Switching To Solar Power — Six Months Later 591
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."
Printable Version (Score:1, Informative)
http://www.extremetech.com/print_article2/0,1217,a%253D235949,00.asp [extremetech.com]
Re:$400 a month? (Score:2, Informative)
It depends on the area of the country. In some areas, tariffs, taxes, and the actual cost per kilowatt hour can easily equate to a $400 monthly electric bill for a decent-sized house.
I have a small apartment, and my monthly bill is almost $100/month.
Re:The author is missing something... (Score:1, Informative)
He did say that one month he was doing a benchmarking test involving several computers running 24-hours per day.
Serious geekitude.
Re:$400 a month? (Score:5, Informative)
Re:$400 a month? (Score:3, Informative)
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:The author is missing something... (Score:2, Informative)
It's probably more efficient and economically viable to eliminate the bank of batteries and feed it back into the grid with a utility hookup. This won't help when the power goes out, but you'll utilize all the energy collected one way or the other without having the need for batteries which need to be maintained/replaced.
And if you have an electric car which needs to be charged, charge it during non peak hours.
Re:$400 a month? (Score:3, Informative)
Actually it's usually the opposite - Air conditioning is almost always powered by electricity and AC load can't always be reduced with insulation (e.g. heat-generating devices need their heat removed regardless of external insulation), while heating has numerous options - gas, oil, electric, wood, downstairs neighbors, solar thermal (much cheaper and easier than PV), and upgraded insulation.
Re:$400 a month? (Score:5, Informative)
Re:$400 a month? (Score:5, Informative)
The house I currently live in was powered with solar panels here in Southern Ontario before I bought it. The guy who sold it to me took the panels with him. They did just fine at consolidating his hydro to the point where he was paying almost NOTHING to the power company. They're not worthless at all. A large investment that might take longer out here to recoup costs, but definitely not worthless.
Re:$400 a month? (Score:4, Informative)
He is a PG&E customer in Northern California. That's how he spends $400 a month on electricity.
PG&E = Pricks Grabbing Everything
Re:$400 a month? (Score:3, Informative)
Re:A waste of time (Score:4, Informative)
Because this is a follow up article. The first article includes the Roi figures along with the fact that California Rebated half the cost of the system ($36,000.00 dollars), which explains his up front costs of $36,000.00. Not bad for the size system he had installed and yes I've read the first article and understood the reasoning for the selected installation method, which was to reduce peak Energy Usage during Peak Summer Cost. That's right, his goal was to cut the summer cost of energy during the most expensive part of the year from PG&E (his uutility company).
Note that PG&E has a variable Rate cycle that has the greatest impact during the summer cooling period. This is why he wanted to reduce his summer electric costs, which the system did quite successfully.
Re:The author is missing something... (Score:3, Informative)
Agreed. The batteries are a massive recurring expense that pretty much makes the investment impossible to break even.
Additionally there is so much research going into batteries and super capacitors, that I'd be hesitant to invest in a big battery infrastructure without a clear and pressing need.
Re:$400 a month? (Score:3, Informative)
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 workstation with all slots filled (650W power supply)
- dual proc p3 (yes pentium 3) file server with attached storage array
- dual-core 1CPU myth-backend with hdhomerun tuner (so external power)
- celeron myth-frontend upstairs
- wife's dual-core desktop
- wife's laptop in charging mode
- laserjet printer
- inkjet printer
- wife's lcd
- two lcd's on my desk
- WAP
- 3 network switches on different floors of the house
- External (eSata or FW) drives on both desktops
- DSL modem
That's just the computing stuff. Let's not forget the consoles, dvd player, amp and tv.
Now in all fairness, much of that gear is in low-power/powersave mode but you might look at my power bill and wonder the same thing.
A sun-tracking system is better (Score:5, Informative)
Re:$400 a month? (Score:2, Informative)
See this article showing that Buffalo is one of the sunnier places around.
http://www.buffalonews.com/home/story/545065.html [buffalonews.com]
Re:$400 a month? (Score:4, Informative)
He spends so much because he pays a premium to buy electricity from renewable resources.
And the house is his home office, so he doesn't have an employer paying for energy used during the day.
Re:Solar panels and Snow? (Score:3, Informative)
All the ones I have seen installed around here are either on sun tracking stands or building side mounted at a fairly steep angle
to keep the snow off of them.
Re:guy should try conservation first (Score:2, Informative)
Re:$400 a month? (Score:3, Informative)
Al Gore?
He spends 20 times [snopes.com] the national average for one of his houses.
From your own link: "factors (such as the climate in the area where the home is located and its size) make the Gore home's energy usage comparable to that of other homes in the same area. "
And he makes an effort to get power from "green" sources.
But a good right wing libertarian think tank can make him sound like a hypocrite, that'll discredit him!
Comment removed (Score:5, Informative)
Re:$400 a month? (Score:3, Informative)
Re:$400 a month? (Score:2, Informative)
The house is less than 2 years old so it should be decently insulated though the windows are only single paned.
So it's not.
But if you put the same money in the market (Score:3, Informative)
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.
Re:$400 a month? (Score:3, Informative)
You could, conceivably, install a snow-melt system on the panels. You'd need 0.02 kWh per square foot or panel to melt an inch of solid ice, obviously less for an inch of snow since it's less dense.
300 watts to clear a 3'x5' panel covered in one inch of solid ice in one hour. That's not too bad. It's only slightly more than what the panel itself should produce once it's clear, so if it takes 0.3 kWh to clear the panel in an hour and it can spend the next four hours generating, you still come out ahead.
The tree is another issue, though.
=Smidge=
Shh... (Score:5, Informative)
Don't tell anyone, but there's a tab on the first page that's labeled "print". I don't get to wait for ads and pictures to load, but it has the text.
Re:$400 a month? (Score:1, Informative)
Best consumer rate in Hawaii is roughly USD$0.42/KWh, almost everyone I know gets billed around $300/mo.
Re:$400 a month? (Score:3, Informative)
May parents live in an old (1930s?) farm house that used knob and tube wiring in parts of it. They had a leak in the roof one year and the electric bill skyrocketed because the blown in paper insulation got wet and allowed electricity to transfer through it at high resistance. It's amazing the fuse didn't blow or the house didn't burn down actually. The electric bill went from $130 to about $50 a month. My dad re-wired that part of the house after that. Something he probably should have done earlier. He always complained about the energy costs and was trying to track down what was using all the electricity.
It Will Pay Off in 9 Years (Score:5, Informative)
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:$400 a month? (Score:3, Informative)
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:3, Informative)
Here in the Northeast (Massachusetts) because of high cost of living, most people's houses are very well insulated. I'd be very surprised if you could buy single pane windows in Massachusetts at this point.
Solar Water Heating Even Better (Score:3, Informative)
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.
Re:$400 a month? (Score:2, Informative)
To get my hydro bill down, I did the following:
- Replaced *every* bulb with CFL. Even the outdoor ones that they're apparently not designed for -- which has resulted in ONE dead bulb.
- Bought energy efficient appliances. They weren't significantly more expensive than the lower efficiency stuff, either. I basically walked through the furniture store, wrote down the expected kWh/year for each item, and then narrowed it down to the most efficient ones. Picked amongst them.
- Convinced my wife and son to turn lights, the television, and anything they're not using off when they leave a room.
- Consolidated 3 servers into one, and put a super high efficiency power supply in it.
- Removed every single CRT in the house.
- Bought a gas stove (which interestingly, didn't make much difference in my gas bill *AT ALL*, but made a significant difference in my electricity bill.
- Replaced my furnace with a 92.5% efficiency unit that has a variable speed DC motor and programmable thermostat.
My electricity bill is on average $39/mo (just under $80 bi-monthly). That's just under $40 of actual electricity, and just under $40 of 'delivery', 'storage', 'debt retirement', taxes, and all that other crap they add to our bills.
The overall expense versus not buying high efficiency stuff was pretty negligible (with the caveat that I bought my first house, and so I was buying my appliances for the first time; someone else replacing their current appliances would incur much more expense, obviously.)
Re:$400 a month? (Score:2, Informative)
Re:$400 a month? (Score:3, Informative)
"do the utilities have to sell at a loss?"
Of course not, if they sold art a loss they'd already be out of business. Their executives just don't get to collect multi-million dollar bonuses on top of their 6-figure salaries. It's really a criminal example of the horrors wrought by socialism, just imagine all the money those poor guys didn't get to rape off of consumers because there were laws preventing them from doing so... really quite terrible when you think about it.
Re:It Will Pay Off in 9 Years (Score:3, Informative)
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, even if you go with 5-year. It's also inflation-protected, since any decrease in dollar-value means nominal utility costs go up, which means you save "more" and your percentage nominal return goes up. I don't think it's quite good enough of a return to make it worth it, but it depends what your alternatives are for your money. If you have an outstanding loan/mortgage of more than that, and you don't think lots of inflation is coming, then you probably want to pay off the loan before investing in this. Paying off a loan is like making a risk-free compound-interest investment at whatever your loan rate is, whereas these solar panels have an uncertain return that depends on electricity rates, lifetime estimates, hell even climate change! Of course, inflation probably IS coming, in a big way, but that's a completely different story...
This all assumes a purely financial perspective. If you derive personal value from "living green," then you'd have to add that in. 4.4% is a bare minimum return.
Btw, other parts of your post are dead on. Taking out a mortgage to do improvements to your house like this is pretty much the ideal way to do it... you don't see much change in day-to-day cash flows, and even if you have to sell the house early, the presence of a solar panel setup will increase the value by (more than) enough to cover paying back the extra loan principal. And if you expect inflation, taking out a loan is ideal. You get to pay it back with future-dollars-that-are-worth-less.
Re:$400 a month? (Score:3, Informative)
http://geekpi.com/?p=142 [geekpi.com]