Quick`n`Dirty Heliostat - Get Some Sun Into Your Home




Introduction: Quick`n`Dirty Heliostat - Get Some Sun Into Your Home

About: I like to make / fix / improve "things"...

This is work in progress...

I just want to give you an impression on what great effect a simple mirror in your garden might have on your life, well-beeing and energy consumption... Please try it for yourself!

My girlfriend and me live in a nice, quiet, green, but still urban place.
We are surrounded by other buildings, we have a nice lawn with direct sunlight in front and a little garden under tall trees in the back.
Well, I really can not complain about those things.

BUT our flat itself is like a cave and pretty dark. You have to turn on the lights even at noon time in summer with a cloudless sky. Pretty cozy in wintertime though.

So today I just wanted to try out, what effect a heliostat could have. Had this idea in mind for years now, but never really tried it.

The effect was AMAZING! And I will definetely put some more work in it in future.
I was only using an old mirror of 55 x 35 cm (0.19 sqm) and I never saw my home office that bright before. (Made me realize that it could need a thorough clean up,... *cough*...nevermind...)

First pic is the "heliostat" (or better adjustable mirror, since it´s not self-aligning yet), second is my room without artificial lighting AT NOON, third pic is with mirrored sunlight (2nd and 3rd pic for comparison at the same time; same aperture, exposure time and ISO setting).

Materials (which I used, the setup is so simple that you can use anything laying around which fits the purpose):

- an old mirror I found in a garbage pile in the basement (used for testing, you can get mirror tiles for about 0.27 sqm via amazon for 9,99 € or 7.33 $) (and I will get loads of them, hrhr)
- an old document holder
- an old TV-Turning platform, this one was from IKEA
- screws / screw hooks
- some rope/cord


- a drill might be useful, but you can do without (We´re just testing/getting an impression in this step)

- some scissors

- your eyes

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Step 1: Testing

Basically, the only thing you have to do is setting up a mirror in direct sunlight and align it´s reflection towards the window of the room you want to have more (sun)light in. Just place the mirror on the ground and support it with a gardenchair or whatever fits.

Now go back inside and watch the result.

Step 2: Awesome or What...

I never saw my room in such bright light before.
Got 140 W of halogen lamps plus a 100 W standard lightbulb plus indirect light through the window. All combined not slightly as bright as the 55 x 35 cm junk mirror... not to mention the light quality.

For testing purposes I simply attached some strings to the base. Works for horizontal "tracking" and for switching from bureau to living room "remotely". Vertical tracking is yet unsolved.

But this was only a three hours first test which proved the great potential, usefulness and DIY-capability of that technique.
I´m looking forward on the effect of 2 x 2.7 sqaremeter of pure sunlight shining in our "cave" ;)

Found several tutorials on the net regarding tracking of solar panels and heliostats, check them out.
Go on and build your own, as I will do and tell me your experiences, please!
Will update as soon as I can!

[Edit: See next page for updates.]

Step 3: Poor Mans' Linear Actuators

Today I worked on the vertical tracking.

I´m still lacking some appropriate motors and gears so my cordless screwdriver had to serve as a substitute to check the technical feasibility.

A threaded bar and a fixed nut work astoundingly well as a linear actuator.

The fixtures are from metal construction kits I stumbled upon in a 1$/1€-store.
If you happen to see some of those kits for 1-2 €/$, BUY THEM ALL (ore maybe at least 2-4), the parts come in pretty useful for all kinds of projects.
And you probably won´t get those any cheaper anywhere!

To be continued...

Step 4: Bigger and Concentrating Mirror (stainless Steel)

Quick update (more details to come):

Ordered some sheet metal for experimental use via amazon marketplace.

Not that cheap, but not as expensive as one might think.
1500 x 500 x 0,8 mm stainless steel with mirror finish for about 25 € + shipping.
Easily bendable, so suitable for a concentrating mirror.

See the effect in the pictures.

Warning:NEVER look directly into the concentrated light! Avoid exposing your skin to the concentrated light for longer than a few seconds!

Got a pretty nice one-sided sunburn in my face trying to clean my window while the mirror was oriented to it...
In less than five minutes.

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    12 Discussions


    Question 2 days ago on Introduction

    This is a wonderful idea. I am going to see if I can reflect light from a window into another room. Have you tried this?


    5 years ago on Introduction

    Nice! I've got a big dark room with a big window AND a big mirror laying around. Guess what I'll be spending waay too much time on tomorrow. One question: how much heat does it carry with it? Guess I'll find out tomorrow!


    Reply 5 years ago on Introduction

    Thanks and sorry for the late reply;

    I think while you don´t attach a special filter/coating to either the mirror or your window, (almost) the whole spectrum of radiation will be redirected to your room, including infrared aka heat (with minor losses).

    If you have any before / after pics, I would be really glad if you could post them here or send a link.
    My efforts are paused atm (winter time), will continue next spring, but it´s still work in progress.

    For even bigger, unbreakable and bendable (focusing/concentrating) mirrors, research for sources of stainless steel sheets with mirror finish as seen in step 4.

    For more advanced setups and components needed for tracking follow the link redrok posted below or visit his website www.redrok.com


    5 years ago on Introduction

    Have you tried your setup yet?

    On your pictures it seems like the mirror is a little concave.
    As most make up mirrors are, to provide a little magnification when you look at yourself from a close distance.

    Regarding the distances shown in your photos, your room / window will likely be "somewhere out of focus" and you might not notice any effect in your room, even if you aim carefully.
    The curvature of the mirror will spread the reflected light to a pretty large area (or concentrate it to a tiny dot of light if your room luckily happens to be in focus).

    Try attaching a planar mirror to the chassis.

    I added a step to the instructable to show the effect of a slightly curved mirror.

    Akin Yildiz
    Akin Yildiz

    Reply 5 years ago on Introduction

    i'm really busy these days, and when I said I was going to do it, the next 2 mornings were very cloudy. hopefully this week, but good call on the mirror being concave, although one side of it is more straight, which I was going to test with. maybe I can find a small straight mirror to secure on the chassis like you said. thank you for your reply, don't worry I will let you know once I am done :) thanks again !

    Akin Yildiz
    Akin Yildiz

    5 years ago on Introduction

    i'm getting ready to do a test run sir... I will be using an adjustable make up mirror that I have found at the thrift store. this thing actually adjusts to all angles, horizontal and vertical with much ease. I will be mounting this to a stirdy/heavy - flat piece wood to stabilize it and put it on the roof of the garage.. that you see in the picture. nobody goes to that roof and it is very easy to climb to :)

    picture 1; my room at 10am

    picture 2; it's been sunny since 6:30am on the other side of the building

    picture 3; the test run mirror, i may upgrade the size depending on how this turns out

    picture 4; the garage rooftop for the placement of heliostat

    hopefully tomorrow morning I will be up there, trying to learn how to aim it :) if I can make the bottom board heavy enough, then I will be attaching ropes to all 4 corners of the mirror, so I can actually adjust it both horizontal and vertical...

    Akin Yildiz
    Akin Yildiz

    5 years ago on Introduction

    the only reason I have started posting on instructables is because i'm in the same situation. our apartment gets almost no direct sunlight. i moved from a house with a backyard and lots of plants. please check out my posts to see how I am trying to overcome this situation. i am so glad to see this post, it is really amazing. i have always dreamed of having such technology. didn't they light up inside of the pyramids this way?!

    That is amazing! I could really use one of these; I can never get much natural light in my house no matter what time of day :P


    Reply 5 years ago on Introduction

    It really does, much more as one can tell from the pictures. Can´t wait to get bigger mirrors and to work on the tracking. Will update soon (hopefully).