The temperature sensors are AD22100AT
http://docs-europe.electrocomponents.com/webdocs/077f/0900766b8077fedc.pdf
The humidity sensors are HIH4000-001
http://docs-europe.electrocomponents.com/webdocs/06ba/0900766b806ba122.pdf
The arduino is powered by the USB/Serial Light Adapter
To activate the power to sensors I use a IM23TS relay, coil of 5volts 50mW
http://docs-europe.electrocomponents.com/webdocs/0f95/0900766b80f95686.pdf
For the SD power suply LM3940IT-3.3/NOPB
http://docs-europe.electrocomponents.com/webdocs/06e8/0900766b806e8b70.pdf
and a shifter 74HC4050N,652
A RTC PCF8563P/F4,112
http://docs-europe.electrocomponents.com/webdocs/0f65/0900766b80f65100.pdf
A demultiplexer M74HC4051B1R
http://docs-europe.electrocomponents.com/webdocs/0edc/0900766b80edc224.pdf
I think this is all, of course the condensators, resistances, diodes etc...
but the current when it´s measuring is arround 30mA, i think that is not very much.
All the components are powered with the relay, during sleep they are out.
Regards