Q. Is it really greener to solar charge your laptop? I want to write my book on green media the greenest way possible. Since I cannot yet afford to solar-panel my house, I thought, why not get a solar charger for my laptop? Turns out you typically charge a battery and then charge your computer from that. That seems like a lot of gear, some of which becomes toxic trash within a few years if you are lucky (within one year seems not unheard of). Better to power from the wall after all? (Note: My local utility runs on 80 percent fossil fuels.)
Kyoto, Japan

A. Dearest Gabi,

What a lovely concept: a book about environmental topics, powered by 100 percent renewable sunshine. And what an exquisitely good way to put off writing said book: taking the time to fret about this situation and then writing to yours truly. I salute you, Gabi, and all writers who share your passion for procrastination. Let’s see what we can do to help you stall.

Going off the grid, at least in the laptop department, could boost your inspiration as well as your eco-cred. But as you’re discovering, rigging up a solar charging system is a bit more complicated, and certainly more expensive, than relying on the standard plug-and-play method. So are those nifty little chargers worth it?

Grist thanks its sponsors. Become one.

In my digging to help answer your question, I’ve confronted volts, milliAmp hours, watts, kilowatt hours, energy payback estimates, and one nasty sunburn (I do like to go method with my research). Now that I’m sufficiently aloed up, let’s break all that data down into news you can use.

First, to follow your laptop’s power cord: These days, we rely on computers like never before, but that doesn’t mean they represent a huge slice of our electricity consumption. One 2014 report found that the average laptop fizzles through just 53 kWh of juice every year. When you consider that the average American household tears through 830 kWh of electricity per month — that’s 9,960 per year — you’ll see that the clickety-clack of our keyboards is a relative drop in the bucket. (Households in Japan use an average of around 5,500 kWh, but the laptop is still a sliver of that amount.) Still, that battery ain’t free: If your power comes from coal, for example, then your laptop is responsible for about 115 pounds of carbon emissions per year. Fossil fuels = bad, no matter how much or how little we use.

Grist thanks its sponsors. Become one.

So one idea is to erase those emissions with a personal solar charger. But you’re right that it’s not as simple as all that, Gabi: Setups with enough heft to charge a laptop typically require a backpack-size or smaller solar panel, a separate power pack or battery to store the energy generated by the panel, and associated cords. The panel will have to be big enough to handle the computer’s voltage requirements (larger panels equal faster charging), but even these larger spreads can take anywhere from 6.5 to 16 hours to fully top up the power pack, depending on conditions. The pack, however, transfers that free, sunny electricity to your laptop in more like two hours. So one might start one’s workday with a charged machine and set up the panel nearby to refill the power pack, then recharge at night. This set-up might cost you a few hundred dollars.

It’s true that all of these pieces certainly have an environmental impact of their own, starting with their manufacturing. Building solar panels requires the use of several toxic chemicals, not to mention plenty of electricity (though overall impact varies widely depending on where the panels are made). But the energy savings you reap as soon as the panels are in action should fairly quickly pay off that initial debt: for rooftop solar panels, at least, The National Renewable Energy Laboratory estimates you break even energy-wise after one to four years.

And as to the longevity question: a single year of use for one of these solar doohickeys sounds unacceptably dismal. One brand estimates its panels will yield five to 20 years of good service, which would give you a much better return. But even then there’s the tricky matter of disposal. Right now, it’s very difficult to recycle kaput solar panels, so your green purchase could indeed end up part of the e-waste stream. The industry is working on improving this, though, so the news may be brighter in the future.

So in the end, how best to charge your writing sessions? As often happens with these kinds of questions, a crystal-clear answer is elusive. Personally, I believe our goal in life should be to own fewer gadgets, not more, so although I am a solar-power supporter, I’m not sure it’s worth cluttering your desk with this adorable piece of e-waste. But if you do decide to go for it, aim for the longest-lasting charger you can afford, and use it wisely (anything powerful enough to handle a laptop may also be able to charge tablets, cameras, and phones — the more you do so, the more coal-fired electricity you’ll save). If you choose the non-solar path, don’t fret too much about plugging in. Follow the energy-saving practices I’ve outlined for computer use before, trim your carbon elsewhere (drive less, everyone!), and you’ll be OK. As long as you keep yourself safely out of the sun, that is — ouch.


P.S.: Good luck with the book! Keep me posted.