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solar powered swimming pool

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Started 11 years ago by ME109
Latest reply from ME109

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ME109
Member

Hello all, I have a project to power a swimming pool by stand alone solar, powering a 240 volt, 160 watt pump.
I need to run the pump 24/7 as the pool is biologically maintained and the micro organisms which live in a bio-filter need a constant supply of oxygenated water.
I may be able to construct a system where the pump cycles 1/2 hour on and 1/2 hour off, however 24/7 is best.
The pump I would like to use is a Laguna pond pump which has a 200 litre per minute flow rate

I made some inquiries today at a regional solar supplier and was startled by the quoted requirements and price tag.

The type of pool I wish to build is a very green pool in that it never uses chemicals or additives of any description.
There is no wasted water due to back washing.

Being able to run this type of pool by solar would be the icing on the cake so I'm not prepared to give up yet.

What would be the ideal size and type of system for this application?
And who would be the best supplier of such a system?

Any help greatly appreciated.

Posted Friday 4 Feb 2011 @ 10:47:10 am from IP #
OptexSolar
EcoOnline

Hey ME109,

If you ever get the system up and running, I sell a no mains power solar pool heater at http://www.EcoOnline.com.au. The pool could be the first to use no mains power for filtration and heating

I also have 12v and 18v solar powered pumps and I think I've seen a controller that you connect to a battery that will do what you want, but my pumps are higher pressure lower flow type ones and are probably unsuitable for your application.

Posted Friday 4 Feb 2011 @ 1:04:09 pm from IP #
ME109
Member

Thanks Optex, I'll check out your link.
The pool systems I design are generally very low head, and there is no conventional sand filter that has water forced through it.

Posted Friday 4 Feb 2011 @ 8:25:53 pm from IP #
swanning_it
Member

I think your problem is going to be winter solar hours. Do you need the pump running as much in winter? Because you need 24/7 (or 12/7 if 1/2 hour on, 1/2 hour off) all year, you won't be able to average out the yearly generation (as is done for maximising grid connect returns) and so you'll need to elevate your panels for maximum winter effect and they will be oversized in summer but elevated at a lousey angle. On top of this, you'll also have to oversize your battery bank to allow for days and days of inclement weather.

If you have grid supply available, you may be better to look at a hybrid system of solar for the most part with the ability to charge via grid supply and a charger when necessary in winter or crappy weather. The charger could be supplied from a controlled tariff (as you have the batteries when the power is off). You'd have to check with your supply authority as to what they permit on their controlled tariffs. Here in Qld the you can use a controlled tariff provided the charger is permanently connected, but your supply authority may be different.

Posted Friday 4 Feb 2011 @ 9:20:04 pm from IP #
ME109
Member

I turned my own mains power pool off for 5 months from April to September last year without major consequences, as the biological activity lessens considerably through winter.
I would imagine that the pool I'm designing at the moment would also be turned off for a similar time period.
There is no grid power within the vicinity of the current pool project, so it's solar all the way.

swanning_it, you gave me some advice 2 or 3 months ago regarding this project in another thread about swimming pools but I couldn't log back in under the user name 'jeff' so I started out with another user name.

I was quoted approximately $20,000 for a system to suit my requirements and nearly fell off my chair.
So I'm looking at ways to reduce the circulation requirements of the current pool design project.
I may be able to further reduce the circulation at night down to 1/2 hour every 2 hours, or keep the system flowing at a much reduced rate.

I'm wondering if a programmable DC solar pump will give much more flexibility in controlling flow rates or whether a 240 volt pump on a timer would be better.

Posted Friday 4 Feb 2011 @ 10:01:48 pm from IP #
swanning_it
Member

Just as a quick idea, on 1/2 hour on, 1/2 hour off, you'd need 2kW per 24 hour. I'll assume 3 solar hours per day (winter approx. Albury....I've guessed at that), which means in optimal winter conditions, you'll need 640W of installed solar to break even. If we allow 10% recharge and sundry losses, about 700W or about 6 x 120W 12V panels @ say $500 = $3000.
Regulator - $450
Battery - $300
Charger - $500
Inverter - $300
Sundry - $500

(assuming labour is by you)

Total - approx. $5000.

Posted Friday 4 Feb 2011 @ 10:07:35 pm from IP #
swanning_it
Member

OK, so grid supply is not an option, so take out the charger and add in more batteries add a timer (it'd be cheaper with a 240Vac pump and timer) and experiment with the time the filtration can go without power.....via the timer and not by dragging the guts out of the battery bank

I'd be curious to hear from others in case I've been too simplistic in my quick mental calc. but $20k seems to me like a big profit margin for someone.

If the filtration in fact doesn't need to run as much as you've initially indictated, it may well be possible to ditch the battery banks altogether and run direct from the panel power.

Posted Friday 4 Feb 2011 @ 10:19:06 pm from IP #
Lance
Key Master

You might want to start by talking to people who do this sort of pool for a living, there's a lot of natural pool mobs out there now, such as http://www.bionovanaturalpools.com.au, http://www.mynaturalpool.com.au etc as they will know the best setup to use. They don't necessarily us solar to run the pumps etc, but they should be able to help you minimise energy requirements by selecting the best setup, you can bet that people who buy these types of pools often ask for energy minimisation as well...

Posted Friday 4 Feb 2011 @ 10:23:18 pm from IP #
ME109
Member

Thanks swanning_it and Lance, 5 years ago I also set out to build natural pools for a living and built a display pool at my home. Then the drought worsened and cost me the last three years.
I have some unique design features in my pool that are not used by the major players that I know of. The primary goal of very clear and healthy water has been achieved in my system.

When I started out to build my pool, the option to purchase imported components was not there so I had no choice but to design my own system.
By doing so, I have created a system that is much cheaper than imported ones.
I'm familiar with the two companies mentioned above.
They would use power 24/7 mostly.
There are many ways these pools can be built but they all come down to where a pump/s can be plugged in.

The supply of solar power for these pools to operate is there, it's a matter of optimising pool design and sourcing the appropriate solar set up.
Most of the major natural pool builders would be reluctant to give away their information unless you were using 'their system'

I think $5,ooo may be acceptable for this particular project.

Posted Friday 4 Feb 2011 @ 11:43:41 pm from IP #
Lance
Key Master

You should check out the Viron P300 DC pool pump if you haven't already, has a 3 speed controller and an 8-star energy rating, supposedly...

Posted Saturday 5 Feb 2011 @ 12:33:14 pm from IP #
swanning_it
Member

It'd be nice if Hurlcon actually gave some meaningful data on the Viron. Until then, it's largely a guess, trial & error and consumer feedback (from forums like Whirlpool).

For Jeff though, I'd lean toward the Viron being oversized for his needs. Jeffs current pump (which is exchanging an adequate volume of water for the required filtering) is just 160W. The Viron is claimed to be far more efficient than a typical pool pump of say 1500W so I'm not sure efficiencies would be better at all and even on the low speed, may have an adverse effect on the filtration substratum.

Alternatively, it may be great, but $800 or so is a bit of a gamble to find out.

Posted Saturday 5 Feb 2011 @ 8:16:40 pm from IP #
swanning_it
Member

I've just re-read some of your messages Jeff. If the winter requirements are extremely low (you suggested none at all may be OK between April and September) and night time in summer may be 1/2 hour every 2, then this changes things somewhat.

A decent programable timer will enable the system to be designed with less charging capacity. If we assume summer daytime pump run (12 hours, 6am to 6pm) of 0.5 hour on, 0.5 hour off and summer night time (12 hours, 6pm to 6am) is 0.5 hour on 1.5 hours off, then you have a summer requirement of 1.5kW/h per day. Add back our assumed 10% losses and work to 4.5 solar hours per day and you need 4 x 120W, 12V panels for average summer conditions. Winter would need to drop considerably in pump run time, but would still be able to manage a daily filtration of perhaps 3 hours max. Change to a 12Vdc pump and drop the inverter.

A big problem with any theory calculations is relating it to the real life conditions. This summer, for example, has been fairly dismal for solar charging (plenty of rainy days and heavy cloud cover) and regardless how big the battery bank is (which you have to oversize for the crap days) you need to remember that whatever you draw out, has to be returned somehow plus 10%. The calcs. here are only marginally on the conservative side so if the proposed installation does not have grid power available for recharging (if needed), perhaps a battery powerpack priced into the system supply may be a way of overcoming any charging shortfalls that may occur from time to time. It may pay to experiment on your pool first. You could join in the solar panel buying group running on another thread and swap the 40A Plasmatronics PWM for perhaps 4 x GSM MPPT regulators (about the same price all up) which allows you to use the typical 35Voc panels and save on the panel costs plus get MPPT charging at the same time.

Personally, I think it is do-able for a fraction of the $20k quoted.

Posted Saturday 5 Feb 2011 @ 9:06:54 pm from IP #
Johnnojack
Member

Yes drop the Inverter and use a 12 or 24v pump (more efficient than the 240v one)
Also time the pump to run more during the day less during the night.(Timers can be converted to run on 12v). That way power goes direct from the solar panels to the pump without the losses incurred by charging batteries. I know this is common knowledge to lots of readers here but worth repeating.

Posted Sunday 6 Feb 2011 @ 6:50:10 am from IP #
ME109
Member

Thanks very much for the replies, there is some good information for me to follow up
I think it will be wise to keep the pools power requirements separate from the house, instead of adding to the existing solar system to power the pool.

I am interested in 12 volt pumps as well, because of their ability to run on varying power input (please correct me if I'm wrong)

So, could it be as simple as the appropriate number of the appropriate solar panels with X batteries for night time running, and the most efficient 12 volt pump, with a suitable timer?

The pump I've mentioned above, the Laguna 'Maxflo' was the most efficient 240 volt pump that I could find, at 200 lph for 160 watts.
I was/am thinking of using this pump with an expanded 'existing'solar system.

I suppose it's a matter of which system is generally more efficient.

a, 12 volt pump, solar panels, batteries,regulator, timer.

Or

b, 240 volt pump, solar panels, inverter, batteries, timer.

I guess they would both have their good and bad points including cost, but which way would be the generally accepted 'best way'

Please forgive my ignorance. I am on a near vertical learning curve, but that's ok'

Jeff.

Posted Sunday 6 Feb 2011 @ 11:03:47 am from IP #
swanning_it
Member

There are some not so obvious points which may also impact the decision.

You said the grid was not available, but the house has solar. If so, that means the house has batteries and a suitably sized and angled solar array. If this is correct, you may be able to simply run off the house if there is sufficient capacity, or add to it so as to save buying more batteries.

If so then how far is the house from the pool pump position? If it's a considerable distance, then a 240Vac pump may be better as it's more efficient to transmit low voltage electricity (ie 240Vac) than extra-low voltage (ie 12Vdc), but there are less onerous regulations in the ELV (example, the depth of cable laying if underground).

If you decide on a separate installation you will also need to think about where the panels are going to mount. Is there a pool gazebo or something to use and is it in sunlight for the most part of the day or in shade?

All these are site specific requirements that have to be addressed for each individual site and can change the ideas entirely.

Posted Sunday 6 Feb 2011 @ 7:49:46 pm from IP #
OptexSolar
EcoOnline

Hi Jeff,

As Swanning_it points out, at 160W a 12VDC system will require 13Amps (I=P/V). Even a 24VDC system will require 7.5Amps. I'm not sure, perhaps someone that knows more about PV system can correct me but that seems a bit excessive. You'll need really thick cables and even then the loss in the cables might be excessive.

Point is if you want to stick with extra safety low voltages will need higher than 12V.

My 60W pumps run on 24VDC for this reason.

Posted Sunday 6 Feb 2011 @ 10:55:26 pm from IP #
ME109
Member

Ok, some more information regarding the clients solar setup.
I think it may only be a 3 kva? system with batteries, inverter and generator.
Looking at some photos I took I can see 3 square solar panels on the shed roof. Each square is made up of two rectangular panels.
There is room on the shed roof for the same quantity of solar panels again.
Finding more room for panels shouldn't be an issue as there is lots of open space.
The distance from the existing solar panels to where the pool pump would be is approx 20 metres.
I hadn't considered the voltage drop issues with twelve volt.

I would hope that if the existing solar set up was added to, the planned pool would not rob the house of power.

I will ask my customer (hopefully) for more specific information regarding their existing solar set up.

Thank you for your responses.

Jeff

Posted Monday 7 Feb 2011 @ 8:18:20 am from IP #
ME109
Member

I had a good read of the Whirlpool site re the viron pump.
Apparently the viron is most efficient at its lowest setting. Unfortunately it still uses a claimed 300 watt on the low setting.
The viron is still appealing though for other projects.

Posted Tuesday 8 Feb 2011 @ 10:21:30 am from IP #
ME109
Member

Did I say kva above?? what a dummy....
Today I learned to be skeptical about solar power retailers.(contradictions)
What has been suggested by the sellers of the 'existing' solar system is to add more solar panels to start with and see how it goes.
Then, if the battery bank is inadequate, buy a whole new bank of batteries to go with the increased amount of solar panels.
Apparently it is not good to add new batteries to an existing bank of 3? year old batteries?
I'm thinking that if the generator is being used at times to top up the battery bank, then either the battery bank is insufficient, or there are insufficient panels to fully charge the batteries in the first place,or the panels and batteries are compatible and too much power is being used....undersized system?

I think I am 'beginning' to understand the complexities associated with solar power.

Posted Wednesday 9 Feb 2011 @ 10:53:16 am from IP #
swanning_it
Member

Using a gen to charge RAPS batteries occasionally, is quite normal. The largish capital expenditure required to account for 100% of requirements via renewables and batteries under all circumstances is quite often mitigated by a decision to use the gen and a quality charger from time to time as dictated by the weather, their work loads and their finances.

Depending on their current gen use, you may find they can acceptably re-charge with the additional drain with no additional panels and perhaps no additional batteries. For example, if they run a 5kVA generator daily just for battery top up, they are most likely wasting available power for the same (or very similar) fuel usage. Once again, this is where an understanding of your clients lifestyle will dictate the best option for them. Alternatively, since they are installing a pool, perhaps their finances could stretch to include upgrading the main solar supply to account for the pool and also give some additional charging during good weather meaning a lower need for the gen. As they already run the gen to charge the house batteries and are comfortable with that and the winter requirements for the pool is considerable less than summer, then the panel tilt for the new array may be maximised for the largest generation ability year round rather than being so restricted to maximise the winter generation. Lot's of options. Sounds like an intersting project.

Posted Wednesday 9 Feb 2011 @ 9:53:09 pm from IP #
ME109
Member

Thanks swanning_it, I've asked my potential customers to again consult with their solar system supplier and ask for reasonably firm figures, based on the information they (the customer) supply.
The last thing I want to do is build a pool and then find a major upgrade is needed to run it.
I can re-design the pool to suit whatever power is available......down to the point of it becoming a small fish pond, but who wants that!
I can design a certain sized pool to be as power efficient as possible, however if it falls outside the available power supply, then it is a failure.
I hope to have some more information in the near future on which to base my design.

Jeff.

Posted Friday 11 Feb 2011 @ 8:42:38 am from IP #
jeff
Member

Howdy folks, I seem to be here under two names. ME 109 and jeff.
Oh well.

Just a little further down the road of building a totally chemical free swimming pool and running it on stand alone solar power.

I have two solar powered pools up my sleeve now. One runs on a single 100 watt pump.
The other has two 100 watt pumps, with one being switched off at night and on low energy days.

To sum up, both pools (and my home pool on mains power) produce drinking quality water with absolutely, positively, incredibly, zero chemicals or additives. Ever.
Visibility is probably around 50 metres.

"Oh, so it's salt then?" is the most common reply to that statement.

No, not salt, or any other state of the art, imported, latest technology, patented, whiz bang,gizmos.

Just a pump, circulating the water.

Both solar powered pools are approximately 45-50,000 litre capacity.

I think these are the greenest swimming pools ever.

They contain tadpoles, frogs, water scorpions, back swimmers, boatmen, spiders, mud eyes, etc,etc.

I am impressed with how much power I don't need.

Posted Sunday 20 Jan 2013 @ 7:50:14 am from IP #
Harry Stottle
Member

Hi Me 109, glad you're not a silly Focker!
From my own experience there is no need to run the pump 24/7.
Sunlight is what causes all the problems for swimming pools.
You can avoid the cost and hassle of batteries by using a MAXIMISER to provide enough start-up current for a DC pump.
I built my own but you can buy one e.g. http://www.energymatters.com.au/energy-matters-140w-12v-pump-maximiser-p-2565.html

Decide what size pump you would like to run and choose a panel and maximiser to suit.
I was a bit short of cash so I just used a bilge pump.
If you really need 200 L/M this one will do it https://www.whitworths.com.au/main_itemdetail.asp?cat=133&item=67041&intAbsolutePage=2

Cheap as chips and does the job just fine.
(The real cheap ones I used usually lasted about 2 years before the brushes wore out and were not repairable.)

Nowadays you might be able to buy a DC brushless pump which would probably be better.

Much cheaper, safer, and more DIY approach than a 240 Volt pump.

If you avoid using batteries you will have less hassle and can spend the cash on panels and pump instead.

(my experience and opinion only, could be total B***OCKS!

Posted Sunday 20 Jan 2013 @ 8:48:58 am from IP #
ME109
Member

Gidday Harry, I'll go with ME 109 then. Unless of course someone calls me Jeff.....
Not quite sure how I came to have two log ins.

The main reason for running 24/7 is to keep aerobic bacteria in the bio-filter alive, and to also maintain a surface skimming action which allows me to remove any floating 'junk'

Also I run a separate bio-filter which is lower than the swimming pool so if the power is turned off, I lose the head from the pool.

But as you say, fewer hours of pump operation will still produce quality water.

Thanks for those links........I'll look at them in a minute.
12/24 volt pumps are an area I wish to investigate further. So far I haven't found a pump that I would say is ideal.

Posted Sunday 20 Jan 2013 @ 10:36:42 am from IP #
Harry Stottle
Member

Here is a 24V brushless pump 115l/M which should last for years in your application.
You could use two of them if you really need the flow.
http://www.daviescraig.com.au/Electric_Water_Pumps-EWP115__24V___ELECTRIC_WATER_PUMP___PART_No__8026-details.aspx

Maybe you could use a small pump and battery to keep the filter flowing.
Most pool pumps don't run 24 hours and you just need to use a scoop net for the odd leaf that falls in.

If you stay away from 240 Volts then it's obviously safer and easier to DIY.
If you use the maximiser and only run in daylight you save a heap of money and hassle by not having batteries.

Posted Sunday 20 Jan 2013 @ 11:13:10 am from IP #
ME109
Member

Interesting pump Harry with a decent flow rate. Ideal with its own panel for daytime boost pumping.

The two homes where I built these solar pools already had a stand alone system in place and have only required doubling of the panels, from 6 to 12.
Not many panels actually.
All pumps are dry mounted, out of the pool.
Thanks for your insight into maximisers etc,

Posted Monday 21 Jan 2013 @ 7:07:21 am from IP #
benservice
Member

I was thinking about the initial problem here "I may be able to further reduce the circulation at night down to 1/2 hour every 2 hours, or keep the system flowing at a much reduced rate" rather than storing the power to run the pump why not store the water in a tank.

Basically the idea is that during the day when you have solar power available pump water up to a tank which is above the pool/filter, this tank would then have a small hole in it (or small valve) which slowly trickles the water back to the filter overnight. You could have a big overflow pipe at the top so that the pump can just pump to the tank all the time and overflow back to the pool or filter all the time. I would have thought a 2000 or 3000 litre tank (actually I think you need two tanks to do this properly) would be cheaper than a bunch of batteries.

I am thinking about trying something like this with a gravity fed sand filter reed bed or something like that at a house we are planning to build in the next few years.

Posted Sunday 7 Apr 2013 @ 9:01:27 am from IP #
ME109
Member

Thanks benservice,

I have somewhat incorporated your ideas into one of the solar powered pools.
The pool has a head of about 1000 litres that flows back into the bio-filter if/when the pump power is turned off.
The last I spoke to the owners the pump was running for half an hour, every two hours, through the night.

Here's a pic of the pool at 12 months old.

http://i277.photobucket.com/albums/kk42/jeffr100rs/IMG_1547.jpg

Posted Monday 8 Apr 2013 @ 10:35:04 am from IP #
benservice
Member

Great looking pool, be great to be able to tweak the design and water storage a bit to be able to leave the pump off all night. Not sure how the cost of batteries for the overnight pumping compares to tanks and pipes for the extra water storage. I'll let you know how I go when I finally get around to figuring it all out and building it, I'm sure I'll make some mistakes but learn a fair bit in the process.

Posted Tuesday 9 Apr 2013 @ 10:44:43 am from IP #
ME109
Member

Running the pump overnight is more necessary through summer when there is perhaps a higher ammonia load due to swimmers. The reason for constant circulation is primarily to ensure the survival of the aerobic bacteria colony. If the water flow slows too much, the colony will die off. That may or may not be a problem depending on the ammonia input to the pool at a given time of year.
The constant circulation also ensures the highest water clarity, which should be very clear, because it can be.

Regards batteries for overnight pumping, it really comes down to what is necessary to achieve and maintain the desired water quality.
In summer it appears there is enough reserve power to run overnight with enough in reserve the next morning.
The options are to increase solar power charging and storage, or reduce operating times to within the systems capabilities.

Winter time is another thing all together, the pumps can be set to run for minimum circulation to maintain clarity.
The bacterial activity is greatly reduced due to water temperature and lower nutrient input.

There are no set rules with this type of pool because there are so many variables.

Good luck with your project!

Posted Tuesday 9 Apr 2013 @ 9:35:02 pm from IP #

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