Name: The Problem with Solar Energy in Africa
Uploaded: 2021-10-29T06:41:53.000Z
Duration: 18 min 20 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

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 3 times more electricity than the same panel, placed in Germany. [1]

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, 1 square metre in size, would on average generate 5

to 7 kWhs of energy each day. Increase that to 1 square kilometre and we are generating

5 - 7 Gigawatt hours of energy each day. Increase that to 1000 square kilometres and we are

generating 5-7 Terawatt hours of energy each day.

Enough to satisfy nearly 100% of Europe's energy needs. [2] Multiply that by 10, and

we are generating 50-70 Terawatt hours a day. Enough to power the entire world. [3]

This is an impressive and often repeated statistic. [4] Napkin calculations that draw a drastic

new vision of the world. A solar powered Eutopia. 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 a 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

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

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's

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 parsal 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

Desertec is, or perhaps more appropriately was, a German led initiative centred around

a half trillion dollar investment fund [6] 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. [6]

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

If we plot transmission losses per kilometre for AC and DC transmission, it would look

something like this, with DC losing less power per kilometre. [7] 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 kilometre mark. [8].

This is the break even point where DC becomes more cost effective. So, lines connecting

Morocco directly to Spain, which spans only 28 kilometres, don't make sense for high

voltage direct current. While longer lines connecting Tunisia to Italy will likely be

Transmission losses for High Voltage DC is about 3% per 1000 kilometres and Germany's

capital is only 1,800 kilometres from Tunisia. [9] Transmitting power, with this much investment

money, is perfectly feasible. The technologies exist. So let's move into the generation

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 Sahara and Arabian Deserts.

One such facility already exists in Morocco and it's the largest concentrated solar

It is massive, with 3 separate sections, Noor 1, 2 and 3, each using slightly different

variations of concentrated solar power, combining to provide the 510 MegaWatts.

Noor 1 and 2 are both trough based systems that use parabolic mirrors with a 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 308000 square metres. This oil becomes extremely

hot, as high as 400 degrees celsius, which allows it to boil water in a 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 Noor 1 can store enough heat to keep the plant operational for 3 hours while

Noor 2 has enough storage for 7 hours. However this salt solidifies at 110 degrees and if

that happens, the plant won't work in the morning, so Noor 1 and 2 need a fossil fuel

burning system to keep all the working fluids of the system at minimum operating temperatures

over night and to keep the oil system pumping. This fossil fuel burning system can also keep

the plant operation as a reliable baseline energy source. Removing the need for separate

Noor 3 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 Noor 3 to rid itself of

the oil, plumbing and pumps of Noor 1 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 an 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

This allows the tower based system to use more efficient steam turbines and using molten

salt as the working fluid removes the need for a oil to molten salt heat exchanger in

the heat storage system [11] Noor III is the world's only operating tower based concentrated

solar power system with molten salt storage, after 2019's shutdown of Nevada's Crescent

The Crescent Dunes plant ceased operation in 2019, after only 4 years of operation.

[12] NV Energy broke it's purchasing contract with the plant after it failed to meet performance

requirements. Being marred by maintenance issues, including an 8 month shutdown due

to a leak in the molten salt tank. Even when fully operational [13], the plant's electricity