Extrinsic Motivation: Off-grid Solar System Monitoring Solution


This solar monitoring project was entered in The Hackaday Prize and didn’t make the semifinal cut, but it is worth featuring on the site because we think that it is pretty cool. The idea started all the way back in May of 2013 when [Michel] was planning to attempt to bring his house totally off the grid in an effort to become as independent from the local Utility company as possible. After a bit of calculating, he figured out that the solar cells on the roof could potentially provide about 80% of the power needed, which of course took into account the lack of sun during the winter months in his area.

[Michel] posts a lot of the technical details on the Hackaday.io page and lists the components that were required to set up this system. At night, a lighting mechanism shows whether the building is being run off of the Photovoltaic (PV) System or if it is getting power from the grid. He states in the projects logs why it is important to monitor the solar cells and provides some amazing graphs of the data that was recorded through the energy-intelligence platform that he integrated into his home. An example can be seen posted below. A few quick specs of the project include the solar field being made of 16 solar modules providing 4300 Wp (Watts – peak) of electrical power. The system comes with a comprehensive remote control as well. We like this idea a lot. Now, would you install something like this up on your own home or office? Let us know in the comments.

SpaceWrencherThis project is an official entry to The Hackaday Prize that sadly didn’t make the quarterfinal selection. It’s still a great project, and worthy of a Hackaday post on its own.


19 thoughts on “Extrinsic Motivation: Off-grid Solar System Monitoring Solution

  1. nice job!
    the graphs clearly shows what are the downsides of an off-grid pv islands.
    of course it depends on the local regulation whether one is allowed to feed back
    juice to the grid. but if you can have an on-grid setup, your spring-summer-fall overproduction can cover the missing energy during winter. the provider does billing
    on yearly basis, so nothing is lost.

    besides pv islands’ batteries tend to die sooner or later, say in 3-4 years. and they are not that cheap to throw them away, indeed, as they are hazardous waste.

    i’m lucky enough to have an on grid system, but the electrical provider will not allow me to connect the otherwise isolated S0 outputs of the counter to measure the power i fed back. so i also needed a solution to monitor how things are going.
    there were some ready to use solutions available by the inverter’s manufacturer, needles to say for big $$.
    then i found an rs422 board on ebay which connects to the inverters internal bus, and normally is used to daisychain multiple inverters to provide common management. it was like 30Eur or so. then i just needed an usb-to-rs422 dongle (also from ebay, never the less, it needed some soldering as it came with a wrong diode installed) and the all-rounder TP-Link MR3020 (16EUR where i live + TAX), installed a stripped down openwrt, and my monitoring solution was ready. Fronius has a pretty good documentation of their stuff, which also included the coms protocol on the rs422 bus, so as long the inverter produces something i can read several values from the bus (actual power, actual current, actual voltage [ac and dc], daily maximums).
    as i am lazy i didn’t wanted to build visualisation for the data i gather, i just send them off from the mr3020 to my emoncms.org feed.

    1. “i’m lucky enough to have an on grid system, but the electrical provider will not allow me to connect the otherwise isolated S0 outputs of the counter to measure the power i fed back.”
      Thats odd isn’t it ? They don’t want you to know how much power they are getting from your installation? So I guess they don’t want to pay you properly HuH?

    2. The standard lead acid batteries are far from expensive to dispose of. In fact, if you buy new batteries to replace the old ones, they’ll actually knock off the price since they can reprocess old batteries into new ones.

  2. Looks nice for timing appliances and home automation Run the washing machine, dryer, dishwasher, fridge, etc during low load times. The fridge can top off the cooling during dips and then coast for a while. A combined washer/dryer could get a load of laundry done any time after noon. Bitcoin mining to fill in the gaps ….

  3. Just need to adjust loads. Afternoon where all the lost power is, you crank up the AC to cool the house way down so it can coast all night long. Someone mentioned that batteries don’t last long, I know guys with solar installs that have batteries that are 10 years old. If you buy garbage batteries they don’t last, you have to buy high end batteries and do the maintenance on them every 3 month as well as have an automatic watering system. And you don’t throw away old batteries, you take them to a metal scrap yard and sell them for their lead content. So he needs to install a smallish battery bank and start there to offset night loads. Problem is you cant top off batteries and ride through winter, not unless you have some very exotic batteries that can hold a charge for 1 year without power loss.

  4. I have 12 Yingle cells on my roof, which can cover about 3000 peak. Minimum tends to be about 250 during the day – which still enough for our pcs, fridge and lighting.
    Luckily we live in an area where the grid buys from us at the same rate they sale, effectively being a battery.

    My only grumble is the inverter has a fancy wi-fi model and monitoring *that requires you to send the data to their off-site website only to display it back to you*
    Havnt found a way to get the data directly and dont have time to invest in that project.
    Which is a shame, as Id like to link it up to my LIFX bulbs to reflect usage.

      1. How exactly am I being ripped of? They buy my energy back at the exact same rate their sale it to me :?
        Sure, I could probably shop around and buy cheaper PV’s, but paying a little extra to get the installation done for me and my power company (GreenChoice) to sort it all out is fine by me. They gota make money somehow.

        Their online monitoring software is good enough too – I get similar graphs to this, and can export the data easily enough.

        My concern was purely from a privacy standpoint. I dont see why the data needs to go to their computers and back to mine, rather then just straight to mine. It sends it though my own wi-fi network after all. Would it hurt them to put up some documentation and let me poke around with it?

  5. I know I know this is hack a day and not product a day, but because there seemed to be some expressed interest in a simple solution https://www.egauge.net/ makes a really nice product, not super cheap, but in comparison to a 16 panel install, it is cheap. You can hook up multiple current transformers to the gauge and then write basic math formulas for displaying the information in near real time. Hook a couple up around the service mains, and then one up to one of the hot leads coming in from the solar array (as that will almost always be balanced you don’t need two) and and you can set up the formulas to show total house consumption, total array production, and then total array production sent out to grid if ever you are able to achieve that. With the extra inputs you can put it on things like your freezer, ac, heat pump, w/e

  6. I would really like to read this project through and comment but the black background is unreadable for me . The layout is weird too on this blog site and I don’t think I can post without joining something and I have joined enough spam sites . so I’ll just express my disapointment and dislike here.
    Maybe someone will take it on board when they post their project .

    1. My not-so-old, but probably as tired (holes in a retina ain’t fun) eyes see white-on-black better than other way around.
      Layout could use some work (most of the monitors sold now are landscape yet most of the internet insists on using only 25-30% of their width), but color scheme is fine.

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