I have mentioned in another thread the potential for solar thermal energy to our general ambitions of a better world (for those of us who share such a goal).

The basic hypothesis is that this kind of technology can power the Solar Socialist Revolution.

I’ve made this thread to discuss both the theory and the practical aspects.

I have over 20 years accumulated a lot of experience, and everything was open source up until about 2014. A company was founded because open source hardware development is super underfunded and the limiting factor for scaling was at that time simply the designs we were working on were not proven in practical commercial settings and to do so would take a lot of money, and being a “normal business” was the only way to raise the capital required. However, the original hand-craft, local designs developed in open source were and remain the cheapest way to build the technology. I’ve assembled a small portion of the open source work from what was easy to find in my archive here:

https://drive.google.com/drive/folders/16eIpgNP7vvBcm_P6nfFzywqjcHuTV9qD?usp=share_link

And seeing is believing, here is the video of the state of the open source development pre-incorporation: https://youtu.be/CXJgAmft2jI . At that time I was focused on exploring what was possible and I thought simply demonstrating what was possible would motivate people to build real use cases, but that didn’t happen so I decided what was more important was doubling back and proving the economic viability of the smallest economically viable unit (which is the roughly 6 square meter oven unit).

In particular, what’s important is the software modelling; for the problem that arise is that even if you have a method that is super cheap per square meter to build a solar concentrator, that does not resolve both how big a solar concentrator is required and also how best to design the application for a particular use case. In the same way that knowing how to build a wall doesn’t mean you know how to build a good house, there are higher order problems than the basic techniques of building.

In short, there is still the need to engineer actual solutions, and this engineering works requires software modelling to get even remotely close to a practical and cost effective solution. All the software in the folder above I open sourced.

Developing new applications requires even more software modelling.

So in terms “what’s there to do about all this”, the first and most essential task is to refactor and make the software available and easy to use for a variety of tasks.

The main reason collaboration is essential is that due to finding evidence that the company I founded was also being used as a front to launder African diamond money, I am liable to be murdered at any time and, personally at least, I find it would be a shame if 20 years of work (which absorbed also decades of work before I was even involved as well as collaborators) did not live on somewhere. See this link:

https://drive.google.com/drive/folders/16eIpgNP7vvBcm_P6nfFzywqjcHuTV9qD?usp=share_link

If you’re interested in international money laundering.

Where this connects to the pressing matter of the genocide is in “vision competition”. The fascist elements of society are trying to impose a dark vision of the future and beak any spirit of resistance. Fundamentally resistance is fuelled by a competing light vision of the future, of which solar energy provided. Furthermore, there are many regions in the world in which there is simply not much to do fighting genocide wise, but there are still poor people in need and environments needing protecting. So it’s a situation of “Yes we need to resist the genocide and we have to somehow keep doing everything else,” in my view.

To give a top down view of the theory:

From a theoretical point of view, solar thermal energy is a pathway (I would argue the only viable pathway) to not only massive scaling of actual sustainable energy (i.e. that actually displaces fossil consumption) but inherently lends itself to the workers controlling the means of production.

Since the 60s, solar thermal energy can be built with comparable efficiencies and costs to photovoltaic today, even for grid connected electric production, even more so if solar thermal experienced the same massive government capital expenditures as photovoltaic. Photovoltaic has required incredibly large sums of research and development, starting with military applications to power satellites, and the capital expenditures to scale up to reach grid parity costs.

The reason the system takes little interest in solar thermal is because it simply does not require these massive expenditures resulting in massive barriers to entry. There is a similar dynamic with wind power, in that wind turbine efficiency increases proportional to the 3rd power of the blade diameter and so giant wind turbines (and thus massive capital expenditures) can easily outcompete smaller turbines. There are of course exponential costs in building massive structures (hence a size limit at any given time) but since the gains too are exponential with the right engineering it’s possible “win” in gigantism, but theoretically and as we’ve seen in practice.

When it comes to solar thermal, there is no such exponential growth in efficiency with system size. Power is simply proportional to surface area and you could make a tiny solar even with a tiny magnifying glass essentially as efficient as a giant one.

Not only does this render gigantism not intrinsically advantageous, but actually a lot worse. For, if you make gigantic solar thermal systems, these must be in remote locations and no one is otherwise living or doing anything there. It “sounds” like it makes sense to put a solar system in a desert as it’s very sunny, but the gains from simply there being more sun are not exponential but can be quite moderate. A desert is due to a lack of water and not actually an excess of sun.

However, what is a drastic reduction in efficiency is that in a remote desert location all energy existing an electric production process is simply wasted … and getting rid of waste heat in a desert is not actually so great. The desert also causes efficiency problems as one wants a cold source to make the temperature difference that drives turbine cycles (why other thermal plants tend to be next to water) as well as mechanical problems of being exposed to the elements such as being in an effective blaster.

So, whereas a system on a farm could make electricity and then heat a greenhouse or dry produce or any number of heat applications, a remote system in a desert has to spend money to dissipate heat (in a desert, which is less than ideal).

To make things far worse, one then needs to transport the energy over long distances which requires further capital expenditures and efficiency losses.

All in the context that there is no intrinsic advantage to gigantism in the first place, and in fact can gigantism works against efficiency. For, just as wind turbines are exponentially more costly to build with height, so too are solar receiver towers. The difference is that where wind turbines increase to the third power, there is no increase in efficiency simply because a solar system is bigger. In fact, things get less efficient because reflection accuracy is proportional to distance. Hitting a target by reflecting light 100 meters away is a lot harder than hitting a target 10 meters away or 4 meters away.

From the point of view of capital, everything required to make a solar thermal system, even one that produces electricity, was invented in the 19th century. Even if we can make even more efficient steam turbines today, there is no need if the waste heat has some economic use. Why thermal-to-electricity systems become incredibly sophisticated is that squeezing out every possible efficiency increase is extremely difficult and all sorts of little problems arise that may require adding an entirely new part of the cycle or new sort of device to manage.

However, if you are in the station that you anyways want to heat a greenhouse, then the problem of extracting a more modest proportion of the energy and convert it to mechanical power is far simpler to solve. To make a long technical story short, in converting temperature differences to mechanical power, whether with pistons or turbines, more stages means more conversion of heat to mechanical (and then electrical) energy. If electricity is your only concern, such as in a nuclear reactor which is not built to in part heat local farms but to make electricity for a huge region, then more mechanical conversion means more efficiency. However, if there are other economic uses of the energy then efficiency in terms of overall cost effectiveness has nothing to do with simply maximizing electric conversion. If one needs 100 kw to heat a green house and only 10kw of electric energy, then converting 10% of the thermal energy to mechanical power is a much easier problem to solve than faced by designers of nuclear reactor power stations. Of note, even the mechanical energy can still be captured by the green house if the mechanical process is simply situated in the green house (so one does not even need 110kw to power both processes).

In practical terms, every piston or turbine stage converts energy over a temperature difference. For a long list of reasons it’s not practical to build a single stage that drops many hundreds of degrees. The more stages the more mechanical complexity, once the stages are maxed out then efficiency can be increased further in a steam system by various intermediate stages of reheating to superheated steam, adding a vacuum to then add more stages and so on.

In short, if you have economic use for 100 kw of thermal energy at 100 C, and a solar concentrator can provide steam at 200 C, then one doesn’t need many stages, likely just one stage (i.e. one piston), to extract the desired mechanical energy. There is no need for mechanical complexity to maximize the extraction of the temperature difference available, and no need to increase temperature to then add more stages, no need to reheat steam to superheat between stages, as well as no need to decrease temperature and pressure (i.e. vacuum pump) of the final heat sink. In short, all the problems engineer of fossil thermal plants and nuclear power plants face go away if electricity is essentially a byproduct of much larger thermal processes.

Now, this wouldn’t matter if we needed a lot more electricity than thermal energy, but that’s not the case even now, the world consumes far more energy to heat processes and spaces than it consumes electricity. Electricity is more visible and seems “more important” but the amount of energy that goes into just heating things (mostly under 200 C) is vast. So, if producing electricity is a byproduct of these heating processes which are the foundation of economic activity (space heating, roasting, boiling, drying, baking, processing of various kinds) then the mechanical complexity of the mechanical system can be very low, which makes them both easy to make and maintain. Maintaining a one cylinder steam engine is very far from the task of maintaining a nuclear power plant.

There’s plenty of other interesting details to expand upon, but the basic point of this consideration is that the failure of solar thermal systems (which not all have failed, but they often failed due to overselling the efficiency due to a lack of due diligence: if the government pays you may not care much if you get paid to build the system and it proves not so cost effective many years from now) in the desert is not indicative of the potential of the technology and is in fact a terrible use case.

For the advantages of local use don’t even stop at the process efficiency. It’s far easier to build and maintain a solar concentrator locally than a giant solar concentrator in the desert, and again if there is no intrinsic efficiency advantage to making something giant then the maintenance complexity is another critical advantage to doing it locally. For, it costs money to send people out in the desert and maintain mechanical systems, but when an artisan, or community of artisans, build and maintain themselves a solar thermal device there is zero transport cost to daily maintenance.

However, I focus above on the production of electricity as that is the only use case for giant solar thermal systems in the desert. Locally, all sorts of applications are possible with the direct application of solar thermal energy that we would normally associate with electricity. For example, absorption fridge processes require only thermal energy to run (and were the most common fridge before and around WWII). The compressor fridge is only more efficient if the energy source is electricity. If your energy source is thermal energy, and especially the temperature at which absorption ridges typically run, then the efficiency of a compressor fridge is zero. If you had high temperature energy source then the efficiency of converting the heat to electricity to then drive the compressor fridge would be about the same as just using the heat in an absorption cycle, just only the absorption way would be far simpler and cheaper.

However, if one needs to transport the energy long distances, such as the heat of a nuclear reactor, then there is no practical way to transport heat any significant distance and the only option is electricity, and so then driving a compressor on the other side is more efficient than turning the electricity back into heat and then power an absorption processes.

So, outside a few niche areas, compressor fridge technology is only efficient in the electric conception of society.

The analysis of the matter changes entirely if the primary source of energy available to society is incredibly cheap locally captured solar energy. What powered absorption fridges was still fossil energy and so required it’s own distribution, and it is in that circumstance in which burning the fossil energy in central locations and distributing the electricity is more streamlined and more multi-use and so electricity-grid-compressor fridges can outcompete fossil-distribution-absorption fridges

Likewise for water, if what is available is electricity than reverse osmosis is very efficient. However, if low cost thermal energy is available then it is cheaper and far less sophisticated to distill water in (multiple stages, for similar reasons as pistons and turbines, but far easier to do as it’s just the steam produced by one stage boils the next).

There is a whole technology tree of thermal based applications that would outcompete their electric counterparts given a local source of heat that’s cost effective enough. Obviously if the energy is free, simple devices that produce the value in question directly are going to be more efficient than far more sophisticated series of devices that first convert the heat into electricity and then that electricity into the value concerned.

Doesn’t remove the value of those applications which by nature require electricity, but there is a surprising amount of applications that have direct thermal powered cycles, that are very simple in terms of capital expenditure, and are more efficient than an electric driven cycle if heat is the primary source.

To give a rapid idea of these sorts of opportunities, if you imagine having a source of wood, then it’s really not difficult to burn the wood to drive an absorption fridge. You can just get an absorption fridge, workout how to burn the wood to deliver the required heat, and you’re now producing cold. However, if you imagine having the same wood but wanting to power an electric compressor fridge, you have really a series of very complicated problems to solve and then an extremely complicated resulting series of systems that will be very difficult to maintain.

To summarize the central message of the above examples, is that there’s an entire tech tree of applications to develop or adapt suitable to cheap-enough solar thermal energy. Any given application there is a cost of solar thermal energy below which that system will outcompete whatever is usual in fossil powered civilization.

Of course, many applications are by nature sophisticated (even if less sophisticated compared to trying to produce electricity with the same thermal energy), such as multi-stage distillation systems.

However, if there are simple applications that can be deployed and creates income now, that then builds the skills locally to then build the next level of the tech tree.

Where the software comes in again is that it is essential to develop new applications to then deploy in suitable conditions right now (plenty of communities would have the skills to maintain fairly sophisticated systems right away) as well as motivate groups starting with the simpler devices as there’s this upgrade pathway to further and further value generation. Just like smart phones required a critical mass of applications to be adopted exponentially, as each application adds value to “getting into the ecosystem”, so too there is the exact same dynamic to unlock in solar thermal energy. The more applications are developed and demonstrated the more that drives directly use of the technology as well as motivating more developers to develop more applications. If one solar thermal base can power hundreds of applications either available on the market or can be built locally, that is massive incentive to get started with the technology; more people are doing more people are going to do it. And we see viral grassroots adaptation of solar technology generally speaking, such as water heaters (solar thermal energy for an important use case, but of limited application scope) and PV systems in the Global South even without any government involvement at all. So the exponential potential of solar adoption is already proven, the difference is what we currently see is mostly grassroots adoption of imports of big capital outputs whereas with additional effort this can be extended to exponential grassroots technology transfer covering a far wider scope of applications.

Of course, all this theory depends on the practical question of whether “cheap enough” solar thermal energy access can be created locally. Obviously if one had a magical free source of heat energy then it stands to reason just getting simple thermal-to-value systems when they exist would be cost effective, so the question is “how close to free can we get” and “is that close enough”.

So, it is in the careful consideration of the above linked material that this question can be addressed, as well as people taking upon themselves to use and help continue developing the open source software to build numerical models that demonstrate various things. For example, better economic analysis and environmental analysis can be added to the modelling of the technology itself to demonstrate better cost effectiveness (all about that ROI and pay-back-period); I built wrote the first versions of the software to answer specific design questions having a lot of practical experience with the technology to interpret the results; a more complete software would model out as much as possible all those real world considerations (for example include models of how businesses typically gets done and the real world constraints of it to calculate value production; rather than a simple formula relating watts to bread baked).

However, there is a simple thought experiment that is useful to start visualizing the potential.

In the medieval period Europe had less than 1 fourth the population but actually drove deforestation to below 12% forest cover, largely to fuel pre-industrial revolution metallurgy, ceramics along with all the agricultural food and material processing.

So, when people dream of returning to a simpler more feudal burning wood powered form of production, there is simply no practical way to go back to back to wood burning as a primary source of energy, with 4 times more people using on average more than 10 times more energy. We’re talking more than a 40x difference in energy consumption and that does not include embodied energy from imports into Europe. To represent 1 / 40th the energy consumption of a typical European in a pile of wood is really not that much wood … and that’s not even sustainable! Medieval Europe was deforesting which is what then motivated burning coal, which people knew about but didn’t burn because it made sick.

Now, one way to understand solar thermal energy and its potential, is that it is simply an upgrade to the medieval primary energy source of the tree. When converting sunlight to trees to heat to power stuff, the overall efficiency is less than 1% (can be far less than 1% if the tree needs to be transported long distances or then the ecosystem is arid and doesn’t produce much biomass).

Solar thermal devices, and in particular concentrators (that can power a wide range of applications) on the other hand can operate easily above 40% efficiency for direct heat capturing applications (such as an oven), so that is your 40x factor in efficiency to make the entirely non-viable return to feudal economics suddenly entirely viable. If we imagine the same kinds of local farming, gardening and artisan technology with 40x more efficient “tree” in capturing energy, it’s entirely possible to decentralize and not only be actually sustainable, where feudal economics was not, but have far more energy consumption, such as what we currently consume, to do all the basic things we need and also power many of the comforts we are accustomed.

Of course, such as local solar thermal powered society would look very different, but if “living standards” is more or less proportional to energy consumption, it is possible therefore to build a genuinely renewable economic system with the same living standards, and in fact far better as there would not be the pollutions of pesticides and cars and mega industry and so on (personal gardening, which is possible in decentralized system, is very intensive in production, if it even matters to compare yields on a weight basis only with an unsustainable system).