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You're Doing It All Wrong: Solar Panels Should Face West, Not South
HughPickens.com writes In the U.S., a new solar project is installed every 3.2 minutes and the number of cumulative installations now stands at more than 500,000. For years, homeowners who bought solar panels were advised to mount them on the roof facing south to capture the most solar energy over the course of the day. Now Matthew L. Wald writes in the NYT that panels should be pointed west so that peak power comes in the afternoon when the electricity is more valuable. In late afternoon, homeowners are more likely to watch TV, turn on the lights or run the dishwasher. Electricity prices are also higher at that period of peak demand. "The predominance of south-facing panels may reflect a severe misalignment in energy supply and demand," say the authors of the study, Barry Fischer and Ben Harack. Pointing panels to the west means that in the hour beginning at 5 p.m., they produce 55 percent of their peak output. But point them to the south to maximize total output, and when the electric grid needs it most, they are producing only 15 percent of peak.
While some solar panel owners are paid time-of-use rates and are compensated by the utility in proportion to prices on the wholesale electric grid, many panel owners cannot take advantage of the higher value of electricity at peak hours because they are paid a flat rate, so the payment system creates an incentive for the homeowner to do the wrong thing. The California Energy Commission recently announced a bonus of up to $500 for new installations that point west. "We are hoping to squeeze more energy out of the afternoon daylight hours when electricity demand is highest," says David Hochschild, lead commissioner for the agency's renewable energy division, which will be administering the program. "By encouraging west-facing solar systems, we can better match our renewable supply with energy demand."
hedge your bets and go 50/50 south and west. Maybe 50% southwest, 25% west, 25% south and setup a water wheel and perhaps an agrarian society.
Obviously the panels should be motorized so that they are always facing the most optimal direction. A system that moves the panels shouldn't add that much to the cost and will probably pay for itself very quickly with the extra energy collected.
Anthropic principle: We see the universe the way it is because if it were different we would not be here to see it.
Having them point down is definitely not good, even if it *is* day in Australia.
At 5PM the sun is down where I live, 4 months out of the year. No, I didn't RTFA, so I assume he has a good rationale for not taking into account seasonal changes.
--fatboy
It depends on what you want to do with that solar power. If you want to use it yourself, particularly during a power outage, then point it south. If you're in it to make money at these heavily subsidized rates, then point it west.
In any case, I doubt this solar cells really make that much difference during peak demand.
I take it you can't just use that electricity during the earlier hours to help keep it cool? Or does it work that way?
Also, does the argument lose some power if electricity rates are the same 24/7?
Wouldn't it be better overall to have panels that move throughout the day anyway?
If you're offgrid and storing excess power in batteries then point in the direction of most efficiency.
If you're connected to a meter and can run it backwards then point in the direction of most efficiency.
If you're only producing half your own power and pay a flat rate for electricity then point in the direction of most efficiency.
There are only a few specific situations where an individual would benefit from aligning solar panels with their usage patterns instead of maximum efficiency.
My guess is the majority of homeowners don't fall in that category.
When we've all got grid-interactive electric cars, that will be the lowest demand time because everyone will be on the roads trying to get home. Solar tracking is the right way. Fixed position is a financial and maintenance compromise.
Unless you are going to rotate the house.
Priest: "Universe from nothing, no laws of physics, sped up time"+ huge discrepancies. Creationism? No. Big Bang Theory
Great. So once solar installations start producing more total power than is consumed during peak production hours we should consider intentionally reducing their total output in order to better align production with consumption. Until then total peak solar production is only a fraction of the total energy consumed at the time, so there's nothing to be gained by intentionally sabotaging your total energy production. At least not or the people installing solar panels.
But sure, if you're more concerned about the power-transmitting capacity of your grid infrastructure than actually producing as much power as possible for a given investment, by all means point your solar panels west. Should be useful for California and, umm, anywhere else is the power companies are allowed to play ridiculous profit-optimizing games at the expense of the citizenry. And you'll be doing your part to please both the solar panel and fossil fuel industries. Good job consumer, the corpoatocracy thanks you.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
... that are not North-South or East-West aligned?
Actually this is news from at least one year ago
The real "Libtards" are the Libertarians!
The article overstates the difference in angle -- not due west, you mean adjust west of due South. If you are in the northern hemisphere, there is an optimal angle depending on latitude. If you want to shift to later in the day, that is Southwest. If you live in Australia, that would be Northwest.
I've always heard that peak usage occurs during the day, when businesses are operating at full tilt. Yes, when people are at home they use energy, but when compared to business use, it's not as great. Southern California Edison in fact has a program that gives use credits called "Save Power Days" where they encourage you to reduce usage from 14:00-18:00. Here is the link: http://goo.gl/TT0q7a Additionally, during peak periods there are rotating outages... these happen during the day, not after 17:00... that said, seems to me it's more better to send that extra power to the grid during the day rather than after 17:00...
If you are a home owner, You should have some on both south and west if possible. At my house, we have 43 panels of which 7 are east, 14 are west, and the rest are to the south. As such, we get a lot more electricity when needed, then the average home.
I prefer the "u" in honour as it seems to be missing these days.
My first though without even reading the summary:
Of course pointing it to the South would "catch" more integrated spectrum, but not all of that can be converted to electricity efficiently (they are more efficient for longer wavelength), so it should not *hurt* much to till them westwards (or eastwards), where/when blue light ("useless for") is filtered by the atmosphere...
By the way, blue light is still absorbed/heats/damages the cells, but not gets converted to voltage. Or some such... ;-)
Aligning with peak demand might make more sense though.
Paul B.
Agreed.
A solar array will generate more energy, overall, if pointed south (in a Northern Hemisphere installation, of course). If you use batteries, or essentially use the grid as a battery, then south-facing still makes most sense. The fact that electricity is more "valuable" in the late afternoon is irrelevant if there is storage somewhere.
This article is loaded with suppositions and guesses that don't really nail down any hard believable hypotheses or facts for a reader to take away. There is no takeaway message. I came away from this read having wasted my time. The whole article can be summed into a single line that could maybe be a popular tweet "For some people, maybe, angling solar panels westward might pick up energy when they need it most."
But the article is clickbait by the whole 'you're doing it all wrong' part that makes potential readers think there is some new big fact that will prove something worth learning. NOPE.
Lame article.
I just purchased a solar panel system for our home, and I've been learning a lot about all of this stuff during the process.
The problem with the author's suggestion is that he's concerned about a problem that, by and large, we haven't quite come to yet. Solar adoption is still such a small percentage of the total number of electric consumers that the "saturation point" hasn't usually been reached yet. The entire "net metering" model for solar isn't really sustainable if you get more than a single digit percentage of homeowners in a given area going solar. I think that will hold true EVEN if you could convince all the new solar installations to use west-facing panels to time shift their power production hours.
Right now, practically everything about PV solar adoption centers around government regulations creating an "artificial" incentive for it. For example, in my home state of Maryland and a number of others, they have an SREC program in place (solar reclamation credits). How does it work? Basically, they made a rule that the state's utility companies have to obtain a certain percentage of their electricity generation via "Green" sources like wind or solar. If they fail to hit that target, they must purchase these SREC certificates in a sufficient quantity to offset it. (In reality, they're always going to pay for the SRECs rather than adopt more alternative energy generation themselves -- because for them, it's still the more cost-effective and sensible option. They don't want to spend a bunch on new infrastructure and land to place it on, just to meet those percentage targets.) For every megawatt of solar power your home solar panel setup produces, you earn an SREC which you can turn around and resell to the power company (directly, or via one of several auction web sites designed for the purpose). There's even one offering to buy 10 or 20 years' worth of your SRECs in advance, at some discounted price, giving you more "up front" cash to pay off your system's initial installation cost - should you find that the best option.
Don't forget the Federal tax credit of 30% of whatever you spent to buy the solar panel system, and states like mine who kick in another $1,000 or so. This stuff just doesn't make the same financial sense with all of these constructs removed from the equation.
The real elephant in the room that everyone's ignoring is the fact that power DISTRIBUTION is the limiting factor for the power companies. As soon as too many people start putting power from solar back onto the grid at one time, in one area? They can't really do anything with it, so it gets wasted. Yet the "net metering" rules require that pay you back for it anyway, at full retail prices. For a SHORT time, you might be able to postpone this by switching more panels to face west instead of south, but soon enough - it will become a problem again.
Honestly, I predict that what we'll see playing out is government withdrawing all of the tax breaks, followed by the value of your SRECs dropping to very little as they ease up on the requirements the utilities must meet. This will put the brakes on solar adoption, making it one of those things that only paid off for the people who got in on it early - or who have a situation where it STILL pays off (due to especially high power costs). In Hawaii or parts of California, for example, I believe the utilities sometimes bill as high as 90-some cents per kilowatt-hour used. In Maryland, by contrast? I pay closer to 11 cents.
Mounting sllghtly off the roof, to the roof, gets decent solar generation and shades the roof in high summer and ... minilmizes the danger
from high winds. Having panels up in the air on one of those
rare 50MPH winds is... scary.
Or at least that's what our system does on a nice south facing roof in the UK
Effective local energy storage would solve that problem.
Make the panels as efficient as possible and store the resulting energy. Then use the stored energy at the time of peak need.
For instance, if it's going to be used for heating or cooling. Just heat or cool an insulated mass inside the house then run the house air through it during peak load times. The cooling process would not be 100% efficient, but it needn't be less efficient that a normal online AC unit.
The heating process would be 100% efficient, measure from the point of the output wires of the panels.
I should use this sig to advertise my book ISBN-13 : 978-1501515132.
and God will handle the details.
. . . yeah, we pretty much know this, but sshhh! Don't tell anyone!
Electricity prices are also higher at that period of peak demand.
Only in areas where they have variable pricing. Looking at a map of avg pricing, my state is pretty low anyways and we have fixed pricing whether using it all at 5pm or 7am makes no difference.
So I wonder if those areas that have variable, are the power companies trying to push demand to other times due to lack of capacity or are they gouging the customer (or both). If either of those are true, that doesn't sound good.
Course on the flip side, around here you can't sell back to the power company with your solar or wind power self generation. You can power your own home but cannot put any back on the grid.
You could mount them on a small motor powered by the panel and have the things rotate with the sun. Doesn't seem like it would be all that hard to do. Then you get the better alignment all day long.
The optimal position of solar panels depends on several factors:
Tracking mechanisms work, but they are mechanical and can fail, and they cost money. It may be cheaper to add panels than to add trackers. For seasonal adjustment, some mounting hardware allows relatively easy manual adjustment of the slope.You don't have to change this but a few times a year.
I have been off the grid at home for ten years, depending mostly on solar but with a little wind. Our panels are pointed in three directions: Southeast to get power in the early morning when the batteries are lowest, south for use during peak sun, and southwest to end the daylight hours with fully charged batteries. We have home-made mounting, and it was cheaper to add a few extra panels than to add tracking hardware.
From PG&E's website during summer low demand is 0.143/kWh, high demand 0.336/kWh cents... About 20 cent/kWh differential.
With EV batteries into the 100 kWh range in our not so distant future and talk of breaking $100/kWh storage barrier market incentives to disruptively break-thru with cost effective buffering seems to be plausible in the short to medium term.
Solar panels last 20 years...
Then, the prevailing winds can break the mast and send the panels crashing into my neighbor's house. He is an AGW denier. So, he and his spawn must die and it would be appropriate for them to perish from wind and solar.
I'm installing solar neutrino panels, and facing them down. That way I can get power at night when I really need it.
so what orientation creates the most power without considering rates?
My solar panel setup is done by net metering. So, it doesn't matter what time of day I generate electricity. Just that I generate the most in a day I can. So, it's still more valuable to point them south if it squeaks even a few more KWh out of it.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
If you have batteries to accumulate power to be used during peak times, you absolutely want your panels pointed where they'd get most of the sun.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
I'm not interested in electrons, I'm interested in electron credits. I'm out of my house much of the day and my solar array will be facing S-SW. During those hours, my system is accumulating electron credits that trade with PG&E (my utility) at a 1:1 ratio. I give them 1KWh in the morning that I can't use but somebody else can, and they give me back 1KWh in the evening that I need. Cost of electrons is never factored into the equation.
It seems to me this is only true when connected to the grid with no storage. If you're running off-grid and storing electricity in batteries to use later, you want to position your panels for maximum output. (This is how mine is configured. Not grid connected, with marine batteries storing power during peak output, and panels facing south.)
But I would opine that any system, even grid connected, that didn't allow for solar panels to be placed for maximum solar exposure is not designed properly. If this requires some method of storage during peak solar output, well, we knew that would be an issue sooner or later. Renewables tend to fluctuate, and a practical means to smooth out those fluctuations must be engineered.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
Seriously, am I the only one wondering why we don't do both? South (North for us in the Southern Hemisphere) for regular use, West for peak?
Posting from upstate New York.
Homes here are usually oriented east-west with rather steeply pitched roofs and minimum western exposure. What is wanted here most in winter is warmth and light and shelter from gale force winds, rain, sleet, and snow.
From the didnt-we-post-this-one-before dept.
Was the idea to save money, or to save electricity?
Depends. With classical panels it is due south, obviously. ... like placing them "randomly" instead of one clumped installation.
However if you can mount panels that can convert sun from both sides, then the edge should be going south to north, so one side of the panel goes west and the other one east.
The problem with that approach is that usually the panels would shadow each other. So you need a suitable area
Bottom line the efficiency is on par with tracking panels. (There was an article about that in the late 1990s by Fraunhofer I believe)
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Why don't we have some people go east too so they can peak out in the morning while others can peak out at noon and the most in afternoon.
We're in the southern hemisphere, you insensitive clod!
Our solar panels face east in the morning, 27.5N around midday and west in the afternoon... but that's because they're mounted on solar trackers. Glad to see the US finally catching up on this "no, shit buckwheat" level of knowledge.
When electric companies are considering policies that don't allow consumers to to net metering then if you won't get any gain when you produce more power than you consume. If you point west then you'll be more likely to consume more power than you produce.
a homeowner can buy a device called a tracker that will pivot them
For those of us up in Canada or Northern Europe you need to mount the pannels on a vehicle which heads a long way south or west trailing a cable if they are going to be pointing at the sun in the late afternoon since the sun sets here around 15:30-16:00 this time of year. Simply pivoting or pointing west is just not going to cut it.
If you're a utility you have your panels set up so that they rotate to face the sun. If you are a smaller player with only a single panel or a few at most and no economical way to rotate them to track the sun, then what matters to you is how much you can earn from the panel, and that likely means pointing it to get maximum generating capacity, not maximum capacity at peak time of demand. Unless the power company is buying the power at higher prices at times of high demand. And I doubt that they are doing that in many places.
I'm an American. I love this country and the freedoms that we used to have.
So why wait until the animals are thirsty? Point south to maximize power generation. Start pumping as soon as you have power and pump as long as needed to supply water for the day. You're not going to have that much evaporation loss by pumping slightly early, and the animals are better of drinking throughout the day rather than waiting until the hot part of the day.
I'm an American. I love this country and the freedoms that we used to have.
so what orientation creates the most power without considering rates?
It depends on where you live. There are places on line that can give you the tilt for your area. For example;
http://energyworksus.com/solar...
This perfectly illustrates how Not Ready For Prime Time solar is.
The retarded owners haven't even figured out which way to point the damned things.
problems is that with string inverters the maximum output is limited by the weakest panel, thus all panels need to face in the same direction. on the other hand with microinverters where each has its own panel, one could point each panel at a different direction. ...
this way one could install a "bulge like" system where the east most panel points east, the middle one south and the western most panel would point west
since with microinverters each panel gets its own mpptracker...
>Great. So once solar installations start producing more total power than is consumed during peak
>production hours we should consider intentionally reducing their total output in order to better align
>production with consumption.
Exactly.
We form OSEC, the Organization of Solar Exporting Consumers, and limit our production to keep prices up.
hawk
and when the electric grid needs it most, they are producing only 15 percent of peak.
Do why not mount the panels on something that can change their orientation to keep them pointed at the angle that maximizes expected power collection based on time of the day?
Or just point south to maximize power collected during the day by charging batteries.
At 5pm start discharging the batteries to offset increased demand and sell energy back to the grid at the higher price.
Solar collectors should be mounted as high as possible, so they can collect the suns rays for longer
Prefferably 40,000KM higher, above the effects of cloud and wind.
in the subject makes it difficult to parse.
Even on a roof. Put them on the south facing roof and then put servos under the panels to TIP them east or west. The panels don't even need to have sensors. Just give the panels a simple clock and sync that clock to specific positions. Basically a giant lookup table for the whole year. So, the system would need a bit of memory but we're talking about perhaps a megabyte. You could even build a simple little equation into the system that asks your latitude, the year, the month, the hour... and from that self generates a serviceable tracking pattern. At noon, the panels would face south assuming you are in the northern hemisphere. They would tilt towards the east during the morning and tilt towards the west in the evening.
I've decided to stop wasting my time responding to AC trolls/sockpuppets... so if you want a response from me... login.
For us southern hemispherians, facing panels south won't do us much good....
On a more serious note: It looks like motorized sun-tracking mounts for panels can be quite expensive, while a fixed mount can be sub-optimal.
So how about a hybrid mount? I'm thinking of a fixed mount with a number of predetermined positions that need to be adjusted manually (e.g. fixed with a bolt/split pin/similar). Coupled with this is an algorithm that calculates the optimal position for the day (or more realistically, for the week) and sends the homeowner to the roof to make the adjustment if necessary. Factors that such an algorithm would need to take into account would differ from home to home and from jurisdiction to jurisdiction, so it should be customizable to each individual case - e.g.:
Free, as in your money being freed from the confines of your account.
Just design a house with a roof providing several orientations for solar panel installation.
Location and local pricing conditions should be considered.
If local pricing conditions change, consider if a roof reform is advisable.
Regards
Rotating houses is what we need. Not this silly, several orientatated roof design.
...the sunflower panel.
Lest's face it. the ideal direction to point solar panels is dynamic. I highly recommend a panel positioning system that will move the panels during the day.
The movement does not need to be continous, that would be a waste of energy. motors that postiion x, y, and angle. Do not use servos.. use motors and an assembly that locks in place. I think if the position is updated 6 times during daylight hours that would be enough. Also a fresnel lens layyer above the panels that will collect light and beam out of focus would increase effeciency.
I imagine a giant space mirror to reflect sunlight so that one place has 24 hours sunlight, and another is in total darkness. I like most IT people would flock to the dark side.
I only look human.
My mother is a halfling and my dad is an ogre, so that makes me an Ogreling
This article was written by accountants. Quite simply, stationary panels should always face in the direction that would net them the largest total ammount of energy through out the day. Instead this "article" suggests to point them in the direction that would make the largest net gain of money.
Something is very wrong here, as a species we no longer value knowledge and scientific discovery. Instead we are just buying more into this consumer nightmare, always looking at the money and ignoring the consequences.
One problem less to solve since I move here to Ecuador haha
Individual homeowners aren't trying to meet their peak instantaneous demand, they're trying to generate as much power as possible over time. Pointing your panels more westerly will severely decrease your overall power production. As long as people are interested in solar power as a method of reducing their carbon footprint and pollution, pointing west is stupid.
To get the best performance out of solar, you still need batteries to save power for when the sun isn't up. Assuming you have sufficient batteries, you should *still* point the collectors southwards, to gain the greatest total amount of power.
Thanks, Cap'n.
Whatever happened to the idea of 3D solar panels? I remember slashdot talking about them years ago. All they would have to do is have a refractive surface that focuses light from any direction into the solar panel, then direction would be meaningless.
How long until humans realize they could just put solar panels on a programmable rotating base with power supplied by the panels?
Install the panels so they rotate as the sun moves across the sky to maximize output the entire day
is to provide maximum profit for the Grid?
Here's a new bifacial (double sided) 22% efficient solar technology that will increase your output whether you point you panels to the West, South or East. This advanced technology has been around for the past 6 years but it was always considered to be far too expensive to install. Now because of new technological advances Hyper X 2 Bifacial solar panels can be purchased at a much lower cost than many standard single sided solar panels.
Instead of boxy looking 1 1/2 to 2 inch thick framed Gen 1 solar panels, these new higher performance Gen 2 solar panels are only 1/4 inch thin and are made with a stronger, see through, glass on glass, frameless, construction that allows sunlight to pass through and reflect off the roof's surface, thus illuminating the backside of the double sided solar cells, producing additional power.
The new 300 Watt, 60 cell solar panels that are used in Hyper X 2 solar systems offers a better PTC to STC ratio "Real World" performance according to the California Energy Commission's performance rating listings than over 119 of SunPower's solar panel models.
And they offer a very high 94.3% PTC to STC performance ratio. They also offers a heat resistant -0.28%/degree C temperature coefficient for better performance in warm/hot climates. And when it comes to aesthetics, nothing even comes close to Hyper X 2's panel's glass on glass, see through, frameless construction.
With N-type mono-crystalline bifacial cells for double sided power production, up to a 22% efficiency rating, superior aesthetics, and a price that outcompetes the solar lease and PPA company's offerings, very few products on the market compares to Hyper X 2 Solar. http://vimeo.com/113178906
My experience has been that the best direction is the one that serves the panel owner best. While west may make the grid happier, the real question is what actually provides you with the best ROI and that may not be west.
... they can point them west. When the homeowner pays, they are free to maximize their financial benefit from the installation.
Or utility charges have to go up by 1/3 or more due to utilities abusing their monopoly status and price gouging. It can see that happening in a few places within a very short span of years.
Consider the farm windmills that have been in a lot of places for the last century. They pump when there is wind. When there is no wind it doesn't matter so much because they have filled up a water tank, and the tank is large enough that there's going to be more wind some time before it runs dry.
With a solar driven pump you'd do the same - aim for decent output and it fills the tank when it can.
Take a look at load fluctuation during a day. Those five hours in the middle are a long way above base load so slicing that off saves a shitload of coal and maybe even means one or two less boilers running for most of the year. There's two 500MW units that have been mothballed near me due to that, which is not a bad thing since firing up things like that for only daytime use puts a lot of strain on them and reduces their life a lot more than running constantly. However that's in a place where it never snows and you can even get badly sunburnt outside of your five hours.
Yeah, technically that's a good point ... except I think what you'd see happening instead is the power generated by your PV solar going on out to the grid and getting used *somewhere*. But that somewhere might be far enough away that transmission line losses, and need for the power company to supplement it via a "step up transformer" along the way means it wasn't saving them any money over just generating the power centrally themselves and delivering it.
So from the power company's standpoint, they're not too happy about all of that happening on their grid....
It's hilarious that people still think solar is green or viable.
I bought some solar panels made in Pakistan, and the instructions say to install them facing Mecca.
Wait a minute, I thought the energy from those solar panels was being collected in a bank of batteries. Therefore, you'd still want to face the panels to the south so you can collect more energy. You'd still use more of the energy in the evenings/nights but it wouldn't matter what time of day it was collected.