CleanTechnica is the #1 cleantech-focused
website in the world. Subscribe today!


Biomass water energy nexus

Published on October 4th, 2014 | by Important Media Cross-Post

16

The Energy-Water Nexus

Share on Google+Share on RedditShare on StumbleUponTweet about this on TwitterShare on LinkedInShare on FacebookPin on PinterestDigg thisShare on TumblrBuffer this pageEmail this to someone

October 4th, 2014 by  

Source-ncsl.org_

Via Green Living Ideas and author Peter Young:

Did you know that it takes 3,000-6,300 gallons of water per year to power just one 60W incandescent light bulb? Now, I know that that must sound a little farfetched, but unfortunately it’s true. But how can this be, don’t light bulbs use electricity? In short, yes, but what most people don’t know is that we use large amounts of water to produce electricity. You see, electricity and water are connected through what is known as the energy-water nexus, and while that phrase may not mean anything to you at the moment, it will by the end of this article. So what exactly is the energy-water nexus, and why should you care?

The water-energy nexus is best understood as a connection between water and energy, however it goes much deeper than that. First, let’s look at the connection between the production of energy and water. The three most common ways we produce power today are coal, natural gas and nuclear power and all three of these require the use of water. Essentially these systems heat fresh water and turn it into steam, and that steam spins a turbine which creates energy. Curious just how much water these systems use? Click on the image below to see just how much water each of these systems needs to produce just 1kWh of energy:

water costs per energy

As you can see, supplying power to our homes requires a ton of water, but what about supplying them with water? Well, in short, it requires a ton of energy. You see, before water reaches your home it’s passed through a water treatment plant which ensures that it’s safe to drink and use in your home. After its been treated a series of electrical pumps will bring the water to your home where it will be used and then pumped back to another waste water treatment facility to be re-treated and sent back out. All the while, using energy which requires water to create it. So what does this mean to you as both an energy and water consumer? Take a look at your latest water bill, odds are you’ll find an electrical charge listed under your current charges. This is to cover the cost of the electricity required to pump the water to your home. Now let’s take this one step further.

It stands to reason that the more water and energy we consume the higher our monthly utilities will be, but what happens when we deplete a fresh water resource or experience a drought? Take a look at the video below to get a recap of the water energy nexus and to find out what happened to Texas in 2011 when it experienced an extreme drought:

http://youtu.be/pCOaU-JPfyE

As you can see water and energy a far more than just connected, and by conserving one we can directly conserve the other. If you’re looking for good ways to conserve both water and energy in your home, try installing a low flow faucet aerator. Also, be sure to check out some of our green home improvement projects: Green Living Ideas, after all, is a top 20 home improvement website!

Photo courtesy of the Environmental Defense Fund and Harvesting Rain Water.

Keep up to date with all the hottest cleantech news by subscribing to our (free) cleantech newsletter, or keep an eye on sector-specific news by getting our (also free) solar energy newsletter, electric vehicle newsletter, or wind energy newsletter.



Share on Google+Share on RedditShare on StumbleUponTweet about this on TwitterShare on LinkedInShare on FacebookPin on PinterestDigg thisShare on TumblrBuffer this pageEmail this to someone

Tags: , , ,


About the Author

-- CleanTechnica is one of 18 blogs in the Important Media blog network. With a bit of overlap in coverage, we sometimes repost some of the great content published by our sister sites.


Related Posts



  • Will E

    it is an old steam machine technique from long time ago, still and only used in utility plants. steam train gone, steam boat gone.
    as all oldtimer steam machines was abandoned in history, this oldtimer way of producing energy will disappear because it has become non economic and will be replaced by Solar and Wind.

  • Joseph Dubeau

    Oh great, blame the drought on the poor defenseless cows.

    • tmac1

      Joseph I agree they are so cute! Docile large animals, all 1.5 billion of them! One for every seven humans.

  • Joseph Dubeau

    There plenty of water on earth. 2/3 of the planet is covered by water.
    You just can’t drink. Crops don’t grow when you throw salt water on them.
    You can’t farm with it. People, farm animals, and crop require fresh water.

    If you ask someone who lives in a third world, where does your water come from? They can probably show you. Most people in the U.S. And Europe don’t have a clue.

  • Kevin McKinney

    Yes, that’s right; the water is not destroyed. But planning for energy needs to include water availability, too–which is why thermal energy for northern China is a bad fit, whether it’s nuclear or fossil fuels. (Taking just one important example.) That area is incredibly water-stressed already, is experiencing fast economic growth, and will likely see increased drought due to climate change over the next few decades. Not a good mix…

  • Joseph Dubeau

    I’m glad to see an article on water use in generating power.

    “39% of fresh water withdrawn in the U.S. Is for thermoelectric power-generation cooling system” That is for cooling. Take a moment to think about that.
    “2/3 of heat-energy potential is lost.”

  • Steven F

    “IVANPAH and other solar thermal aka Concentrated Solar Power recycled most of the steam they use to drive the turbines”

    IVANPAH is an air cooled power plant. No Water is used for cooling. A small amount of water is used for the turbine and mirror cleaning. Most of this water comes from a brine aquifer under the power plant.

    The water used by the turbine is filtered and is typically cleaner that drinking water. This is done to minimize damage to the turbine. Due to the time it takes to make clean water for the turbine the water and steam is operating in a closed loop eliminating evaporation and water loss.

    The article is mainly about water used to cool the turbine water loop. The cooling water loop and turbine water loop are kept seperate and the water doesn’t mix. Water evaporation is allowed int water cooling system since it is very effective in removing heat.

    • Joseph Dubeau

      Produces a lot free BBQ wild game poultry.

  • tmac1

    Great article
    I never knew connected water use and electricity
    On similar note, the meat and dairy industry uses 50% of California water vs 5% for showers laundry,etc! Instead of urging less meat and dairy consumption residents are urged to check for leaky faucets. That is they are focusing on tiny part of the problem instead of major factor!
    At least CA is encouraging rooftop and utility PV which is right way to go

    • Matt

      Did you include all argo in you meat/dairy % for California number? Else it sounds a bit high, link to support? I know it takes a lot of water to farm in the deserts of CA.
      In the article where did the 4.5-30 number for hydro come from. Is that increase evaporation because of the lake verse free flowing river? I understand cooling tower evaporation.

  • Oscar Martín

    With the exception of hydro, all plants could use the refrigeration to desalinate sea water or clean dirty water, making the refrigeration a double function. Cool the plant and make fresh water.
    But some plants, like nuclear or coal could be dangerous for some considerations. This grows the costs too, although the doble “production” could be profitable.
    Solar thermal could be a very good option on arid and desert zones near the coast. A lot of sun, water and the capability to generate water in a dry area could be used to create good revenue using on agriculture.
    Very good option for north africa and south mediterranean zones.

  • Mint

    Some context should be given for these numbers. For example, modern desalination need 3kWh or less to produce 1 m3 of water (265 US gallons).

    So when plants use ~0.5gal/kWh, it would take well under 0.01kWh to replace that freshwater using seawater. Less than 1%.

    Also, what the calculations for saying a 60W bulb needs 3,000+ gallons per year? If the bulb is on 24/7/365, that’s only 526 kWh/yr, and according to the table that’s around 300gal/yr.

    • Timothy

      Loving the calculations!

  • JamesWimberley

    The large number given for water use by geothermal energy must be wrong. A geothermal plant supplies and uses its own water or steam from underground. This is usually heavily laden with salts and neither available for nor competing with other human uses. It’s either evaporated as vapour into the atmosphere, or reinjected. More here (link).

    • Mint

      According to your link, this data is from geothermal plants in CA, not new systems that could be implemented using less water. There are ways of using non-potable water at thermoelectric plants, too (e.g. seawater cooling, as we see in the UK and California).

      Anyway, the funny thing about thermoelectric generation is that higher temperatures need less cooling water per kWh generated, and at a high enough temperature you don’t need any water. I’m pretty sure that’s why coal < nuclear < CSP < geothermal when it comes to water use.

    • Steven F

      The Geysers Geothermal field is one of the first large geothermal power production areas in the world. At the time the hot water was brought to the surface, flashed to steam to drive the turbine, the steam was dumped into the air, and the remaining water was dumped into streams or allowed to evaporate. This depleted the water underground and reduced power output. Today a lot of waist water from nearby cities is being pumped underground to maintain water pressure and less steam is dumped into the air.

      http://www.geysers.com/water.aspx

      Most new geothermal power plants use the binary cycle . In the binary cycle the geothermal water is pumped through a heat exchanger and then re-injected into the geothermal reservoir. The heat exchanger heats a hydrocarbon (ususally bentane or butane) which in turn spins the turbine. The hot hydrocarbon is then cooled air heat exchangers (dry cooling) and recycled. Most new geothermal power plants use no water for cooling or reservoir recharge.

      http://en.wikipedia.org/wiki/Binary_cycle

      Due to the occasional droughts California a long time ago passed a law outlawing the use of drinking water for power plant cooling.Today most California power plants use waist water, sea water, or brine for cooling. Some also use air cooling.

      Water is the preferred coolant for a power plant because it is cheap and cools very effectively. Air cooling is generally avoided due to it’s cost and lower efficiency. However if laws or environmental factors do allow water cooling, air cooling is used.

      http://www.ucsusa.org/clean_energy/our-energy-choices/energy-and-water-use/water-energy-electricity-cooling-power-plant.html#.VDAymWddUqM

Back to Top ↑

© 2014   Sustainable Enterprises Media, Inc.



Back to Top ↑