Harvesting the Sun

Energy is life.

Everything is energy, and energy is everything.

With much promise and an incredible beauty that I never tire of gazing upon, the sun rises each day.

Each morning begins the process of bathing the earth in the suns energy at a rate of approximately 1360 W/m2. This is largely consistent and not highly variable. This energy powers the biosphere and is harvested by the world’s plants, algae and cyanobacteria to produce the planet’s magnificent and enchantingly beautiful biomass, of which we are a part. It is of little surprise that so many ancient cultures worshiped the sun in some form.

In this context a successful organism is the one that can exploit the available resources to the produce a calorific surplus, meaning that the energy intake is greater than the energy required to stay alive. Surplus energy is in turn directed towards growth and reproduction.

Growth however is constrained by negative feedback within the system and a particular population will generally expand to the boundary limit of the net energy available. For example, the number of ruminant animals a grazing area can sustain. This is commonly referred to as carrying capacity and could also be described as the equilibrium between positive and negative energy feedback in a biophysical system.

Evolution shows us that biological systems will arrange themself to optimize the energy available in a particular niche through the process of selection driven adaptation. This is known as the maximum power principle and is often referred to as the fourth law of thermodynamics. This principle posits that successful species, that survive in competition, are those that develop more power inflow and use it best to meet the needs of survival.

Energy is indeed life.

Humanity as the superorganism

Humanity collectively as a global species, or superorganism, adheres to the same principles. We optimize for energy and have expanded over time in direct relationship to the energy available.

Our success as a species has been for the most part determined by our ability to harvest the energy of the sun.

In the modern lexicon we think of harvesting the sun as solar panels however this does not capture our ability to harvest historical sun accumulated over time.

• New sun energy = Solar and wind (wind as global thermal convection)

• Old sun energy = Woody biomass.

• Ancient sun = Oil, Gas, Coal.

Ultimately the only energy source not derived from the sun is nuclear, which in terms of biophysical limits, is of major significance to our carrying capacity for reasons that shall be explored later.

Human progress is a history of harvesting the sun.

The history of human civilization is one of becoming more adept at harvesting the suns energy to ever greater per capita calorific surpluses. This process was supercharged when we discovered we could access ancient sun to increase our calorific surplus. The history of energy transitions is one of moving to ever more energy dense forms of energy derived from the sun.

The history of energy transitions - credit Govind Bhatada

Here we see that the primary energy source prior to 1800 was dry wood biomass with an average energy density of around 18MJ/\Kg.

In the early 1800’s coal was discovered as a source of energy with an energy density of 24-35MJ/Kg. Not only was it almost twice as energy dense in some cases (you can get the same amount of energy with half as much by mass) it was also much less disperse. This meant that a single deposit (typically a rocky outcrop on a hill back then) contained the equivalent energy as many hundreds or even sometimes thousands of hectares of forest. It was also much easier to handle as it was far less bulky in terms of energy equivalency and could be left in the rain and then burnt without any problems. The calorific surplus this energy source provided was the dawn of the industrial revolution.

Around 1860 oil is bough to an energy hungry market. Originally in the form of kerosene for lamps, much to the relief of the whales whose blubber had previously been fulling the lamps and lanterns of the world. One does have to wonder what happened to all the lighter oil fractions of a barrel of oil before the kerosene was produced during this period. I grimace at the thought. However, I digress, oil had phenomenal properties that the human superorganism was egar to exploit. It had an energy density of around 42MJ/Kg and was found in vast concentrated quantities. As a liquid it was not particularly volatile, and stable at atmospheric temperature and pressure. It could be transported in pipelines and provided a huge range of products with each fraction that boiled off in the distillation columns of the refineries, that were popping up all over the world. The utility of this product was exceptional from plastics, pharmaceuticals, fertilizers, fuels, to bitumen and everything in between. With the coming of oil civilization expanded at exponential rates the world over.

Natural gas was initially considered an unwanted byproduct of oil extraction and flared at the point of production. The problem was that gas is highly volatile, lighter than air and not as easily handled as oil. It couldn’t be pumped into a simple tank at atmospheric pressure and be transported by a truck or ship. However, it wasn’t long before the value of gas was fully appreciated, and a network of gas pipelines and specialized transport infrastructure emerged. Natural gas had an energy density of around 54MJ/Kg and was great for spinning turbines or firing boilers without the particulate air pollution issues of coal. It was not long before wells were being drilled to exclusively extract natural gas and the human super organism continued to grow.

Enter nuclear. Following the discovery of concept of nuclear fission by Otto Hahn in 1938 the first nuclear power station was bought online in the Soviet Union in 1951. For the first time we were exploiting a non-solar based energy source. The energy density was like nothing seen before, or seen since, at a staggering 710,000MJ/kg for uranium. Today there 412 nuclear power stations in operation around the world. Nuclear however lacks utility when compared to oil and gas. It can only generate steam primarily for electricity generation. Although, several empires have found it quite useful to threaten and subjugate each other. Today there is consideration given to its use in commercial shipping and as a source of process heat for chemical and manufacturing processes. The reality though is that the full utility of nuclear has not been fully explored due to the nightmares of nuclear war and Chernobyl that are etched into large swathes of the human psyche.

Transitioning to renewables, the first transition to lower energy density in human history.

It is not possible to make a comparison between wind turbines and solar panels to other forms of energy in terms of energy density on a mass basis.

Instead, we have to use the somewhat problematic EROI (Energy Return on “energy” Invested) metric. This is problematic for the reason that there is a huge variation in EROI depending on at what point you start the analysis. Is it at the point you start mining the materials or energy used in manufacturing? There is also country to country, well to well, and hundreds of other variations that make this murky. I will do a whole post on EROI at some point, although it is problematic it is interesting, and has a lot of implications.

To give a basic and very crude order of magnitude comparisons that does allow for infrastructure lifecycle:

• Nuclear = 60-70

• NZ Natural Gas = 70-100

• Crude oil = 30

• Wind = 16 unbuffered (not backed up by other generation).

• Wind = 4 buffered (backed up by an alternate source).

• Solar = 6-12 (has to be buffered because the sun doesn’t always shine)

The key take away here is that the renewables we are planning on transitioning to here in New Zealand are ultimately less energy dense, more disperse, and less reliable than anything that came before them. Furthermore, they have limited utility and can only produce electricity.

This is the first time in human we are moving to an energy source that is less dense.

We are also proposing to stop using the other forms of energy that have powered our growth to date, whereas historically these transitions have only added to and not displaced other forms of energy. Except for the whales of course.

This has significant implications.

Boundary limits, maximum power, carrying capacity, and economics.

Humans often struggle to think in ecological terms. I think that in part this is due to urbanization and decoupling from nature. It is also in part due to a belief that a technology will always emerge to save the day ensuring that energy is always abundant and cheap.

Because it has been so cheap and so abundant, we don’t consider that energy is the primary component of anything we purchase, and the price is directly related to the energy required to provide the goods. Money is for the most part simply a claim on energy and debt is a claim on future energy.

We can think of Energy Return on Energy Invested (EROI) in economic terms and this is perhaps a better way to unpack the concept.

Think of an investment that has a moderate upfront cost but is low risk and provides a high rate of return. The initial investment is quickly recovered, and the ongoing return can be reinvested. This is essentially high EROI described in economic terms.

Now think of an investment with a high up-front cost and high risk. It provides an unreliable rate of return and takes a long time to recover the initial investment. The investment lifecycle is short and once the initial investment is recovered the investment does not have a long productive life left. The total returns are insufficient to fully fund the next investment. This is low EROI in economic terms.

Moving to lower EROI or lower energy density sources is akin to eating an ever-increasing amount of your seed corn each year.

Luckily New Zealand is not a closed system in terms of energy flows. We can import the energy required to address a deficit. But at what cost and are we ultimately limiting our ability to grow? What other vulnerabilities emerge as a result of this dependence on imported energy? What form will this energy take? I’m going to suggest it will look a lot like shiny black rocks.

What does a growth constrained or even post growth economy actually look like? Particularly when you consider the debit we have accumulated in the last six years, which requires a claim on future energy to service? I can’t quite decide if it will look more like the Hunger Games or Mad Max.

These are complex questions, but the answer is simple.

We need to transition to a higher energy density to feed the superorganism, and you know what that means…