/sci/ - Science & Math

Watts are power and there is no given time so it would be in joules. Are you talking about the potential energy of the water because it would just be E=mgh

98,000 Joules or .0272 kwh

E=mgh as has been posted
also dont forget about the efficiency of your generator

>>2950996
>Watts are power and there is no given time so it would be in joules.
>kWh
>kilowatt-hours
>1000*watt*3600*seconds
>power*time=energy
herp

E = mgh is only the gravitational energy that can be extracted. I'm sure there's some chemical substance that can be reacted with water to produce energy.

At 4 degrees celsius, 1 cubic metre of water weighs 1000 kg. This will serve as an approximation for our purposes.

Assuming g to be 9.8, we get 98 kilojoules.

>>2950973
OP, we already have these systems. Off-peak a pump moves the water up a few stories. Then on-peak the water spins a turbine which powers a generator supplying power.

To do this you have to learn how to design water turbines. Just draw it in s/w send it to a plastic prototyper and that''s all there is to it.

>>2951085
I know, but I'm also trying to figure out how useful it could be for a standard house, i.e. it it's realist or if you need ten olympic-sized pools at 3km above your roof to power your blender for three seconds.

Did you account for the energy used to pump the water into the tank? Maybe that's why your value appears too high...

>>2951126
What? Obviously you're going to end up with negative energy if you account for the whole system...

>>2951113

it is not useful for private applications. everything is done more efficiently in commercial settings. e.g.

LEMME JUST GET MY 10 kW NUCLEAR REACTOR RUNNING SO I CAN TAKE A HOT SHOWER

How funny, I have a fellow business student friend who recently went through a competition hosted by wall mart.

The competition was for green technology. But of course in the business environment it had to be profitable. His team had an idea to treat waste water with bacteria that produce hydrogen.

They lost to a team that had this idea of a physical battery from MIT I think (MIT or duke) like OP demonstrated. The idea was that power companies can store electricity in this way when power is cheap, and then utilize it when power is expensive.

Anyway he was pretty bummed when he lost.

>>2951126
The pumping would be done with solar panels and/or wind turbines. I need power for when there's no wind nor sun.

>>2951137
Really?
Okay so we're talking clean energy here, no coal, petrol or nuclear power plant.
What is more efficient, the biggest solar plant you can think of, with focusing mirrors and all, or solar panels on each and every roof in the area?

>>2951170

Yes. Solar is about 12 times more efficient in large scale operations because they can boil water and use steam turbines instead of photovoltaics. Steam turbines are VERY efficient.

>>2951204
It can be as efficient as you want, it will not even come close to the surface of every house combined, even with a lower efficiency.
Besides you don't have to worry about transporting the power from the plant to the cities

>>2951223

I'm not talking about total output. I'm talking about cents per kilowatt-hour. Commercial will beat private any day.

>>2951261
That's where you're wrong.
Even if the commercial power is more efficient, do you really think YOU are going to profit from that efficiency?
Nope, all this extra money is going to go right into their pockets.
Now who do you want in charge of your power bill, a company that aims for profits?Or yourself, who's aiming for efficiency?

>>2951310

>implying businesses dont want to be efficient.

>mfw when

>>2951327
Businesses want profitability. This doesn't always necessarily correspond to efficiency.

>>2951333

actually, yes it does. Even if they're making a lot of money, being more efficient allows them to make more money.

>>2951333
Businesses supply a demand, if consumers demand the wrong thing then that's not the fault of the business, it is also a flaw that is omnipresent and so relatively speaking is inconsequential.

>>2951339
Being efficient may sometimes need require the purchasing of fairly expensive machinery and so forth. They may forgo the machinery if it isn't profitable for them in the relatively short term.

>>2951339
Not necessarily, they can also increase prices for example.
Besides, let's say they get more efficient, so what? They will just increase their profits and in the best case your bill will stay the same, maybe even increase.

Technology in this industry has greatly improve effectiveness in every sector for a long time now, but tell me, when was the last time you heard about an electricity company actually lowering their prices?

>>2951339

Making the most money isn't always the most "efficient", so to speak.

Take ammonia production for example. Haber's process for ammonia production produces the most yield at low temperatures due to Le Chatelier's principle, but low temperatures also slows down the reaction rate. Therefore, the industry uses a high temperature, which makes the reaction occur really fast, but wastes a lot of energy and decreases the efficiency. It does produce more ammonia in a given time though, which means more profit to them.

>>2951339
>wrong
Accountants do not care about how efficient you are.

>>2951347
>may sometimes need require
Inurdaes can English good derp

>>2951333

Oh they absolutely want to be efficient.

I cant disagree enough really.

Efficiency is about minimizing the loss of input per output. Profitability is about maximizing revenues and minimizing cost.

Profit = revenue - costs
Profit margin = profit / revenue

Inputs = costs
outputs = revenue

If you arent being efficient, your costs are going up, and your profit goes down. I can relate this idea to every class at my university

>>2951347

You are looking at efficiency in a shallow way.

If it costs you a lot of money to produce a watt of electricity "efficiently" then you arent really efficient.

>>2951347
So? Everyone thinks in the short term, no one's perfect, the crunch here is how good something is compared to it's alternatives. What's up with all this kierkegaardian leaps of faith for perfection in this thread?

>>2951374
>Everyone thinks in the short term

Whoa whoa whoa, way to generalize.

>>2951366

Finally, someone else who has at least taken a BASIC economics course.

>>2951385

I think I fucked part of that up. Efficiency is about maximizing input/output.

Also saying inputs=costs and outputs=revenue is a generalization.

If you looked at the whole company, and said, the sale is outputting, and the costs it took to sale are the inputs then yes.

But lets say, you make something, and then you dont include the cost of shipping, then you arent really measuring efficiency, because if you are covering your costs except what it takes to ship our product out of your factory, you arent making a profit.

So my point is each part of a supply chain can be measured for its efficiency. How much energy does it costs to screw in car part number 5A or something. How many cookies can be baked per hour of labor. You have to measure a TON of things. You have to look at each part of a business on the microscopic level to maximize efficiency. Its not enough to look at a whole business as being efficient enough from any perspective.

>>2951366
so say I have a tree farm

at 200 trees my tree farm can produce 85 apples per tree. Forevery tree that I plant after the first 200 trees and the apple production falls by 2 apples per tree. How many trees should I plant to get the maximum amount of apples?

>>2951438
help me "resident /sci/ economist". I know your economist knowledge can be applied to this problem.

<span class="math">E = \gamma m_0 c^2 [/spoiler]
To find gamma, we'l assume we can find <span class="math">v_f[/spoiler] with nonrelativistic kinematics in a uniform field. This give <span class="math">v_f = \sqrt{2gh}[/spoiler]
So the full expression in terms of given variables is
<div class="math">E_{total} = \frac{1}{1-\frac{2gh}{c^2}} (a^3 \cdot \rho_w) c^2</div>

>>2951438
>>2951449
243, but this doesn't have much of anything to do with his posts.

>>2951452
Derp
<div class="math">E_{total} = \frac{1}{\sqrt{1-\frac{2gh}{c^2}}} (a^3 \cdot \rho_w) c^2</div>

>>2951404

No wait, I double fucked that up.

Efficiency is about maximizing output/input

My bad

>>2951438

You should plant 242.5 trees. At the 242.5th tree you will be producing 0 apples per tree. But it costs something to plant a tree, so that should be factored in. and it would help if you knew how much it costs to sell each apple, and how much each apple will sell for on the market.

Also sorry for the late reply I was somewhere else.

>>2951459
lol the maximum is actually less than 200 lol

>>2951504

If the maximum was below 200 trees, like, lets just pick 150 trees. Which equals 300 apples. At 151 trees you have 302 apples.

We are maximizing apples. Also somehow we can produce negative apples.

>>2951510
From clean energy to negative apples.
I love 4chan.

Economists' definition of 'efficiency':

-how profitable something is

Economists' way of getting 'efficiency':

a) raise prices
b) slash wages

of course, if you consider actual mechanical efficiency (or the lives of your minions) to be important, you shouldn't go into business.

>>2951545

>dont know if to think was joking or to correct

Shit guys I am stuck.

So to find out how many apples at your max you take 200 * 85 + (83 + 81 + 79 ...) How do you express this mathematically? I forgot

Another thread derailed by tripfags sprouting nonsense.

Keep up the good work tripfags.

>>2951545
ironically Adam Smith believe that under capitalism prices and profits would fall but wages would rise. Funny how its the total opposite.

>>2951372
Only if you use money and energy interchangeably. The most efficient form of energy storage from an energy perspective could easily be expensive as fuck financially.

>>2951562
(200+x)(85-x)

>>2951545

well Efficiency has many forms in economics; theres productive, distributive, and allocative

productive efficiency occurs, usually, when marginal rates of technical substitution among producers are equivalent; or when Marginal Cost = average total costs, etc

profit maximization depends on what kind of market you are dealing with and has to do with setting marginal cost = price, (efficiency isn't the right word)

>>2951566

not surprising since we have central planning via the Fed, the government, and anti-free-market practices

I think it might be like this.

>>2951571

Wait what?

What does x equal? The number of apples?

>>2951572

I think he was trolling or something.

But anyway, price doesnt always imply marginal cost = price.

>>2951578
>he thinks that isn't the result of rich people protecting their own assets
>he thinks that's not the inevitable conclusion of capitalism

>>2951584
x equals the number of trees after 200

(200+x)(85-2x)

-2x^2-315x+17000

you can take the derivative then solve for zero then add that to 200 or you can use algebra.

>>2951584
>But anyway, price doesnt always imply marginal cost = price.

i know, but sometimes thats how you maximize it

in a monopoly you set it to MR=MC

>>2951606

Im trying to find out how many apples the maximum number of trees will produce. I think we determined that maximum number of trees is 242.5

-4x-315 = 0
-4x = 315
x = -78.75
200 + (-78.75)

This is obviously not the ideal number of trees.

Am I not understanding something?

>>2951619
what you're not understanding is that the questions was a troll.

>>2951614

Thats how you maximize it in the circumstance of perfect competition, which is never ever the reality.

I always like to tell people price = marginal cost + some extra the seller knows you will still be willing to pay.

I think your monopoly equation is also unrealistic. Even If you have a monopoly (unrealistic) on a good, you are still competing with substitutes for that good. A perfect monopoly is just as unrealistic as perfect competition. Reality is always somewhere in between.

To calculate price is very complicated.

>>2951629

The apple tree question was a troll?

Withdrawn by what method? That's a lot of fissionable mass...