A couple of weeks ago I came across solar hydropanels for the first time. Developed by an American company called Zero Mass Water, these are panels that use solar PV to draw moisture out of the air. Each panel can make 2-5 litres of water a day, depending on humidity conditions. It’s the same quality or better than bottled water. Since these SOURCE panels can be placed anywhere, even in the desert, it’s potentially a way of bringing clean water to people who don’t yet have it. “Every person on this earth should have perfected water” says the website. “With SOURCE this is possible.”
If you want to install hydropanels on your home, each panel currently costs $2,000 plus $500 installation. Meeting my own family’s drinking water needs would be in the region of $4,500 dollars. Assuming the panels worked at the upper end of their efficiency, it would still take years before each litre of water I got out of the system was cheaper than bottled water.
But it’s new technology. Let’s say that as they improve the design and build bigger factories, they’ll be able to bring costs down to just a tenth of the current expense: $500 for a family of four. Now we’re talking, right? Maybe for me, so I can save on bottled water – if I was drinking bottled water in the first place. But it’s still not cheap enough for those who most need access to clean water, those living on less than $2 a day.
Let’s be generous. Let’s say they can make it a hundred times cheaper, and I could get a system for $50. With financing or philanthropy, you could get these out to Sub-Saharan Africa and make a difference. Maybe – unfortunately the panels have moving parts and need their filters replacing from time to time, so it’s not a one-off expense. But let’s be generous again and say those matters are solved in later iterations. Now we’ve got a technology that could provide “the water of everyone on the planet”, to quote Zero Mass.
Erm, no. We still don’t. Because it only makes 2-5 litres a day, hydropanels can indeed provide drinking water in the middle of nowhere. But they don’t make enough to provide water for cleaning and cooking, or any of the other things we might use water for.
Imagine a household in Madagascar where there’s a girl who isn’t in school because she’s sent to carry water every day. If a charity were to fit a hydropanel on her home, she’d still have to go and carry water.
Even though hydropanels can work anywhere, you’d still need to have another source of water nearby for all your other water needs. A river, a well or borehole – something that can provide water for non-drinking purposes, not to mention agriculture or animals. And if you’ve got another source of water, even seawater, then you can make yourself something like this:
A solar still heats up in the sun, and turns salty or dirty water into clean drinking water through the natural process of evaporation. There are many different designs, from basic lined pits in the ground to glass or perspex boxes. You can make one yourself, or there are off-the-shelf options like the Watercone. An elegant clay version won a design award a few years ago. These are all true appropriate technologies – affordable and easy to make with local materials. If you want a more advanced version, an Italian company called Solwa has combined one with a tiny solar PV panel to make an ‘active solar still’. It can make 8-10 litres of water a day.
So if you’d need another source of water anyway, and you can use passive solar power to purify it, what do we need hydropanels for? Why has it won awards, got so much attention, and attracted $24 million in start-up funding?
Don’t get me wrong – the SOURCE hydropanel is very clever. I have no interest in talking the company down. But they’re the ones making the big claims about meeting the world’s water needs. Green blogs such as Treehugger or Inhabitat have reported these claims uncritically, but this isn’t a system for ‘the world’. This is a system for rich people who currently drink bottled water.
It’s easy to be dazzled by high-tech solutions. But often what would work best for those who really need it is something simpler, cheaper, and low tech.