As you know by now, I often try to kick off these little weekly musings with a bit of
light-hearted repartee just to get you good folks in the mood for the brain bending technological
information download that usually follows. But this week's program has to do with agriculture,
and with the possible exception of some entertaining images of fruit and vegetables
that are hilariously taking on the form of male genitalia, I couldn't really find anything
terribly amusing in the data that I was analyzing. So I've decided to just give it to you straight...
unlike that carrot... oh come on!
Hello and welcome to Just Have a Think. Our global agricultural systems account for more than a third
of all human-induced greenhouse gas emissions. They also use a huge amount of water. According
to the World Bank, agriculture consumes about 70 percent of all fresh water withdrawals,
and an even higher share of what's known as consumptive water use,
as a result of evapotranspiration of crops. Rapid changes in the global climate mean that
if we carry on with our current agricultural methods there's no way there'll be enough
water even to grow the current level of food production, let alone what we'll need by 2050.
Right now that system is struggling to feed more than 7.8 billion people. In 30 years time that
number would be more like 9.8 billion. And as more and more of those people are lifted out of poverty
and begin to adopt a heavier, more varied diet, food production will somehow need to
double over the next three decades at a time when the rapidly increasing impacts of climate change
are making current farming practices look less and less sustainable as every year goes by. Access to
food will need to be drastically improved so that some of the gross inequities in the world
are addressed. And food waste will need to be dramatically reduced too. Right now we throw away
more than 30 percent of everything we produce. If nothing changes at all then we will quite likely
be looking at food shortages, water scarcity, regional conflicts and economic destabilization.
We could just all stop eating meat and switch to plant-based diets of course.
That would immediately and sustainably fix the entire problem,
and provide every human on the planet with all the calories and nutrients they need.
I've done it, and I love it. And so have hundreds of thousands of other people around the world.
But let's be honest here - it's unlikely that billions of people, especially in the richer
industrialized nations, are going to voluntarily give up the practice of eating dead animals.
So all sorts of agricultural systems are now being developed and promoted all over the world to try
and make the whole thing more sustainable. And one of the ideas gaining a lot of interest right now
is to combine food production with energy production in a concept known
as agrophotovoltaics, or agri-voltaics or just APV for short. There's a strong clue in the name
of course, and sure enough in very basic terms it means putting solar panels in a field where crops
are also grown. So how does it work in practice and what do we gain from doing it? Well, it turns
out there's a limit to how much sun any individual plant can actually use. It's something known
as the light saturation point. Any extra light received beyond that point makes no difference at
all to the plant's photosynthesis. All it does is make the plant sweat, which makes it more thirsty.
So by strategically placing solar panels directly above a crop growing area it's theoretically
possible to precisely regulate how much sunlight reaches each plant so that they've got the optimum
level for maximum growth with minimum water loss. All the excess sunlight that would otherwise be
wasted on the plants would then be captured on the upper side of the solar panels to generate energy.
And if the panels are raised up high enough above the ground then livestock, farm workers,
and even agricultural machinery can all operate very happily in the cool shade beneath the canopy.
And it's not a one-way street either. It's a mutually beneficial symbiotic relationship. As
the plants grow beneath the panels they help to keep the panels cool. Ironically solar
panels don't actually like getting hot. It reduces their operating efficiency. So anything that can
draw heat off them will help to make the panels more productive. According to a study by Oregon
State University, panels positioned correctly above plants can produce as much as 10 percent
more electricity. That electrical energy can be used to run the farm
with electric tractors and equipment, and to power precision agricultural technology
that helps further reduce water usage. All of that obviously reduces the running costs for the farm.
And any surplus energy can be stored in battery banks or sent to the grid for consumer use. So
you're effectively using the sunlight twice - to grow cash crops, and to generate a second income
stream from the solar power generation. Farmers all over the world are finding it increasingly
difficult to make ends meet without huge government subsidies. In the USA that
struggle is starting to nudge towards something more like an existential crisis, as trade wars,
commodity prices and climate change all combine into a perfect storm of economic disaster.
Between 2011 and 2018 more than a hundred thousand farms were shut down across America,
so the ability to use the land more profitably while still providing crops for the nation
is a potential lifeline that could keep many farmers from going bankrupt.
And the OSU study also calculated that converting just one percent of American
farmland to agri-voltaics could meet the entire US national renewable energy target, not to mention
saving a significant amount of water and creating sustainable long-term food production systems.
But it's not just happening in America. APV technology is being quite enthusiastically
embraced all over the world. Japan implemented 654 projects between 2013 and 2018 with a peak
generating capacity of about 150 megawatts. South Korea currently have about two megawatts worth,
and of course the mighty China, who as we've learned on so many occasions on
this channel never ever do anything on a small scale, installed an estimated
four gigawatts of agricultural PV capacity just in the three years between 2015 and 2018.
It's a system that's yet to gain significant momentum down in Australia though,
despite the huge potential benefits that could be reaped in that country. Competition for land in
Oz is pretty fierce. It's a vast landmass, more or less the same size as the 48 contiguous states of
America, but food production is only possible in fairly restricted areas that have enough rainfall,
agricultural value, and existing infrastructure - especially easy connections to the electricity
grid - to make any operation economically viable. And that proximity to the grid
draws solar PV developers to exactly the same geographical locations. And in many cases that's
actually caused a conflict between developers and farmers in those areas. So agri-voltaics
would seem like a bit of a blindingly obvious solution! There are no legislative barriers to
APV in Australia today. The only obstacles, to be honest, are wilful ignorance, and an unwillingness
on the part of farmers and solar developers to cooperate for everyone's mutual benefit.
There is a growing media exposure to the idea though, like this superb report by Remy Rauline
for the Renew website. And I'll leave a link to that article in the description section
below here. Over here in Europe, according to this report by Agora Energiewende and the British think
tank Ember, 2020 marked the first time that the EU generated more power from renewable sources than
from fossil fuels. Renewable energies made up 38% of the European energy mix in 2020, compared with
37 percent from oil gas and coal. So the potential for agri-voltaics here is huge. France is already
getting involved, led by the wine making industry. Sun 'Agri - a subsidiary of French solar developer
SunR - has installed a viticulture agri-voltaic system in the wine growing area of Piolenc in
Herault in South Eastern France as part of a programme to test how agrivoltaics perform in
specific crop cultures. The project is running in partnership with the local chamber of agriculture
as part of a program supported by the French Environment and Energy Management Agency.
In a recent interview with PV magazine a Sun'Agri spokesperson
said "Vines are among the crops most affected by the effects of climate change, so it's essential
that they be at the heart of our experiments". A thousand square meters of vines in the test area
were planted with the black Grenache red wine grape.
600 square meters were covered by a system of 280 panels with a generation capacity of 84 kilowatts.
The panels were mounted 4.2 meters or about 14 feet above ground and are remotely controlled by
an artificial intelligence algorithm that Sun'Agri have been developing for more than a decade.
The algorithm determines the ideal tilt of the panels based on available sunshine, the water
requirements of viticulture, the growth model of the crop, as well as soil quality and weather
conditions. And in the event of extreme climatic hazards like drought, heatwave, hail, frost or
heavy rain, the system positions the panels to protect the crops. Water demand was reduced by
as much as 34 percent in the PV sheltered vines, thanks to that reduction in evapotranspiration
that we looked at earlier. There are some challenges that could stand in the way of
widespread use of agri-voltaics though, as this recent research paper by the German Fraunhofer
Institute points out, not least of which is the higher initial capital costs compared to
conventional ground-mounted PV installations. those costs are mainly due to the much taller
support systems used for the modules, as well as the need for site-specific
system design. But the report also found that compared to other renewable energy sources today,
APV overall looks quite competitive. The industry comparison standard known as levelized cost of
electricity, or LCOE, comes out at 7 to 12 euro cents per kilowatt hour for agri-voltaics. That
is higher than the ground mounted systems but it's already comparable with small rooftop PV systems.
And as a bit of a bonus, freestanding APV installations also provide a valuable habitat for
other plants and wildlife. With careful management the extra protection from excess harmful sunlight
improves the health of the soil and increases the level of nutrients creating important ecosystems
for plants and insects, which in turn increases the availability of food for field animals
as well as birds and bats. Agri-voltaic technology itself is improving all the time. Panels can now
be made translucent to allow finer control of the amounts and specific wavelengths of light
that are either absorbed by the panel or allowed through to reach the crops. And there are even
completely mobile PV systems like this one from US company Tracker Sled, providing plug-and-play
style modularity and mobility regardless of what type of terrain or topography it's deployed on.
Despite the fact that the basic principles of APV have been known for about four decades now, the
industry is still young, and it's only recently started to evolve. Research is ongoing to find
the best ways to adapt the system for producing as many types of fruit and vegetables as possible,
and clearly more work needs to be done to ensure it's economically viable on a global scale,
but agrivoltaics do look very promising and the technology could play a major role in diffusing
the current conflict between agricultural land owners and solar developers especially
in higher populated countries where space is at a premium. Now I'm hoping there may be some
folks watching this who have direct experience of working with one of these systems. If you do,
or if you have other comments and observations that you think would be constructive and helpful,
then dive down to the comments section below and leave your thoughts there.
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