As staff author of the California Energy Commission’s report on the Water-Energy Relationship, I must say that the report is often misquoted.

1. Approximately 5% of California’s electricity is used for the water use cycle – taking water out of the environment, treating it, delivering it to customers and then taking it away, treating the wastewater and discharging the treated water back into the environment.

2. The energy from approximately 15% of the state’s electricity and 33% of the state’s natural gas (excluding that used to generate electricity) and a bunch of diesel is added to water by consumers, on their side of the meter. This includes pumping, heating, cooling (buildings with cooling towers for air conditioning), clothes drying and a variety of industrial purposes.

3. California is in fact a subset of the rest of the nation. Approximately 25% of the urban water consumers and 50 percent of the state’s agricultural customers receive gravity fed water, for which the energy intensity is very close to zero. At the other extreme, the southern portion of the state has very energy intensive water that comes from the Colorado River and the State Water Projects. No other state has the magnitude of these extremes.

4. Based on data for northern California, the average energy intensity for the water use cycle in the United States is likely to be between 4 and 7 kWh per 1000 gallons, based on well depths ranging from 500 to 1000 feet. Nationally, the water use cycle is likely to consume about 3-4 percent of our electricity.
   Overall, approximately 20-25 percent of the nation’s stationary energy use goes to water in some way. This does not count bottled water or the water used to generate electricity.

5. It is necessary to have a public policy that recognizes the interconnectedness of the connection between water and energy. Energy is used for water, so too is water used for energy. A compact fluorescent light bulb is actually a water conserving device.

6. Saving water saves energy. Saving energy saves water. Saving outdoor water is good, saving indoor water is better. Saving indoor hot water is better still. Saving the most energy intensive water is best. So let’s start saving indoor hot water at the top of our tallest buildings and work our way down until we are done with the job!

7. I have spent much of the last 15 years focused on developing solutions to the problem of waiting too long for hot water to arrive at faucets, showers and appliances in our buildings. These devices interact with the water heater and with the plumbing layouts.

8. We call the best plumbing configuration Structured Plumbing, which locates the trunk line of the hot water distribution system within 2 cups of every fixture. The trunk line is primed with an on-demand pump (the only energy efficient pump system I have seen in 15 years) whenever someone wants hot water. The hot water piping is insulated from the water heater all the way to each fixture. Go to http://www.gothotwater.com for the best description of the technology.

9. Storage water heaters are actually “instantaneous” water heaters, since they start out with hot water before you turn on the tap. Since they are generally volume limited, they are not typically continuous water heaters, unless there is a demand for hot water with a very low flow rate.

10. Tankless water heaters are not “instantaneous” water heaters, since they start out with cold water before you turn on the tap. It takes 10-15 seconds for the water to be heated to at least 105 F (okay for showering) to come out of the water heater; this is in addition to the volume of not-hot-water that is in the pipes. They are continuous as long as the demand for hot water falls within their range of operation, neither too high nor too low.

11. What we need to have are water, energy and time efficient hot water systems. We know how to combine water heaters, hot water distribution systems and faucets, showers and appliances into systems that are 90 plus percent efficient, with the time-to-tap no longer than 10 seconds, and to do so at the same or less cost to install than current practice.

12. Any bill that looks at the water energy connection must take hot water into account. Please direct the USEPA’s Energy Star and Water Sense programs to properly address the topic; currently they do not get it quite right.

Also please direct the USDOE to revise the test standards for water heaters so that all water heaters are treated equally, regardless of technology, so that customers can better understand how to select a water heater than is currently possible. While they are at it, please have them change the heading for water heaters in the current standards that is labeled “Instantaneous” water heaters. None of the water heaters sold in the US that fall under that category are and the title is very misleading. USDOE should also be directed to look more closely at the Energy Star for Water Heaters program to more properly account for the water-energy connection.

1. It must also take into account what I call “future proofing”. It is certainly possible to foresee the day when all lavatory faucets will have flow rates no more than 0.5 gallons per minute (gpm), which is the current federal standard for public restrooms. If we assume that it is acceptable to have a time-to-tap of 15 seconds at 2 gpm, then at least 0.5 gallons will run down the drain while waiting for the hot water to arrive. This is because there is roughly 0.5 gallons of not-hot water in the pipes; this is the structural waste. The structural waste is built in and will be there for many years, hopefully the term of the mortgage or the life of the building, whichever is longer.

Now fast forward to when 0.5 gpm faucets are the norm. There is 0.5 gallons of structural waste, so it will take at least 1 minute for hot water to arrive. If the 15 seconds at 2 gpm wasn’t acceptable, waiting more than 1 minute will have consumers screaming!

We know how to prevent this waste, both cost effectively and energy efficiently and we should do so starting today. Even in our current economy, we are building new homes and commercial facilities and every building in which we don’t prevent the problem is a lost opportunity.

1. There is an organization, Green Plumbers, that is devoted to teaching plumbers how to be part of a green solution. They can be found at http://www.greenplumbers.com and click on the link to the United States. Who better than plumbers to work on the water-energy connection?