Google can tell you if solar roof panels will pay off

August 17, 2015
'Project Sunroof' uses high-resolution aerial mapping to calculate a roof's solar energy potential and figures out how much sunl
'Project Sunroof' uses high-resolution aerial mapping to calculate a roof's solar energy potential and figures out how much sunlight hits a rooftop throughout the year

Google has got a good look at your roof, and can tell you if it is worth the investment to install solar energy panels.

The US tech giant said its "Project Sunroof" online tool is now available in the area around San Francisco and Fresno in California and around Boston, Massachusetts.

The new tool "uses high-resolution aerial mapping (the same used by Google Earth) to help you calculate your roof's solar energy potential, without having to climb up any ladders," Google engineer Carl Elkin said in a blog post.

The website "figures out how much sunlight hits your rooftop throughout the year, taking into account factors like roof orientation, shade from trees and nearby buildings, and local weather patterns" and then "combines all this information to estimate the amount you could potentially save with ," Elkin said.

It can also connect homeowners with local solar providers.

Elkin said the effort aims to overcome consumer concerns and encourage the use of green energy that reduces carbon emissions.

"The cost of is at a record low," he said.

"A typical solar home can save hundreds or even thousands of dollars per year on their electricity bill.

"But, as a volunteer with the Boston-based solar program Solarize Massachusetts and a solar homeowner myself, I've always been surprised at how many people I encounter who think that 'my roof isn't sunny enough for solar,' or 'solar is just too expensive.'"

Google hopes to expand the project to additional regions "in the coming months," Elkin said.

Explore further: Google to finance home solar systems

Related Stories

Now you can determine the solar efficiency of your roof

October 17, 2011

It is becoming more and more common to install solar panels on roofs in order to obtain green electricity, but not all roofs are equally suitable. Scientists from the University of Gothenburg, Sweden, have launched a tool ...

Shedding light on solar power

November 27, 2014

Everyone wants to save energy, but not everyone knows where to start. Grid Resources, a startup based out of the Centre for Urban Energy's iCUE incubator, is developing a new website that seeks to help homeowners make informed ...

New research to improve solar cells

August 13, 2015

New research from Professors Saiful Islam and Aron Walsh could lead to more efficient solar cells. The work appears in the leading journal Nature Communications.

Recommended for you

Apple issues update after cyber weapon captured

August 26, 2016

Apple iPhone owners on Friday were urged to install a quickly released security update after a sophisticated attack on an Emirati dissident exposed vulnerabilities targeted by cyber arms dealers.

Sponge creates steam using ambient sunlight

August 22, 2016

How do you boil water? Eschewing the traditional kettle and flame, MIT engineers have invented a bubble-wrapped, sponge-like device that soaks up natural sunlight and heats water to boiling temperatures, generating steam ...

Auto, aerospace industries warm to 3D printing

August 25, 2016

New 3D printing technology unveiled this week sharply increases the size of objects that can be produced, offering new possibilities to remake manufacturing in the auto, aerospace and other major industries.

60 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Lex Talonis
1.9 / 5 (13) Aug 17, 2015
This article shows how much stupid people compromise themselves by their inability and refusal to THINK about anything, and study the situation...

And so they have to go to "an authority" on the subject, instead of pulling out a pencil and note pad and figuring this BASIC kind of shit out for themselves.

My NEW and APPROPRIATE definition for "Retard" is this:

"Some people can mentally calculate quite difficult things, and others can barely register "If we have 4 apples, and we take away the 2 apples, how many are left?"

This is people doing their very best - and one's skill set is different to another, but their "best" is not.

A true "RETARD" is a person who is mentally and socially and emotionally under developed by choice."

So the RETARDS in the article - are losers who have opinions, based upon assumptions, that they made up themselves, RATHER THAN, surveying the situation, and then calculating the results.

Lazy people need whipping, not patting.
Lord_jag
2.5 / 5 (11) Aug 17, 2015
You're pretty much correct, though far more insulting that I would have been.

These are pretty basic calculations. Anyone with basic education should be able to do these calculations.

What happened to taking pride in not being dumb?
RM07
4.6 / 5 (10) Aug 17, 2015
Some people waste their lives being angry, unhelpful, high IQ morons. Really brilliant. We're all impressed at how smart and angry you anonymous Internet tough guys are.

So glad you found a physics forum to spout your hatred. Brilliant use of your time.

Steve 200mph Cruiz
4.3 / 5 (6) Aug 17, 2015
Lex,
It's kind of retarded of you to think people are going to figure out all the trigonometry of this when you can just use a damn calculator.

These are complex equations, you probably don't know them yourself. Would you have this same attitude if you were talking about your family or friends? Why hold people you don't know to a standard that you don't actually care about in the first place?
Eikka
5 / 5 (19) Aug 18, 2015
A true "RETARD" is a person who is mentally and socially and emotionally under developed by choice."


If by choice, then the technically correct word would be "idiot". It means "private" which in ancient Athens in Greece referred to people who were too self-centered and ignorant to take part in democracy.

These are pretty basic calculations. Anyone with basic education should be able to do these calculations.


Well, care to explain in short how one calculates the solar insolation of a roof?

You have to factor in at least the angle of the roof, direction, latitude, and the production curve of the panels themselves relative to sun angle, add these up and integrate the resulting trigonometric function over time to arrive at an estimate.

A person who knows college level calculus should be able to do it, but not necessarily with ease, especially considering that some of the information is hard to come by.

Then they have to figure out the local subsidy policies
antigoracle
1.5 / 5 (8) Aug 18, 2015
Now, how many of you AGW Chicken Little hypocrites are going to install solar?
Eikka
5 / 5 (20) Aug 18, 2015
What makes the calculation hard is that it's done in three dimensions instead of two as the usual math examples in school.

You essentially have to project the shadow of a flat surface in an arbitrary angle onto the surface of a sphere, and calculate the area of that shadow to figure out the amount of radiation falling on the roof at any given moment. Then you have to figure out how the surface rotates throughout the year to make the time integral. Then finally divide the result by two, to remove the amount of sunlight "recieved" by the backside of the panels.

Or you could consult charts and tables prepared for you by companies like Google.
gkam
1.3 / 5 (23) Aug 18, 2015
"especially considering that some of the information is hard to come by."
---------------------------------------

Not anymore. We have had good charts for a generation.
Uncle Ira
4.4 / 5 (25) Aug 18, 2015
"especially considering that some of the information is hard to come by."
---------------------------------------

Not anymore. We have had good charts for a generation.


Google-Skippy can also tell if you don't have any solar panes on your house like you claim to have. Thanks to the Skippy on the other article who found the pictures of glam-Skippy's house.
tekram
3.7 / 5 (6) Aug 18, 2015
https://www.googl...roof#p=0

This tool is not available for most parts of the US right now.

However, tt is a nice tool incorporating a lot of data that may not be at the fingertip of the average homeowner. It calculates the available space for solar panels on our roof based on 3D modeling of your roof and nearby trees and then it analyze the day to day weather pattern to reach the number of available usable sunlight per year.
gkam
1.2 / 5 (21) Aug 18, 2015
"Google-Skippy can also tell if you don't have any solar panes on your house like you claim to have"
----------------------------------

You ARE otto! Like him/her, you invent things I was supposed to have said.

Nope, not yet, but we decided today to do it. I had been waiting for the prices and deals to fall, along with the costs of the systems themselves. I have what they want, areas with both Western and Southern exposures without shading. The time-of-use periods will change to later afternoon for peaks, and they really want those electrons.
abecedarian
2 / 5 (4) Aug 18, 2015
And now they can map your address to your IP and possible Google username. Surely nothing bad can come of that.
antigoracle
2.6 / 5 (5) Aug 19, 2015
Nope, not yet, but we decided today to do it. I had been waiting for the prices and deals to fall, along with the costs of the systems themselves.
--gskam
So, please share with us those deals you've found.
antigoracle
2 / 5 (4) Aug 19, 2015
So, instead of sharing those great deals on solar panels, gskam, the Master of Scien....er...FRAUD, chose to down vote me instead.
gkam
1.2 / 5 (21) Aug 19, 2015
When they come in, I will share them. You will not like it.
gkam
1.2 / 5 (21) Aug 19, 2015
"And now they can map your address to your IP and possible Google username. Surely nothing bad can come of that."
---------------------------------------

They already have everything on you they want. I got dispossessed of any naiveté when I served on the Federal Criminal Grand Jury.
antigoracle
2.6 / 5 (5) Aug 19, 2015
When they come in, I will share them. You will not like it.

There must be a company/website that you can share with us.
gkam
1.2 / 5 (21) Aug 19, 2015
"There must be a company/website that you can share with us."
------------------------------------

Gosh, just look them up. Only one has called, because I just put in my information to the state.

I suggest you just look up who does it in the SF Bay Area, and I'll will hear from them - at least four-five. Neighbors on three sides are or will have them as soon as they can be put up. They use different options for financing. One bought them, and will have a long payback. Another essentially rents out his roof, at no cost to him. He gets about 10 cents/kWh or so off his power bill, and everything he produces over his use he gets paid three cents/kWh for. The one who owns his own will have battery storage soon, as well, and the grid can be his backup.
antigoracle
2 / 5 (4) Aug 19, 2015
"There must be a company/website that you can share with us."
------------------------------------

Gosh, just look them up. Only one has called, because I just put in my information to the state.

I suggest you just look up who does it in the SF Bay Area, and I'll will hear from them - at least four-five. Neighbors on three sides are or will have them as soon as they can be put up. They use different options for financing. One bought them, and will have a long payback. Another essentially rents out his roof, at no cost to him. He gets about 10 cents/kWh or so off his power bill, and everything he produces over his use he gets paid three cents/kWh for. The one who owns his own will have battery storage soon, as well, and the grid can be his backup.

Hmmm, so all your neighbours around you already have solar, but you the Master of Science who shouts the loudest about them, DOES NOT!
Tell us, did your neighbours consult you before they bought their solar panels?
gkam
1.2 / 5 (21) Aug 19, 2015
Do you silly folk sit up at night dreaming up this silly stuff?

Go out and count chemtrails.
antigoracle
2.6 / 5 (5) Aug 19, 2015
Do you silly folk sit up at night dreaming up this silly stuff?

Go out and count chemtrails.

gskam, what I want to do is install solar panels like you...well...actually, like your neighbours.
Tell us, how much power did you calculate you would generate?
gkam
1.2 / 5 (21) Aug 19, 2015
"Tell us, how much power did you calculate you would generate?"
---------------------------------------
I haven't yet. Are you hoping for some kind of wedge issue? Some kind of downside?
Uncle Ira
4.3 / 5 (24) Aug 19, 2015
"Tell us, how much power did you calculate you would generate?"
---------------------------------------
I haven't yet. Are you hoping for some kind of wedge issue? Some kind of downside?


So let me get this right because I am one of those silly peoples who reads the postums on here and gets slowed down by remembering what else a person wrote even he does not.

You been studying this for years. You know your neighbor gets a 10 cent per kWh break. You been waiting for the costs to come down. You finally decided yesterday to bite the bullet and put in your order. Because the sun shines perfect for your roof.

But haven't gotten around doing the calculating what it will mean to YOUR pocketbook? Skippy you are one very unfortunate person when it comes to the common sense way of doing things.
Uncle Ira
4.2 / 5 (24) Aug 19, 2015
@ P.S. for you glam-Skippy.

And all that stuffs in the before postum does not even include all the crowing about YOUR system you were crowing about back in Sept and Oct and Nov and so on and some more so ons.

You still haven't caught on to the fact that EVERY THING you have ever written on here is still here and for anybody who wants to see it?
gkam
1.2 / 5 (21) Aug 19, 2015
Wow, that fixation is contagious!

No, Ira, I said I would ask for some quotations, and just put my name in for some. I have not bought nor even priced any of the offerings. Ask your wife how she decides on what is real or not, and do what she does. You seem to make a lot of stuff up.
antigoracle
3 / 5 (6) Aug 19, 2015
So gskam, no calculations, no prices but you've requested quotations.
I'm still waiting for those websites so that I can request quotes myself.
Thanks.
gkam
1.2 / 5 (21) Aug 19, 2015
anti, somebody called while I was outside. I'll check up on it, so you won't be worried.
Uncle Ira
4.5 / 5 (22) Aug 19, 2015
You seem to make a lot of stuff up.


Don't you try to put that off on me podna. I get all my material straight from you. If you don't like how it sounds to me, maybe you should spend a little more time looking it over before you push the "Postem Up" button.
antigoracle
2.3 / 5 (6) Aug 19, 2015
anti, somebody called while I was outside. I'll check up on it, so you won't be worried.

gskam, I only worry when you go outside, for I suspect you look directly into the sun.
I keep asking for the links to where you requested your solar panel quotes and instead I get a different irrational story every time.
Da Schneib
5 / 5 (5) Aug 19, 2015
Personally I'd rather not have to figure out weather effects, and solar panel prices, and installation costs, and debt service costs, and not only current but predicted electricity prices, and several other pretty complex variables. Sure, I could do it, but why bother when there's a nice easy tool to use? This is a good thing. It also helps people who shouldn't install solar avoid unnecessary investments, when they could be using the money for something more effective. I don't see any losers here except the typical naysayers whining about how meaningless everything is. Suck it up and go find out if you should be investing in this, and don't whine.
Eikka
5 / 5 (18) Aug 20, 2015
Not anymore. We have had good charts for a generation.


It's not that simple. Calculating just the insolation over a roof area is not sufficient to infer solar energy production.

At sufficiently large angles from the panel normal, you get total reflection and no power is generated - depending on what sort of anti-reflective coatings your panel has. Then, the pattern of current collector wires on the PV cells cause shadows within the cells which reduce production from off-angles. The apparent thickness of the silicon also changes depending on the direction from which the photon enters. This makes for a complex interaction where an equal angle-offset in the horizontal or vertical plane, or in a diagonal plane, does not cause an equal change in output, and the panel only works at its nominal efficiency over a fleetingly short moment when the sun is straight ahead.

The charts are more "theoretical maximums" rather than representative of real power output.
Eikka
5 / 5 (18) Aug 20, 2015
Of course you can use some fudge factor to guess what the average daily production will be, but that really depends on what panels you buy, and then how diligently you keep cleaning them.

The question of shadows from the current collectors is interesting; could there be more optimized patterns that take into account the sinusoidal motion of the sun in the sky?

The reason why there has to be such a pattern of wires on top of the cell is that the conductive ITO glass over the panel has a rather high resistance in the range of 100 Ohms per inch, which would add up to kilo-ohms if you tried to collect the current from the edges of the cell. That's also why replacing the expensive and rare Indium in ITO glass with less expensive zinc and aluminium would result in lower efficiency - AZO glass has higher resistance.

gkam
1.4 / 5 (21) Aug 20, 2015
Eikka, I took SEIA's Solar Engineering course decades ago, and still have the charts in a large binder (no women),. They work.
antigoracle
2 / 5 (4) Aug 20, 2015
Eikka, I took SEIA's Solar Engineering course decades ago, and still have the charts in a large binder (no women),. They work.

It's a good thing your neighbours did not take that course, then they would not have installed solar, like you.
gkam
1.2 / 5 (21) Aug 20, 2015
I guess if one is losing on all fronts that is the kind of silly statement which one makes.
Lex Talonis
4.2 / 5 (5) Aug 20, 2015
Hmmm all idiots - the lot of you.

Trigonometery? None of you have ever designed and set up solar panels and tracking systems.

Look up the weather patterns, for the substantially overcast vs the substantially clear days, work out solar angles from min to max above horizon, be mindful of trees and buildings casting shade, and work out by testing a decent sized panel i.e. 20W, what the degree of misalignment to the sun the panel tolerates until output drops substantially,, figure out if your going to use tracking or not, and then do your sums....

Power generated, optimum times of day,

Perfect enough is fine... Obsessively perfect is not.

Your never going to get or need perfect calculations to the milliamp... 24/7 all year.

But you can THINK and LEARN and get it all fairly right....

Enough to say, "This will pay for it's self within 3 years or 20 years....

Or can I create the peak power to the grid times, to coincide with the highest consumption times?
antigoracle
2 / 5 (4) Aug 20, 2015
I guess if one is losing on all fronts that is the kind of silly statement which one makes.

It's only silly to the pathological liar.
gkam
1.2 / 5 (21) Aug 20, 2015
Is that your post on a thread for solar power installations? Do you have these emotional outbursts often?
antigoracle
2 / 5 (4) Aug 20, 2015
gskam the pathological liar. I'm still waiting for those links to get my

Is that your post on a thread for solar power installations? Do you have these emotional outbursts often?

Have you got a response back for those solar installation quotes you never requested?
gkam
1.2 / 5 (21) Aug 20, 2015
What? Is that supposed to prove anything?
antigoracle
2.3 / 5 (3) Aug 20, 2015
What? Is that supposed to prove anything?

It proves you are a pathological liar.
Why don't you give me the links to those companies you requested quotes for solar installations.
gkam
1.2 / 5 (21) Aug 20, 2015
OMG, is that the level of your dialogue?

SunRun will be here tomorrow. But it is not your business. You are just a political troll, and advertise it with your pseudonym.
gkam
1.4 / 5 (22) Aug 20, 2015
http://www.utilit.../404288/

The chair of the Ohio PUC told the First Energy utility to stop trying to scare their customers into giving them huge subsidies for their uneconomical coal and nuclear powerplants. The utility lobbied for deregulation, but now wants regulation back to force their customers to buy their overpriced power.

Their loser plants are killing them. Bad decisions last a long time in the utility business.

antigoracle
1.8 / 5 (5) Aug 20, 2015
OMG, is that the level of your dialogue?

SunRun will be here tomorrow. But it is not your business. You are just a political troll, and advertise it with your pseudonym.

Spoken like the true pathological liar you are.
You'd think that you, who screams so much about AGW and claims to know so much about solar, would be eager to share the companies you chose and the reasons why. But, all you post are your lies.
gkam
1.2 / 5 (21) Aug 20, 2015
"You'd think that you, who screams so much about AGW . . "
--------------------------------------

Well there you go again, trying to think. Why not just react emotionally, like you did with those liars screaming "WMD!" at you?

Oh, . . .
antigoracle
1.8 / 5 (5) Aug 20, 2015
"You'd think that you, who screams so much about AGW . . "
--------------------------------------

Well there you go again, trying to think. Why not just react emotionally, like you did with those liars screaming "WMD!" at you?

Oh, . . .

Ahh, there it is, the ignoRANT of the pathological liar. Take a gander at your posts, even your "friends" know what you are.
Eikka
5 / 5 (17) Aug 21, 2015
Eikka, I took SEIA's Solar Engineering course decades ago, and still have the charts in a large binder (no women),. They work.


You might want to take a refresher course and update your binder.

"Decades ago" you had approximately one type of solar panels from one manufacturer available (the one who wrote the course), and everything else was too expensive to actually use or you didn't know it even existed.

But today, take for example monocrystalline vs. polycrystalline vs. amorphous silicon cells, not to mention thin film and then the upcoming perovskite and dye-sensitized cells - all with various possible coatings and films on top. Each of them respond differently to changes in the incident angle of photons, and it's usually the cheapest panels that respond the worst and get the biggest gap between theoretical and actual production, so your cost-benefit calculations just got a whole new factor to consider and your old charts from decades ago no longer apply.

Eikka
5 / 5 (18) Aug 21, 2015
Eikka, I took SEIA's Solar Engineering course decades ago, and still have the charts in a large binder (no women),. They work.


You might want to take a refresher course and update your binder.

"Decades ago" you had approximately one type of solar panels from one manufacturer available (the one who wrote the course), and everything else was too expensive to actually use or you didn't know it even existed.

But today, take for example monocrystalline vs. polycrystalline vs. amorphous silicon cells, not to mention thin film and then the upcoming perovskite and dye-sensitized cells - all with various possible coatings and films on top. Each of them respond differently to changes in the incident angle of photons, and it's usually the cheapest panels that respond the worst and get the biggest gap between theoretical and actual production, so your cost-benefit calculations just got a whole new factor to consider and your old charts from decades ago no longer apply.

Eikka
5 / 5 (19) Aug 21, 2015
Here's a good article about SEIA:

https://www.maste...er-seia/

Why I'm Not a Member of the Solar Energy Industries Association
By David Bergeron -- October 10, 2012

"On-grid solar is a perfect storm for taxpayers: concentrated benefits for the industry, diffuse cost for ratepayers and taxpayers, and a strong positive public sentiment for solar created by energy Malthusians."


...around 2006, the federal government began heavily subsidizing solar installations.
From that grew net metering laws and other state and utility subsidies for what otherwise was uneconomic energy. Since 2010 or so, I could have almost 90% of my solar home system paid for with free subsidy money.
But of course the money is not free. It is taken from the pockets of ratepayers and taxpayers...

SEIA is an industry lobby group that lobbies for ever more subsidies, to sell solar power to people who don't understand the real cost of it.
Eikka
4.8 / 5 (19) Aug 21, 2015
Enough to say, "This will pay for it's self within 3 years or 20 years....


Whether you have to pay interest on a loan for 3 years or 20 years kinda makes a huge difference in what the final cost will be.

A dollar tomorrow is not worth as much as a dollar today, both because of inflation and because of lost interest from investing that dollar, so if you intend to pay for your solar installation with tomorrow-dollars, you have to pay more.

The longer the payback period, the bigger the pile of tomorrow-dollars you have to pay. That is also why huge up-front subsidies on solar power make it look cheaper than it is. From the investor's point of view, it makes it appear as if you had produced all the energy today, which is more valuable than waiting for it to trickle through for 30 years, but that doesn't actually happen.

gkam
1.2 / 5 (22) Aug 21, 2015
Come to California and see the future. It will scare you to death.
antigoracle
2.7 / 5 (7) Aug 21, 2015
Come to California and see the future. It will scare you to death.
--gskam
Well, it has certainly scared you stupid and that does scare me to death.
gkam
1.2 / 5 (22) Aug 21, 2015
" . . . and that does scare me to death."
-----------------------------------------------

Oh no, . do we get more of the Republican Police State?
hangman04
3.7 / 5 (3) Aug 21, 2015
come on Eikka don't be so negative, for better or worse, this solar hype is urging the companies to get better designs, and from what i understand you don't have a problem with green as longs as it is net cheaper than alternatives. the producers are indeed complacent and they are filling their pockets from subs but they also putting pressure on r/d to get better products. Since there is a hype investors are competing over the market which it's overrated and competition will probably drive the tech onward...
antigoracle
4 / 5 (4) Aug 21, 2015
Has anyone here actually used this tool to calculate if installing solar is worth it?
Lord_jag
2.1 / 5 (11) Aug 22, 2015
Enough to say, "This will pay for it's self within 3 years or 20 years....


Whether you have to pay interest on a loan for 3 years or 20 years kinda makes a huge difference in what the final cost will be.


So whats the payback time frame on all the current energy technologies solar is being compared to?

The fact that it pays for it self in any time frame makes it worth your while.
chapprg1
1 / 5 (1) Aug 22, 2015
Duh!
antigoracle
3 / 5 (4) Aug 23, 2015
The fact that it pays for it self in any time frame makes it worth your while.

So, how many solar panels have you installed?
gkam
1.4 / 5 (21) Aug 23, 2015
How many coal furnaces do you have at home?
antigoracle
2.3 / 5 (6) Aug 23, 2015
How many coal furnaces do you have at home?
--Pathological LIAR
Same amount as the number of times you've told the truth....NONE.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.