Solar pool pump questions

Above the equator optimal installation for non-tracking solar panels is facing due south at an angle equal to the latitude of the location.

a reply to: daskakik

a reply to: Dalamax
Yes, but the sun still moves across the sky being able to provide direct sunlight hitting the panels for an hour or two and that second hour isn't really 100%, it's just half an hour on each side when it is deemed close enough to peak.

Correct! Maybe it’s our strong sunlight down here.

a reply to: daskakik

If you do consider the solar option, don't EVEN consider using motorized (tracking) solar panels!! BTDT (have used every kind in the market). These bring a whole litany of other problems to the table, not the least of which is maintenance. If there's a loss in efficiency with a static panel for not having the sun directly overhead, then an inoperative motorized panel pointing away from the sun is ten times as bad! This is especially true if you live somewhere where there is winter. Ice wreaks havoc with these panels, and many of them are powered by oil hydraulics, and the viscosity of the oil skyrockets in the cold which makes it not flow as easily, and this coupled with things binding up in the cold causes the whole system to destroy itself.

We've got one solar field which is about 200 acres using these panels, and there has been a maintenance person dispatched to do something on this location constantly, every day, 365 days per year, for the past 7 years that this system has been installed. No kidding. Movable 'tracking' type systems are very cool for sure, but they are the most maintenance intense systems there are. Stay very far away from these unless you want to take up a new hobby called Solar System Maintenance.

a reply to: Dalamax
There is no spot on earth where you can get direct sunlight on those panels all day except maybe the equator and OP isn't there.

a reply to: Flyingclaydisk
I agree 100%. I wasn't saying they should go that route, I was saying that that the amount they can squeeze out of stationary panels is only 1 or 2 hours at peak because OP said "...as long as it pumped a good bit of the day..., and that isn't going to happen because the window for peak production is so small.

originally posted by: daskakik
a reply to: XL5
Maybe I did the maths wrong but that battery would only run a 1.5hp motor for about an hour.

They cost $385 each so, if OP wanted to store enough energy from solar, they would need 18 or 19 of them, that's about 7K just in batteries, not to mention all the extra panels needed to charge them so they can run the pump during the 18 to 19 hours when the panels are not producing at peak efficiency.

Mates here in the very overcast UK use second hand forklift truck batteries for around £15 each - I'm terrible at electrics but most of the figures here seem crazilly high; they power a sauna, soundsystem and several caravans/an ecofarm with laptops etc...off four panels.

My Mum recently got several panels installed to power her home for £5500 and it pays for itself within five years as opposed to the 10 - 15 of previous gens. Does the US just charge crazy ammounts for solar?




EDIT: May be worth looking into buying UK panels as they cost ~£200 per 550Kw panel and can't see it costing any more than $700max for a full system if you/a friend are a qualified electrician and can use second hand storage.

a reply to: daskakik

I linked that battery because Flyingclaydisk quoted $1000 for 1kwh of battery, the one linked is $200 for 1kwh and it has the BMS in it as well. Flyingclaydisk calculated he would need 15kwh of batteries which would cost $15,000, with the one in the link, it would be 8 batteries at $3080. The shipping might be the killer though unless you live close enough for local pick up. Was just shocked at $1000 per kwh.

a reply to: bastion
I'm not in the US so I don't know what the prices for solar in the US are like.

Here in Guatemala we are having panels installed, 8 x 550 watt panels with a 5kw inverter tied to the grid for around $5kUSD. No storage.

I'm guessing those £15 dollar batteries you mentioned are lead-acid.

EDIT: May be worth looking into buying UK panels as they cost ~£200 per 550Kw panel and can't see it costing any more than $700max for a full system if you/a friend are a qualified electrician and can use second hand storage.

OP wants to run a 1.5hp or 1.12Kw pump for a good portion of the day, which I guess would be 16+ hours. 3 550Kw panels ain't going to do that since they only work at peak for a couple of hours in optimal conditions.

a reply to: XL5
Sorry about that, I didn't see it was a comparison to a given price.

I was just thinking, that is still going to be a lot of money for the amount needed to run the pump described for most of the day.

Hey no problem Daskakik, I agree though batteries cost way too much. With solar I can understand the cost a bit more. I think it might be better to make light guides where a huge panel directs light into a 1 inch fiber optic and then direct that to an enclosed steam turbine system or reverse thermo electric cooler array.

a reply to: XL5
I honestly think that since OP isn't trying to get off the grid, more panels and a bidirectional counter would be the best option.

I mean they are going to need more panels anyway if they need to charge batteries because you can't set up say 3 550w panels and run the pump and store 15kwh worth of charge. With the bidirectional counter you avoid the cost of the batteries altogether.

I'm looking at the estimate we were given for those 8 x 550w panels I mentioned earlier and according to their calcs each panel should produce about 1.6kwh per day. Looked up sunlight times and we are getting 12 hours of daylight but I think the most important thing Flyingclaydisk said is that you can't do your calcs with what is printed on the box.

You would think a 550 w panel in a place with 12 hours of sun might produce 6kwh a day but it is nowhere close to that amount, even on the sunniest day. Seems to be about a quarter of that. So, to capture and store those 15kwh for the batteries you would need 10 of those panels and that isn't including 2 or 3 panels needed to run the pump while the other 10 are charging the batteries.

Forego the batteries, install a 10kw inverter and 15 550w panels so that for those couple of hours when those bad boys are putting out 6 to 8 kw the meter is running backwards, that is credit that you use towards powering the pump for the rest of the day, night and until the next morning.

I agree. But if a panel is set up how I suggested it will receive the optimum amount of sunlight available.

a reply to: daskakik

a reply to: Dalamax
That is how they are set up, facing south at the optimal angle but the sun moves across the sky so that at 5:30 AM at the crack of dawn, the sun is hitting the sides of the panel and only hits them head on for a couple of hours, after that it again hits at an angle until it is again just hitting the sides of the panel and then it is lights out.

Also, throughout the year the arch the sun traces changes. That is why solar arrays are sometimes installed with tracking capabilities in both x and y axis. They need to tilt side to side during the day but also up and down during the year.

Well now I have a reference online for how the day works and what the tropics of cancer and Capricorn indicate.

The mariner in me wants to advise you just move your boat and follow the sun, also that solar arrays come in flexible panels now so you can obtain more exposure to the good stuff for a longer length of time.

www.caravanrvcamping.com.au...

And rollable ones as well.

inhabitat.com...

a reply to: daskakik

And some very interesting emerging technology reaching maturity.

www.energymatters.com.au...

a reply to: Dalamax
Difficult advice to follow when your a landlubber also, for the price of those flexible panels. and I do realize they are in AUD, you may as well triple up on the rigid ones.

ETA: Seems like those flexible panels are good for some applications, especially where weight is an issue; boats, RVs, camping but they are not all that efficient and don't last as long.
Problems With Flexible Solar Panels And Their Solutions

Actually, I am thinking of building a windwall to make use of the inverter when the solar panels are sleeping.

Nice. Trompes are an interesting idea if you have running water nearby.

practical.engineering...

But trompes and windmills are a little outside the scope of the op.

a reply to: daskakik

a reply to: Dalamax
OP wants to pump pool water through a filtering system.

Don't know if they have running water or if they would want to use it like this.

ETA: Actually a wind turbine generating electricity might be a good companion to the panels. If they did have a small creek or something they could even use a micro-hydro turbine.

If your going to water turbine you may just as easily use compressed air to run a pneumatic pump and scratch solar altogether.

It’s be cheaper and safer than playing with electricity and a trompe has no moving parts except a water flow.

a reply to: [post=27176072]daskakik[/post

Anywho, still a tangent. Apologies to the OP for the topic drift, I hope you find a cost effective solution.]

a reply to: Dalamax
Sorry about that, my brain pulled the ram pump file instead of the trompe file.

A wind turbine running a water pump would be another option. Pump to an elevated water tank and you have pressure for filtration when there is not enough wind.

I don't think it is topic drift, just alternatives to the getting the same job done.