A presentation given to GeeKyoto in London by Adrian Hon and Naomi Alderman, examining the environmental impact of the Sabbath, and introducing the Secular Sabbath concept

1. A Secular
(and Environmentally Friendly)
Sabbath
Adrian Hon and Naomi Alderman

2. Orthodox Jews
don’t all look like this

3. “Remember the Sabbath day, to keep it holy”
Exodus 20:8
(number four in the ten commandments)
“Six days shall you work but on the seventh day
you shall rest”
Exodus 34:21

4. What’s work?
According to the Orthodox Jews, work
includes:
• writing
• cooking
• driving a car
• changing the state of anything electrical

5. Changing the state?
• You can leave a light on or off, or on a
timer, but can’t alter the settings
• No using computers, telephones, cameras,
televisions, any other electronic devices
• All food has to be cooked in advance

6. What’s left?
• Meals with friends
• Going for walks
• Reading
• Sleeping
• Singing
• Conversation

7. Adrian: I’m not Jewish - obviously. Originally interested in experiencing a sabbath, having day of rest
away from mobile and computer and tube. Then got thinking about whether sabbath was
environmentally friendly or not.

8. Power Consumption
Device Model Quantity Hours Power Change
(W)*
Lightbulbs 15W energy saver 16 -2 15 -480
Urn +24 +2690**
Small LCD TV Samsung SM741MP 1 -8 42 -252
Big LCD TV Toshiba 37WL66 1 -8 240 -1920
Computer iMac 20” Core Duo 1 -8 80 -640
Console Xbox 360 1 -3 185 -555
Laptop Dell Inspiron 1525 1 -5 30 -150
Astra 2008 5-Door
Car 1 -40km -156g CO2/km -6.24kg
Hatchback 1.6i
* Power consumption = (average on mode) - (standby mode)
** Overall change as measured by power meter over Sabbath period
Based on family of four, relatively environmentally friendly.
This is not scientific - rough estimation of changes in energy usage.

9. Results
• Total change:
-1.307kWh, -2.6l petrol
• Cost savings:
£2.99 (£2.86 + £0.13)
• CO savings:
6.998kg
2
This is per week. Over a year, savings add up; if you did it every month, save £40. If every
week, over £150; CO2 saved would be 350kg.

10. Recommendations
• Consider inviting friends over for a monthly
“secular Sabbath” - no TV, phones,
computers, just chat, walks and good food
• Don’t use an urn
• Don’t drive
• The benefits aren’t just environmental: it
really does feel good for the soul
Energy savings don’t have to be seen as sacrifice, especially when people are getting
information overload - can be see as a good byproduct of a new ‘day of rest’

11. Sources
http://www.energysavingtrust.org.uk/energy_saving_products/
Lightbulbs 15W energy saver types_of_energy_saving_recommended_products/
energy_saving_light_bulbs
Small LCD TV Samsung SM741MP http://www.ebuyer.com/product/120778
http://www.home-entertainment.toshiba.co.uk/consumer/
Big LCD TV Toshiba 37WL66
products.nsf/pages/lcdplasma-regza-37wl66?opendocument
http://weblog.infoworld.com/enterprisemac/archives/2006/02/
Computer iMac 20” Core Duo
imac_keeps_its.html
Console Xbox 360 http://www.hardcoreware.net/reviews/review-356-1.htm
http://www.dell.com/content/topics/global.aspx/corp/
Laptop Dell Inspiron 1525
environment/en/prod_datasheets?c=us&l=en&s=gen
Astra 2008 5-Door http://www.vcacarfueldata.org.uk/search/vehicleDetails.asp?
Car
Hatchback 1.6i id=20260
CO2 emissions http://www.scottishpower.co.uk/small_business/
from electricity customer_services/where_we_get_our_energy/default.asp

12. More Information
• http://www.secularsabbath.org
• http://en.wikipedia.org/wiki/Shabbat
• adrian@mssv.net
http://mssv.net
• naomi.alderman@gmail.com
http://naomialderman.com