Solar Powered Water Systems in Humanitarian Context III - Q&A

This page documents the questions that were asked during the webinar: Solar Powered Water Systems in Humanitarian Context

Note: This page is still being developed!

How best can you clean the panels when the pole mounts are high? What is the recommended height for the pole mounts for the solar panels?

The height depends on what you are trying to achieve, is it a flood-prone area? is it to discourage theft?....cleaning of panels mounted on poles can be achieved by, for example, equipping the water operator with a ladder and a telescopic handle with a cloth....in other places we have seen a holed pipe going along the top of the panels and having water flowed every now and then might be an option.

How long can the solar system battery serve or no need to have batter for tropical regions like Ethiopia?

Better to design your system so that batteries are no needed

Did you ever take a regeneration of power by using the downstream pressure just with the same pump? so that the pump would work as a generator turbine?

No, never.

How much its cost solar water project per watt?

Depends on a number of factors, the country where you are based, the quality of products used, the size of the system.

What's the range or cost?

It depends on those factors and others, I can't say.

Which kind of solar inverter brand do you prefer?

More than brands we like to see at manufacturing certifications. The control equipment must meet EN 61800-1, EN 61800-3, EN 60204-1 or internationally recognised equivalent standards.

Would an inline chlorinator be an appropriate way of dosing the chemical in a solar set up

Yes, if the injection is proportional to the water flow

How to anticipate best the local conditions of irradiance (especially in emergencies)?

There are databases (NASA, EU, others) with historical data for long years that are used for that.

How does the GLOWSI solar manual arrive at a tank size of 1 to 3 times daily demand?

As said in the manual, that is a quick approximation when for some reason, you can not do a proper analysis of water pumped vs demand to size the tank...the data of 1 day comes from field assessments showing that the great majority of systems retrofitted from diesel to solar with tanks of less than 1 day of water demand volume faced overflow problems. The limit of 3 days is given with the risk of having too low chlorine concentrations for water stored for longer than that period of time.

How about opinions in regard to charging some money for received water?

Please see the webinar recording.

How was the number of taps/person determined in such a large camp? I imagine the population density and terrain makes things very difficult with queuing.

Please see the webinar recording.