planet finite diameter

Non infinite planet

Enough with reminiscing for now, lets look instead at the present and the future. This post is not one I have been looking forward to since the topic invariably raises peoples intellectual defense mechanisms, so I’ll try to keep it short and straight to the point. Besides, there is an enormous amount of information on the subject of oil, energy and modern civilzation on the net already. The point of the post is more of a summary of the situation and its intersection with boats.

It’s no secret that modern civilization relies on petroleum, but it’s easy through habituation to forget at what point.

For instance; there’s a high chance that the clothes you’re wearing are at least partially made from synthetic fibres, made from petroleum. Even if you’re wearing all cotton or linen clothes, those crops were undoubtedly nourished with synthetically made nitrogen, sprayed with pesticides made from petroleum, the fields mechanically tilled by machinery that runs on petroleum. Then the fibres are irrigated, harvested, processed, transported, woven and sewn with yet more machinery all ultimately running on fossil fuel energy.

The computer you’re reading this on is made from metals mined with machinery running on petroleum and plastics made from petroleum. A comparable amount of energy goes into building the computer as it will use during its lifetime.

Cars are much the same except worse.

Of greatest concern of all, food has become extremely reliant on petroleum. Depending on which study you read, between 10 and 14 calories of fossil fuel energy goes into producing one calorie of food. This is a less than parity EroEI (energy returned on energy invested) which is clearly untenable, but which has permitted, temporarily, for us to vastly exceed the earth’s normal carrying capacity.

Indeed, there are very few things left in modern society that does not depend in some way on fossil fuels.

rate pop growth vs per capita oil

Rate of world population growth
upper graph aligned with
per capita world oil extraction rates
lower graph

A useful mental exercise is visualizing how far your car can go with just one litre of fuel. Then imagine you have to push the same car that same distance, up and downhill. There is a lot of energy in that litre of fuel!

Then think that we burn more than 70 million barrels every day to power our industrial society… This is a staggering amount of added energy. It is only because of this that we have an industrial society at all.

There is a tremendous amount of unrealistic wishful thinking that goes on in the attempt to believe otherwise; that we will be able to transition to alternative energy sources and carry on with all the energy hungry modern technological marvels, but this does not stand up to closer analysis. A typical reaction is “I’m sure they’ll think of something” which is about the least useful response possible. This not only downplays the gravity of the situation but also reveals humanity’s hubris and arrogance.

The main issue is that of exergy. Fossil fuels have remarkably high levels of exergy, as the mental exercise of pushing the car illustrates. There is ample total energy in renewable, but the exergy is nowhere near high enough to be a reasonable replacement for fossil fuels.

Simply put, the only energy that we can use sustainably in the long term, is a small fraction of the total solar energy throughput that falls on our orb. And fossil fuels are nothing other that stored solar energy accumulated through millions of years of minutely imbalanced biological energy flows. Energy that we are using in a blink of an eye compared to the time it took to accumulate. There we come to the crux of the matter; we have become accustomed to a situation which is by definition unsustainable, and no amount of denial will make that fact go away.

Energy can neither be created or destroyed, only transformed from one form to another form and this is crucial to understand. What happens instead is that as any process is performed by high exergy energy the energy gets transformed into different forms always of lower exergy. This is the conclusion of the second law of thermodynamics. In other words, the same amount (almost exactly) of energy shines onto the daylight side of the planet from Sol as our planet radiates away on the night side. The big difference though, is that the exergy of the outflowing energy is always lower than that of the inflowing energy.

Our planet is finite and thus contains finite amounts of every resource. The rate of usage of every non renewable resource (and even renewable resources whenever the rate of consumption is sufficiently greater than the rate of renewal) tends to follow a roughly bell shaped curve. Over half of the world’s oil producing countries have already peaked and have declining production rates. Conventional global crude peaked around 2005 which caused a persistent increase in the price of crude, allowing previously economically non-viable fields to be exploited. This then has created a certain plateau to world oil production, at the expense of future decline rates. Cantarell oil fields in Mexico is a good example of this process at work at smaller scale. They were able to extend the peak using unconventional means, but when the decline finally came it was precipitous.

The EIA and IEA Have been quietly revising their projected date of expected world peak oil for the last few years, reflecting the dawning realization that the day has come and it is us, rather than the not yet born that will have to deal with this.

Oil production vs price

Oil production vs price

The above plot should be reminder enough that economics is a subset of environment, not the other way around… No matter how high the price goes, physical laws refuse to concede to economic fanatsies.

When the predominant form of energy peaks it tends to put pressure on other sources of non renewables making them peak sooner in turn.

Nuclear power needs uranium or other unstable elements which itself will peak soon (uranium ores are already becoming very poor) and mining uranium itself requires petroleum. Additionally, nuclear power plants take over a decade to bring online and at enormous monetary and energy cost. In fact, the only way nuclear power is economically feasible is through government subsidies and by working symbiotically with the nuclear arms industry.

Besides, de we really want the next ~100 000 generations curse us for leaving behind impossible to dispose of toxic waste just for the sake of running AC units etc for ours and maybe one more generation?

Nuclear fusion I think can be safely relegated to the aptly named “vaporware” closet, after the better part of a century spent investing enormous resources into researching nuclear fusion, the solving of the immense technical difficulties remain perpetually over the horizon..

Coal will peak too in the not too distant future, and dirtily.

Gas the same but cleaner.

Tidal energy is interesting, although it also requires a large energy investment, and may well prove to be a false avenue once fossil energy subsides are no longer available or are being used on other more urgent applications.

Geothermal can also be useful, but only in places where the subsurface temperature gradient is steep enough for the energy investedto be a sufficiently small fraction of the energy payback over the lifetime of the heat well.

Biomass, wind energy, solar power, hydro and wave energy are all ultimately derived from the energy of the sun. As such, there are very definite limits to how much can be extracted, nevertheless, this is about our only viable long term strategy. Remember that biomass means without any fossil fuel inputs, otherwise it is just fossil energy transformed, and that usually at a loss! In practice, and for most applications, the most efficient use of cropland is to fuel humans with food. Solar panels are massively over rated. Their EroEI is quite poor and can really only be justified for specialized applications, such as boats where space and weight are very limited. Wherever weight and space are not at such a premium (industrial, residential rather than on board transport) it makes much more economical sense to use solar thermal rather than photovoltaic.

It is important not to be fooled by claims to the contrary; there is no way we can maintain present day energy use into the future.

That is why this is a predicament, not a problem. Problem implies solution.

However, that is not to say that there aren’t plenty of worthwhile mitigating strategies that one can apply, and despite the inevitable process of technological triage in the decades and centuries to come, there are useful and low energy technologies which can and ought to be preserved moving forward.


So what does all this have to do with boat design?

A lot actually.

There are a great many ‘modern’ boats which will be seen as curious relics of a by gone age within a generation or two. The first to go extinct will be the highest energy consuming boats, of course, but a lot of standard design and material choices which are commonplace nowadays will soon feel the squeeze too.

wake monster

Only with plenty of cheap fuel can something like this exist

Here is a short list of the embodied energies per mass of some common boat building materials in MJ/kg. The ranges represent the spread depnding on source of information and their method of calculation.


Titanium                                                       361 – 745

Aluminium sheet, virgin, sheet                 160 – 217

Aluminium sheet, recycled, sheet            14.8 – 27.8

Epoxy resin                                                         ~125

Fiberglass cloth                                                  ~55

GRP composite  approx                                  100

Bronze                                                                 77

Stainless Steel                                                    57

Lead                                                                  35.1

Steel , virgin                                                    25 – 35

Plywood                                                           10 – 14

Timber, softwood air dried, roughsawn    0.3 – 7.4

Timber, hardwood air dried, roughsawn   0.5 – 7.8


These numbers agree to a certain extent with the graph of per capita oil above, when one considers when the different materials became commonplace boat building materials.

The other side of energy use is energy used to operate during lifetime.

Here the first line of adaptation will be towards greater efficiency. Huge motors pushing motorboats that have more than a passing hydrodynamic resemblance to household appliances will get rarer with each passing decade. Most cargo ships are already very efficient, but yachts and most ferries can be tremendously improved in terms of efficiency. Another thing will be the trend towards slower speeds. Resistance is roughly proportional to speed squared, while passage time is inversely proportional to speed. Fuel consumption is proportional to power neededwhich is speed times resistance, so fuel consumption is proportional to speed cubed. Therefore a lot less fuel gets used when going slowly, despite spending more time powering. We can already see this trend with large commercial ships; the so called ‘slow steaming’ approach.

It’s pretty much a given that sailing will become more and more used as it’s comparative economic viability improves.

Eventually motors themselves will become rare, although this will take a long time still and potentially heat engines will never completely disappear evn if they are limited to special uses where the energy equations make sense despite there being no more fossilized sunlight to exploit.

Welcome to the new paradigm.