[sclug] Wood vs GHC

Ed Davies sclug.xu.1106 at edavies.me.uk
Fri May 17 09:49:11 UTC 2013


On 2013-05-17 08:33, Bob Dunlop wrote:
> Back to Pi's and heating projects.  Once you add a computer into the
> equation there is a lot more interesting things you can do even inside
> the realms of what might be considered sane.
> 
> If I ever get my grandiose schemes off the ground?

I have somewhat more grandiose schemes which some might
not consider sane.

At the moment I'm sitting in a mobile home on a caravan
park in Caithness waiting for the Crofting Commission to
sort out the bureaucracy to allow me to buy a largish
building plot (actually two plots) on the top of a hill
overlooking the Moray Forth.

The plan is to build a very well-insulated and airtight
house which is not connected to the grid (mains electricity,
water, gas, whatever) other than internet (and 'phone I
suppose).

Mechanical heat-recovery ventilation, of course.

Primary power will come from PV and solar thermal. I
plan to start with about 6 kW of PV and 8 ? 20 ? 47 mm
solar thermal tubes (already bought and sitting, with a
lot of my other stuff, in a shipping container up on the
north coast). Energy storage will be a huge heat store
(about 10 tonnes of water) giving near interseasonal
heat storage and, initially, about 10 kWh of LiFePO?
batteries. I'll see how that goes (with a little petrol
generator for backup) over a winter or two then decide
whether to add more PV, a small wind turbine (I have a
particular 1 kW model in mind but will see what's
available in a year or two) and/or more batteries.

Anyway, there's a lot of opportunity to control the
way that all operates to make things run more efficiently
than the typically fragmented control setups I've seen
bodged together on many off-grid houses. Anticipating
the weather will be important (particularly if there's a
combination of PV and wind) but I've yet to see any system
do that. My plan is to initially manage it all fairly
manually (switching stuff on and off as required) at first
then automate as experience and money allows.

I've been playing with Python and Node.js quite a lot
over the last year or so including on a little ARM
Pogoplug (http://edavies.me.uk/2011/09/ssh-pogoplug/).
No strong feelings one way or the other between the two
(I've got to quite like JavaScript now that I think of
it as Lisp with semicolons, not baby-talk C++) but I
do find the Node.js idea of using the same language
(and even the same code) on the server and client
attractive.

More about the house on my blog and web site:

http://edavies.me.uk/blog/tag/houses/
http://edavies.me.uk/2008/11/house/

Ed.



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