar power is awesome, but no company has found a way to scale the manufacturing up enough yet.

I'm with you. Too expensive an investment. I'm sure it's only going to be inside of 5 years that that number will approach the happy point of like 7-10G for what this man did.

However, I too live in Atlanta, and was surprised to find out that we get plenty of sun for solar power to be a viable option. I had a few companies quote my house and was told I could expect 80% efficiency given the amount of sun around here.

Re:Eh (1)

maxume (22995) | more than 6 years ago | (#24282819)

Yeah, but how big? I'd be happy to install 10 Watts for you. Hell, I'll even do it for $2,500.

Re:Eh (3, Interesting)

MobileTatsu-NJG (946591) | more than 6 years ago | (#24282559)

So he saved about $330/month. It cost him $36K (which really cost $50K, but let's say). So it'll take 109 months to get back the money, or 9 years, not adjusting for inflation and investment opportunity cost. Let's say that brings it up to 12 years. Not including maintenance and repairs. It might even need complete replacement at that point. At 50K, which is the real cost, we're talking more like 16-18 years.

It seems to me that could change rather dramatically if the price of electricity goes up. I wonder what effect his solar array will have if he buys an electric car that can be plugged in.

Re:Eh (2, Insightful)

blue l0g1c (1007517) | more than 6 years ago | (#24282615)

It's saving them money now. The value of the installation is added to the value of the home. If they ever sold the house, it would justifiably raise the asking price just like a pool, deck, or other improvement to the home.

Bantha Poodoo (1)

mckwant (65143) | more than 6 years ago | (#24282787)

Value of the addon != Increase in house price. The new owner has to want (and be willing and able to pay for) the solar augmentation. It might even be worthless to the new owner, who's not willing to deal with the maintenance.

Plus, there's depreciation, replacement cost for the panels and other materials, and so on. If he breaks even on this, either through sale or plain old energy generation, I'll be amazed.

Re:Eh (1)

CensorshipDonkey (1108755) | more than 6 years ago | (#24282945)

Excellent point, and often overlooked.

Re:Eh (2, Funny)

Tony Hoyle (11698) | more than 6 years ago | (#24282697)

No way a panel will last 16-18 years.. Try 2-3. You've got to factor in the price of complete replacecement. Hell, lets say he gets really lucky and they last 10 years.. he's still making a net loss.

Re:Eh (5, Informative)

d34thm0nk3y (653414) | more than 6 years ago | (#24282769)

No way a panel will last 16-18 years.. Try 2-3. You've got to factor in the price of complete replacecement. Hell, lets say he gets really lucky and they last 10 years.. he's still making a net loss.

From the Article:

These particular panels were guaranteed to deliver 90% of their rated peak capacity for at the twelve year mark, and 80% at the 25 year mark.

Re:Eh (0)

Anonymous Coward | more than 6 years ago | (#24282719)

Mods are smoking crack.

You're 100% right. Whatever he's saving in electricity costs, he's spending on a loan to buy panels. And those panels' power diminishes every year. That's also not counting maintenance costs or anything.

Also, we're talking about savings in a partial month, during summer where sunlight is at is peak, and where we don't need to heat our homes.

I've done the math before, and it would take a good 20 years for to pay for itself. You're essentially just paying someone else i.e. your bank loan instead of the power company.

I opted to keep paying the power company, and not having a loan of several 10's of thousands. I'll consider it again once panels come down in price and generate more power.

Re:Eh (1)

d34thm0nk3y (653414) | more than 6 years ago | (#24282739)

From the Article:

The payback time, assuming energy costs don't spike steeply, is a little under nine years. If we sell the house, we should get it all back immediately.

Re:Eh (4, Interesting)

arth1 (260657) | more than 6 years ago | (#24282763)

So he saved about $330/month. It cost him $36K (which really cost $50K, but let's say). So it'll take 109 months to get back the money, or 9 years, not adjusting for inflation and investment opportunity cost. Let's say that brings it up to 12 years. Not including maintenance and repairs. It might even need complete replacement at that point. At 50K, which is the real cost, we're talking more like 16-18 years.

It's worse than that. The $11 bill was for 19 days, not a month. And 19 sunny summer days, at that. He won't save $330 per month. Let's see what the figures are after a whole year. My guess is that he'll save around $200, at most. For a $36k investment.

Seriously, if I had a $300+ monthly electricity bill, I would start by seeing how I could reduce the amount of electricity used.

Re:Eh (1)

Xyrus (755017) | more than 6 years ago | (#24282879)

You are assuming energy prices are going to stay fixed, which is a very bad assumption.

To project actual savings you can use historical electrical prices and get an average rate of change. That will give you a better idea of actual savings.

Given that this is California we're talking about, I'd expect breakeven probably in the 7 year area.

~X~

Re:Eh (0)

Anonymous Coward | more than 6 years ago | (#24282905)

From TFA:

These particular panels were guaranteed to deliver 90% of their rated peak capacity for at the twelve year mark, and 80% at the 25 year mark.

And as for "investment opportunity cost" as was stated in the article the solar panels are an investment in their home value.

380.00 bill? (3, Insightful)

cybrthng (22291) | more than 6 years ago | (#24282419)

Sounds like someone who threw money at a problem better handled by conservation.

Believe me, i LOVE solar, but solar works better when it isn't the only solution.

Re:380.00 bill? (0)

Anonymous Coward | more than 6 years ago | (#24282579)

Screw conservation for the sake of conservation. If there is an option to live in excess without ill effect, that is the course to take.

yeah I said it.

Be willing to conserve when there is a drawback to over use? yes. But when you're stealing power from the sun, I think you're in the clear for leaving your nightlite on without feeling bad about it.

I have no more intrest in being made to feel bad for living a comfortable life then I do for being made to feel bad for being born.

So solar power = linux? (0)

Anonymous Coward | more than 6 years ago | (#24282425)

And the grid = Windows?

Re:So solar power = linux? (0)

Anonymous Coward | more than 6 years ago | (#24282645)

no, linux is a guy giving blow jobs in the alley to buy some smack and windows is the guy at the bar who has a real job and can pay for his own drinks.

Verizon Math? (1)

pete-classic (75983) | more than 6 years ago | (#24282441)

The baseline rate in March was 0.15566 cents per Kwh, and the baseline quantity was 390.6 Kwh.

The next 30% beyond baseline gets charged at $0.13 per Kwh. From 131% to 200%, the rate nearly doubles, to $0.227 per Kwh.

Does it really go from less than a cent per kWh to 13 cents? Or is this Verizon Math?

Assuming it's 15.566 cents, why does it go down and then up based on use? Bizarre!

-Peter

Don't buy a house & save $2 million (3, Interesting)

heroine (1220) | more than 6 years ago | (#24282459)

Well a house in Calif* with a clear view of the sky & enough room for 27 solar panels is about $2 million. So it's a choice between saving $250 on electricity or saving $2 million on housing.

Re:Don't buy a house & save $2 million (1)

Jeremi (14640) | more than 6 years ago | (#24282717)

Well a house in Calif* with a clear view of the sky & enough room for 27 solar panels is about $2 million. So it's a choice between saving $250 on electricity or saving $2 million on housing

California is a big place, and housing prices vary greatly. If you don't mind living out in the sticks, you can buy a house with plenty of land and sky for much less than $2 million.

And of course there are many people who already own a suitable house, or would have bought such a house anyway for other reasons.

imagine . . . (1)

cashman73 (855518) | more than 6 years ago | (#24282473)

. . . a beowulf cluster of solar panels on your [mother's] house! It ought to power your beowulf cluster in your [mother's] basement!

DC - AC - DC (2, Insightful)

mcelrath (8027) | more than 6 years ago | (#24282477)

So this guy is using DC solar panels, converting it to AC with an inverter, and then using it primarily to power...a computer lab, which just convert it back to DC. There must be at least 50% loss in this. AC was designed for transmission lines, which run for miles.

When the distance from source to sink is measured in meters instead, wouldn't it make sense to avoid the inversion step, and just use a voltage stepdown transformer, keeping everything DC? You'd have to install DC power supplies into your computers. Do those even exist? Of course power not going to computers could be run into an inverter to power other household AC things...

I think the switch to local power generation may require the (re)invention of DC infrastructure for within the house.

-- Bob

Re:DC - AC - DC (1)

david_bonn (259998) | more than 6 years ago | (#24282513)

Actually, when solar power is used in a lot of off-the-grid installations a lot of things like lighting are done in DC (dc lights are widely used in RVs so they are pretty commonly available).

Usually an inverter costs you about 30 percent, and I'd agree that converting back to DC would cost about the same.

Re:DC - AC - DC (0)

Anonymous Coward | more than 6 years ago | (#24282539)

But he has to convert it to AC to be able to put his power back on the grid.

Re:DC - AC - DC (4, Informative)

MrSteve007 (1000823) | more than 6 years ago | (#24282597)

There are indeed losses, but much less than you propose. Most solar DC to AC inverters are 90-93% efficient in their conversions - so only a 7-10% loss. http://www.beaconpower.com/products/SolarInverterSystems/docs/M4_M5_plus_datasheet_web.pdf [beaconpower.com] The same goes for the conversion back to DC on the equipment side.

Re:DC - AC - DC (1)

John.P.Jones (601028) | more than 6 years ago | (#24282653)

Very interesting, I think the right thing to do would to run two independent circuits throughout new house construction, standard AC for legacy appliances and DC for a new 'smart' home standard, then add the transformers that inter-convert AC & DC on the centralized power input which takes in both grid power (AC) and solar power (DC) and feeds both circuits (as well as converting DC-solar-out to grid compatible AC), minimizing conversion and centralizing it.

We can even standardize the plugs like this || (AC) vs. |- (DC)

Re:DC - AC - DC (1)

rcw-home (122017) | more than 6 years ago | (#24282977)

We can even standardize the plugs like this || (AC) vs. |- (DC)

Oops. [google.com]

Re:DC - AC - DC (1)

rcw-home (122017) | more than 6 years ago | (#24282687)

So this guy is using DC solar panels, converting it to AC with an inverter, and then using it primarily to power...a computer lab, which just convert it back to DC. There must be at least 50% loss in this.

There are plenty of always-inverting UPSs that are upwards of 90% efficient (pretty much anything over a few kVA capacity). They are AC->DC->AC convertors, so they perform the same steps in a different order.

wouldn't it make sense to avoid the inversion step, and just use a voltage stepdown transformer, keeping everything DC?

Exactly what do you think such a voltage stepdown transformer does?

Re:DC - AC - DC (1, Redundant)

Smitty825 (114634) | more than 6 years ago | (#24282695)

Not that I'm an EE or anything (I'm not), but I do know that the higher the voltage on your system, the lower the power lost due to resistance (assuming the same amount of power is transmitted) So even at short distances, it likely makes sense to lose a bit of power for the conversion from DC to high-voltage AC and not lose the power in the line.

(Also, again, I'm not an expert, but I don't believe DC to DC transformers exist. (Flame-proof protective suit on in the likely event I'm wrong) If I'm right, if you wanted to convert 12V DC to 3.3V DC, it would have to be converted to AC before being transformed to a lower voltage...)

Re:DC - AC - DC (1)

Gibbs-Duhem (1058152) | more than 6 years ago | (#24282943)

Yes, current through resistance is where power is lost, so higher voltage means less current through your load at the same power.

DC to DC converters do exist, but they're trickier technologically than AC transformers. Instead of relying on basic physical principles of magnetic fields, they use switched outputs, feedback, and filters.

An example of a step down converter is the buck converter. An example of a step up converter is the flyback converter. They generally are based on switching the input voltage on and off over a capacitor + inductor filter so that the average voltage is correct, and the filter smooths the output voltage so it is close to DC.

They are frequently ~90-98% efficient depending on the operating frequency, and can be an order of magnitude smaller than a 60 Hz transformer because they don't need a large inductive core to deal with saturation issues. Not needing an inductive core frequently means they are cost competitive with AC transformers per unit power despite being far more sophisticated (all that raw iron is pricey).

Re:DC - AC - DC (1)

Gibbs-Duhem (1058152) | more than 6 years ago | (#24282951)

duh, i obviously meant the line resistance, not the load. obviously the power dissipated in the load is constant.

Re:DC - AC - DC (1)

Max Littlemore (1001285) | more than 6 years ago | (#24282979)

, it likely makes sense to lose a bit of power for the conversion from DC to high-voltage AC and not lose the power in the line.

I'm not an EE either, but I have practical experience of living in a house with 12VDC and 240VAC wiring with power generated from small scale hydro. We had a TV that ran on 12VDC or 240VAC which, before we had the inverter to provide 240VAC, used to switch itself off if it was plugged in to the furthest points from the batteries/regulator etc. The voltage drop on the line was enough to cause that, and we had invested in some fairly hefty cables to run the 12V system. Also, the power cupboard, with the batteries, etc, was almost as far from the place in the lounge where we wanted the TV.

I don't remember the efficiency of the inverter, but the fact that we had plenty of water in the creek and therefore plenty of power meant that the conversion was definitely worth it for us.

Re:DC - AC - DC (0)

Christopher_Olah (1317943) | more than 6 years ago | (#24282713)

When the distance from source to sink is measured in meters instead, wouldn't it make sense to avoid the inversion step, and just use a voltage stepdown transformer, keeping everything DC? You'd have to install DC power supplies into your computers. Do those even exist? Of course power not going to computers could be run into an inverter to power other household AC things...

No.

DC transformers, in the traditional sense, are impossible for anything longer than a few seconds. A transformer relies not on the existence of an electromagnetic field but on the change of an electromagnetic field.

V=-n \delta \phi / \delta \phi

v_1/v_2 = n_1/n_2

Now, it is possible to step down in some ways. Firstly, you could use a resistor. This means that the rest of your load needs to be known. You could also put you voltage sources in parallel...

Disclaimer: This is just my understanding. I'm a high school student. Don't take my word for it.

Re:DC - AC - DC (1)

btempleton (149110) | more than 6 years ago | (#24282883)

As noted, there are losses but not quite so high. Today good PC power supplies are 85% efficient.

You would still need a power supply to use DC. You can get them, they are made for automotive PCs etc. You need to regulate the unreliable power of the panels into the smooth 12v, 5v and other voltages the PCs need. The best way to do this is to invert it to high freq AC and bring it back.

Note that during the non-sunny parts of the day, which last longer than the sunny parts, you would then need to turn grid AC into DC to go into your DC power supply -- and that is even more wasteful.

Ideally you would want a special power supply, able to use DC in the range the panels put out, and also AC, as needed. Not hard to build, but will cost more as it is not made in quantity 1 million.

Note that most solar systems do not run at 12 volts, either, they often run at 36 or 48 or sometimes far more. So you need a PC power supply able to use that unusual voltage.

Re:DC - AC - DC (1)

bavid (842765) | more than 6 years ago | (#24282889)

Someone might want to correct me if I'm wrong, but I think that a typical solar inverter will have an efficiency of something around 90% (maybe 80%, to be safe). No idea what the efficiency of a typical PC power supply might be. I think one advantage to going DC-AC-DC is that the AC part is very stiff -- it's connected to the utility and it's not very sensitive to you turning on another machine. Another is that if you want to go DC-DC-AC the DC-AC part needs to be bi-directional, which makes things more complicated and even more expensive. I have heard that telecom stuff tends to be DC, so getting the DC PSUs might be reasonably easy if you knew where to go.

The Breakdown (1)

Adreno (1320303) | more than 6 years ago | (#24282511)

so... He states that it was an approximately $36,000 initial investment (http://www.extremetech.com/article2/0,2845,2308684,00.asp). Also, approximately $332 in monthly utility fee savings (http://www.extremetech.com/article2/0,2845,2326045,00.asp). That's just over 9 years before he breaks even, assuming no significant maintenance costs or other "surprises". Not bad... personally I can't wait until this technology improves a bit further and prices drop so the initial investment is a feasible option for the average family!

Questions? (4, Funny)

140Mandak262Jamuna (970587) | more than 6 years ago | (#24282519)

1. How heavy are these solar panels? Easy enough to be lifted and carried down by one or two persons?

2. Are they bolted on? Any locking mechanisms?

3. Is it easy to climb on to the roof?

4. Do you have good access to a road from the home?

5. When are you planning to take a vacation?

6. Does it have any kind of GPS thingie or Wifi thingie attached that will phone home?

Thanks buddy.

Re:Questions? (Answers) (5, Funny)

Surt (22457) | more than 6 years ago | (#24282683)

1. They are somewhat heavy (50 lbs). They are awkwardly large at 5ftx3ft. Two person job if you don't want to risk a rooftop fall.

2. They are typically bolted on. Uninstall time will be in the several minutes per panel range. Be sure you have an electrician with you to avoid death by electric shock.

3. You can see in the pictures he has a typical roof. Bring a ladder. And a crane if you want an easier time lowering the panels.

4. Yes, see the pictures.

5. Don't know about that one. Probably end of December or next summer.

6. Doubtful.

Hail (2, Insightful)

strelitsa (724743) | more than 6 years ago | (#24282557)

The panels the author referenced in the story are guaranteed to resist up to 1" hail falling at 52 MPH. But 1" is considered small in this part of the country - we routinely get tennis ball-sized or even larger chunks during storms, and they're falling a hell of a lot faster than 52 MPH. So some sort of robust shielding material as an add-on would be a necessity if I were to install these. Either that or the first thunderstorm we got would destroy a $50,000 investment.

Re:Hail (1)

delysid-x (18948) | more than 6 years ago | (#24282657)

there are all kinds of 1" steel meshes you can get. they'll cut down your power a little though.

Solar is not a good choice if you want to save $ (0, Troll)

shaitand (626655) | more than 6 years ago | (#24282589)

I hate articles like this because they mislead people. Solar is NOT a way to save money and every sucker who is drawn in by this idea will be turned off solar for a long time.

These kind of articles always ignore the real costs and usually just look at the cost of the panels. But the panels aren't the only consideration, you have to consider the cost of the battery bank and the cost of replacing the batteries periodically. You won't get the full life out the batteries either, that constant charge and discharge is going to reduce the capacity of those batteries quickly.

The other cost is both in terms of economics and comfort. To actually be able to come close to living on that small solar output you are going to need to install all new appliances and run a water heater that will deliver luke warm water at best. You are going to have to come to terms with being frugile with power in almost action you take from there on in.

Re:Solar is not a good choice if you want to save (5, Informative)

cassius2002 (675501) | more than 6 years ago | (#24282655)

Residential solar installations typically have no batteries, so there is no maintenance cost for batteries, nor replacement costs. This type of installation uses the grid as a kind of giant battery, feeding power to the grid during the day and drawing from the grid at night.

Re:Solar is not a good choice if you want to save (1)

Darkk (1296127) | more than 6 years ago | (#24282863)

I like this approach better and it's a win / win for everybody.
 

Re:Solar is not a good choice if you want to save (1)

toadlife (301863) | more than 6 years ago | (#24282955)

It doesn't matter if there are no batteries. The low efficiency of solar panels keep small residential installations from being cost effective in the long run. A friend of mine runs a solar install business and the first thing he does when a potential customer calls is to warns them that unless their power bills are around $1000* a month, it won't save them money.

*I don't remember the exact dollar amount he told me, but the average residential power bill is not nearly enough.

Re:Solar is not a good choice if you want to save (3, Interesting)

pclinger (114364) | more than 6 years ago | (#24282685)

For some people it's not only about saving money but being a good environmental steward.

Re:Solar is not a good choice if you want to save (1)

gothzilla (676407) | more than 6 years ago | (#24282797)

That's a terrible way of being a good environmental steward. He could use those resources in a different way that is much more efficient but instead they are being wasted on something highly inefficient. That's like saying building an ethanol plant is being a good environmental steward.

Re:Solar is not a good choice if you want to save (1)

snuf23 (182335) | more than 6 years ago | (#24282969)

I realize in the article's case they are plugging into the grid so they don't need batteries but how green are batteries used in off the grid housing?

Of course the always leave out the real costs (1, Interesting)

DerekLyons (302214) | more than 6 years ago | (#24282635)

Posting an $11.34 electric bill

$11.34 + this months payment on the loan covering the costs of installation + costs of maintenance and operation.

pink (3, Funny)

Anonymous Coward | more than 6 years ago | (#24282699)

He's should've bought like 2 less solar panels and used the money to paint his house some color other than pink.

Do the math -- is he really saving money? (3, Insightful)

btempleton (149110) | more than 6 years ago | (#24282851)

Today it's hard to make solar actually pay for itself. At California's high-tier rates, it is possible, but still takes a lot of work.

He says he put in $36,000 and will save $3,300 per year in payments to the power company. Now the historical annual rate of return of an S&P 500 index fund is 11.3% over the last century, so $36K put there would return over $4,000 -- enough to pay the $3,300 to the grid, have $700 left over and of course, still keeping the principal. Compared to that, the panels are losing money each year and will never pay for themselves -- unless grid power goes up a lot.

And grid power might go up, but only so far. Because eventually the grid power hits the solar price, and the grid itself starts putting in solar sources at that price -- because it's cheaper.

Most solar installations lose money hand over fist outside of California's high priced tiers. Today, solar comes in about 20 cents/kwh (at more like a 6% interest rate, not the 11.3% rate of the stock market.)

Try this spreadsheet:

http://spreadsheets.google.com/ccc?key=pWKShknjJFBt7sOTCJre_SQ&hl=en [google.com]

To work out the real cost.

It's worse if you consider that at the true cost of the system before rebates -- $48K if I read right, it really loses money.

Now, I'm not saying it's not good to put in solar to be greener, or that the government shouldn't be providing subsidies to make this happen.

I just don't want people to use the wrong math to think they are saving money, when in fact they are spending more (for a purpose.)

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