Is it possible to harvest and store enough solar in summer to carry you through winter?

[OffGridForGood]

We spotted him while servicing a tower in north-west Ontario;

Damn, I've been spotted!

he was able to squeeze just over 7 weeks

Actually, solar is generally good by 15-21 of January until mid October. If he could build up that system to get 10-12 weeks, he would be set.
I don't know what daily energy they are running, but in my own system even with 99kWh ESS I am 2.5 days with 'normal operation' or 4 if we are in conservation-mode (no dryer! limit Hot water!) - it all depends on how you live, and how many teen-agers are in the house!

 

[sun_of_a...]

Pumped Hydro Storage. You could dig any size ponds/lakes you want. Scale it up enough and the OP's seasonal storage becomes feasible.

I would love to just have enough pumped hydro storage for just a few cloudy days, but, alas, it's dead flat where I live, and mounding that much dirt for an elevated pond seems cost prohibitive. But if I had natural elevation, I'd sure love to do it.

 

[Johneb]

Pumped Hydro Storage. You could dig any size ponds/lakes you want. Scale it up enough and the OP's seasonal storage becomes feasible.

I would love to just have enough pumped hydro storage for just a few cloudy days, but, alas, it's dead flat where I live, and mounding that much dirt for an elevated pond seems cost prohibitive. But if I had natural elevation, I'd sure love to do it.

Water tower.

 

[DIYrich]

Pumped Hydro Storage. You could dig any size ponds/lakes you want. Scale it up enough and the OP's seasonal storage becomes feasible.

I would love to just have enough pumped hydro storage for just a few cloudy days, but, alas, it's dead flat where I live, and mounding that much dirt for an elevated pond seems cost prohibitive. But if I had natural elevation, I'd sure love to do it.

Until the lake freezes.

 

[summit]

Water tower.

actually thought about this, as we're on a slight hill, having a tank top & bottom. But upon looking into the effective effeciency (pump loss/regen...), back of envelope estimate is ~60% at best.

 

[OM617YOTA]

How much water do you need at what height to store a meaningful amount of energy? Seems like it would take a multi acre pond at the very least to have any hope of getting close to supplying needs across the winter months.

 

[sun_of_a...]

Until the lake freeze

How much water do you need at what height to store a meaningful amount of energy? Seems like it would take a multi acre pond at the very least to have any hope of getting close to supplying needs across the winter months.

Water tower.

Yea, you'd have to scale it way up, and in cold climate drain water from upper reservoir from deep enough not to freeze, and possibly use power to heat the exposed lines, etc. It rarely freezes that bad for very long where I am, but it's dead flat. I've thought about a water tower but limited capacity is a bummer. Compressed air, by the way, turns out to be an interesting way to lift water without water pumps. Bubbles naturally rising lift water in, eg, a 6 inch diameter pipe as they rise, but only up maybe 50-60 feet vertically, as I recall.

EDIT it could be as little as half that vertical maximum/head. 25-30 feet, not sure.

 

[Johneb]

Water tank on your roof.

 

[sun_of_a...]

Water tank on your roof.

Pitched roof here. But in attic? And as a thermal battery and home heating? (But what about water leaks! Good for fire suppression, I suppose. Ha ha

Water tank on your roof.

Do clogged gutters count?

 

[Hedges]

60% efficient is fine, if it lets you store PV generated power from the summer until winter.
PV costs you about $0.025/kWh. Generator would cost you $1.00/kWh
50% efficiency would mean winter electricity costs you $0.05/kWh

 

[kommando]

Been tried in Ireland

https://scanhome.ie/research/solarseasonal.php

Used solar thermal to heat up 23m3 of water in an insulated tank.

Once you read the study you find, as the house was unoccupied for months in the study period and no heat was being consumed, its not viable.

 

[OM617YOTA]

Water tank on your roof.

I've thought of downspout power. We get 20+ inches of rain some months here.

Yea, you'd have to scale it way up, and in cold climate drain water from upper reservoir from deep enough not to freeze, and possibly use power to heat the exposed lines, etc. It rarely freezes that bad for very long where I am, but it's dead flat. I've thought about a water tower but limited capacity is a bummer. Compressed air, by the way, turns out to be an interesting way to lift water without water pumps. Bubbles naturally rising lift water in, eg, a 6 inch diameter pipe as they rise, but only up maybe 50-60 feet vertically, as I recall.

EDIT it could be as little as half that vertical maximum/head. 25-30 feet, not sure.

Might have to raise water in steps using a bubble pump. Get mighty Rube Goldberg in a hurry.

 

[sun_of_a...]

Get mighty Rube Goldberg in a hurry.

Yes, I won't even mention my hair-brained imaginings for storing compressed air. All I can say is, never gonna happen, but dreamers dream.

 

[Johneb]

actually thought about this, as we're on a slight hill, having a tank top & bottom. But upon looking into the effective effeciency (pump loss/regen...), back of envelope estimate is ~60% at best.

Water tower at top of incline. Dig hole at bottom of incline for botyom tank. Windmill to pump water back to top tank.

 

[sunworshipper]

Like how we grow crops in summer to take us through winter can the same be done for solar or do batteries not hold charge for long enough for it to be feasible?

I know you could do what my mum does with the solar on her roof and sell solar back to the grid and buy that back again but that does not apply here as I am talking about self sufficiency.

I tried this almost 15 years ago on a limited scale. I bought four 100 AH lead acid flooded type batteries (12V). Charged them fully. Then drained the acid/electrolyte in to a polyethylene container, rinsed the cells with distilled water and put them away. After several months, refilled the cells with the acid. As I recall, I was able to a significant amount of energy and was quite surprised. Don't have my notes from those tests. I think I repeated it a couple of more times, storing the acid for several days and refilling the cells. Don't recall why I stopped those tests, most likely got distracted with something else. I believe this method has some value for long term energy storage, but I see one drawback. The Pb & PbO plates of the cells participate in the reaction and are ultimately covered with PbSO4. Once this happens, the reaction must be reversed. Unlike lead acid cells, the electrodes of a redox flow battery don't participate in the reaction. As long as you have a steady supply of "charged" electrolyte, you can generate electrical power.

 

[wpns]

This is where Net Metering (aka: The Grid Is My Battery) really shines. It's infinitely large, and there are no infrastructure costs. Also why Net Metering is under attack, and going away in many places.

 

[Nobodybusiness]

This is where Net Metering (aka: The Grid Is My Battery) really shines. It's infinitely large, and there are no infrastructure costs. Also why Net Metering is under attack, and going away in many places.

You don’t have to net meter.
Just use the grid when needed.
That’s what I do.
No agreement.

 

[Solar Guppy]

Also why Net Metering is under attack, and going away in many places.

Net Metering is economically a loss for any electric utility, always has been.

It was always intended to help get solar to a point it would be economically viable without incentives and it has done just that. my first system in 2002 was $5 Watt for just the solar panels, now just about everyone can get them in the ~20 cent range, so they make more sense now than ever even if your home can't use all the energy the solar arrays produce.

 

[Hedges]

Utilities may not like net-metering vs. buying power wholesale, even if dirty.
But there is so much rooftop PV (installed primarily because there was net metering) that it can offset a significant amount of fossil fuel.
Whether CO2 "pollution" is a hoax and money grab or a legitimate issue, avoiding consumption of fossil fuel reduces fuel prices (bad for the gas/petroleum industry) and improves national security.
So we ought to find a way to use it, while being fair to consumers, utilities, and rooftop PV owners.

 

[Doggydogworld]

I've thought of downspout power. We get 20+ inches of rain some months here.

12" of rain on a 3000 sqft roof @ 62.4 lb/cu ft is 187,000 lbs. Sounds promising!
187,000 lbs with a 10 foot drop is 1.87 million ft-lbs or 2.5 million joules
2.5 MJ = 2.5 million Watt seconds / 3600 seconds/hour = 705 Wh = 0.7 kWh

About a dime's worth of electricity. Per month.

 

[OM617YOTA]

12" of rain on a 3000 sqft roof @ 62.4 lb/cu ft is 187,000 lbs. Sounds promising!
187,000 lbs with a 10 foot drop is 1.87 million ft-lbs or 2.5 million joules
2.5 MJ = 2.5 million Watt seconds / 3600 seconds/hour = 705 Wh = 0.7 kWh

About a dime's worth of electricity. Per month.

It's even worse than that, my house is only 1k sqft, shop is another 1k sqft.

 

[OffGridForGood]

It's even worse than that, my house is only 1k sqft, shop is another 1k sqft.

Well check it out then...

First of Six or Seven vids on the topic!

 

[robby]

12" of rain on a 3000 sqft roof @ 62.4 lb/cu ft is 187,000 lbs. Sounds promising!
187,000 lbs with a 10 foot drop is 1.87 million ft-lbs or 2.5 million joules
2.5 MJ = 2.5 million Watt seconds / 3600 seconds/hour = 705 Wh = 0.7 kWh

About a dime's worth of electricity. Per month.

Yes but water IMHO is the only way you could possibly store enough energy.
You just have to go at it on a much larger scale!
By my rough calculations you would need a reservoir of about 1.5 Acres in size with 10ft depth and a drop of 10ft or more to produce about 50KWh per day for 90 days.
The land you would need to run off and collect that amount of water would be dependent on rainfall.

A 5000Kwh battery bank would also do it, but it would cost about $1.5 Million and then you have to get the panels to charge it in the summer and deal with the normal energy loses that come with natural discharge over time.

 

[OffGridForGood]

Yes but water IMHO is the only way you could possibly store enough energy.
You just have to go at it on a much larger scale!
By my rough calculations you would need a reservoir of about 1.5 Acres in size with 10ft depth and a drop of 10ft or more to produce about 50KWh per day for 90 days.
The land you would need to run off and collect that amount of water would be dependent on rainfall.

A 5000Kwh battery bank would also do it, but it would cost about $1.5 Million and then you have to get the panels to charge it in the summer and deal with the normal energy loses that come with natural discharge over time.

The question: "Is it possible to havest and store enough solar in summer to carry you through winter"
Answer: Yes.

The question was NOT -"is it economical "

 

[Nobodybusiness]

The question: "Is it possible to havest and store enough solar in summer to carry you through winter"
Answer: Yes.

The question was NOT -"is it economical "

Anything is possible if you throw enough $ at it..