anyone use solar power for water pump

[whensparksfly]

Hi all I'm thinking of putting in a underground rainwater storage tank for the toilets in the two bathrooms in the house it would use a 12v pump to the house.I was looking at the solar panel kits on ebay I wonder would they be fit to keep the batterys charged to run without mains power.

 

[piman]

Hello Whensparksfly,

no reason why not as long as the solar panel capacity is large enough. Bear in mind that in winter the power from a solar panel drops off considerably so you will need to factor this in or else have a mains powered charger to keep the battery fully charged.

Alec

 

[Wendelspanswick]

For a small install like that I would be tempted to have the panels adjustable to cater for the varying height of the sun depending on the seasons. Also use the solar to pump the water from the UG tank to a large as possible roof space tank during daylight.

 

[Mee]

It would be advisable to have battery back up with separate mains charger so if your battery drops it can charge from the mains.

 

[whensparksfly]

Thanks guys I wonder what type of batterys would I use

 

[Robotstar5]

I use leisure batteries at the stables, not sure if it's the right one to use, but seems to work OK.

 

[rtbcomp]

+1 for leisure battery. Try to find reviews on different makes, especially obscure ones, some are a lot better than others.

 

[MattH]

You could build a small Powerwall with LI-ION cells!

 

[Shox Dr]

You could build a small Powerwall with LI-ION cells!

Holly fek, wow

 

[The_Yellow_Ardvark]

Take a look at canal boat solar panel bilge pumps.

They consist off a decent panel, the leisure battery you buy yourself.

New panels work on UV, not sunlight. So if it s day light they will produce a voltage. The Black box of Electronics will regulate the OP voltage and ensure the battery is kept at a decent charge level.
Some kits will give you a option to fit a secondary supply to it. DC or AC.

The kits I have bean involved in have one weak point. The electrical connections to the battery connections and on the end of the panel wires.
Junk hem and fit decent connections.

 

[piman]

Hello Y. A,,

whatever you want to call it the output is variable depending on the weather and time of day, little current and voltage gives little power.

Alec

 

[voipio]

New panels work on UV, not sunlight. So if it s day light they will produce a voltage.

Do you have a reference for this? As far as I know, PV quantum efficiency increases with wavelength, so red is better than violet by a factor of ~2 at producing output current from a given rate of incident photons. Also, red gets scattered less than UV by clouds and atmospheric aerosols, so if the UV index is high, the infra-red index will be higher still.

 

[The_Yellow_Ardvark]

Do you have a reference for this? As far as I know, PV quantum efficiency increases with wavelength, so red is better than violet by a factor of ~2 at producing output current from a given rate of incident photons. Also, red gets scattered less than UV by clouds and atmospheric aerosols, so if the UV index is high, the infra-red index will be higher still.

http://www.ukboatyard.com/

That's the place what supplied the kits for the 2 boats I helped on. The only thing we did not buy from them was the deep cycle leisure batteries and the extra cabling we needed. I can get them at a better price.

The kits are a emergency kit, so when the boat is left for extended time there is a bilge pump available to remove water seepage.

I have seen similar kits fitted to a Scout and Guide camp site to pump water from a pond into the toilet block, so it is an adaptable bit of kit.


Yes, brighter they day more UV and this more power is produced, very good for the house panels as the extra can be sold to the grid. Something Everest are pleased to tell you.

The ones fitted to my dad's house, this time of year are really only suitable to keep the water in the heating and hot water system at a constant. In the summer it switches over and the extra is sold into the grid.
As I am no longer speaking to my family for more information on that you will have to google Everest.

 

[piman]

Hello Voipo,

simply the measured output of solar panels against time of day. See this site and see the variation on weekly solar output (column 2):-http://www.gridwatch.templar.co.uk/france/ Also the recent report of Germanys solar and wind generated power last December, Both wind and solar was significantly down on output due to still conditions and cloudy weather.

Alec

 

[voipio]

Thank you for the interesting links.

The statement.... "New panels work on UV, not sunlight. So if it s day light they will produce a voltage." ....aroused my curiousity and, typical forum member, am always eager to learn. I took it to mean that newer types of solar PV panel were better at converting the UV part of the solar spectrum into electricity. However, as I couldn't find any information in support of this posit (sic), I posted the request for a reference or link to further information in support of it.

My trawls through the interweb found this:

http://www.pveducation.org/pvcdrom/solar-cell-operation/spectral-response

which illustrates the fall off in solar cell output with decreasing wavelength, particularly dramatically towards the UV (i.e. below ~ 390nm wavelength), but also mentioned is that the fall off is partly due UV absorption by glass.

 

[Shox Dr]

Thank you for the interesting links.

The statement.... "New panels work on UV, not sunlight. So if it s day light they will produce a voltage." ....aroused my curiousity and, typical forum member, am always eager to learn. I took it to mean that newer types of solar PV panel were better at converting the UV part of the solar spectrum into electricity. However, as I couldn't find any information in support of this posit (sic), I posted the request for a reference or link to further information in support of it.

My trawls through the interweb found this:

http://www.pveducation.org/pvcdrom/solar-cell-operation/spectral-response

which illustrates the fall off in solar cell output with decreasing wavelength, particularly dramatically towards the UV (i.e. below ~ 390nm wavelength), but also mentioned is that the fall off is partly due UV absorption by glass.

Wave length changes in winter does it not; longer?

 

[piman]

Hello Voipo,

Th eother factor is the angle of the light relative to the panel, so variations in seasons also affect the output unless the panel is on a gimbal or such to vary the angle.

Alec

 

[voipio]

Trying to understand this more clearly has taken a while. My original assertion (red gets scattered less than UV by clouds and atmospheric aerosols) is not entirely true, well, at least the clouds bit isn't. Red skies in the morning or evening do arise from the differential scattering of red vs blue light, with red light being favoured for getting through and the blue light being scattered. However, on a cloudy day, the balance of light wavelengths tends to shift slightly in favour of blue (and UV). A good example to help accept this fact is manually setting a camera's white balance control to compensate for cloudy conditions. The effect is to make the resulting images warmer than those taken with the camera set to sunny white balance i.e. the camera is compensating for the increased proportion of blue light under cloudy conditions. It would seem that blue light is reflected better by the water droplets in a cloud than red light, and this is the reason for the blue enhancement in lighting conditions under cloud.

As far as photovoltaic solar panels go, clouds generally reduce the output from the panels by quite a lot, unless the clouds are very thin, even solar panels that might have an enhanced response to blue light.

As Piman said, The incident angle of light is a large factor in the total energy that can be obtained using solar panels, so actively pointing the panels directly towards the sun results in a substantially greater energy yield than fixed panels. There is a large steerable array, 10kW peak per unit, not too far from here. The central mounting pillar is massive, but a 35% increase in energy is claimed, compared to using fixed panels.

A nugget of interesting information: every point on the earth's upper atmosphere receives the same total amount of sunlight over a year.