Op-Ed: Water, Energy and Climate Change

Today, The Oregonian ran a piece I wrote describing how water conservation can save energy. I used my hometown of Portland, OR as an example to show how communities often rely on auxiliary, or marginal, water supplies that require more energy than primary supplies.

I'll begin by apologizing for shamelessly shilling this article, but there are a few things I'd like to elaborate on.

The print edition ran under the headline, “Water, Energy and Climate Change: Energy strategies could help ensure water supply” (they dropped the first part for the online version).

While it is awesome that The Oregonian ran the piece, I have to admit that I’m worried the subtitle may be a bit confusing. If anything, I was trying to say that water strategies – such as conservation, efficiency, reuse and low impact development – can address climate change by reducing energy use and helping us adapt to less reliable water supplies in the future.

Update 10/19/09: The Oregonian has changed the title of the online version to, "Water: Portland should conserve water and keep purer Bull Run water in its taps." This is a big improvement.

I used Portland, OR to illustrate my point that water conservation and efficiency can address climate change by reducing energy use and helping us adapt to less reliable water supplies in the future:

For most of the year, the Bull Run watershed on the flanks of Mount Hood provides Portland's water. But when Bull Run is unable to meet "peak" demands -- or when permit restrictions limit withdrawals to ensure adequate water is available to support fish habitat -- the city's Water Bureau pumps water from its Columbia River well fields, located on the banks of the river between the Troutdale Airport and Blue Lake Park.

In late September, the Water Bureau began pumping 36 million gallons of water each day from these well fields, supplying 35 to 40 percent of what comes out of your tap. This will continue until Bull Run is recharged. Higher mineral content in the groundwater supply means that many of us can taste the difference between these two water sources. What we can't taste is the significantly greater energy cost and greenhouse gas emissions embedded in this backup supply.

The Bull Run supply system is gravity-fed and requires almost no pumping at all. Well water, on the other hand, is drawn from the ground, then pumped 4.5 miles south and about 750 feet uphill to Powell Butte Reservoir. Consequently, well water requires 6.5 times more energy to reach your tap.

Now factor in climate change. A study commissioned by the Portland Water Bureau in 2002 found that global warming will likely cause the Bull Run watershed to experience warmer and drier summers, decreasing its water supply when demand is at its highest. Along with population growth, this will create a vicious cycle in which the energy required to pump well water to meet growing water demands will contribute to climate change while climate change continues to reduce our water supply.

Portland offers a great example of how marginal water supplies often entail a greater energy cost, but I wish I had done a better job framing the article more broadly and focusing less on Portland specifically. Although I don’t have exact figures, many communities, like Portland, often rely on more energy intensive marginal water supplies. Because every water system is different, it is important to know your own water system’s energy intensity and how the energy embedded in water varies throughout the year.

For information on how to estimate the energy embedded in your community's water and wastewater systems, download our resource How to Estimate the Energy Embedded in Your Water Supplies

Every community – even communities with low-energy water supplies – can save energy through water-oriented approaches:

Nationally, nearly 4 percent of the country's annual electricity consumption is used to pump and treat our water and wastewater -- more than the annual electricity consumption of all the microwaves, color TVs and computers found in our homes.

As high as this figure is, it does not include the energy needed to heat, cool or pressurize water in our homes, businesses or schools. A recent assessment by River Network found that adding in energy needs for water heating alone pushes water-related energy consumption in the U.S. to the equivalent of 13 percent of our annual electricity use -- the power output of approximately 150 coal-fired power plants.

With so much energy embedded in our water, we need to be looking at water conservation and efficiency as strategies that save energy and reduce our carbon footprint. A study conducted in California found that urban water conservation and efficiency programs could achieve comparable energy savings at 58 percent of the cost of traditional energy-efficiency programs.

It is also important to support a water utility’s efforts to offset their energy use by installing renewable energy capacity – such as PV solar, small wind or micro in-conduit hydro. Using and developing energy typically has negative water consequences by exacerbating climate change through greenhouse gas emissions, consuming water for cooling or discharging water pollution. Promoting energy efficiency or the development of low impact renewables can have a number of direct water benefits.

The Portland Water Bureau (PWB) itself is leading the charge in greening water delivery. Due to length constraints I couldn’t go into detail about PWB’s clean energy initiatives, but here are PWB’s comments to a draft of the op-ed that I sent them for review:

Using a third party financing arrangement, we are installing a photovoltaic facility at the groundwater pump station that will partially offset (by 5%) the power used by the groundwater system. We already have microhydro generation at Mt. Tabor, and are planning to install microhydro at the Vernon pump station as well. We are investigating other opportunities to install solar and microhydro generation over time. We've also been working on improving the operating efficiency of pump stations around the city, which are our largest uses of electricity. Recent improvements at our Fulton-Carolina pump stations increased efficiency at those facilities from 620 gal/kWh to 741 gal/kWh.

So, the Water Bureau joins River network is encouraging continued dedication to using water supply efficiently. Water conservation is, however, only one of many approaches to reducing the energy footprint of the water system.

As you can see, PWB is taking a number of measures to negate the energy/carbon footprint of providing water to their customers. I’ll admit, it feels great to be served by such an environmentally conscious water utility (PWB will even send their customers a free water conservation kit, I picked one up and the devices are great!).

I concur that water conservation is but one of many approaches to reducing the energy footprint of the water system. However, it is a critical approach that offers the rare opportunity to prepare for and help prevent climate change in one fell swoop.

The water bureau is doing their part but we should do ours by using water as efficiently as possible – especially in the summertime when water demand is at its highest. Regardless of PWB’s renewable energy capacity or pumping efficiency, it still takes a lot more energy to bring groundwater to Portland’s taps than Bull Run water (the Bull Run actually produces a surplus of hydroelectricity because it is gravity fed).

The less groundwater we use, the less energy required by the water system. As we transition to a clean energy grid, using less energy is an all around good thing. As I wrote in a longer draft:

While the Portland Water Bureau is commendably committed to offsetting the carbon emissions of its operations, we are all connected to the same, overwhelmingly dirty electrical grid. Until we have a 100% clean energy grid, every kilowatt hour saved in our region will continue to help mitigate climate change and free up our clean energy capacity for other uses.

Imagine if PWB installs solar panels at their pumping stations and they are able to sell excess clean power back to the grid because the groundwater pumps are rarely used. Reducing groundwater use will get harder as climate change makes the Bull Run supply less reliable, but let’s think ahead and try to minimize the need for groundwater today.

We also can’t forget about end-uses of water which constitute at least 75% of the total energy embedded in the water cycle. In most homes, water heating is among the top two or three energy uses. More efficient hot water uses – through faucets, showerheads, clothes washers or dishwashers – means reduced energy demand regardless of whether or not your water supply is gravity fed.

Businesses often use water for more complicated processes, embedding more energy through heating, cooling, advanced purification, pressurization or any other number of ways. Reducing the amount of water used in these processes can reduce the energy that ultimately goes into them.

All of this is to say that while the details are somewhat complicated, one thing is simple: saving water saves energy and helps us adapt to climate change. Reducing energy use ultimately reduces greenhouse gas emissions by freeing up scant renewable energy for other services. Learning to do more things with less water will be crucial when climate change disrupts our water supplies. Water conservation, efficiency, reuse and low impact development are cost-effective approaches to protecting the environment and creating more livable communities.

Thanks again to the Oregonian for running the piece (and thanks to my coworkers Matt Burke and Kevin Kasowski for editing the piece down to 500 words!). To view the complete article, click here.