Solar Panels Plus Farming? Agrivoltaics Explained

This video is brought to you by all my 
great Patrons at Patreon.com/mattferrell  We have a world population expected to 
grow by 1.2 billion people within 15 years,   coupled with a growing demand for meat, eggs and 
dairy, which soak up over 70% of fresh water for   crops, plus electricity demand that’s growing 
even faster than population growth … what are   we supposed to do about all of that? Well, we can 
combine two of my favorite things: technology and   food.

Both of which I’ve been accused of having 
too much of. But, could combining solar panels   plus farming be a viable solution to all of those 
problems? Let’s take a closer look at electrifying   our crops … not literally electrifying crops … 
never mind … let’s take a closer look at adding   solar to our farm land as well as some of the 
side benefits … and challenges … it creates. I’m Matt Ferrell … welcome to Undecided. The problem with solar panels is that they need 
a lot of space to generate serious amounts of   electricity.

Agrivoltaics or APV for short, 
combines agriculture with electricity generation   by farming under a canopy of solar panels … and 
there’s some really interesting recent examples   that make a compelling case for it, but before 
getting into that it’s a good idea to understand   the challenges around solar parks in general and 
some of the solutions that have been developed. Solar parks in rural areas have been around 
for almost two decades. The major problem   with this type of solar installation is that 
the ground beneath the panels can’t be used,   mainly due to the small spaces between 
the rows of panels which aren’t large   enough for modern farming 
equipment to pass through. It is possible to convert a typical 
solar park into dual land use when   it’s designated as a living area for 
grazing by small livestock like chicken,   geese, and sheep, as well as for beekeeping. These animals are beneficial to solar 
farms because they reduce the cost of   maintaining vegetation growth and 
don’t introduce any risk to the   panels themselves. The same can’t be said 
of something a bit larger like pigs, goats,   horses, or cattle … it’s a known 
fact that cattle hate solar panels.

When more space is allowed in between the 
solar panel rows, crops can be grown there.   However, the space beneath the panels still 
isn’t usable and needs to be maintained.   This is considered alternating land use 
instead of dual land use because there   are areas of the land that are one or the 
other … not both solar and crops at the   same time. The land between the rows will 
be shaded during some hours of the day,   meaning you’re altering the characteristics of 
the land and the types of crops that can be grown. So what if we started to go vertical with 
our solar panels? That’s where we start to   get some interesting alternatives to standard 
ground mounted solar park style installations. Using vertically mounted bifacial modules allows 
for more arable land. And if you don’t know what   bifacial solar panels are, they can collect 
solar energy from both sides of the panel.   This type of installation would work particularly 
well in areas that suffer from wind erosion,   since the structures reduce wind speeds which 
can help protect the land and crops grown there.   The bifacial panels also can generate more 
power per square meter than traditional   single faced panels and don’t 
require any moving parts.

Then there’s also the option 
of mounting panels on stilts,   which allows farming machinery to pass underneath. In this design you have to maintain a certain 
clearance between rows to protect the stilts   from the machinery, so there is a modest 
arable land surface loss … usually 3-10%.   Many variations on this theme are currently under 
active research. Instead of fixed panel mounting,   panels can be mounted with actuators, allowing 
the panels to tilt in one or two directions,   which allows for both solar energy 
and plant growth optimization.   This can be particularly important during 
the initial stages of growth for some crops. But what about growing crops 
… UNDER … the elevated panels? You’d think that solar panels casting shade 
on plants would be a bad thing, but the way   photosynthesis works makes things interesting. 
Plants grow their mass out of CO2 with the help   of sunlight.

They literally are growing from the 
air … BUT … not all available sunlight can be   converted into biomass. After a certain threshold, 
which is called the light saturation point, plants   can’t absorb any more energy, so they need to get 
rid of that excess energy by evaporating water. If we oversimplify this, we can divide 
the plants into two groups: “I’ll have my   light supersized” plants and “can I order my 
light off the kids menu” plants. That group,   the so-called shade plants, are particularly 
useful in combination with solar panels,   since the panels obviously block 
some of the available sunlight. Now sun plants are sometimes referred 
to as shade-intolerant plants,   which makes them sound like jerks. This 
is a slight misnomer, since these plants   just require more sunlight than shade plants 
but can also suffer from too much sunlight.   When any plant reaches their threshold, they 
can suffer from ‘sunburn’ and heat stress,   just like me, causing increased amounts 
of water evaporation … just like me.

According to a report from the German Fraunhofer 
Institute for Solar Energy, nearly all crops can   be cultivated under solar panels, but there may be 
some yield loss during the less sunny seasons for   sun hungry plants. In the RESOLA project conducted 
between 2016 and 2018 in the German area of Lake   Constance or the Bodensee as the Germans call it, 
they demonstrated that during a relatively ‘wet   and cold’ year in 2016 APV-crop yields were 
25% less than the non-solar reference field,   but in the ‘dry and hot’ years of 2017 and 2018 
the APV-crops yields exceeded the reference field.   That’s a sign that APV could be a 
game changer in hot and arid regions. The amount of experience with agrivoltaics is 
still fairly limited and the big successes have   been mainly with shade tolerant crops like 
lettuce, spinach, potatoes, and tomatoes. Which leads us to some of the 
super promising examples that   make a compelling case for agrivoltaics. But before I get to that, I want to give a 
quick shout out to today's sponsor … me!   Seriously though, be sure to check out my follow 
up podcast based on your feedback and comments   on these videos, Still To Be Determined, which 
you can find on all the major podcast services   out there or at stilltbd.fm, as well as a video 
version here on YouTube.

I'll put all the links   in the description. It's a fun way to 
continue the discussion on these topics. Let’s switch over to The 
Netherlands. Tiny as it is,   it is the second largest 
exporter of food in the world! The company “GroenLeven”, a subsidiary of the 
BayWa group, which is headquartered in Munich   Germany, has started several pilot projects 
with local fruit farmers. Their largest site   is in the village of Babberich in the east of 
the Netherlands, close to the German border,   at a large 4 hectare raspberry farm, which is 
about 10 acres for those of us not on metric.   They’ve converted 3 hectares into a 2 MW 
agrivoltaics farm.

The remaining part was left   in a traditional farming setup. Raspberries are 
a fragile, shade tolerant fruit that’s typically   grown in rows covered with plastic to help protect 
them from the elements and ensure high yields. In this project the raspberry plants are grown 
directly under the solar panels, which have been   placed in alternating rows facing east and west. 
This maximizes solar yield, but also protects the   plants from the prevailing winds. They did test 
traditional solar panels in this project, but   they took away too much of the available sunlight, 
so they switched to panels with a larger spacing   between the solar cells to let more light through. 
The amount and quality of the fruit produced under   the panels was the same or better as the fruit 
produced under the traditional plastic tunnels. One big benefit for the farmer was the amount 
of work saved from managing the plastic tunnels,   which are easily damaged 
by hail and summer storms.   In those cases fruits may become 
unsellable from the damage,   but they still have to be harvested anyway. 
During the last summer storms, the fruits under   the panels didn’t sustain any damage, while the 
harvest from the reference field was destroyed.

Another major difference between the argrivolatic 
test field and reference field: the temperature   was several degrees cooler under the solar panels. 
Not only is it more pleasant for the farm workers,   but it also reduced the amount of irrigation 
water by 50% compared to the reference field.   Even cooler is how the crops affect the solar 
panels. The crops and their limited water   evaporation actually keep the panels cool. Solar 
panels actually don’t like to be hot, since it   reduces their energy efficiency; the cooler a 
panel can be, the more energy it will provide. So just based on that, agrivoltaics appears 
to be a winning strategy. If we were to   convert even a fraction of our current 
agricultural land use into agrivoltaics,   a large portion of our energy needs can be met 
… easily.

And with the added benefits in reduced   water consumption, agrivoltaics can also be a 
game changer in hot and arid regions of the world. So what’s keeping us from rolling out this 
dual-purpose, game-changing system at a massive   scale? What’s the catch? Energy production 
is a different ball game from agriculture,   which can slow down farmers 
from embracing the technology.   But the actual obstacles are sadly 
… mundane … and some frustrating. It boils down to the the not-in-my-backyard 
effect (NIMBY), bureaucracy, and the free market. So let’s start with the NIMBY crowd. Not all 
renewable energy solutions are receiving a   warm reception. Prime example is obviously the 
sight and sounds of a giant wind turbine in the   vicinity of your home. Community pushback 
from the residents of Reno County in Kansas   killed a proposed NextEra Energy 
Inc. wind farm. Also in agriculture,   there are examples where current laws enabled 
building giant biogas plants that weren’t always   welcomed by the local communities. No matter the 
reason behind the community outrage and pushback,   it's this type of reaction that has 
killed or delayed many projects,   as well as made many local governments 
gun-shy on pushing them forward.

So in order to prevent communities turning against 
agrivoltaics it's important to control its spread,   especially pseudo-agrivoltaics (a 
practice to build large solar farms   under the guise of agriculture). In protecting   the people’s interest it helps to build 
community support, which is essential. The Fraunhofer institute recommends that 1. Agrivoltaics should be deployed mainly 
where synergistic effects can be achieved,   for instance by reducing the 
water demand for crop production. And… 2. To maintain proper local 
support, agrivoltaic systems   should preferably be operated by local farms, 
energy cooperatives or regional investors. With these guidelines in 
mind, community resistance   against agrivoltaics can be kept to a minimum. Next, rules, regulations, 
and bureaucracy can also hold   it back, which varies from country 
to country or even from city to city. “As part of its agricultural policy, the EU 
grants direct payments for land used primarily   for agriculture. So, an important question 
is whether farmland loses its eligibility   for financial support due to the use of 
agrivoltaics [….] … Whether the land is   mostly used for agricultural 
purposes is decisive here”.

In the EU, agrivoltaic systems are usually 
considered to be physical structures in terms   of the building regulation laws, so they need 
a building permit. In Germany for instance,   it’s usually prohibited in rural areas unless it 
doesn’t conflict with a list of public interests.   Agrivoltaics, however, isn’t on 
the list of public interests yet. Lastly and maybe most important is the free 
market, which is pretty easy to wrap your   head around because it all comes down to costs and 
investment.

Just like putting solar on your home,   the big number to look at is cost per 
kWh. Because agrivoltaic solar doesn’t   yield as much energy per square meter 
compared to a traditional solar park,   on top of the construction costs, the 
cost per kWh can be 10-20% higher. And there’s the big question of who owns the 
solar panels. In the Dutch example, the farmer   wasn’t the investor or owner of the installation. 
A farmer’s willingness to participate all comes   down to avoiding negative impacts to the crop 
yield and having lower operational costs from   the solar panels. In this case the solar array 
owner was able to demonstrate those benefits. The Fraunhofer institute found that farmers 
are only willing to engage in a project if the   crop yield never falls below 80% of the reference 
field, but … that’s only if the farmer owns the   solar array. That's because the farmer can make 
up the crop shortfall from the energy produced.   But that also raises the question, if they own 
the array, how are they going to optimize the   solar panels … for solar energy production or for 
crop yield? For the highest energy production per   square meter, solar parks win out.

For the highest 
guaranteed crop production, dedicated farming wins   out. It all comes down to costs and investments. 
Without government intervention through subsidies   or price guarantees, agrivoltaics may not 
stand a chance against other solar initiatives. Agrivoltaics is a very promising concept that has 
the potential to kill two birds with one stone:   helping our food supply and transitioning 
us to a cleaner energy source.   The main benefit comes from the fact that solar 
panels are great at reducing GHG emissions,   without sacrificing arable land. Especially 
if we can convert land that’s currently being   used to grow biofuel crops, like palm oil and corn 
farms, into land for actual human food production   and consumption … or even reforestation, that 
would be a huge win! Looking at the big picture   and deciding where we want to go can help us find 
ways to overcome the difficulties along the way.

Dave Borlace over at the ‘Just Have A Think’ 
YouTube channel created an incredible introductory   video on the agrivoltaics concept as well, so 
be sure to check out that video too. But what do   you think? Should we be trying to use agrivoltaics 
everywhere? Are there any other dual use renewable   energy examples that you know about? Jump into 
the comments and let me know. And a special   thank you to Patreon producer Rob van der Wouw 
for all his help on pulling this script together.   Thank you, Rob. And thanks to all of my patrons 
for helping to make these videos possible.   If you liked this video be sure to check out 
one of the ones I have linked right here.   Be sure to subscribe and hit the notification 
bell if you think I’ve earned it.   Thanks so much for watching and 
I’ll see you in the next one.

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