Is There a Better Way to Harness Solar Power Than Photovoltaic Cells?
By Thomas Neuburger
Several weeks ago I published a piece entitled "Can We Have Both Industrial Civilization and a Habitable Planet?" which took a preliminary look at the idea that because manufacturing destroys something in one place to create something somewhere else, we may not be able to "manufacture our way out of the climate crisis."
Must We Destroy to Build?
I'll let you read that piece to get the gist of its point. It presented what seem to be compelling arguments that trying to sustain a high-energy-use, manufacturing-intensive society will ultimately fail. But I ended with this thought:
I want to leave the question of the viability of industrial civilization open for now, because the implications are so broad. I want to see the numbers on which the conclusion depends, which I think the book provides, though I suspect the authors are way beyond right. ... Must we surrender manufacturing to survive? If so, how does that happen?
I've since been looking for those numbers — it hasn't been easy — and also looking for technologies that seem less unsustainable in the long run than others.
Did you know, for example, that photovoltaic cell–based (PV) solar panel farms likely need roughly two gallons of water (for cleaning) for each megawatt-hour produced? The planned giant Indian solar farm will produce 4,000 megawatt-hours of electricity. By these calculations, the farm will require 8,000 gallons of water per hour or almost 200,000 gallons per day.
For comparison, daily fresh water use in the U.S. in 2015 was about 280 billion gallons per day. Still, 200,000 gallons of water per day doesn't seem like a lot, unless the farm were located in one of the sunniest places in the country, the drought-ridden Southwest.
And that's in addition to the high-energy cost of creating these farms in the massive quantities needed. As someone once noted, the short-term cost of replacing fossil fuel as energy burns a hell of a lot of fossil fuel.
So you see the problem. The entirety of the climate salvation effort — by Big Green and Little Green alike — rests on the assumption that we can manufacture and technologize our way out of the climate problem and end up with a sustainable version of modern life. Yet nowhere have I seen that (what seems to me massive) assumption verified.
A Positive Note
On a more positive note, consider the video at the top. Heliogen, the company that produces the featured product, claims it can generate energy from the sun at a cost of one cent per kilowatt-hour without photovoltaic (PV) cells, using simple motors and mirrors instead to capture and concentrate solar rays, thus shifting the technical challenge from hardware to software. Its solution is highly efficient, storable (using the hot-rock method) and transportable (using the conversion to hydrogen method).
Could this be a solution to the problems inherent in solar energy use?
Its positives, as near as I can tell:
The system is efficient and imminently scalable, from 5 megawatt modules on up.
Which means the project can be implemented and controlled locally.
Mirrors are likely easier (and much more earth-friendly) to manufacture than PV cells.
The "hot rock" storage idea is brilliant and very low tech.
The company has caught the eye of investors, so the project will be funded, though privately.
It's negatives, as near as I can tell:
Water use — the mirrors still must be cleaned on a regular basis.
Mechanical maintenance — We have no information of the durability of a field of thousands of motors, planted and run constantly outdoors in sun, wind and weather, year after year after year. (PV solar farms, in contrast, are basically without moving parts.)
Software vulnerability — Centrally located AI is required to run and fine-tune each array. Thus any software glitches, or sabotage aimed at this single-point vulnerability, would bring down an entire town's or state's energy supply until fixed.
As the climate emergency unfolds, it's possible that the higher the tech requirements of an energy installation, the greater the vulnerability. To wipe out energy production from a hydroelectric dam, for example, you'd have to wipe out the damn, or a large chunk of it. Sabotaging one dynamo won't do it. To wipe out energy production from a Heliogen installation, on the other hand, that could be done in a day by a single top-flight hacker.
Plus, Bill Gates is involved in the project, always a bad sign. The company's CEO shows his Gates-like naiveté when he says, at 6:50 into the video, that "beating the prices of fossil fuels is the only thing that matters. If we can be even a fraction of a cent cheaper than fossil fuels, the world will adopt us at scale." This is the techno version of Cloud Cuckoo Land.
Still, this is a fine example of good news on the technical side of the climate change front. Is it possible that we can manufacture and innovate our way out of this global, existential problem? The shape of our future depends on getting the answer right.