Weird, New Electricity Generator Takes Baby Step Into Real World

Yesterday, in Mark's post about new technology that could one day generate power from slow moving currents in rivers and oceans, commenter SamSam wondered whether "any weird and new generators ever get out of the lab and start providing meaningful amounts of power?" It's a fair question, and I think a lot more technologies are announced than do (or ever will) make it to market. Partly, that's just the nature of invention. Partly, it has to do with the fact that it takes a long time to develop this stuff and we're still kind of at the beginning of the alternative generation industry. But sometimes, the crazy ideas do work, at least well enough to move out of the lab and into beta-testing. For instance, today, Norway's state-owned utility opened a prototype generator that produces electricity via osmosis.

The plant is driven by osmosis that naturally draws fresh water across a membrane and toward the seawater side. This creates higher pressure on the sea water side, driving a turbine and producing electricity. The main issue is to improve the efficiency of the membrane from around 1 watt per square meter now to some 5 watts, which Statkraft says would make osmotic power costs comparable to those from other renewable sources.

The prototype is very small--it only produces about a coffee-pot's worth of electricity--but if the kinks with the membrane can be worked out at this small scale, the utility could have a full-scale plant powering 30,000 homes by 2015. Also, I have to give a shoutout to the Norwegians for not claiming that their osmosis-based generator will magically solve the world's energy problems--instead describing it as part of a mix of different technologies that, together, could make a difference.

Norway Opens World's First Osmotic Power Plant in Reuters

Image courtesy Flickr user neogabox, via CC

• [TheMadLibrarian]

  I remember having heard about this several years ago. As I recall, it was originally developed for desalinization, with electricity production being a happy byproduct. Which came first, the chicken or the egg?

  • [mn_camera]

    Eggs preceded chickens by millions if not billions of years.

  • [CANTFIGHTTHEDITE]

    Known as Salinity Gradient Power, the two methods are essentially performing the reverse of the desalination process. Passing salt water through semi-permeable membranes using pressure (reverse-osmosis), or using ion-exchange via eletrical potential difference (electrodialysis), can create fresh water from salt water by adding energy. Theoretically, allowing the reverse of those processes to occur could create energy, and that’s the basis of these technologies. But I’m no expert, so I might be off about the exact details.

    I’d like to see a pilot plant built alongside a desalination plant, using the brine and regular seawater to grab some power back prior to sending the brine to an evaporation pond. The difference in ionic potential and/or osmotic pressure might be big enough to produce a meaningful amount of energy. I’d settle for a feasibility study, though.

• [SamSam]

  @holtt: I’m not really sure that millions of tiny solutions really are an answer. Each of those generators in your shoes needs to be manufactured, needs to have batteries made out of heavy metals, will generally break, and will anyway produce, what, enough to fill a tenth of your cellphone a day? And yet the number of fans and other gizmos I can buy to attach to my bike to semi-charge my iPod is huge. Why do people spend so much time inventing these things that make us feel green but do so very little?

  @Maggie: Thanks for the dedicated post! I guess my real question is, is it that there isn’t enough investment money to fund the projects that could go places? Or are most of the projects not worthy of investments?

  Or maybe I’m just impatient, and the flurry of new inventions to generate green energy is only just accelerating now, and it always takes a long time for such things to actually get to the outside world. But how much time do we have while still burning hydrocarbons at the rate we do?

• [Lobster]

  So they need to make it 5 times more efficient to make it stack up against other renewable energy sources, then what, 10 times more efficient to make it economical?

• [holtt]

  SamSam, if someone told me about a power making scheme to generate electricity from osmosis, I’d probably call it a crazy idea too.

  The world is FULL of small energy sources that rely on the basic idea of a gradient – that there’s more of something on one side of an interaction than another.

  • [SamSam]

    Yes, but the osmosis plant is a little different from the idea of generating useful power from hoses and shoes. It’s designed to produce meaningful power.

    For example, while this article is long and rambling, he does a pretty good analysis of why attaching tiny solar panels to consumer electronics is almost always bad for the environment, given the energy that went into producing the solar panel vs. the energy one would expect to harvest from it over the course of the gizmo’s life.

    Anyway, I have no doubt that we could be harvesting all sorts of energy out of all sorts of crazy ideas that have been posted here over the years. It’s just that they clearly either don’t get funded or production just happens to move at a snail’s pace…

    • [Ito Kagehisa]

      SamSam, the article you linked contains logical fallacies and uses suspect numbers.

      I admit that it’s good to see some skepticism about “green technology” since so much of it is simply self-serving greenwashing (think Intel’s Energy Star program) or blatantly misrepresented. I applaud you for that.

      On the other claw, substituting one set of biases and shoddy reasoning for another is not such a great improvement. The article exemplifies this problem.

      As a single example: Your linked article says using attached solar panels on gadgets is “insane” and then uses loaded language and misapplied data to support this idea. Let’s apply a little common sense… looking around me, the most common “gadget with a solar panel on it” is the calculator. Like a many other such gadgets, it does not require the insolation that the article says it requires, because it runs off the light already required to illuminate human work areas where calculators are universally used. Such calculators are truly using “free power” because they run on unavoidable waste. Further, comparing this power draw simply to the absence of the device entirely, or to perfectly converted grid-supplied power, is completely disingenuous, since the alternative is actually battery power (which is economically and environmentally a total nightmare) or at best an inefficient wall-wart converter – these devices have environmental costs of production and use that exceed the costs of small solar panels. In the real world, solar panels on calculators have been a titanic benefit to human environments; solar powered calculator have kept billions of tons of toxic waste out of the water table (most people discard used batteries in the trash, despite probable horrific consequences to future generations) and solar powered calculators last longer due to the lack of corrosive capsules (batteries) inside the mechanisms. Solar panels on gadgets, at least in this case, is an absolutely pure win.

      The article laudably does not assume that alternative power sources are always a great thing. Unfortunately it does not fulfill the promise of reason and skeptical evaluation that one might hope for, and instead is essentially substituting one bad set of assumptions and flawed reasoning for another.

      • [mdh]

        and instead is essentially substituting one bad set of assumptions and flawed reasoning for another.

        Another example of this would be assuming most gadgets have power requirements similar to a pocket calcuator.

        • [Ito Kagehisa]

          Another example of this would be assuming most gadgets have power requirements similar to a pocket calcuator.

          The existence of a single exception to a generality framed as an encompassing rule is enough to discredit the generality and arguments based upon it.

          If “solar panels mounted on gadgets are completely insane” and calculators are gadgets, then photovoltaics mounted on calculators are insane. Since PV powered calculators are clearly not insane, the statement is disproved.

          Note that the definition of “gadgets” in the article is stated as “like laptops or cell phones” (this is called begging the question, because using the term like ambigiously embeds the conclusion in the arguments’ premise – gadgets is effectively defined circularly as those things which suit the desired outcome of the argument). While the conclusion to an illogical argument may be true (Theresa is a dolphin, therefore fish live in the sea) it is not reasoned discourse.

          I actually kind of like the low-tech magazine site overall. My beef is that the article SamSam linked is not well reasoned. It ignores the reality of solar panel re-use, it makes false assumptions (such as, only the sun will be used to power small PV devices, and small PVs will not be used in place of toxic battery technologies), it uses discredited arguments (solar panel production is not necessarily highly polluting) and it generally starts from the conclusion backwards. The author likes muscle-powered devices such as cranks better than PV, and attempts to support this preference but mostly fails.

        • [Anonymous]

          I strongly agree.

        • [Anonymous]

          OMG, I just literally made an “I agree” post.

          I have to go perform some sort of expiation now… cutting my belly would probably not be sufficient. I’ll think of something. Please accept my humblest apologies.

• [Anonymous]

  holt: certainly there are many small energy sources that don’t scale up. But a hydraulic pipe across the road? Think about it, theenergy that you’re getting is taken from the automobiles, by adding to their rolling drag. So you’ve added an inefficient generator to the already inefficient automobile. Sure, it’s somebody else’s energy that you’re stealing but the net effect is an extreemly energy inefficient means of generation.

• [Anonymous]

  Time for some good news: Alternative energy of all sorts is really taking off…

  In the UK there are now two test centres setting up where wave/tidal power systems can be plugged in for testing (while generating power to grid) and an operational tidal power station in Northern Ireland. I count 5 or more wave/tidal power systems in full scale testing (e.g Oyster, Pelamis sea snake). Not very long now before we see many commercial installations… tidal flow power, offshore or estuary, is even bigger than wave and the Severn estuary is not the only place you can deploy it.

  There are many biomass power plants setting up – some using coppiced or waste wood, many using waste food or waste products from brewing or distilling and some using animal waste. Quite a lot of these incidentally reduce landfill.

  Offshore wind is likely to increase from current 1GB to 33GB generating capacity by 2020 – and since much of the new windpower is going offshore we won’t be swamped by windmills on every patch of ground as some claim.

  And I found a survey of British wind resources: did you know that there would only be a case where there was no wind across majority of UK due to high pressure on average for 1 hour in every 5 years? Onshore, amount of time wind plants could operate was estimated at 30%, better than Germany’s current 27% – offshore wasn’t measured then but could be 30 to 40 %.
  (Spain has twice this year generated more than 30% of its electricity for a month from wind power). The amount of ‘standby’ power needed to back wind seems also to be vastly overstated by many (check out BWEA site).

  Then there’s energy reduction – ban on incandescent lightbulbs: 1 100w bulb from every household apparently equals 200,00 cars off road for a year in carbon terms, so must be saving a heck of a lot. My local council switched off most street lights (which I have mixed feelings about!).

  I’m not saying problem solved – but I am saying solution at hand and with a concerted push, great things can be done. I’ve been deliberately vague on details, so you can google your own way to more good news.

  Did I mention the new poer lines, the grants, the small scale community council funded projects, the off the shelf solar panels from high street outlets that save 50% of your power cost over a year (ok they are £ 16 to 25k !) and there’s more…

• [Anonymous]

  Has history taught us nothing? Have we forgotten about the greedy Enron “power-brokers” already? It is essential that we develop smaller, decentralized boutique power sources that can be on-person (powering your personal appliances while you walk) or home-based (wind, solar, osmosis). Allowing power companies to centralize the generation of alternative power will simply continue the status quo of continually rising prices and failing infrastructure. It’s way past time to break the grip of the PowerCos and develop individual plans that work on the micro-level. Have a stream or river nearby? Add a turbine. Windy area? Ditto. Live in Sunnyvale? Roof-top solar panels. Walk to work? Shoe-based micro generators for your PDAs. Electric car (someday)? Recharge your house batteries with leftover electricity generated by you car’s braking system. This is such a no-brainer that I’m surprised there’s any discussion at all. The only ones opposed to home-spun, decentralized power sources are those who stand to gain from keeping us dependent.

• [turingcub]

  Isn’t the mechanism of all potential energy sources a membrane of some sort, creating a gradient that can be exploited?

• [CANTFIGHTTHEDITE]

  The reason why alternative energy has remained fringe is because oil prices have been kept low via government interference, both foreign and domestic. No one will invest in a market if they think the bottom will drop out of it as a result of government moving on a hot-button political issue like oil prices. I strongly believe that the best thing that a government can do to promote alternative energy and investment in those technologies is to leave the price of oil and let nature take its course.

  Has anyone else seen the documentary “Houston, We Have A Problem” ? I’m not claiming it to be the ultimate defense for the above paragraph, but I found it to be fairly compelling, if only from the standpoint of independence and defense.

• [cymk]

  Environmental impacts aside, putting something like this membrane at the mouths of rivers as they empty into oceans could generate quite a bit of energy. Maybe even combining it with the technology posted yesterday, so not only do you get energy from osmosis, but also from the natural current going into the oceans.

• [holtt]

  The world is just brimming with low energy power sources. As long as you think in terms of lots of little power plants instead of a few big ones, the potential of it all is huge.

  Just think how much power you’d make by placing a small hydraulic filled hose across a highway for example. Every time a car drove over it, you’d get a jolt of energy. And it doesn’t have to be a big “thunkathunk” bump.

  Or if you don’t like the idea of getting a bit of energy out of cars (which would burn a bit more fuel), then have sidewalks that generate electricity when people step on them. It’s not going to light a city, but it’s going to do something.

  Or a few solar panels on every house.

  Or roof ridge wind turbines (http://www.thepowercollective.com/ridgeblade.htm)

  Or something in your shoes that charges your phone while you walk.

  etc.

• [Anonymous]

  We’ve been at the beginning of the alternative energy revolution for 20 years. It’s a decade since I studied an undergraduate engineering module on Passivehaus design, solar and wind and prototype tidal systems. All remain fringe.

• [efergus3]

  One drawback is that membranes have to be cleaned often.