Getting Inked: How Kiwi Scientists Could Solve the World’s Energy Problem

(Top image via Flickr)

Every hour, the energy that falls on earth from the sun is enough to power the globe for an entire year. Harnessing just a fraction of that would provide the world with all the energy it requires.

The problem is finding a cheap and efficient way to do that—and a team of Wellington scientists thinks it has the answer. It might just be all the world needs to be powered entirely by renewable energy.

The secret is polymers, plastics with the properties to create lighter, more flexible, easier to manufacture solar cells (and therefore cheaper) than the silicon ones you currently see on rooftops. With this technology, powering up could be as easy as going to a hardware store, buying a roll of solar cells printed with a kind of "solar ink", rolling it out on your roof, and plugging in.

Dr Justin Hodgkiss, principal investigator at The MacDiarmid Institute for Advanced Materials and Nanotechnology, hosted by Victoria University of Wellington, has been researching printable photovoltaic technology for the past nine years. VICE talked to Justin to find out more.

VICE: Hi Dr Justin. So, how does it all work?
Dr Justin Hodgkiss: The technology I'm working on is printable photovoltaics (PVs). It can be formulated as ink and printed in a roll-to-roll manufacturing process. A little bit like how newspapers are printed, where there's just a roll that flies through and the ink gets printed on and you get photovoltaics coming out a rate of metres per second. That's the vision.

How do polymer cells rate in efficiency compared to silicon cells?
They're not yet as efficient as silicon PVs at converting light into electricity—that's where our research comes in. We're trying to understand what makes good ink and, therefore, how to design better inks.

The potential is enormous if we can get the stability and efficiency up. It doesn't even need to be quite as good as silicon because the benefits of reduced manufacturing costs are enormous and this could potentially make it affordable for many more people to have photovoltaics installed.

The efficiency of polymer photovoltaic cells has almost tripled from about four percent to 12 percent in the past eight years, and that's getting closer to where it needs to be to have some real-world application. Twelve percent might not sound like much, but the silicon cells that you get on your roof are in the order of 16 percent, so we're really not that far off.

How is New Zealand doing in terms of renewable energy?
New Zealand is doing, and has always done, very well by global standards, because we get roughly three quarters of our energy from hydro, which is renewable. We're a bit lucky in that we have a landscape that is very amenable to getting lots of hydro and we have a very low population density.

What could we do better?
We could potentially become 100 percent renewable—that's actually within our grasp, if we were to top up that missing fraction with solar and wind. And then it comes down to smart ways of storing that energy so that we can balance out fluctuations in supply with fluctuations in demand. That's the major challenge in getting to 100 percent renewable.

Why solar?
It's the only renewable energy that can deliver on the scale required. There's an environmental imperative to replace carbon-based fuels with renewables. New Zealand is already largely renewable, but most other industrial countries, let alone developing countries, are not. It could have a huge impact if they had renewable energy.

What's holding solar power back?
The reason is cost, but that's changing. It has reached grid-parity in some sunny places, like the south-western US, and the capacity of solar has been doubling roughly every two years for about the last 20 or 30 years.

The really interesting thing about solar is—unlike fossil fuels, whose price depends on supply and demand—the amount of sunlight is essentially unlimited so it just comes down to effective use of technology to transform it into electricity. If solar PV obeys exponential laws, you'll have exponentially growing capacity and an exponentially falling price because the more you make of something the cheaper it is to make.

How does the future look for solar power?
What I've found quite encouraging in the last couple of years is that in places like south-western US there are solar farms selling electricity at a fraction of the cost of the grid and there are billionaire investors, that are not environmentalists, getting in on this for purely financial reasons. That's when the tide turns and political ideology just doesn't make any difference. Once it gets cheap, the resistance goes away, and I'm encouraged that that's starting to happen and people of all political stripes are getting behind it. In the end the price of PV is only going one way: down. It's now a matter of when, not if.