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Comment by ecpottinger | Hacker News Reader

What I noticed is a lack of mention of installing elevated solar panels so grasses and other plants can grow under the solar panels where the shade reduces the impact of too strong a sunlight exposure.

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Maybe you're thinking of this story?

"Solar panels increase grasses for sheep and cows by 90%" https://pv-magazine-usa.com/2018/11/12/solar-panel-increase-...

"The paper suggests it was mostly due to significantly increased water efficiency – 328%. This efficiency allows semi-arid regions, with a wet winter, to store more water in the ground, allowing for a longer growth during the growing season."

On my own lawn, the shaded areas stay green all summer, the full sun areas turn brown and into dust. I gave up watering the lawn years ago due to endless problems with the sprinklers. (Everything from them simply getting smashed by foot traffic to freeze damage to getting chewed to bits by coyotes.)

The idea of using water via a sprinkler system to keep a lawn green is such an alien concept to most people. Maybe California have a water problem for a reason?

Its pretty common on the east coast too, from my experience.

Maybe the whole country needs a rethink then?

What's the specific importance of a green patch outside your home?

well, there's a lot of value in ground cover. Now, a conversation about moving to native plants instead of grass everywhere would probably be worth having.

I've heard radio announcements asking people to water their lawn to lower fire risk. Ottawa, Canada; no risk of running out of water here.

Yes because of agriculture and because it’s a desert!

I'm curious where you live. Are lawns not common?

Even in Ontario, not particularly hot or dry, people water to prevent their lawns from turning brown in August.

In Wisconsin we rarely need to water a mature lawn. If you're going for close cut and perfectly green you might need to, but on average it's not needed.

UK.

Using water during a water crisis so you can have a green patch next to your driveway is the most excessive American thing I've heard today (a worthy winner in such a competitive field)

There is no water crisis in Canada.

While the concept of using perfectly potable water to water a lawn is a little bass-ackwards, people do do it here. I personally don't, my lawn goes dormant in the heat of summer and that's ok too.

Its eye-opening to see how little understanding of American living conditions are overseas despite the pervasive distribution of American media.

My 'patch' of grass here in Texas is thousands of square feet. The lot my house site on is .33 of an acre, which in metric is 1335 square meters. The house itself is ~3200 sq. feet (306 sq. meters) over 2 stories so the foundation is roughly 1/2 that so you can extrapolate that is a crap-ton of area left for our patch of grass.

This is in no way unusual or extravagant for the suburb I live in and provides lots of enjoyment for our 2 dogs and 6 kids.

Because everyone else has it doesn't stop it from being excessive and wasting water. In California we are seeing more and more people switching to drought tolerant landscaping.

Our part of Texas has overfilling dams and our particular town has enough excess water that neighboring municipalities are buying our unused rights from us.

Our Texas adapted grass goes dormant half of the year as well so the actual consumption is relatively minimal.

Our water use is fractional of a traditional manicured English garden.

Are you sure it's a problem with water?

I've had similar problems with sunny areas and tried watering more. It helped a little. Then one year I tried fertilizing (manure + miracle grow) and my lawn turned completely green, even the full sun areas.

Good. "Kill your lawn", as they say.

I think this is a really interesting point, and am curious about how the shade from the panels will change the ecosystem underneath them. If the natural habitat is mostly low brush having soil that is fully shaded for a large fraction of the day would advantage different types of plants.

There has been some research on this:

https://www.ise.fraunhofer.de/en/press-media/press-releases/...

I hypothesize that the lack of biomass in direct sunlight is mostly because the right seeds aren't yet planted there.

Some cacti or other plants with waxy skin and deep roots would love the extra sunlight.

They’re doing this to avoid irrigation.

I suspect they haven’t thought about what this will do to the topsoil.

Even ignoring the ecological catastrophe of destroying the topsoil, getting the dust it produces off those panels during the summer is going to be expensive.

Planting native pollinator friendly stuff under the solar panels would address my concerns though.

Are you under the impression farmland is not a massive source of dust? It's tilled and aerated soil populated by short-lived crops genetically engineered to spend as much of their energy on the edible part as possible.

If you want a concern to hold, it's that this will probably increase pioneer grass spreading during the rainy season and then then the panels will all get melted in a wildfire. You don't need to plant anything to pollinator-friendly stuff on your land in California. It shows up with a vengeance.

If you don’t water California soil, it cracks and then turns to dust. eg: https://duckduckgo.com/?q=cracked+california+soil&iax=images...

Also, if not controlled, Avena grass (the invasive species that turns the hills yellow during the summer) takes over, killing off anything that would support pollinators during the summer and fall.

The cracked soil is a feature of being a desert, and since the entire point of this is that it's unsustainable to irrigate a desert that far from a major waterway, there isn't much to be done in the long term about what species thrive. That's the wages of climate change.

This area didn’t start out as desert. It is some of the most fertile (remaining) land on earth. (Like the Sahara used to be.)

It also currently, but unsustainably, produces a large fraction of all food on earth.

Here’s an article from 2012 with some anecdotes if numbers aren’t your thing: https://www.nytimes.com/2012/10/14/magazine/californias-cent...

Here is a table of crops: https://republicans-naturalresources.house.gov/newsroom/docu...

(it doesn’t seem to include exports, so the numbers are low-balled)

It is clearly being over-farmed, but the solution to that is crop rotation and letting the fields periodically go fallow.

Blanketing it with solar panels is likely irreversible.

I'm quite aware of how much food California produces. I'm also quite comfortable with California not overfarming and just, you know, letting the rest of the country stop producing subsidized corn.

I can't help but feel like it's a subtle contradiction to propose that without constant watering the soil in California will crack up and vanish and that's not going to happen with crop rotation but will happen with crop rotation (as if many farms in California aren't already forced to do this because of the nature of our groundwater).

Are you also opposed to orchards? They're full of solar panels that make fruit rather than electricity.

An answer, then, is to plant some longer-term grass (or something that can hold the topsoil), and give the panels a short spray of water every morning to remove dust.

Increases efficiency, prevents undesired pollinators taking control of neighboring paddocks, uses an order of magnitude less water than actual crop irrigation.

I'm fairly sure the pollinators are a benefit, even if we're going to have to accept much more aggressive and dangerous varieties populating the state as the average temperature rises and ongoing insect migrations continue.

>getting the dust it produces off those panels during the summer is going to be expensive.

We're talking like a couple minimum wage employees with leaf blowers and ladders. Sure it doesn't cost nothing but in the context of a commercial operation it's not thaaaat expensive.

Vegetation management is an ongoing task for solar farms. Herbicides can be used to keep weeds and vines from growing on the panels, and grasses should be mowed to keep down pollen which dusts the panels and reduces efficiency.

Goats

Remember to toughen up the panels. The goats will find a way to stand on top of them.

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