Converting the Memphis Pyramid Arena into a solar power station

Factual Questions
1

For those who have never been here, Memphis has a big freakin’ Pyramid downtown on the river. It was built in the 1990’s as a new civic arena which would (hopefully) attract an NBA team to the city. Well, for a lot of reasons I won’t go into in this thread, we got the NBA team, but they insisted we build them a brand new arena. Now the Pyramid is a big white elephant, and there are a lot of people wondering what the hell to do with it. Suggestions have ranged from “aquarium” to “casino”. But I have a better idea. I think the city should make it into a giant urban solar power plant. Sound wacky? Well, consider these positives:

  1. It has enormous flat surfaces angled properly to capture the sun.

  2. As will become apparent after perusing the photos below, it’s placement in the city is such that it always has unobstructed sunlight. No nearby buildings cast any significant shadows on the potetial collection surfaces. Plus, it is directly adjacent to the downtown electrical substation.

  3. Memphis now has one of, if not the, largest solar panel manufacturing plant in the United States, run by Sharp, so the panels could be produced locally.

4)TVA, which supplies Memphis with its power, has a history of innovation and support for alternative power generation. Perhaps they would lend a hand and technical support.

The General Quesions:

  1. How much power would the hypothetical Pyramid Power Plant produce? To know this, we will need to figure out the usable surface area of the Pyramid, the efficiency of the available solar panels, the amount of sunlight that falls on Memphis in the average year. I’ll tell you right now, as the temperature outside flirts with 100 degrees, that the answer to the third part is “a whole freakin’ lot.” But the surface area question is complicated by the fact that I was unable to find any measurements of the base of the structure online. The only hint as to how big the thing is comes from the official site above, which says the structure is 32 stories tall.

  2. How much will this cost to do? I don’t really know how to calcualte this, since there are lots of variable to take into consideration. Paging Una!

  3. Once the place is converted, would there still be space left over on the inside to continue to use it as an arena, convention meeting space, casino or aquarium?

I’d rather this not (d)evolve into a debate as to the pros and cons of solar power. Rather, let’s make this a case study. I’ll be happy to open a GD thread discussing what we’ve learned from this thought experiment and how it applies to the larger debate once we’ve got some numbers to kick around. And, of course, I know the best we can hope to come out of this with are back-of-the-envelope calculations, but that’s better than what I have now.

Thank you all, in advance, for applying a small part of your august minds to the problem.

Pics [url=http://www.flickr.com/photos/amiev/16136229/]of thePyramid. Full Google image search results.

2

I can’t help, but I’ll add that if you drive by the Pyramid on I-40 at the right time, the light reflecting off the panels will nearly blind you.
-Lil

3

I did find this .pdf that suggests a square base with sides of 300 feet.
-Lil
http://everett.lansingschools.net/Geometry/lgp12dad.pdf

4

I do know that the Solar power received at the Earth’s surface is 1.5 Horepower per Square Yard or about 1,120 Watts per square yard and that is allowing for 100% efficiency of a solar panel.
We also have to take into account 1) night time and 2) cloudy days which would further reduce the usefulness of such an energy generator.
I’m all for alternative energy sources but as you can see, it is difficult to harness these and make them practical.
Of course, I’m just contributing my bit of knowledge to this thread. Perhaps others can add their thoughts.

5

The sides are 600 feet:

http://www.pyramidarena.com/overview.html

It’s 320 feet tall (32 stories)

I’m guessing that the each triangular face plane has dimensions of roughly 440 feet high by 600 feet at the base (my geometry is rusty … please feel free to correct).

So the area of each face is 132,000 sf.
The pyramid is not oriented exactly north-south

http://terraservice.net/image.aspx?s=11&lon=-90.05208&lat=35.155842&w=2

but let’s say they cover only the southeast and southwest faces, for 264,000 sf. (could probably get the northwest face, too, with angled panels … but let’s leave that out for now).
Now, Sharp makes 140W PV panels, each of which covers about 12.5 sf and retail for $685.

They even are the only makers of triangular panels! They must have seen this coming…

But let’s say the Arena gets the panels for a sweet discounted bulk rate of $625 per 12.5 sf (including the triangular panels, which cost slightly more per sf). That’s $50 per sf. So now we’re talking

264,000 sf x $50 = $13.2 million

So, the panels alone might cost around $13 million. Then you have installation labor, design costs, and the cost of the electronics that handle the electricity/grid intertie/etc. WAG: $15-20 million total cost, minimum. You know how these things bloat. Final cost, after typical unexpected overruns: let’s say $30 million.

21,120 PV panels rated at 140 W each. That’s just under 3 MW.

5 hours average insolation:

http://www.wattsun.com/resources/insolation_data/

so an average of 15MW per day from this pyramidal power plant.

6

Okay, if the Sunlight energy reaching the Earth is 1,120 Watts per Square Yard, then 1,120 / 9 = 124.5 Watts Per Square Foot.

Based on data from toadspittle:
The Sharp Solar Panel has an area of 12.5 Square Feet and should (in theory) be able to produce 1.5 kilowatts. In actuality, it produces 140 watts. This equals a 9% efficiency. (I thought those panels were a lot more efficient than that. Maybe I’ll do some research on that).

7

According to this website:
http://www.101iq.com/infosce.htm
One Square Meter of Sunlight produces 1,000 watts of energy.

1,000 watts / 10.764 square feet per square meter = 92.9 watts per square foot.
The Sharp Solar Panel is 12.5 Square Feet and receives about 1,160 watts of Sunlight.
In reality it produces 140 watts, making an efficiency of 12%. This agrees pretty well with the previous figure.
Also that website mentions that most solar cells operate at slightly more than 10% efficiency.

8

hee-hee!

9

Airblairxxx
:smack: Geez, I was so carefull looking at the numbers in those postings the *words * completely escaped my proofreading.

10

slight hijack…
I wrote a newspaper column a couple of years ago about the rampant public spending to build new sports venues. From 1987-2002, new arenas were built for 84 of the 121 teams in the NFL, NBA, NHL and MLB. Of the top of my head, I count at least 8 more new venues have opened since I wrote that piece (there may be more). That doesn’t include all of the facilities built for minor league teams or college programs.

This is an absolutely absurd trend, and a diversion of funds that will cause massive headaches for state and local budgets for years.

/hijack

11

[hijack continuation]
Yes it’s good to see money being well spent for sports as opposed toward using it for ejakayshun.
[/hijack continuation]

12

[Continuing hijack…]
I’m sorry to draw this thread further OT but why are the Memphis (formerly Vancouver) Grizzlies demanding a new arena when they already have one that’s practically new? Are the Grizzlies such a hot ticket that a 21,000 set arena is too small? I hope the franchise isn’t resorting to the old “build us a new arena or we’ll move” card. They’d have a lot of chutzpah to do that after being in Memphis for only four years.
[/End hijack]
(Maybe this topic should be thread in the BBQ Pit.)

13

Nitpick with toadspittle – you can’t really have “megawatts per day” because a megawatt is already a rate measurement (a watt is one megajoule per second). You could say “kilowatt-hours per day” and that would be a pretty good measurement. Your calculation (3MW * 5hr/day) actually yields megawatt-hours per day.

The only things you need to figure out now are how many people it takes to run the thing during the day (or around the clock if you build a bunch of really big batteries or flywheels to store the juice at night) and their labor rates, so you can determine whether this could be profitable or not. I imagine once you install the panels, you could do most of the maintenance from a substation across the street or even underground.

The good news is that the TVA will already pay 15 cents per kilowatt hour in power credits – and if that $30M price tag scares you, don’t worry: they’ll also give you a $500 credit towards startup costs.

14

The building of the new arena wa part of the deal that got the Grizzlies to Memphis in the first place.

Not sure why a second arena made more sense. Did the University of Memphis basketball teams leave the Pyramid too?

15

Thanks for the catch.

I don’t think there would be any reason to have batteries. That’s a huge expense, and the thing is in the middle of town, not off the grid.

Of course, the cost, amortized over 30 years, would probably be around 18ish cents per kwh. So this is not a smart financial venture–just a smart social/environmental one.

16

Don’t be so hasty with that comment. There are a few points to add.

  1. The cost of electricity is going to go up.
  2. The cost of maintenance for the arrays are not figured in.
  3. You really need to do more work to find out if this is good environmentally. Solar cells take a lot of electricity to produce. You need to decide if it is worth it to generate all that pollution up front so save some down the road.

As a side note lead acid batteries have a finite life time. One of the guys I worked with calculated that the cost of electricity from batteries if charging them was free was about 14 cents a KWH. So they don’t make much sense for storing power unless you are off grid or need power when the grid fails.

17

I’m sorry I neglected this thread over the weekend. I was attempting to simulate that offline phenomenon known as “a life.” Perhaps you’ve read about it on various websites. Me, I found it overrated.

Anyway, to point:

You get a similar effect driving down North Parkway. In fact, seeing all of that energy reflected instead of absorbed is what gave me the idea in the first place.

Ahh, that’s the rub. But what I propose is not a primary power generator, like a hydroelectric, coal, or nuclear plant. This would be a peak generator. Memphis uses the most power in the summer when the sun is blazing and a hundred thousand ACs are going full tilt. That’s when TVA (or, insert power company of your choice here) is forced to start up their peak generators to fill in the gap. These peak generators are typically diesel powered turbines (and at least one locality in the TVA system I know of has begun using biodiesel) and are more expensive and less efficent than the hydro, nuclear, and coal plants. I don’t think we need any batteries, just feed the electricity to the grid when it’s produced. And it just so happens that peak production will come at the same time the city experiences its peak consumption. For the program to be practical, it doesn’t have to be cheaper than coal, it has to be cheaper than peak power production, which is a lower bar.

Plus, the damned thing’s just going to be sitting there, costing the city money. I’m trying to figure out a way to make it pay for itself and perhaps do a little environmental and economic good in the process. In the unlikely event that it would come to pass, it would be a huge advertisement for solar power, which is also an advertisement for the Sharp manufacturing plant, which means jobs for the city. We’re not going to get rid of coal-fired plants anytime soon, but idespread adoption of solar for homes could help decrease the load on the grid and at least slow the growth of greenhouse gases in the atmosphere. Solar panel effiencency is increasing all the time, which makes it more competitive every day.

Major props to toadspittle, my new hero, for the heavy mathmatical lifting!

I’m in absolute, 100% agreement with you there!

Long story short: skyboxes. The Grizzlies wanted more expensive skyboxes in the arena so they would be more profitable. The new arena was a public-private partnership, but to me it still came down to the fact that Memphis taxpayers were being asked to subsidize the building of luxury skyboxes which 95% of them would never even see the inside of. Meanwhile, the public schools struggle.

Yes, they did.
Furthermore, the Grizzlies got a “non-compete clause” in their contract, meaning that no one can book a concert in the Pyramid or at the Mid-South Colesium on the same night the Grizzlies are playing or whenever any other event is happening at the FedEx Forum. So if you want to book a big event in Memphis, the Grizzlies/Forum people have veto power over it.