1. Skip to navigation
  2. Skip to content
  3. Skip to sidebar

Wave Pumps, Fresnel Lenses, and Steam Power?

Home Forums Community Dreaming / Crazy Ideas / Speculation Wave Pumps, Fresnel Lenses, and Steam Power?

This topic contains 9 replies, has 7 voices, and was last updated by Profile photo of Shouri Shouri 5 years, 8 months ago.

Viewing 10 posts - 1 through 10 (of 10 total)
  • Author
  • #1143
    Profile photo of JeffM

    Inspiration for this idea is owed largely to forum user i_is_j_smith and his forum thread here.

    If this idea is stupid, its because I’m an internet user with a keyboard and I know nothing about this sort of thing 😛

    I’ve been drawing up a few poor diagrams for a system which would use one or more large fresnel lenses to boil water to create steam.

    This water would be in a container fed by a reservoir, which would in turn be fed by an extensive system of wave pumps.

    This steam could be used to power stirling engines (these engines can also be powered by just using a fresnel lens to heat hydrogen [better video explanation here]), or it could be concentrated and fed through steam turbines.

    Then, the steam could be condensed or used for greenhouses.


    1. Relies on sunlight.

    HOWEVER, if there were enough of these running all day long on sunny days, I believe that it would provide enough energy to power the seastead and store enough energy to minimally power the seastead during the night (ideally though it would be preferrable if the seastead had the capacity to store enough energy to minimally power the seastead for several days, along with a generator to serve as a last resort).

    2. Unless the Fresnel lens/es were ‘outdoors’, they would require light to be concentrated and continually redirected until it reached the lens which would heat the water container (I have no idea if/how much energy would be lost this way). In either case, a system would need to be established for tracking of the sun’s progress across the sky.

    This could be done manually, or through the use of something called a heliostat.

    One extra idea: Pumps which require manual labour, and can be used to generate small amounts of energy and/or help fill a reservoir.

    Wave power/water pressure, steam power, wind power, solar energy, and human labour seem to be most ideal for running a seastead, so it makes sense that it is on a seastead where the development of the the means of harnessing these things will take place.



    For electric supply you probably want to go for the densest energy source available. For a seastead this will be wind and wave energy. For the most direct and most tested forms to use this energy you might want to look deeper into this –

    Pelamis wave generators

    Standard wind turbines with floating foundation (newly developed). Offshore wind turbines is tested technology for over 20 years –

    siemens wind turbines offshore

    Wind and waves is solar energy already concentrated by mother nature so you may find it much easier to harvest.


    Profile photo of JeffM

    Nice, the sea snake generator looks ingenius. If a seastead had a deployable farm of those available, it would make power generation easier. The siemans line of wind turbines look good too.

    Profile photo of GreenGestalt

    I don’t know about the need for a fresnel lens, tho-

    Lenses, the bigger they are the more delicate and expensive they get. I’d use mirrors, like mylar mirrors over metal/plastic/treated wood, etc. The trick would be how to best use the space. Instead of 100% coverage, though on a roof that might work well, have 75% coverage, then a sheltered greenhouse beneath it. Depends on where in the ocean it operates, but the tropical areas have abundant sunlight so letting light go between into an insulated area would work well. I think, however, it would only work well on the large scale project, such as a football field of area, and something a larger colony should build for their electrical needs. Power generation almost always works on the “Economics of Scale”. A small one with a fresnel, though, perhaps might be fun to build. It’d get you published in MAKE I’d bet;-)

    Aside from that, it’s a math problem:

    1. The area that is focused onto the smaller area.

    2. The thermodynamics of heating and using steam to drive the pump.

    3. Entropy from the process and the cooling to get the water.

    -It’s a 60/40 trade-off in two parts. First, from sunlight into steam pressure, then from steam pressure to mechanical resistsnce to generate the energy. So if you needed 100 parts of energy for your project, you’d need 225 parts of energy from your solar collection to make the process work. How big it has to be depends on how many laptops, light panels, communications systems, stoves, etc. you want to plug into it and use. Adding to the cost, a sophisticated switching system with supercapacitors and batteries is a must along with careful planning on how the electricity will be distributed.

    4 – extra – This is only reccomended on the BIG scale generator, too messy and dangerous for the small one, but consider using a “Sodium Heat Battery”. Sodium melts and stores tons of heat. You could have one of those things constantly charged during the day and then at night or in case of clouds the thing would help the process run steady. And, though Sodium costs a lot from the science catalogs, you yourself can make it from the sea and using some (a bunch) of electricity, just make sure to waft the chlorine outside the stead…

    This project is something well worth doing. However, one would be advised to know how to build it themselves, or have a member who can supervise it.

    I think these things would have mediocre power generating capability for commercial purpouses, except to power the seasteading project, for which they’d be quite worthwhile, though perhaps solar will become cheaper soon. But this you can make with existing technology, you don’t need a semiconductor lab and near nanoscale precision to make.

    However, the clean water they’d produce would be a source of income, or at least favorable relations/trade. Overnight you’d have more water than you’d need (I assume recycling in the hydroponics/terraced gardens to avoid constant fuel for filtering cost?) and you’d almost be tempted to dump it. Then you’d notice all the people drinking bad water, even at the pricey restaraunts in the nearby nations you visited. Drinkable water is getting scarcer and scarcer and scarcer.

    And there’s also Salt taken from that process. I’d use a pre-filter to keep out the plankton and tiny squid from the boiler, but the rest would have to be seperated. Most waste in salt is lighter than the salt, so it goes to the top and this might be usable in the release process. The bottom would have the heavy metals. Salt from the sea is usually evaporated, then torn off in slabs, then re-wetted and pounded into weights. It’s a lot of labor and rather miserable. It’d be clever engineering to find a way to seperate the heavy/light waste first and have it condense in weights ready to be sealed and put on a ship.

    So, as a by-product of power generation, there would be two commodoties to sell/trade with. If I made a trip I’d definitely bring some with me. (what ARE the traditional “Salt Weights”?) But I’d do this more for social interaction than a profit from that alone. Also, a cargo ship coming back from America would likely trade for some. Continued sodium seperation would be a huge drain on the power generated, but might be worthwhile for limited times and profitable if there’s a huge spike (war, trade war, disaster) in the price. Anyone who’d want the sodium is either a manufacturer or a science lab and they could trade nice things for the hardship of limiting the use of the washer/dryers and going back to direct fire woks for a while. (that though might make the women mad and you’d have to buy them something)

    Just my thoughts on it.

    Profile photo of JeffM


    Thanks for all of the useful input. That will definitely give me something to chew on while researching and drawing up ideas on how to make this system more efficient/effective (and the other things you said, like developing a method to separate the waste based on its weight).

    So I see multiple benefits with this;

    One of these can provide drinkable water (possibly even more than enough to sell surplus on land), while at the same time generating power, and creating other waste which can be sold (thanks for the info!).

    Used in conjunction with solar panels, wave pumps, and wind turbines these wouldn’t have to be a primary source of the power (but they certainly could produce quite a bit), and while providing that benefit they would provide the things I listed in my previous sentence.

    I really like the idea of the sodium battery as well, it sounds like it would be right for the scale of steam power production I’m talking about.

    I should go back and play some of the Myst games, they have interesting concepts in energy production, even if some of them are outright impossible (right now).

    Thanks for the reply!

    Profile photo of Aeolius
    Profile photo of Shouri

    Energy isn’t the case…Constructing a hull cheap, large and durable enough is… Find a good spot in equator with strong ocean currents and you will have more energy than you would want, and yes it is feasable. Then use a flag of convenience of a tax haven country,here you go you have your dreamstead. (btw i mean energy isn’t the case for creating a sustainable life at sea, i don’t mean you can get enough energy to start heavy industry in a feasable way, though it is possible if you are planning a 100+ men seastead)

    Just find a remote seamout(shallow) with nearby strong underwater currents and lotsa sunny days…

    You can get as much energy as you want for 5m dollars and it isn’t a big sum for 100 people. You can run aero/hydro ponic, desalination and sewage reprocess facilities easily in feasable way. What matters is the cost of the platform/seastead/ship hull to make it(seasteading) real. Legal issues or infrastructure issues aren’t really important imo (except one subject, internet connection). I still couldn’t find a way to get internet to middle of nowhere in a feasable way, all solutions i’ve found so far are either too fragile or too expensive. Even if i am willing to live in a seastead there is no way i can live without internet o.o.

    Back to the topic, energy cost may rise significantly if you want a highly mobile seastead thus making it(propulsion) a big problem, but i guess no one wants a jet-stead and is fine with a knot or two so its not a big issue as long as hull design is good enough.

    We don’t need a pelamis farm btw a single one generates enough power output for a little community. There are viilages in Portugal with those pelamis worms installed already and as far as i know a single pelamis unit generates enough power for 1200 houses (might be wrong, it’s been a long time since i’ve read about pelamis) and if i’m remembering it correct it’s price ranges between 5-8 million dollars per unit.

    Profile photo of

    The environmental requirements for wave power sort of clashes a bit with the ditto of a seastead, does it not (needs big waves)?

    Wind is sort of the same, perhaps not a smuch though.

    Solar seems more compatible with seasteading (everybody loves sunshine, right).

    Profile photo of i_is_j_smith

    I just posted this link in the Infrastructure section. Google has come up with some new materials that, they say, can cut mirror and heliostat costs by 2X:


    Not much info, but anything that brings the costs per kilowatt down is a good thing.

    Profile photo of Shouri

    It doesn’t have to be wave power you can just tap underwater currents, and at some point seasteading is all about having a wave proof platform, you don’t need tsunamis or hurricanes for generating wave&wind energy, what we need is routine winds and waves that will make our energy output predictable. Wind Turbines auto-lock themselves if the wind is too fast in order to decrease the maintance it requires, it is not like really fast winds are much more efficient than mediocre winds in fact with current (in use)technology it’s far less efficient. (I don’t deny the fact that faster,stronger winds carry much more energy for us to use, but people simply don’t want to use them to decrease the initial cost of the project which is rational in a capitalist world)

    So no, it doesn’t need big waves. Really big waves and strong winds aren’t in good terms with current commercially appliable renewable energy technology.

Viewing 10 posts - 1 through 10 (of 10 total)

The forum ‘Dreaming / Crazy Ideas / Speculation’ is closed to new topics and replies.

Posted on at


Written by