Saving Electricity on Shabbos and Throughout the Week

by Steven Krieger
As humans, we attempt to make our lives as fulfilling as possible. As religiously observant people, we tend to be more conscious of our surroundings. As Jews, we embrace different, and some would argue additional practices into our daily lives. Therefore, it’s not surprising that the idea of Jewish Standard Time (JST) was created. There’s just so much we want to do, but so little time. We’ve all participated in the following “pleasantries:”
“Will you hurry up, we’re going to be late!”
“I can’t find my jacket.”
“You don’t need one, it’s not that cold. Just hurry up, I don’t want to be late.”
“I’m coming, I’m coming.”
Following the dialogue, we run out of the house and invariably forget something. It might be our wallet, keys, tickets, or directions. We go back for some items, but rarely do we go back to turn off the lights and the electricity wastefully burns for hours. The irony is overflowing. Here we are, trying to squeeze so much into a day to fulfill ourselves, but we neglect to see the benefits of spending half a second to flip off the lights?
Leading an environmental campaign or donating thousands to conservationists isn’t simple, but turning off the lights during the work week or using a plug-in Shabbos timer with fluorescent light bulbs is certainly within everyone’s realm. We all have a responsibility to save electricity on Shabbos and throughout the week Furthermore, there are financial and halachic motivations that work towards environmental conservation by minimizing electric waste.


Brightness is the standard for comparing light bulbs and lumens are the appropriate unit of measurement-not watts as one might guess. A typical incandescent light bulb converts 10% of the electricity into light and wastes 90% as heat. Compact fluorescent lights (CFL) utilize technology that reduces wattage while maintaining lumens, which minimizes the wasteful byproduct of heat. Therefore, the only noticeable difference between an environmentally-friendly 15 watt fluorescent bulb a traditional 60 watt incandescent bulb is up-front cost.

Finances, Waste

Pure environmental benefits aren’t always motivating enough, so let’s talk finances. 10%-13% of a home’s electricity bill is determined by the flip of a switch, as people neglect to turn off electric power sources. Additional cost-savings associated with light bulbs can be realized through the use of Shabbos timers, or by purchasing more efficient light bulbs, which will be analyzed below.


In a Shabbos living room, a plug-in light fixture or a halogen lamp burns all night (assuming the light doesn’t disrupt the convened Shabbos shluff). Let’s assume the plug-in light fixture has three bulbs at 75 watts apiece and the halogen lamp has one 450 watt bulb. At a rate of $0.07 per kilowatt-hour it costs us over $10 per year for the plug-in fixture and over $20 a year for the halogen lamp. Home Depot sells timers for $5 and the shipping is included. Depending on your light source and assuming the lights would be off half of Shabbos, the timer would make you money in three to six months. Even if you only use one 75 watt bulb, you’ll still save money in approximately eighteen to twenty months. The saving could certainly increase with additional timers.

Compact Fluorescent Lights

If there was an environmental section of Pirkei Avos, it might say something like, “The one who puts his lights on timers is praiseworthy, but a pious man puts his fluorescent lights on timers.” Environmentally, fluorescent bulb technology has always been superior to traditional incandescent bulbs, but their price tag was a deterrent. Due to a collaborative effort from the U.S. Department of Energy, industry, and NGOs, fluorescent bulbs have become more mainstream and their popularity is reflected in a lower price. By installing fluorescent bulbs in 25% of your home’s light sockets, you can save 50% off your electricity bill. If you can’t afford these economies of scale because of the large initial costs, even replacing one bulb has savings.
A single fluorescent bulb still has a higher purchase price when compared to a traditional bulb. However, the associated savings from the 10-13x longer lifetime expectation and efficient energy production is more than enough to offset the higher initial expense. For example: If you were to go to Home Depot, Lowes, or your local hardware store and purchase a Sylvania 15 watt twist compact fluorescent bulb to replace an incandescent 60 watt bulb, it would cost you about $9. Sure, it’s a lot of money for a light bulb-you could even get a deli sandwich for less than $9, but you can’t analyze it in isolation. After realizing you’d need at least 10 incandescent bulbs to last as long as one fluorescent bulb and you’d be paying 4 times as much in electricity costs to generate light because of the higher wattage, you’d discover that fluorescent light bulbs will save you over $25 per year and that’s enough money to buy several deli sandwiches.
We’ve already agreed that $9 is a lot of money for one light bulb, but they don’t have to cost that much. There are numerous on-line retailers who sell fluorescent bulbs at discount prices-you just have to buy enough to offset the shipping. Fortunately, many of them have a flat shipping fee. Incandescent light bulbs are typically sold in packs of four. If you bought four fluorescent light bulbs on line you could pay as little as $4.75 per bulb , which will ultimately generate a larger financial savings than buying bulbs one at a time.

Single Bulb Cost
Single Bulb % Savings
4-pack Cost
4-pack % Savings

[NOTE: Assumptions: an average household uses 5,000 hours of light per year, $0.07 per kilowatt hour, 7% interest rate compounded monthly and yearly respectively.]


Fine, you’re still not convinced. I didn’t want to do it, but I’m pulling out the trump card- halachah. Rabbi Barry Freundel of Kesher Israel, Washington D.C. explained in Jewish Law and the Environment that the concept of Bal Tashchit (do not destroy) is derived from wartime orders. In the midst of war, soldiers are forbidden to destroy trees-even for useful purposes. Back in the day, tree materials were used to create materials necessary for war, but even this useful cause is forbidden. Furthermore, in Talmud Bavli, Shabbos 67b, “Rav Zutra teaches: One who covers an oil lantern or uncovers naphtha [a kind of fuel] has sinned to Bal Tashchit.” Rashi explains that these actions are wasteful because they encourage the fuel to burn faster. I’m not a rav, but since we learned to preserve oil, and trees during war, I doubt any wasteful behavior (especially allowing our lights to burn endlessly) would be acceptable. Therefore, in order to prevent waste, I contend we have a halachic obligation to be half a second late for the meeting, or to spend fifteen more seconds setting the Shabbos timer as we run out the door.


If everyone in the United States replaced one incandescent bulb with one compact fluorescent bulb, it would be the equivalent to removing 1,000,000 cars off the road. We may not be focused on stopping the largest corporate polluters, implementing environmental policy, or even educating others, but we certainly have an obligation to be responsible for our own actions; especially when the “value to effort” matrix is so blatantly in favor of environmental action. Take that obligation seriously and install CFLs and Shabbos timers this Shabbos because every effort does matter.
Originally posted in “On Eagles’ Wings” January 27th 2004