What’s Possible?

What you’ll find on this page: At the Affordable Comfort summit in San Francisco in March 2011, Gary Klein and Larry Weingarten hosted a 90-minute discussion titled The Future of Hot Water. In many ways, it could as well have been titled The Future of Water. Here are some of the ideas that were thrown about in that seminar.

This was a far-ranging discussion. The point of departure was a giant flow chart. That represented what the seminar could potentially be about, but what it actually was about rested partly with the audience, so not all the items on the flow chart were discussed.

But I present the flow chart first, in textual form, to give some idea of where Klein and Weingarten wanted to go.

On the left side of the chart was The Past and Present, and on the right side was The Future.



New Technology

  • Recycling heat and water
  • Efficient and safe heaters

Old Technology

Lessons of the past
  • Good: simplicity works
  • Bad: safety concerns

How Technology Is Used

How Much Water Do We Need?

How big is the problem?
  • How the world uses fresh water: • about 70 percent for irrigation • about 22 percent for industry • about 8 percent for domestic use (UN)
  • Daily indoor per capita water use in the USA is 69.3 gallons (AWWA)
  • 20-50 litres (5.3 to 13.2 gallons) of water/day needed for drinking, cooking & cleaning. (UN)

Space Station use

“The Water Recycling System will reclaim waste waters from the Space Shuttle’s fuel cells,urine, oral hygiene and hand washing, and by condensing humidity from the air. 40,000 pounds per year of water from Earth would be required to resupply a minimum of four crewmembers.”

That’s about 3.28 gallons per person per day

Recycling Heat

Efficient Distribution

Efficient Fixtures

Unusual Sources of Water

Recycling water

Water from air

Questions to Ask Is

There a Silver Bullet?

It isn’t the heat maker!

It is systems thinking

Can We Afford to Use Less?

How Do We Get Efficient Cheaply?

Space Station recycling is likely expensive

How Do We Make Our Work Durable?

Is Water Saving Different From Energy Saving?

The Future

Very Little Water/Energy Usage

How Do We Get There?

Redefine the need

What Barriers Exist?


How much can efficient equipment do?






Where Do We Learn? The Past

Other places

Getting creative

Imagining The Future Many Possibilities

One Possibility:

No-water toilets

One-gallon showers

Pure water only for cooking/drinking

Heat recovery

Low-water plumbing

Combined appliance scavenges heat

Simple solar preheat

What Was Actually Discussed


Early in the seminar, someone raised the point of delivery systems: Where does water come from? What does it cost to gather and deliver it? This seminar took place in California, where Mark Twain famously said, “Whisky is for drinking. Water is for fighting over.” Ever since, Californians have fought over water, tried to buy it, and tried to steal it.

A lot of California water comes from the Sierra snowpack. It is delivered naturally, by river systems, and unnaturally, by canals, the most notable of which is the California Aqueduct, a concrete river that stretches from the Sacramento River Delta to the Los Angeles area.

Gary Klein pointed out that most water is pretty cheap, but some of the more expensive water comes where the aqueduct has to use pumps to push water over mountains.

Someone in the news said not too long ago that very soon, Californians would be more concerned about conserving water than they were about conserving energy. If nobody farmed, there would be plenty of water for cities, but California is a big agricultural state, so farming pressures meet consumer pressures head-on.

Interestingly, there is plenty of water in the Northeast, but many cities there are in decline, with their people migrating to the West and Southwest. The “stealing it” part is not lost on people there, who created a Great Lakes Compact, agreeing not to let water be piped out of the area, presumably to the thirsty Southwest. There, there are cities built on deserts, making the water equation even weirder.

The Colorado River, which serves the whole Southwest, no longer makes it all the way to the Gulf of Mexico because all the water is diverted along the way.

Klein noted that a few places recycle sewage into drinking water and asked if anybody would have a problem drinking that product. Then he noted that very few people are drinking anything other than recycled water. Unless you can see it fall on the mountainside and run down to you, odds are you are downstream from someone, somewhere.

Someone mentioned wells and Klein and Weingarten pointed out that most water basins were already in overdraft.

Grow Your Own

Well, nobody can “grow” water. I’m just having fun with words. But Klein and Weingarten did point out that people can recover rainwater that runs off their roofs, and there are devices that will recover water out of humid air, such as exists along the coasts. Complex, centralized distribution systems, whether they be for water or food or anything else, are effective as long as they function, but in a crisis, they may leave tens of thousands of people high, dry, dark and hungry. Having a localized backup system makes sense.

They raised the issue of uses of water. As it stands, we spend a lot of money to gather water, purify it, dirty it up, again purify it at least some, and then return it to a river or ocean. They raised the concept of gray water — water used for washing, and black water — water used for getting rid of sewage.

There are some places in the world where there is one tap for drinking-water, and a different one for everything else. A locale thus spends a lot less effort and money purifying water and repurifying it.

How Much Water Do We Need? One of the items on the flow chart pointed out that U.S. daily consumption of water is 69 gallons, far more than anybody uses in the rest of the world. Klein has lived in Africa and pointed out that people there can bathe in one gallon. On the other hand, they may have to carry it manually a mile from the river! Most Americans would have trouble even getting wet in one gallon. Quite a difference!

But innovations are constantly appearing. One of them mentioned is a steam shower, which uses far less water than a regular shower.

Getting Creative Klein mentioned a crude solar water heater a colleague had concocted decades ago. It was merely a discarded gas water heater with the shell and insulation stripped off and the inner tank painted black. It cooled off at night, of course, and was worthless in the winter, but during a good half of the year, its inventor could shut off the gas to his main water heater and let the sun pick up the tab.

So what lies between us and the brave new world? Mostly us. Our current way works for us. We probably won’t change it until it stops working. Also, there are entrenched interests who will probably oppose change. Anybody with a stake in the way things are, and that could be a city, a utility, a manufacturer, a union, an individual, just about anybody. Even people who just don’t want to change. Habit may be the greatest enemy.

After the seminar was all over, Klein reminisced about work he did in Africa decades ago. He was part of a project to come up with effective cookstoves so that people wouldn’t have to cook over an open fire. Doing that was giving Africans asthma. Klein and his colleagues came up with great designs, but had a terrible time getting people to adopt them. Inertia may be the greatest enemy of all.

But……. ….But people DO change the world!

Water Heater Rescue

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