Sun-following Garden Mirrors?

March 21st, 2023
house, ideas, solar
A friend of ours across the street has a small front garden, but since we're in Boston, their house faces north, and it's three stories tall the garden gets almost no direct sun. [1] Could we fix this with a mirror?

If I put a static mirror on the front of our house, even on an angled mount, it would only send light to the garden for a short period each day. To be actually useful, the mirror would need to be dynamic, tracking the sun: a heliostat. Since the movement of the sun is well understood you can do this without any sensors, just calibration.

With a bit of looking I found two companies selling heliostats, though I think the main residential use is bringing more light in through windows and not gardening. Possibly building something would be fun, but I'd be nervous about wind loads and breakage filling our own front garden with shards. Has anyone done a similar project?


[1] Boston's latitude is 42°, so the peak height of the sun on the equinox is 48° (90°-42°). The solstices are ± 23° (axial tilt) so at solar noon on the summer solstice it gets up to 71°. The house is ~40ft tall so its shadow is always > ~13ft (40/tan(71°)).

Comment via: facebook, lesswrong, mastodon

Recent posts on blogs I like:

Solution-Focused Brief Therapy

Look! A therapy technique people don't already know!

via Thing of Things May 14, 2025

Workshop House case study

Lauren Hoffman interviewed me about Workshop House and wrote this post about a community I’m working on building in DC.

via Home April 30, 2025

Impact, agency, and taste

understand + work backwards from the root goal • don’t rely too much on permission or encouragement • make success inevitable • find your angle • think real hard • reflect on your thinking

via benkuhn.net April 19, 2025

more     (via openring)