The Problem with Solar Energy in Africa

the saharan desert and north africa at large is one of the world's greatest untapped energy resources the solar energy that strikes the surface of this desert has the potential to power the entire world a single solar panel placed here in algeria is capable of generating three times more electricity than the same panel placed in germany what was once a geographic disadvantage the scorching sun of these desolate lands could now provide an economic boom for these historically impoverished nations a panel in a solar farm located here one square meter in size would on average generate five

to seven kilowatt hours of energy each day increase that to one square kilometer and we are generating five to seven gigawatt hours of energy each day increase that to one thousand square kilometers and we are generating five to seven terawatt hours of energy each day enough to satisfy nearly 100 of europe's energy needs multiply that by 10 and we are generating 50 to 70 terawatt hours a day enough to power the entire world this is an impressive and often repeated statistic napkin calculations that draw a drastic new vision of the world a solar powered utopia

plans have even been drawn up to transform the simple mathematics into a reality but reality has a way of interfering with futuristic pie in the sky calculations like this every plan to turn this dream into reality has failed in this episode we are going to learn why transporting electricity out of these remote regions is the first challenge currently there are only two interconnections connecting north africa to europe both are located between morocco and spain two 700 megawatt interconnections one completed in 1998 and the second completed in 2006 with a third connection expected to be completed

sometime before 2030 for a total of 2100 megawatts if we wanted to transport enough electricity to power europe ignoring transport losses and storage issues we would need 592 to 831 more of these 700 megawatt interconnections these aren't just simple cables that we lay between countries they are incredibly complicated and expensive pieces of infrastructure the third interconnection joining morocco and spain's grids is estimated to cost 150 million dollars an enormous investment that will see both countries footing half the bill 592 more of these connections would cost at an absolute minimum 8.9 billion dollars and that number

was found by simply multiplying 150 million by 592 but these connections are the shortest route to europe from north africa they are going to be the cheapest to build to build a truly interconnected grid we are going to need even longer interconnections connecting tunisia to sicily algeria to sardinia and onwards to northern italy libya to crete and onwards to greece and turkey and to the rest of the middle east network all the while building enough internal interconnections in europe to facilitate the passing of the solar paracel northwards while wind is traded south this plan will

take billions to complete yet even with these issues european leaders have drawn up plans to connect north africa and the middle east to europe they believe the cost can be recovered desertec is or perhaps more appropriately was a german-led initiative centered around a half-trillion dollar investment fund that would invest in generation and transmission infrastructure across north africa and the middle east 55 billion was allocated to increasing transmission capabilities across the mediterranean this investment would go into both high voltage alternating current transmission over shorter gaps like those from morocco to spain and high voltage direct current

over longer distances there is a critical distance where high voltage alternating current transmission does not make sense if we plot transmission losses per kilometer for ac and dc transmission it would look something like this with dc losing less power per kilometer however in order to convert our regional ac grid power to dc for these long distance transmission cables we need expensive transformers and converters if we instead plot cost versus distance counting in this infrastructure it would look something like this and we can see that the dc and ac lines cross each other around the 500

to 800 kilometer mark this is the break-even point where dc becomes more cost effective so lines connecting morocco directly to spain which spans only 28 kilometers don't make sense for high voltage dc while longer lines connecting tunisia to italy will likely be high voltage direct current lights transmission losses for high voltage direct current is about three percent per 1000 kilometers and germany's capital is only 1 800 kilometers from tunisia transmitting power with this much investment money is perfectly feasible the technologies exist so let's move into the generation part of the desertec plan desertec was formulated

with concentrated solar power in mind which works very differently to photovoltaic solar panels concentrated solar power facilities would be spread out along the borders of the saharan and arabian deserts one such facility already exists in morocco and it's the largest concentrated solar power plant in the world it is massive with three separate sections nor one two and three each using slightly different variations of concentrated solar power combining to provide 510 megawatts nor 1 and 2 are both trough-based systems that use parabolic mirrors with the tube located in the mirror's focal point the tube contains a

synthetic oil which collects the heat from the 500 000 parabolic mirrors spread out over 308 000 square meters this oil becomes extremely hot as high as 400 degrees celsius which allows it to boil water and heat exchanger to drive a steam turbine which provides electricity for the grid the 400 degree oil is also hot enough to melt salt in a molten salt heat storage system the molten salt heat storage system of nor1 can store enough heat to keep the plant operational for three hours while nor2 has enough energy for seven hours however this salt solidifies

at 110 degrees and if that happens the plant won't work in the morning so nor 1 and 2 need a fossil fuel burning system to keep all the working fluids of the system at minimum operating temperatures overnight and to keep the oil system pumping this fossil fuel burning system can also keep the plant operational as a reliable baseline energy source removing the need for separate natural gas peaker plants nor3 does not use these parabolic mirrors and instead uses a tower system it's this striking circular facility to the north it looks less like an industrial facility

and more like a new age burning man art installation this design allows north 3 to rid itself of the oil plumbing and pumps of nor1 and 2 and instead it uses mirrors arranged in concentric circles around a central tower the mirrors are then controlled to focus light on a single point on the tower which directly heats the molten salt which is the working fluid instead of the oil based system the solar concentration here is much higher and in turn the temperatures attained are much higher with the water being heated to 550 degrees this allows the

tower-based system to use more efficient steam turbines and using molten salt as the working fluid removes the need for an oil to molten salt heat exchanger in the heat storage system north 3 is the world's only operating tower based concentrated solar power system with molten salt storage after 2019's shutdown of nevada's crescent dunes plant the crescent dunes plant ceased operation in 2019 after only four years of operation nv energy broke its purchasing contract with the plant after it failed to meet performance requirements being marred by maintenance issues including an eight-month shutdown due to a leak

in the molten salt tank even when fully operational the plant's electricity cost 135 dollars per megawatt hour while a nearby photovoltaic plant was managing 30 dollars per megawatt hour and here lies the crux of the issue concentrated solar power costs per megawatt was extremely competitive with photovoltaics in 2009 but in the last decade photovoltaics have become obscenely cheap concentrated solar power simply cannot compete in a market like this and the same can be seen for nor one two and three however they are currently being measured on a metric called levelized cost of electricity which is

an average of the cost to generate electricity over the entire life of the plant but this does not factor in the cost of storage for photovoltaics which is often just an inherent benefit of concentrated solar thermal power so going forward the industry should be using a combined cost of storage and cost of electricity metric yet the most recent addition to this solar farm is nor4 a solar panel farm contributing 73 megawatts with the rise of cheap solar panels desertec contrary to what you might expect was doomed for failure concentrated solar thermal power by nature needs

a lot of land the plant has a minimum viable operating temperature and to achieve that we need enough mirrors to reflect that light solar panels do not have this problem solar panels can be fitted on top of homes over car parks or even in farmers fields to help shade plants that need shade we don't need massive plots of land to make them work and because they are so cheap it's perfectly feasible to build smaller solar farms in germany and avoid those transmission losses and not incur the massive financial risk of investing billions into a country

that is not your own that's particularly important because a lot of investors are very hesitant to put money into these often volatile countries we need to look no further than the 2013 attack on a bp natural gas plant in algeria to see why this would be considered a risky investment in many parts of north africa it's a vital economic resource for algeria yet it sits isolated in the midst of a vast desert that's a transit route for al qaeda in north africa no wonder it was so difficult to defend and such a tempting target for

the militants this is all exactly why germany is instead investing in its own domestic photovoltaic generation and in 2020 solar power accounted for 10 of germany's power generation this idea of european countries drawing natural resources from africa to benefit their own economy has some undeniable problematic historic parallels any foreign investment like this is going to come with some guarantees of supply for europe beyond the difficulties of organizing cross-border cooperation like this that's not going to go down well when the country hosting these plants needs the power for their own grid to power their economy or

simply stabilize their own grid for current needs it becomes even more problematic when you consider the amount of water these facilities need for cooling for the steam turbine and to keep the mirrors clean this facility in morocco uses 2.5 to 3 billion liters of water every year taking water from a dam 12 kilometers away morocco is already susceptible to droughts so scaling these water demands up just to feed europe's power needs while taking water away from the farms that feed moroccan citizens is even more problematic to truly scale this power generation some technological improvement that

reduces the consumption of water would be needed or just paired the facilities with desalination plants and use the extra water if any to irrigate local farms to boost local economies even more for this dream of turning the earth's barren deserts into energy generation centers to come true it has to be a grassroots movement not some new age imperialism mega project that comes with a whole host of guarantees in exchange for the nearly half trillion dollar investment north africa is one of the hardest hit regions in the world by climate change with desertification and water scarcity

becoming a serious issue this plan despite its surface level good intentions sought to exploit these countries that have suffered most as a result of western industrialization we don't need to look for proof that this was their intention the moment the technology developed to allow european countries to provide their renewable power needs within their own borders the plan disintegrated the plan was never about helping african nations but the idea isn't dead in the water these countries do have the natural resources to benefit from solar energy morocco is in the best position to lead by example its

proximity to spain allows relatively short interconnections to the european grid its government is relatively stable compared to its north african neighbours with a political stability index of minus 0.33 algeria tunisia libya and egypt are all much lower and while morocco has abundant solar resources it also benefits from consistent desert winds along its coast morocco has the potential to invest in its own energy needs while exporting access to europe leading by example slowly shifting away from being a net energy importer of fossil fuels and becoming an energy exporter local infrastructure to benefit local people first an

african nation using its resources to benefit itself first and foremost the potential for africa's solar energy future is undeniable the technologies to facilitate cross-border energy trading exist and investments are happening to increase capacity for trade with this third interconnector between morocco and spain funded equally by both sides ensuring a level playing field figuring out the best practice for growing and improving our electric grids is incredibly complicated electricity grids are effectively the largest machines on the planet hundreds of generators scattered across countries connected together by wires relays and switches the task of managing that by hand

and making sensible decisions for a single human is impossible and more and more of the grid infrastructure is turning towards a smart grid controlled by algorithms battery firms employ coding and math experts to develop algorithms to allow them to buy and sell the electricity they store to maximize profit and coding jobs like that are some of the best pain and highest demand in the world today learning about algorithms and coding like this is an invaluable skill and whether you are a high school student or experienced engineer brilliant is a great place to start learning and

brushing up on your skills i recently started the interactive course algorithm fundamentals and learned a ton of useful and insightful information this is just one of many computer science courses on brilliant that will help you not only understand but enjoy the information you are learning with continual assessment to test your knowledge but critically it doesn't impede your progress when you get something wrong instead each question comes with a detailed explanation of the solution because the best way to learn is to try and sometimes learn through failure if learning a valuable skill sounds like something you

want to do go to brilliant.org forward slash real engineering and finish your day a little smarter and the first 500 of you to do so will get 20 off the annual subscription to view all problems in the archives if you are looking for something else to watch right now we have a two-part hour-long series about my favorite airliner the 787 or you could watch real science's latest video about the insane biology of the axolotl you