A Bold Experiment In A Decentralised Low Voltage Local DC Power Grid

January, for many of us in the Northern Hemisphere, can be a depressing month. It’s cold or wet depending where you live, the days are still a bit short, and the summer still seems an awfully long way away. You console yourself by booking a ticket to a hacker camp, but the seven months or so you’ll have to wait seems interminable.

If you want an interesting project to look forward to, take a look at [Benadski]’s idea for a decentralised low voltage local DC power grid for the upcoming SHA 2017 hacker camp in the Netherlands. The idea is to create a network that is both safe and open for hacking, allowing those with an interest in personal power generation to both have an available low-voltage power source and share their surplus power with other attendees.

The voltage is quoted as being 42V DC +/- 15%, which keeps it safely under the 50V limit set by the European Low Voltage Directive. Individuals can request a single 4A connection to the system, and villages can have a pair of 16A connections, which should supply enough for most needs. Users will need to provide their own inverters to connect their 5V or 12V appliances, fortunately a market served by numerous modules from your favourite Far Eastern sales portal.

This project will never be the solution to all power distribution needs, but to be fair that is probably not the intention. It does however provide a platform for experimentation, collaboration, and data gathering for those interested in the field, and since it is intended to make an appearance at future hacker camps there should be the opportunity for all that built up expertise to make it better over time.

We’ve touched on this subject before here at Hackaday, with our look at the availability of standard low voltage DC domestic connectors.

Wind turbine image: Glogger (CC BY-SA 3.0) via Wikimedia Commons.

29 thoughts on “A Bold Experiment In A Decentralised Low Voltage Local DC Power Grid

  1. Thanks for the article, a great reminder.

    FWIW:
    Micro grids in Sabah (East Malaysia) were all the rage for co’s from Australia
    circa early to mid 1990’s. I went to Mendulong to repair/upgrade a conventional
    Remote Area Power System (RAPS) in mid 1998 and although worked a treat,
    the project was completed 3 weeks before the Asian crash !
    Some data/pics here:-
    http://ii.net/~erazmus/Power/
    Also gradually uploading the whole set of pics on facebook here:-
    http://facebook.com/mike.massen

    Wind turbines are of renewed interest in the region and worth going back there
    in a couple of years…
    AFAIK; Holland manages to generate enough wind power for all their electric
    railiway consumption, would be interesting to compare the maintenance logistics
    with any internal combustion engine eg re diesel electric & tranmisssion costs
    re conventional power stations & power impedance matching with renewable sources…

    1. on windy days denmark produces about 140% of their energy requirement from wind alone.
      the prices are now on average as cheap as any other power source and the wind power tax rebate ended 5 years ago, everyone expecte4d it to still be 10-15% more expensive.

      it was when i signed up for pure windpower.

      1. Great news, here’s a PR vid re Holland, now how can we exploit
        this method as reward/punishment for politicians ;-)

        Would be interesting to see the overall & regional stats re load management
        & whether any niggles determined re impedance/phase matching where short
        term storage comes out of the load sharing algorithm ?
        An Aust co working on this too (likely in competition with Tesla re the Powerwall)
        & disclosing I’m a share holder only on the sidelines, listed on ASX (stock market)
        http://redflow.com/

      2. Here in Scotland we produced 105% of our electricity in a day from wind by 2020 our government want 100% wind power everyday, This shouldn’t be hard Scotland has the shittest weather in the world. It just rains and blows wind here all day everyday except our summer which lasts around 2 days.

        1. Fantastic except that the one day it managed 106% was during a yellow weather warning storm. All we have to do is ask the factories to synchronise their production with how hard the wind is blowing that minute. Scotland might have some decent hydro storage capability but its not enough to regulate the kind of instability wind has to offer.

          1. You are right it was blowing hard that day but we could still reach 100% easily enough by 2020, Scotland is the windiest country in Europe (http://www.bbc.co.uk/news/uk-scotland-15283013), also has 25% of Europe’s offshore wind potential (http://www.gov.scot/Topics/Business-Industry/Energy/Facts). You are right we would have to extra turbines everywhere to switch on and off as wind speeds dropped in other regions, But I think we could get away with it with some added hydro power for back.

          2. Perhaps incentivising smart load sharing appliances and distributed energy storage devices to help balance load (i.e. powerwall type devices in many places that communicate to sink/source energy from/to the grid on demand).

          3. don’t get me wrong, I really liked wind turbines at first, when they were a novelty I suppose. Now if I’m outside I cannot look anywhere without seeing several they are absolutely everywhere. it’s becoming a little tedious. Scotland has about double the potential capacity in offshore as onshore wind but utilises essentially none of it. sure its more expensive but at least i wouldn’t have to look at them. putting a battery in everyones house just seems really messy but I suppose that’s what the whole smart meter push is for right? continuously alter electricity prices to get people to match demand and supply themselves.

  2. In the latest edition of a local alternative energy magazine here in Australia ( Renew) they had an article comparing the costs of different types of energy.

    It is my recollection of the article that just about all forms of energy cost about the same with the exception of solar thermal which was relatively expensive.

    1. Thanks Saabman,
      Just in respect of renewables OR including all sources over period since
      start of industrial revolution – particularly more contemporary ?
      I’d like to see how they compare “net present cost” re best application of
      accounting standards along *with* short & long term (how defined ?) cleanup
      costs for such things as material recycling – which I guess in that magazine is
      primarily renewables and how it compares with coal/oil/gas/nuclear re
      radiation hazards including isotopes in fly ash & air for such as alpha emitters
      in fossil as well as the long term radiation hazards re fallout etc…
      FWIW: Since start of fossil/nuclear our average background radiation up
      by about 1% & with continued used of coal likely to rise similar next ~100 yrs…

        1. Dont be the first to take an engineering discussion down that path.

          I dont actually think fly ash radioactivity is very substantial, one of those situations where it will kill you through pneumonia and other opportunistic infections before the rads do.

          In regards to cost parity there are a lot of studies which calculate particularly wind to be very competitive, especially here in Aus where international markets for our coal and especially gas inflate domestic prices. Our gas is relatively expensive because of export competion. Everything I have read is contemporary, and includes numbers with and without things like CCS (carbn capt tech) for gas and coal plants. According to a gov report, wind is competetive now and solar is forcast to be competetive around 2030.

          https://industry.gov.au/Office-of-the-Chief-Economist/Publications/Pages/Australian-energy-technology-assessments.aspx

          1. Without wanting to open a can of worms, I have rarely seen research into this topic that hasn’t used (to be gentle) flawed assumptions to give weight to a preconceived conclusion. The issue is so loaded with political stakeholders, commercial interests, and ideological positions, that it is almost impossible to find a reliable set of facts from which to form a rational position. And that applies across the board, and to all modes of generation without exception.

            In the latter part of my working career I was often part of groups tasked to evaluate technologies to determine if implementing them would be a viable option for my employers. Doing this, I became quickly aware that the exercise is a minefield and that it takes a great deal of work to try and see through the BS and biases (including my own) that infect the process. While I cannot say I know all that might be at work in this topic, my experiences tell me that they are there, and that they are probably major.

          2. @DV82XL i suspect under those conditions no market research would be any different, the power generation sector is indeed very bad.

            market research as it stands is itself flawed, there is plenty of proper academic economics around but the smattering of pseudo science many people call economics have no place in a modern society.

            i know that vestas and siemens are calculating their externalities in a way i havent seen done by any other industry, they actually calculate from start to finish including externalities, they know how much fuel and resources will be used to put them up , make the materials, everything, some 2 or 3 causal links out in most cases.
            this also means their economic numbers make a different kind of sense than a naive budget.

            this all reflects modern academic economical thinking and hopefully more companies will follow suit.

  3. Ha I love this one.

    In Ontario Canada ( The land of the free.) Haa Haa Haa.
    It is illegal to share any harvested power. Period.
    It is a law they do not enforce. ( Just like it is still illegal to were a bikini in ” Hamilton Ontario Canada ” But you can go Topless.)
    I had a Friend at the time solar panels were starting to be noticed at homes. He was very Hi up in the food chain for making some very important laws in Ontario. One day I was starting to look into solar panels and home power systems and I asked him about what I could do and not do. That’s when I found out.
    Its not the voltage thats against the law. Its the sharing.
    The same with TV antenna signals that’s against the law to share.
    I don’t quit understand how they could put the too together but some how they did. That is what he told me, mined you hi did vote for shareing the DC power.
    But mind you most People that make up laws don’t understand what they are really doing when it comes to things involving a lot of our laws. They are in suits give them a screwdriver and tell them to remove the nail from the wall and they will spend a hour trying and not even know its not the right tool.

    I’m really glad they don’t enforce it. I provide night lighting for 7 houses in the corner of our block. I do wish there was a way for me to cross the street. there is one lady there that really needs power I would give her at least 30As for lighting and heating. Hydro is killing her. She pays more for delivery of hydro then she usages. Sad Very sad

    1. The situation in Ontario with electric power beggars belief. I live in Quebec, and we know how to really screw things up when we have a mind, but watching the unfolding of events next door in the power sector leaves me breathless.

    2. $0.30 per kWh here in London, Ontario. Sure, they’re Canukistani dollars, but still. No wonder manufacturers are closing up shop and moving elsewhere. Electricity rates are putting them out of business.

      I’m still glad they shut down the 4 gigawatt coal plant down the road at Nanticoke in 2013 though. It was pretty awful breathing anywhere near there.

      1. Lemme guess, Canada’s environmental laws and regulations are as screwed up as they are down here in the USA?

        Here we have it that a power plant can keep on putting out the same emissions levels forever, meeting the criteria at the time it was built.

        But if the plant owner wants to make any changes to make it cleaner, it has to 100% meet *current* emissions levels. For a lot of older power plants that essentially means razing it to the ground and building a new one. But if they did that, the environmentalists would file lawsuits and stage protests to block the rebuilding.

        So the environmentalists keep older power plants polluting instead of being happy to have them upgraded as much as is practical.

        President Bush Jr. tried to get his “Clear Skies” plan passed to alter the regulations to make that possible, but congress wouldn’t pass it.

        California does the same with vehicles from 1975 and up. They’re required to keep their original emissions control systems forever. You’re not allowed to make any alterations, not even if those alterations make a 1975 car as clean as a 1995. When the feds passed a law exempting vehicles older than 25 years from emissions regulations, California quickly passed a law saying they weren’t going to obey that federal rule. That’s why on TV shows like Overhaulin’ they don’t do any cars newer than 1974 and ones like Pimp My Ride didn’t do anything to the engines when they did newer cars.

        Government is obsessed with the *process* and *control* instead of what the results are.

  4. I talked about this some years ago and even granting the Negative (pun intended) galvanic effects I stated that a low voltage D.C. Micro grid would have many advantages and be more efficient. Everybody laughed at me. Glad to see somebody is taking it at least semi seriously now.

  5. As an aside, I worked with a German company that had a great wind power system that leveraged electric train technology by having high flying kites pull electric train bogies around an oval track, tacking at the turns. It was elegant, low cost, efficient and safe. They had a working demo but the company didn’t survive. I think that was because it was too simple and non-proprietary, so VCs couldn’t work out how to make a killing on it.

  6. 42V… seems odd… it is divisible by 6V which amounts to 7 an odd number of lead battery blocks at 6V each. A lot of battery storage is available in 6V and especially 2V for larger capacities, but 12V is most common for things usable at home. Telecom uses -48V which is 4 battery blocks of 12V… and is 54.0V on float charge. The 12V battery block is such a common commodity it has the lowest price even in the high quality, pure lead telecom market.

    Looked up the European Low Voltage Directive… it is 50VAC and 75VDC, so charging a 48V battery seems OK… I’m no expert on that directive. I do design 48VDC telecom power plants …it is pretty safe with some common sense… dry skin you won’t feel it. But wet skin will give you a buzz. Spectacular arc welding if you short it with big batteries on the bus. Just saying… 48V has been around as long as the telephone. Lots of equipment available that operates at 48V… inverters, rectifiers, lights and is gaining in LED lighting as well. Check out the off-grid people…. like Homepower magazine to review equipment and batteries available for running a house on DC storage.

    1. Actually it’s the Dutch NEN1010 norm we have to follow. There are much less strict “rules” if we keep everything below 50V DC. There might be safety inspectors checking the installation, that’s why we chose to use the lower Voltage and make sure safety is up to the higher standard. So we don’t have to shut down the whole experiment if there are minor abnormities. So that’s why we chose 42V (+/-15%) as that leaves some room for distributing surplus power to others within the grid.

  7. Has otherpower.com ever been featured on HaD? That site has examples of wind generators made just about completely from scratch, using struts and spindles from old cars for the blade hub and bearings.

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