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How a Solar Revolution in Farming Is Depleting Groundwater

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11–20 of 141 posts

Re: How a Solar Revolution in Farming Is Depleting Groundwater

#11

How is this a solar problem? The article clearly states there’s diesel pumps as well that do the same thing.

Technologies have side effects - some good, some bad. This effect of solar i admit i had not thought about.

It's not a direct effect of solar. It's cheaper energy with undisciplined resource abuse.

Re: How a Solar Revolution in Farming Is Depleting Groundwater

#14
post #5

How is this a solar problem? The article clearly states there’s diesel pumps as well that do the same thing.

Diesel has a consumable that must be purchased when the pump is run. With solar, there's presumably less difference between "run the pump 24/7" and "only run the pump when cost efficient." It's essentially the same argument in favor of solar power generation. Fossil fuel generation = plant-capital-cost + fuel-per-generated-unit. Solar generation = plant-capital-cost + negligible-wear-per-generated-unit.

The water being pumped is basically a battery.

So it's much more effective than solar is on the normal grid.

Re: How a Solar Revolution in Farming Is Depleting Groundwater

#15

How is this a solar problem? The article clearly states there’s diesel pumps as well that do the same thing.

It is not a solar problem.

It is a Tragedy Of The Commons problem.

Solar just happens to be an enabling technology. Other technologies that brought cheap power to those areas would have done the same thing, e.g., wind or very cheap diesel (biodiesel?) would have the exact same effect if they happened to arrive first. Putting Solar in the headline and as the culprit is a truly cheap shot.

The real problem is that now that power is cheap, it is to everyone's individual advantage TODAY to pump more, but everyone's disadvantage tomorrow when the groundwater reserves run dry. Classic Commons problem, and it's screaming to the inevitable result. The only solution is some way to monitor and regulate the draw from the groundwater.

Re: How a Solar Revolution in Farming Is Depleting Groundwater

#16
post #5

How is this a solar problem? The article clearly states there’s diesel pumps as well that do the same thing.

Diesel has a consumable that must be purchased when the pump is run. With solar, there's presumably less difference between "run the pump 24/7" and "only run the pump when cost efficient." It's essentially the same argument in favor of solar power generation. Fossil fuel generation = plant-capital-cost + fuel-per-generated-unit. Solar generation = plant-capital-cost + negligible-wear-per-generated-unit.

Even still, solar has just enabled agriculture on places and on margins that it wasn't viable before. Agriculture itself is also an enabler of the problem, but not the actual problem of the moment. The real problem is how do we, on limited resources, feed a global population that is increasing in size and wealth (and attendant waste)?

Re: How a Solar Revolution in Farming Is Depleting Groundwater

#17

I’m very naive in this space. What percent of water extracted makes its way back into the water table and how long does it take? I assume you lose some to the plant that is harvested and some to evaporation. But how much makes it back?

I am too but the answer is zero, and nobody knows but probably a long time. The whole Central Valley is like 30 feet lower now. A bit of rain isn't going to fix that.

Re: How a Solar Revolution in Farming Is Depleting Groundwater

#18

How is this a solar problem? The article clearly states there’s diesel pumps as well that do the same thing.

From the article:

None of this should be seen as a condemnation of solar power, says Balasubramanya. “The fundamental problem is not the solar technology itself.” Whatever the technology, “if the cost of pumping is zero, then people will pump unless some restriction is put on them.”

The article also discusses that the panels are much cheaper to run than diesel and are subsidized by agencies and governments while the diesel pumps are not. So, yes, it’s not specifically about solar but about the economics of solar.

Re: How a Solar Revolution in Farming Is Depleting Groundwater

#19

I’m very naive in this space. What percent of water extracted makes its way back into the water table and how long does it take? I assume you lose some to the plant that is harvested and some to evaporation. But how much makes it back?

Probably just a fraction. A lot probably evaporates and anything that the plant absorbs and incorporates just goes away when crops are harvested and shipped elsewhere.

Re: How a Solar Revolution in Farming Is Depleting Groundwater

#20

I’m very naive in this space. What percent of water extracted makes its way back into the water table and how long does it take? I assume you lose some to the plant that is harvested and some to evaporation. But how much makes it back?

From what I’ve read, it takes a very, very long time to replenish the water table. Eons.
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