Can I Generate Energy from Lakes to Clean and Revitalize My Backyard?

[nduka-san]

could i convert the pressure underneath a lake around 30 feet deep and another lake that's 10 feet deep to run a boiler and then used to clean the old moldy unclean lake In my backyard and fill it with new fishes suited for the environment .cause there

 

[DaveC426913]

"Convert the pressure"?
You mean like put a dynamo under your lake and generate electricity?

You could *in theory* but you'd be permanently lowering the level of your lake to do so.

Also, how does boiling water help you clean your moldy lake?

Also, is it mold, or is it algae? What does it look like?

So many questions...

 

[nduka-san]

"Convert the pressure"?
You mean like put a dynamo under your lake and generate electricity?

You could *in theory* but you'd be permanently lowering the level of your lake to do so.

Also, how does boiling water help you clean your moldy lake?

Also, is it mold, or is it algae?

for the other lakes its not mold its just a dirty lake and you use boiling to clean the water that way you can drink from it

 

[DaveC426913]

for the other lakes its not mold its just a dirty lake and you use boiling to clean the water that way you can drink from it

OK.
1. Fish don't need potable water.
2. You're going to boil a lake??

Start from the beginning.
Never mind how you want to do it, what are the goals?
You want a lake - with fish.
How big are these lakes? Or do you mean ponds?

 

[nduka-san]

theres no fish in the lake

 

[DaveC426913]

there's no fish in the lake

Right, but you want to put fish in the lake:

and fill it with new fishes suited for the environment

You don't really need to boil the water to make it habitable.
Mostly want you want to do to make the lake habitable is oxygenate it.

 

[nduka-san]

thats true i just wana clean the lakes by boiling it

 

[DaveC426913]

thats true i just wana clean the lakes by boiling it

What do you mean by "cleaning"? Boiling will kill everything for sure, but then you will be left with dead, rotting detritus, and no bacterial cycle to convert it to nitrates. It will convert to ammonia, which will definitely render it poisonous - essentially the lake equivalent of 'Salting the Earth'.(I'm not trying to discourage you - really I'm not. )

 

[nduka-san]

what would you suggest then because for cleaning water that is drinkable your supposed to boil it

 

[nduka-san]

and the point is for one pond for drinking and one for fish both are dirty

 

[jbriggs444]

Let me be sure I have the scenario straight.

We have this lake or pond. It is 30 feet deep (pretty deep, but ok). The idea is to use the 30 foot pressure head to drive a generator. Use the generator to run a boiler. Use the boiler to sterilize the lake water.

Presumably we are not talking about boiling the lake water away and distilling it. We just want to raise it to the boiling temperature (100 degrees C) so that it is sterilized. This will be good enough to kill the mold or algae or whatever. Then we either filter or let any dead contaminants settle out.

Without exploring the reasons why this will not work at all, let us perform an energy analysis. Do we get enough energy out of a gallon of water to raise its temperature to 100 degrees c?

No. Not even close. One gallon of water is about 4 kilograms. Raising its temperature from 25 C to 100 C will take about 300 kilocalories. You can get about 4.2 joules out of a single calorie. So that is about 1.2 million joules that we need.

Lifting 4 kilograms of water by 30 feet (about 10 meters) requires about 4 kg * 10 m/sec² * 10 meters = 400 J.

We needed 1.2 million joules. We harvested 400. We are still about 1.2 million joules short.

Now then, why will it not work at all?

If you take water from the bottom of the pond and put it back in at the bottom of the pond, you've gained no energy at all.

If you take water from the bottom of the pond and put it back in at the top of the pond, you've forgotten to account for the energy you had to use to get it to the top of the pond.

What you can do...

If the pond was created by damming a stream or if you otherwise have a drainage path that is 30 feet below the surface of the pond then you do have 30 feet of pressure head to use for a generator. You could get 1.2 million Joules by draining 3000 gallons (call it 6000 to deal with inefficiencies) from the pond and using the resulting energy to boil 1 gallon.

It is likely cheaper to buy the electricity or use a wind-charger. I worry about the life expectancy of a water turbine running from a dirty lake.

 

[DaveC426913]

and the point is for one pond for drinking and one for fish both are dirty

Ah. OK.

So.

Drinking:
You won't be able to make pond water potable, no matter how much you boil it (that is, if it's going back into the pond after boiling).
The only way you can drink untreated water is if it comes from a well or spring. i.e. you can access it before it gets overrun with bacteria.

Take the water out of the pond, boil it, then put it in a clean container. Even this way, it will only last a short while before bacteria take it over again.Fish:
Fish don't need sterilized water. In fact, they need water filled with bacteria to complete the biocycle. Fish can't live in dead bodies of water.

To make a water body habitable, you want circulation and oxygenation.

 

[nduka-san]

then what would you recommend to make the dirty water clean enough to drink?

 

[DaveC426913]

then what would u recommend to make the dirty water clean enough to drink?

The trick is to only treat as much water as you need at a time.

You can't store it or it will just go bad again - unless treated with chemicals or boiled and stored in sealed, sterilized containers.What you could do is make a system that pumps water from the pond into a holding tank, where it is filtered and boiled on an as-needed basis. You don't want to be drinking several-week-old pond water, no matter how much you boil it.

 

[jbriggs444]

then what would u recommend to make the dirty water clean enough to drink?

In many cases the cost effective measure is to buy clean water from the water company.
In most cases where this cannot be done, you dig a deep well.

 

[DaveC426913]

In many cases the cost effective measure is to buy clean water from the water company.
In most cases where this cannot be done, you dig a deep well.

One of the OP's goals is to make an engineering project out of this. Cost effectiveness is actually not mentioned.

 

[nduka-san]

as long as its under 1000 dollars it wil work

 

[jbriggs444]

One of the OP's goals is to make an engineering project out of this. Cost effectiveness is actually not mentioned.

A quick trip to Google suggests that filtering, boiling and halogenization (chlorine, iodine) are all popular approaches. I've used all three in the BWCA, but would shudder at the idea of doing similar for a farm pond.

https://bwca.com/index.cfm?fuseaction=forum.thread&threadId=97163&forumID=18&confID=

 

[nduka-san]

i chose that imginary scneario for my mit think idea
seee boiling

 

[nduka-san]

A quick trip to Google suggests that filtering, boiling and halogenization (chlorine, iodine) are all popular approaches. I've used all three in the BWCA, but would shudder at the idea of doing similar for a farm pond.

https://bwca.com/index.cfm?fuseaction=forum.thread&threadId=97163&forumID=18&confID=

i like the boiling there

 

[nduka-san]

i like the boiling there

and its not a farm pond its a pong for drinking

 

[DaveC426913]

Fish pond and drinking pond are two entirely unrelated projects. That will double your costs.

We should treat the two projects separately. Do you want to tackle one first? I think we'll need more specs for volume of water and expected throughput.

 

[nduka-san]

drinking pond

 

[DaveC426913]

drinking pond

OK, the short version is: you boil and filter* a small amount water after you draw it from the source, and only on an as-needed basis - i.e. a minimum of processed water that's standing/stored for any length of time.

*if you filter it sufficiently, you don't need to boil it.

 

[nduka-san]

i

OK, the short version is: you boil and filter* a small amount water after you draw it from the source, and only on an as-needed basis - i.e. a minimum of processed water that's standing/stored for any length of time.

*if you filter it sufficiently, you don't need to boil it.

so for powering it by water pressure it could charge and then boil it when neeeded

 

[DaveC426913]

so for powering it by water pressure

Does the pond have an inflow or outflow? And how high is it?
You need an inflow or outflow to power a system.

 

[nduka-san]

it would have to be something that works for all ponds like a one size fits all solution

 

[jbriggs444]

If there is no harvestable inflow or outflow that comes from or goes to an elevation different from that of the pond's surface then there is no ability to harvest hydroelectric power.

Pressure by itself does not provide energy. You need pressure plus flow.

 

[nduka-san]

i mean by depth pressure

 

[nduka-san]

and it would have have around the average inflow give or take 10 percent