[mowbot] solar cells

robin nospam at acm.org
Tue, 24 Sep 1996 21:53:02 +0100

Monta Elkins <Monta nospam at vt.edu> wrote:
> I move that "solar" be an optional component.
> I don't think solar power will put a dent in our
> energy budget.
If they could supply all the energy required, putting solar cells on
Mowbot would be worth doing, because it would eliminate the mechanical
difficulties inherent in a charging station. If we have to have a
charging station anyway, solar cells stand a very good chance of supplying
all the energy because they can be larger and better positioned. On the
other hand, a fixed recharging station can easily be wired to the mains;
a much cheaper solution.

I agree that solar power isn't at ``requirement'' level, but
is a ``suggestion'' worthy of serious consideration when we know
better Mowbot's demand for energy.

> Anyone got figures on power output from $100 of solar
> array?
These figures are all fiddled for 12V, full sun, 66 UKP ($100) +/-10%.
I have included two that cost more than the budget and scaled down their
outputs in proportion to the cost for comparison. Where there are
quantity discounts, I have assumed we will get the best discount
(typically 10 or 25 items) and that no additional sales tax or duty
is payable (true for me).

Supply Qty Part Current Size(mmxmm)
28 BZ46A 840mA 380x455
2 BZ51F 500mA 360x570
3 CJ40T 360mA 278x477
0.6 WD37S 180mA 330x356
RS (Radio Supplies):
6 194-098 270mA 165x304
1 194-111 310mA 334x359
1 194-155 270mA 270x276
Edmund Scientific:
4 A37,333 100mA 101x190
3 A52,288 150mA 247x330
3 A38,805 150mA 175x476
0.6 A35,437 250mA 177x203

The really high efficiency cells are lovely, but well outside our
budget, e.g. 323 UKP ($485) for 8 amps! (266x324)


Copyright (C) 1996 R.M.O'Leary <robin nospam at acm.org>  All rights reserved.