The Exponential View of Solar Energy
The human brain is terrible at comprehending exponential growth.
Much like the power of compound interest is a magical force for investors, it is also possible for innovations and technological breakthroughs to build off each other in the physical world, creating a similar compounding effect.
In this chart, we look at how solar technology has surpassed all expectations from an economics perspective, including those initially set by the International Energy Agency (IEA). Then later, we’ll also look at a new set of predictions for solar energy economics over the next 30 years.
Solar Energy: The Technological Overachiever
Back in 2010, the cost of utility-scale solar power ranged between $0.25-$0.37 per kWh. This meant it was at least three times as expensive as fossil fuels, and that solar was highly cost-inefficient at the time.
Going forward, most organizations projected a linear path for whittling down the cost of solar.
The IEA, for example, forecast that the global cost of solar would drop to roughly $0.22 per kWh by 2020. In reality, however, the price dropped to about one-fifth of that at $0.04 per kWh.
|Year||Actual (BNEF Global) - $ per kWh||2010 Forecast (IEA) - $ per kWh|
Almost all industry forecasters, including the IEA itself, missed the exponential factors at play.
Ramez Naam, the co-chair for energy and the environment at Singularity University, points out in his blog that the exponential decrease in solar costs stem from Wright’s Law:
For most technologies, every doubling of cumulative scale of production will lead to a fixed percentage decline in cost of the technology.
Professor Naam says this occurs through “learning-by-doing”, and more specifically:
- Innovation that improves the technology itself
- Innovation that reduces the amount of labor, time, energy, and materials needed to produce the tech
Put another way, the more solar panels we make and the more we install—the better we get at the whole process over time. And once we’re making thousands or millions of panels, the costs come down exponentially, much like with lithium-ion batteries.
The Future of Solar Costs
Over the years, Naam has taken his own stab at forecasting the cost of solar energy into the future, leveraging the idea of Wright’s Law.
Here’s what he sees coming, based on using a 30% learning rate* for solar:
*The learning rate is the fixed percentage decline that occurs with every doubling of the scale of production.
Based on these projections, even the costliest of solar installations will be more economical than the cheapest of utility-scale fossil fuel plants. This means solar can basically go anywhere, and make sense from a cost perspective.
Underestimate Solar No More?
For fun, here’s a final look at how IEA projections have constantly underestimated solar installations, which are one of the key factors dictating the “learning rate” under Wright’s Law:
With solar energy costs plummeting to record lows and global installations continuing to ramp, it’s possible that solar forecasters may no longer forget about the exponential nature of solar production.
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EVs vs. Gas Vehicles: What Are Cars Made Out Of?
Electric vehicles can have 6 times more minerals than a combustion vehicle and be on average 340 kg heavier.
EVs vs. Gas Vehicles: What Are Cars Made Out Of?
Electric vehicles (EVs) require a wider range of minerals for their motors and batteries compared to conventional cars.
In fact, an EV can have up to six times more minerals than a combustion vehicle, making them on average 340 kg (750 lbs) heavier.
This infographic, based on data from the International Energy Agency (IEA), compares the minerals used in a typical electric car with a conventional gas car.
Editor’s note: Steel and aluminum are not shown in analysis. Mineral values are for the entire vehicle including batteries and motors.
Batteries Are Heavy
Sales of electric cars are booming and the rising demand for minerals used in EVs is already posing a challenge for the mining industry to keep up. That’s because, unlike gas cars that run on internal combustion engines, EVs rely on huge, mineral-intensive batteries to power the car.
For example, the average 60 kilowatt-hour (kWh) battery pack—the same size that’s used in a Chevy Bolt—alone contains roughly 185 kilograms of minerals, or about 10 times as much as in a typical car battery (18 kg).
Lithium, nickel, cobalt, manganese, and graphite are all crucial to battery performance, longevity, and energy density. Furthermore, EVs can contain more than a mile of copper wiring inside the stator to convert electric energy into mechanical energy.
Out of the eight minerals in our list, five are not used in conventional cars: graphite, nickel, cobalt, lithium, and rare earths.
|Mineral||Content in electric vehicles (kg)||Content in conventional cars (kg)|
|Graphite (natural and synthetic)||66.3||0|
Minerals listed for the electric car are based on the IEA’s analysis using a 75 kWh battery pack with a NMC 622 cathode and graphite-based anode.
Since graphite is the primary anode material for EV batteries, it’s also the largest component by weight. Although materials like nickel, manganese, cobalt, and lithium are smaller components individually, together they make up the cathode, which plays a critical role in determining EV performance.
Although the engine in conventional cars is heavier compared to EVs, it requires fewer minerals. Engine components are usually made up of iron alloys, such as structural steels, stainless steels, iron base sintered metals, as well as cast iron or aluminum alloyed parts.
EV motors, however, often rely on permanent magnets made of rare earths and can contain up to a mile of copper wiring that converts electric energy into mechanical energy.
The EV Impact on Metals Markets
The growth of the EV market is not only beginning to have a noticeable impact on the automobile industry but the metals market as well.
EVs and battery storage have already displaced consumer electronics to become the largest consumer of lithium and are set to take over from the stainless steel industry as the largest end-user of nickel by 2040.
In 2021 H2, 84,600 tonnes of nickel were deployed onto roads globally in the batteries of all newly sold passenger EVs combined, 59% more than in 2020 H2. Moreover, another 107,200 tonnes of lithium carbonate equivalent (LCE) were deployed globally in new EV batteries, an 88% increase year-on-year.
With rising government support and consumers embracing electric vehicles, securing the supply of the materials necessary for the EV revolution will remain a top priority.
The Key Minerals in an EV Battery
Which key minerals power the lithium-ion batteries in electric vehicles?
Breaking Down the Key Minerals in an EV Battery
Inside practically every electric vehicle (EV) is a lithium-ion battery that depends on several key minerals that help power it.
Some minerals make up intricate parts within the cell to ensure the flow of electrical current. Others protect it from accidental damage on the outside.
This infographic uses data from the European Federation for Transport and Environment to break down the key minerals in an EV battery. The mineral content is based on the ‘average 2020 battery’, which refers to the weighted average of battery chemistries on the market in 2020.
The Battery Minerals Mix
The cells in the average battery with a 60 kilowatt-hour (kWh) capacity—the same size that’s used in a Chevy Bolt—contained roughly 185 kilograms of minerals. This figure excludes materials in the electrolyte, binder, separator, and battery pack casing.
|Mineral||Cell Part||Amount Contained in the Avg. 2020 Battery (kg)||% of Total|
|Aluminum||Cathode, Casing, Current collectors||35kg||18.9%|
The cathode contains the widest variety of minerals and is arguably the most important and expensive component of the battery. The composition of the cathode is a major determinant in the performance of the battery, with each mineral offering a unique benefit.
For example, NMC batteries, which accounted for 72% of batteries used in EVs in 2020 (excluding China), have a cathode composed of nickel, manganese, and cobalt along with lithium. The higher nickel content in these batteries tends to increase their energy density or the amount of energy stored per unit of volume, increasing the driving range of the EV. Cobalt and manganese often act as stabilizers in NMC batteries, improving their safety.
Altogether, materials in the cathode account for 31.3% of the mineral weight in the average battery produced in 2020. This figure doesn’t include aluminum, which is used in nickel-cobalt-aluminum (NCA) cathode chemistries, but is also used elsewhere in the battery for casing and current collectors.
Meanwhile, graphite has been the go-to material for anodes due to its relatively low cost, abundance, and long cycle life. Since the entire anode is made up of graphite, it’s the single-largest mineral component of the battery. Other materials include steel in the casing that protects the cell from external damage, along with copper, used as the current collector for the anode.
Minerals Bonded by Chemistry
There are several types of lithium-ion batteries with different compositions of cathode minerals. Their names typically allude to their mineral breakdown.
- NMC811 batteries cathode composition:
- NMC523 batteries cathode composition:
Here’s how the mineral contents differ for various battery chemistries with a 60kWh capacity:
With consumers looking for higher-range EVs that do not need frequent recharging, nickel-rich cathodes have become commonplace. In fact, nickel-based chemistries accounted for 80% of the battery capacity deployed in new plug-in EVs in 2021.
Lithium iron phosphate (LFP) batteries do not use any nickel and typically offer lower energy densities at better value. Unlike nickel-based batteries that use lithium hydroxide compounds in the cathode, LFP batteries use lithium carbonate, which is a cheaper alternative. Tesla recently joined several Chinese automakers in using LFP cathodes for standard-range cars, driving the price of lithium carbonate to record highs.
The EV battery market is still in its early hours, with plenty of growth on the horizon. Battery chemistries are constantly evolving, and as automakers come up with new models with different characteristics, it’ll be interesting to see which new cathodes come around the block.
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