As a society and individually, we use energy every moment of our lives to improve our quality of life. Energy 101 will develop the big picture and connect the details of our energy use, technology, infrastructure, impact, and future.
Interactive Solar Map
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From the course by Georgia Institute of Technology
Energy 101: The Big Picture
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From the lesson
Solar and Wind Power Resources
This module explore renewable energy sources
Meet the Instructors
Dr. Sam SheltonProfessor Emeritus
Woodruff School of Mechanical Engineering
Dr. Richard A. SimmonsSenior Research Engineer & Fellow
Strategic Energy Institute
So today we're looking at solar resources as part of the overall energy
resources we have available to us.
And today we're going to look at the interactive map of how
to create maps to find out exactly how much radiation and
solar energy is available to us to utilize to meet some of our energy needs.
It's a little bit difficult thing to calculate because there are so
many variables that the amount of radiation depends on.
It depends on where you're located on a map.
What latitude, longitude you're located, both altitude makes a difference.
Time Of Year makes a difference, panel mounting and
orientation of that mounting makes a difference.
Two Axis Tracking always facing the sun is the best.
We can fix the panel, which is the cheapest way to install them and
tilt them up toward the equator at a fixed angle.
That means if we're in the Northern Hemisphere,
we're tilting them up to the South Pole.
If we're in the Southern Hemisphere, we're tilting them
up from the flat horizontal surface toward the North Pole.
And we can also have Fixed Horizontal Mounting, flat on the ground.
Or we can have vertical mounts on the sides of buildings.
Again just to remind us what we saw last time,
this is what we're talking about here and
the tilt angle we're talking about is this one right here.
This is the tilt angle that we refered to.
And this diagram is written for the Northern Hemisphere.
Because it talks about tilting it to the south, that's gonna hurt you,
if you're in the southern atmosphere and you tilt it to the south.
But it's drawn for the Northern Hemisphere,
US-centric in other words, because it's done by
the National Renewable Energy Lab of the US Department of Energy.
So we can refer back to that if we
get confused about some of these choices that we're going to make.
Now we're going to use an interactive map that they have,
interactive website that produces a map such as this and
to show you what we're going to get.
And each one of these dots on this map by the way,
represents an experimental data point.
In other words they have solar radiation at all of these points.
And they use that to correlate the data, and
so the map corresponds with that.
This is the scale that tells us what the colors represent.
In other words, this yellow, of course, means that on an annual basis,
this one is done on annual basis, creates 5 to 6 kWh per square meter per day.
And this area is the light green.
So that's 4 to 5 kWh per square meter per day.
But now that's not every day obviously, it's not gonna be that.
Winter's going to be less different than the summer.
But on an average basis, cloudy days will be less than sun shiny days.
But on annual average basis, that's how much solar energy will strike
a square meter about 10 square feet, on a daily basis.
A kilowatt hour is 3413 BTU per hour if you wanna convert that.
So that's what we're going to create here, and another example.
This one is, the last one.
This one is, I didn't mention,
is the tilt angle is tilted up to the south,
being in the Northern hemisphere of the US at the latitude and an annual basis.
The next one, Shows it for
a Two-Axis Tracking situation.
Where we're always facing the panel toward the sun and
we're looking at the best month so I took the best situation here.
And you can see that from the scale that we're receiving a lot more energy through
July and if we want to pay the extra cost of the two-axis tracking mechanism,
we'll have a lot more energy strike in our collector
that we can hopefully convert to something useful.
And all in the south, you can see it's around 7
to 8 kWh per square meter per day.
So you can do your trade-offs and determine where it's worth your while to
pay for our two-axis tracking system.
But things are much more uniform across the country
if you do a two-axis tracking situation as you can see here.
Out here, even in the North West,
you're out there at the high point of 10 to 14 kWh per square meter per day.
Those are the maps that we're going to create here and
we do that by using an interactive online map and
this is the link right here.
We'll get it in a minute.
This is the link, and I think if you click on it, we'll have it come up.
Okay, when we go to that link that's on that slide,
this is where we're directed to.
And as you can see here, we got several choices that we need to make.
We need to select the data type.
Do we want the average, the minimum case, or the best case?
Then next we can chose the month.
What month that we're interested in or
we could choose the annual average, which is usually what I pick.
But, let's see.
Here we go.
What's clicked here is January.
And what I showed you before was the annual average for
all of these months of the entire year.
And the first map that I showed you was for a flat plate down here,
tilted south at latitude, tilted south at latitude.
So we go down and we click View Map to see what it looks like.
And this is the map that I showed you before and that I've already had run.
So you can create your own situation if we go back,
to create the second map that I mentioned.
We can look at July.
And July, rather than the annual average, which is the best month,
we can also look at some of the worst months, being say January, if we like.
And look at the single axis, not single axis,
but Two Axis Tracking Flat Plate.
Now let me just mention here, it's got two choices,
Two Axis Tracking Concentrator and Two Axis Tracking Flat Plate.
The reason there's a difference is because a concentrator will only reflect and
concentrate at the point you want it,
the direct radiation coming directly from the sun.
There's some diffuse radiation that's coming from the atmosphere
that gets scattered as the sun is coming through the atmosphere,
so there is less energy coming as direct radiation that
a concentrator can deal with, than if it's a flat plate.
So that's the reason there is the difference there.
But there's a difference between a concentrator and a flat plate.
Here we're talking about a flat plate, is what I've been talking about.
I created the high side that had all the red on it.
Using a Two Axis Tracking Flat Plate and looking at the one month of July,
and if I look click View Map, I come up with the map that
I showed you before where it's more uniform across the country.
Much higher the radiation intensity per unit area.
With the scale down here, shown,
goes from 10 to 14 out here in the West down to the tan,
which is about 7 to 8 over here all up and down in the East.
So there's some real advantages to being tracking and of course being in July.
We can look at that.
Let's just look real quickly at what it looks like for
annual average if we do a two axis tracking.
We go back and Return to menu and we go down.
And we look at annual average rather than just
July that we just looked at and we'll do the two axis tracking.
Two Axis Flat Plate again, the only think I've
changed from the previous case was annual, rather than July.
And in that case you can see that the annual average is
significantly higher out here in the South West.
So there's some real differences in the characteristics of the amount of radiation
that's available to you depending on where you're located.
So that's the interacting map for the US and I hope you find it beneficial.
And by the way, if you click the PDF version,
up there at the top, it will create a,
before you [INAUDIBLE].
I got some software problems on that, but you can show it as a PDF and
download it and it's a little clearer, cleaner picture.
But that completes the interactive solar map that shows you how to determine how
much solar energy is available to us in different situations, in the US at least.
And their means to do that also any place in the world.
Okay, thank you.
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