Solar Pumps

[MrWiggle]

Has anyone had any actual experience with this pump ?

http://www.thaisolarpump.com/ThaiSolarPump/HOME.html

Interested to hear how it performs or if nobody has actually used one, then how they think it would perform and why or why not.

[rice555]

Hello MrWiggle, would this question be better answered on the housing-garden forum? I think that the cost of solar for FARM use has been covered in past threads.

rice555

[Maizefarmer]

Its a good quality product - but as a solar powered pump, the amount of water it lifts is really about voltage/current obtainable from the solar panel than about some or other unique advantage it has over other good European brand name submersible pumps(which it doesn't have) The safety features, and the efficiency features built into the control electronics are used by other big name submersible pump manufacturers (e.g. Grundfoss, Goulds ... and others).

From a practicality point of view, which pump one uses often comes down to representation in Thailand - and in that respect, yes Lorentz is here and is well established. The other big name for top quality submersibles (in Thailand) is Grundfoss.

Edited March 3, 2010 by Maizefarmer

[MrWiggle]

They recommend 2 x 100 watt cells....so what should that be able to do given a fine and glorious sunny day.

[lannarebirth]

PM TV boardmember "brahmburgers", he's got one:

http://www.thaivisa.com/forum/Solar-Da-Go-t263904.html

[Maizefarmer]

They recommend 2 x 100 watt cells....so what should that be able to do given a fine and glorious sunny day.

.... for domestic usage/supply - 200watt should be plenty fine, and should easily move all the water you need whenever you need it - but it really is all about how deep you are going to be lifting the water from out of the bore hole that is going to determine just how much water you will be able to pump per watt. Somewhere around on the Lorentz website I think there is a chart which illustrates cubic meters(volume) versus depth versus wattage (amps & volts). If not there dig around on the Grundfoss website and you'll definetaly find one (for an equivilant sized pump) - and if you come unstuck, drop me note and dig out one from the catalouges I have lieing around.

Having a storage/resivour tank (on a tower outside - nice and high for good tap pressure without having to use a second pump, or a smaller one in the attic) is a must because there will come a day on which for some or other reason your pump won;t work. The day will come on which it will get blocked, or the switch will break, or a bearing will go, or there'll be in-sufficent sunlight to support your water consumption for 2 or 3 days in a row - and you'll be mad for not having put in a storage tank to cover "pump downtime".

Don't skip the storage tank - the higher & bigger the better.

But in short: yes - 200watts should be just fine for the average domestic requirement.

[MrWiggle]

Cheers for that.

On the info they sent me, they quoted the larger pump, the ps 1200, can lift water 'up to' 240m at a rate of 21m3 per hour.

wondering if this is realistic or somewhat exagerated....again, given a fine and glorious sunny day and all things good in the world.

[Maizefarmer]

Cheers for that.

On the info they sent me, they quoted the larger pump, the ps 1200, can lift water 'up to' 240m at a rate of 21m3 per hour.

wondering if this is realistic or somewhat exagerated....again, given a fine and glorious sunny day and all things good in the world.

Hang on a sec - I'll go dig up PS 1200 graph out, but what little I remember of my 6 years or so of engineering study, something tells me that while those figures are certainly theoreticaly poss as max figures idependently, it's certainly ain't going to be 21tons per hour at 24bar ........ hel_l no, that would require 100kw (160hp) or more - not 2 x 100watt panels. Maybe, just maybe 1ton with 2 x 100watt panels!! It must mean the max lifting height would be around 240meters, at which point you'd get a few litres per hours, or if you were getting 21tons per/hr the lift height would be something like a couple meters at most .... pretty sure thats what Lorentz mean.

[Maizefarmer]

Okay – here we go …................ the key info in the attached PDF flow chart (which are the figures for the PS 1200 I have managed to find on the net) is the info on the right against the yellow background: which illustrates wattage required/used (the figure in the very last yellow box on the right hand side of the page preceding the letters “Wp”) for a particular flow rate.

Perhaps it would help if I explained what a complete row of figures on the chart mean't in layman terms:

Starting from the top left hand side of the 2nd page of the PDF doc, the first row of block surrounded figures (immediately underneath the conversion tables) starts off like this:

80m 90m 100m 120m 140m 160m 180m 200m 230m vertical lift solar generator

Underneath each figure followed by the letter “m” are the words “fixed” or “tracked” - below which start a set of figures typed in blue boxes. The “fixed” or “tracked” words refer to the solar panel setup you have: fixed means the solar panels are stationary and are not mounted to a mechanism which moves them around to follow the sun in an arc, and tracked means they are mounted on a mechanism that allows them to moved around, angled perfectly with the sun so that max energy is obtainable throughout the day.

… and following that, underneath are 2 flow rate figures e.g. under 80m are the figures 3.8 (below the word “fixed”) and 5.1 (below the word “tracked”) - the meaning of which I'm pretty sure you understand i.e. you'll get 3.8 m3 (cubic meters or tons) per day pumped from solar panels which are “fixed”, or 5.1 m3 per day if the solar panels follow the sun around ("tracked").

But what power is required to pump that amount of water(?) - and that's where the figures in the yellow boxes on the right hand side of the page come into play: they tell you 3 important pieces of info:

1) the quality of the sunlight over a square meter as an irradiation figure in kilowatt hours per day (given as kWh/m2/day)

2) the power your pump will actually need (Wp i.e. watts) and

3) the the thickness that your copper needs to be in the cable that is carrying the current to the pump over whatever the distance is (the longer the distance the thicker the cable needs to be – else you will suffer substantial voltage/current drop between the solar panels and the pump).

… and using the first row of figures as an example, it simply means that from a depth of 80meters, your PS 1200 pump will be able to lift/pump 3.8 cubic meters of water if you are using enough stationary solar panels which can supply your pump with 350watts of energy – and to generate that amount of energy, the sunlight quality will need to be at least 4.5 Kw/per square meter (but the more the better) up to around 7.5 Kw per square meter.

If however you have a solar arrangement that can follow the arc of the sun as it travels across the sky, then you are going to be able to use the sunlight more efficiently, and you could now get as much as 5.1 cubic meters per day pumped from the depth of 80meters – simply because, by tracking the panels with the sun the average amount of power they will be able to extract from light per square meter will be greater (i.e. more energy)

As a side-note, if you compare the energy per square meter from the sun to what a modern solar panel actually produces you quickly see just how inefficient solar panels actually are!!

Notice how as you move down the graph so the amount of water that is pumped (as the depth increases) drops, and at the same time, the amount of energy required (yellow boxes) increases … and both quite dramatically so!

In short Mr Wiggles, no way are you going to get 21 tons of water per day from 240meters – not a chance in hel_l. Those sorts of figures manufacturers love to print up – they are accurate figures, but they need to be understood in their correct context, which are seldom (if ever) real world conditions.

You are going to get flow rates from given depths as illustrated in the chart - which are going to be dependent on not only the amount of solar panels you have, but also the quality of the sunlight avaliable and the solar panel angle relative to the sunlight (and therefore there ability to extract energy from the sunlight), and the thickness of the cable supplying the power to the pump.

PS - just because a solar panel is a 100watt panel does not mean you will get 100 watts from it - how much you actually get will be dependent on the quality of the sunlight and the angle of the panel to the sunlight, which changes throughout the day, meaning the only time you are likely to get the full 100watts is for that brief period of time that the sunlight is falling directly on the panels. The rest of the time the wattage they produce will vary from as little as 10watts/20watts to 70watts/80watts - as the sun moves through the sky and the intensity of the light on the panel changes. In reality the average power a 100watt panel produces throughout each day is something like only half its rated output i.e. 50watts or so!!!! I think this is the one factor that folk fail to factor into solar pump setups.

The reality of solar setups are somewhat/very different to how they can appear "in print".

EDIT NOTE ... the dam_n PDF won't upload - I suspect it has something to do with the fact that I use LINUX and not Windows is my OS - anyway, the webpage for the PS 1200 data is:

http://www.lorentz.de/en/products/ps/1200

Download and print it out your side for reference.

Edited March 4, 2010 by Maizefarmer

[MrWiggle]

Cheers, might send off and ask them directly about the quoted flow versus height and see what they say

[finner]

Thanks for the download MF, good info.

From what I see in the specs, for the PS1200, you need 72-96 volts, meaning 3-4 solar panels just to supply the voltage (assuming 24volts per panel). For 350-1200 watts, (for full rated output), assuming that the panels are supplying 100watts (5 amps) as mentioned above, then 4 - 12 panels are required. Very expensive.

Mr Wiggle, are you sure you can't get away with the PS200 pump (or a similar one from another manufacturer) which uses 24-48 volts at 80-300 watts (2-3 panels). That will supply up to 2.7 cubic meters per hour.

PS200 HR-04 80 watts, 48v, 800litres/hr (2 panels)

PS200 HR-07 200 watts, 48v, 1200litres/hr (2 panels)

PS200 HR-14 300 watts, 48v, 2700litres/hr (3 panels, 2 in parallel)

Check the lift numbers too, of course and hope for sunshine.

By the way, has anyone noticed that these pumps are 3 phase? Most are from what I've seen.

[MrWiggle]

Finner...dunno yet about what I will get away with, its all just in the planning at the moment and I am interested in Solar because of what I want to do will probably cost a lot in monthly electric bills. Or as mentioned once before, a petrol or diesel engine alternative will be to noisy for what I want....so the consideration of solar is what I am doing now.

What I want to do and what I will be able to do may in fact be a hel_l of a big difference.

[finner]

For what it's worth Mr Wiggle, the government has had a program of giving away solar panels and 220volt inverters (one of each) to farmers that applied at the tambon. Enough power to watch TV, a couple of lights, and listen to Cambodian radio stations (Surin area). We have 5 of these setups out in the boondocks. The government is now electrifying this area and are asking for the setups to be returned so it might be worth a talk to the local mayor to see if your family can qualify for new ones or returned old ones.

Still doesn't solve your pump dilema though. The one we have for the government local water supply, similar to the Lorentz, lasted 10 years before seizing up. When they pulled it out, I was dumbfounded to find out that it wasn't DC, it was 3 phase AC. I'm going to spend some time researching that one when I can. Must have something to do with efficiencies or conductor size or corrosion prevention I would think.

finner

Edited March 12, 2010 by finner