Hydroelectric Question (appliances, home, calculator)

[Grassyknoll]

Thought I would ask this on here as maybe someone has some insight into the subject.

Since one of the downsides to solar is the issue with storage (ie needing a battery bank) has anyone toyed with the idea of having two catchment tanks and using solar to pump from a downhill tank to an elevated tank during the day and then at night, draining the elevated tank to the lower tank through a hydro electric turbine to produce power?
I figure someone is doing it, has tried it or run the calcs to figure out if it's even a feasible method.

[67Cam]

I remembered reading about this years ago. It may have been this thread or another;

https://www.city-data.com/forum/big-i...generator.html

I did a little google search at the time and found small hydroelectric generators are out there and they have calculators for volume of water and the distance it needs to fall to get usable power. Something tells me that a few hours of catchment water in the evenings may not generate much, but could be wrong.

[hotzcatz]

Yup, power storage is the biggest problem with PV systems and one HELCO is having problems with as well. They're getting a lot of PV folks now with loads of daytime power, but most power use is evenings and nights so PV doesn't help there.

I think it's one PSI per foot of elevation minus any line losses, if you're doing rough calculations.

An engineer was talking once about some sort of ice to power thing, where water was frozen during the day and somehow the energy of freezing was gotten out of it at night. I forget the details, but the water lift sounds a lot more feasible.

[Grassyknoll]

Just thinking that if you had NG/Propane for cooking and clothes dryer, and had led lighting and other energy efficient appliances, nighttime electric needs could be minimal and therefore the output needs of such a system would be minimal.

[whtviper1]

What is the downside to batteries - aren't the new batteries by Tesla supposed to be good. If I read the literature correctly, 2 powerwalls have enough energy for a 1,600 sq ft home with AC, they only run about $12,000 for the pair. From the picture, they don't even look very large.

[hotzcatz]

Batteries don't last all that long and have to be changed out occasionally. Pumping water up and running a hydroelectric generator from the falling water should - in theory anyway - not produce as much waste.

[whtviper1]

Originally Posted by hotzcatz

Batteries don't last all that long and have to be changed out occasionally.

The Tesla batteries have a 10 year warranty

[terracore]

The cheapest way to store solar power is with flooded lead acid batteries (like golf cart batteries). That is not to say it's the BEST way, just the cheapest way. These batteries require maintenance and if not performed can crap up a battery array in no time.

Pumping water uphill to be used for downhill power generation later doesn't past the math test for solar power. It works with fission reactors but they have completely different economies of scale.

"The Tesla batteries have a 10 year warranty"

I would be surprised if you could even get one purchased and installed here, and with the impending SEC investigation, no guarantee there will be a company in 10 years to fulfill such a warranty. Tesla batteries are a lot of hype, but not a lot of market availability.

The only non-battery power storage I've discovered in my research for solar power involves electrolysis on salt water (the DC format of solar panels is already setup for this) and harvesting and storing the resulting hydrogen, and then passing it through a fuel cell to produce electricity when there is no sunlight. It's been done for at least 30 years, is much more efficient than converting sunlight to electricity converted to mechanical energy, and then converted back into mechanical energy to convert back into electricity again (the water pumping idea... most of the energy is lost in conversions of energy). But electrolysis and fuel cell units aren't exactly "off the shelf".

Maybe it's a great idea, but since Musk can't patent 100 year old technologies, don't expect to find it on Amazon anytime soon.

[MickeyE]

Originally Posted by terracore

The cheapest way to store solar power is with flooded lead acid batteries (like golf cart batteries). That is not to say it's the BEST way, just the cheapest way. These batteries require maintenance and if not performed can crap up a battery array in no time.

Pumping water uphill to be used for downhill power generation later doesn't past the math test for solar power. It works with fission reactors but they have completely different economies of scale.

"The Tesla batteries have a 10 year warranty"

I would be surprised if you could even get one purchased and installed here, and with the impending SEC investigation, no guarantee there will be a company in 10 years to fulfill such a warranty. Tesla batteries are a lot of hype, but not a lot of market availability.

The only non-battery power storage I've discovered in my research for solar power involves electrolysis on salt water (the DC format of solar panels is already setup for this) and harvesting and storing the resulting hydrogen, and then passing it through a fuel cell to produce electricity when there is no sunlight. It's been done for at least 30 years, is much more efficient than converting sunlight to electricity converted to mechanical energy, and then converted back into mechanical energy to convert back into electricity again (the water pumping idea... most of the energy is lost in conversions of energy). But electrolysis and fuel cell units aren't exactly "off the shelf".

Maybe it's a great idea, but since Musk can't patent 100 year old technologies, don't expect to find it on Amazon anytime soon.

Ummm check out https://www.greencarreports.com/news...rgy-for-hawaii for info on Kaui's Tesla energy bank. Maybe someone in Kaui can give us a on-site report.



There is some information on Tesla Powerwall for home use at https://www.energysage.com/solar/sol...-home-battery/ .


Of course you can build your own Powerwall typ battery system. See
https://www.youtube.com/watch?v=Bk50IuWXg-c . There are companies making battery connectors that eliminate soldering or welding cells together. See https://vruzend.com/ for one example.


Note that I have not done this myself - yet but it's an interesting alternative to lead acid batteries.


Remember "Google is your friend".


Mickey

[terracore]

I think it's great that it's delivering electricity at "only" three times the cost of the mainland. Unfortunately, this technology has not yet intersected with the real economy.