I used to be skeptical. I can wash the dinner dishes by hand using barely four liters of water, while energy saving dishwashers use around 4 gallons per full load, plus all that energy to heat the water and slosh it around.

In this article I will share my techniques for cleaning dishes by hand with as little water and energy as possible. But don't forget that, for most of us, efficient dishwashers are a better option than hand-cleaning, as long as you use the dishwasher properly.

If you watch a typical American wash dishes by hand, it's easy to see why a dishwasher wins over hand washing almost every time. Some people let the tap run continuously as they clean; some fill a sink with hot water and then run cold water in the second sink to rinse; some are constantly pumping dish soap into a sponge. When you consider all the energy that is required for heating the water, making the soap, and even the energy for purifying and pumping the water to your house, it can wind up being considerably more energy than you think.

When people think about the energy use of a dishwasher, they usually think of the electricity used to pump water around inside the dishwasher. They might think that they can save all that energy if they clean dishes themselves. It turns out that pumping the water uses less energy than heating the water - only 20% of the total, compared to 80% for heating both in your hot water tank and in the dishwasher proper.

You might think that hand-washing dishes would at least save you the remaining 20% of the energy used for pumping. But since people typically use much more water than energy saving dishwashers, the end result is more energy use in hand-cleaning than when using a recent-vintage dishwasher. (Older dishwashers may use up to twice as much hot water as the most recent models, so it is possible to do better by hand than that old avocado-colored dishwasher!)

Efficient dishwashers can wash dishes with a tiny amount of water by doing two things you cannot match when hand washing: Heating the water to 140F - too hot for your hands - because hot water is better at getting grease and food waste off dishes; and pumping the water at high pressure, which blows food off plates and cutlery more effectively than you can do with a scrub brush, consuming a tiny amount of water in the process.

Where energy efficient dishwashers are less energy efficient is where people sabotage the energy saving features of the unit, by pre-rinsing, maintaining too high a hot water tank temperature, using too long a cycle, making excessive use of the rinse-and-hold or heated-dry features, running the unit half empty, and wasting dishwasher detergent.

It is possible to outperform a dishwasher in terms of energy efficiency. Whether it's worth the effort is moot. Energy efficient dishwashers with an ENERGY STAR logo can do a full load of dishes for the energy equivalent of at most 1.54 kilowatt hours (kwh) of electricity (including all the energy for mechanical and heat). At a typical cost of $0.10 per kwh, and assuming you clean the dishes in cold water, the most you would save is about a dollar for every six loads.

And this is for a full dishwasher load - which can accommodate 6-8 place settings as well as 6 serving pieces. Assuming bread plate, dinner plate, bowl, cup and saucer, knife, fork and spoon, that works out to 72 items cleaned, so you might save about a cent for every five items if you clean by hand and use no energy.

Let's suppose, for argument's sake, that you want to wash dishes yourself. I rather enjoy cleaning dishes; it's often relaxing, plus it leaves my hands soft and clean! How can you clean dishes by hand using as little energy as possible? Here are my pointers:

Never drain used water. After you've washed a load of dishes by hand, or rinsed vegetables, leave the water in the sink. Use this gray water to pre-rinse the dishes to remove the bulk of the food residues. That way, when the time comes to wash, you'll need a lot less water.

Go easy on the tap. Turn it on for short bursts, only when you really need water.

Use a faucet aerator. You can rinse dishes effectively while saving water using a faucet aerator, which injects a stream of air into the water.

Use cold or just lukewarm water. Where I live in the tropics, no one cleans dishes in hot water, although of course the cold water tap is a pleasant 70F. This just goes to show that you can, at a minimum, clean in lukewarm rather than hot.

Start with a hand's depth of warm water in the sink. Wash dishes in that, and rinse in your second sink with cold water. Otherwise stack the dishes after cleaning, and then rinse them all in cold after you finish the soap wash.

As your mom told you, start by washing the cleanest dishes - glasses, cups, cutlery, plates, leaving the dirty pots and pans for last.

By following these tips I can clean dishes from a meal for four people in about three liters of fresh water. But why would I want to do this? And how many of us can really outperform the efficiency of a well-built, energy saving dishwasher?

If you think you can outperform a new dishwasher, here's convincing research that energy saving dishwashers not only clean with less energy, water and detergent than human subjects, but also get the dishes cleaner.

A German study asked over 100 subjects to wash a dozen place settings of methodically soiled dishes. Each volunteer was given the run of a washing area and taped on camera; energy, water and detergent consumption were tracked. The dishes were then inspected for residue using a recognized standard for clean dishes. The same dishwashing setup was tried using efficient dishwashers.

The energy efficient dishwashers used 15 liters of water and 1-2 kwh of energy to wash 12 dinner place settings, while only two of the over 100 hand-washers used less than 20 liters of hot water. (Over a third of the human subjects consumed more than 100 liters of water each!). However, 70 of those tested did succeed in using 2 kwh or less of energy - and a quarter of the test subjects used 1 kwh or less.

From this study we can conclude that it is possible to match the energy performance of efficient dishwashers, or even beat their performance slightly. But the energy saved is so small that it doesn't justify the extra effort. All test subjects took at least 40 minutes to do the load, while the energy saving dishwashers needed only a quarter hour of human effort for loading and unloading. Considering that the US government rates dishwasher efficiency based on 215 loads of dishes per year, a typical hand washer would be adding 25 x 215 minutes, or 89 hours of effort to their year. That's more than two weeks of 9-to-5 work out of your life!

You would do better to save that time and consider other things you can do to conserve energy. Imagine how efficient your home would be if you devoted an extra 89 hours a year towards weather-stripping, insulating, sealing air leaks, and changing light bulbs to more energy saving lights. Or how much more relaxed you'll be by using the energy efficient dishwasher. You just gained two extra weeks of free time!