Solar Powered Pump?

[SamSipEt]

Just a thought that popped into to my mind this morning….why not use a solar powered pump to move the water from the well, 4 meters deep, to the tank on the water tower, 6 meters high. The solar panels could be fixed on to the side of the water tower making quite a neat solution. I suspect that the pump would not be powerful enough to move a lot of water but given that it would work all day it may be more than enough for a small 2 bedroom bungalow. Anybody have any thoughts pros or cons on this please?

As a side issue 6 meters appears to the minimum for reasonable pressure in the house can someone please confirm this with first hand experience?

[chownah]

I've been considering a water tower for my place so I got out my pumps manual to use its cut in and cut out pressures as estimates for the height I would need for a tower to get the same pressures.

My pump turns on when the pressure gets to 1.3 kg/cm^2 and turns off at 1.9kg/cm^2.

To convert these pressures into heights you need the fact that 1 kg/cm^2 is the pressure you would get from 10 metres of water height.

This means that if I want to build a tank to provide the same pressure as the lowest pressure that my pump develops the water surface in the tank needs to be 13 metres above the ground (since my pump is sitting at ground level). If I want to build a tank to provide the same pressure as the highest pressure that my pump develops then the water surface in the tank needs to be 19 metres above the ground.

I can conceive of building the 13 metre tower....but 19 metres is really tall...I don't know. My wife says that for showering the low pressure is (unenthusiastically )OK but she'd really like the higher pressure better........

If you want to find the shortest practical tower you could build then read in the instructions for your water heater....I bought an electric water heater (I am not using it presently) and I remember its instructions clearly stating how much the water level needs to be above the unit for it to function....and remember that this minimum distance ABOVE THE HEATER ITSELF is an absolute minimum (I think) and you have to have that minimum verticle distance even when the tank is almost empty....when the water level is at its lowest.

Edited August 5, 2006 by chownah

[mobile69]

A 12m water tower looks very high! Ignoring the figures you're quoting about pressures (saturday night, beers kicking in), my 12m tower seems to supply pretty reasonable pressure to 2nd floor showers. The solar heaters are on the roof, about 3.5m above the shower heads. Water pressure not great, but adequate if only using hot water, but as you usually need to cool it down with some cold water, shower pressures are ok. Just running cold water, a an electric shower would use, the pressure sholud be ok. When you connect your water tower to the house, use larger diameter pipes as far as you can, connecting to the half inch pipes supplying the showers.