"Let’s go. Another big day on the planet!"
The Benefits of Walking
Like planting a tree, there are many benefits to walking from maintaining a healthy body weight to maintaining the health of the community and planet.
The City of Baldwin Park, California holds the dubious distinction of being the home of the nation’s first drive-in fast food restaurant, an In and Out burger joint in 1948. Now City leaders there have taken a bold position: A moratorium on new drive-through fast food joints.
BENEFITS OF WALKING
• Burns calories
• Strengthens back muscles
• Slims your waist
• Easy on your joints
• Strengthens your bones
• Lowers blood pressure
• Allows time with family and friends
• Shapes and tones your legs and butt
• Cuts cholesterol
• Reduces risk of heart disease, diabetes, & more
• Reduces stress
• Helps you sleep better
• Improves mood and outlook on life
• Can be done almost anywhere
• Great way to sightsee in new places
• Tackle errands at the same time
• Avoids air pollution from driving
• Requires no equipment
• Clarifies thinking
• Stimulates visual and olfactory senses
• AND it's Free
Tips to 10,000
How far is 10,000 steps?
The average stride is 2.5 feet; thus every 2,000 steps is about a mile; 10,000 steps is five miles. You can get a pedometer to measure this for you for every waking moment. Every mile walked will burn approximately 100 calories; 10,000 steps is worth about 500 calories. Every 3,500 calories is reportedly worth a pound of flesh.
• Take a walk with spouse, child, or friend
• Walk the dog
• Use the stair instead of the elevator
• Park further from the store
• Better yet, walk to the store
• Get up and change the channel
• Window shop
• Plan a walking meeting
• Walk over and visit the neighbor
• Get outside and weed the garden
Storing Renewable Energy
The most basic limitation of renewable energy is intermittency. The sun does not shine all the time; the wind and waves do not blow and roll all the time at the same intensity. To be sustainable, we’ll have to match renewables with conventional sources in the interim, and later convert part of the renewable energy to forms of kinetic energy for later use, be they chemical, mechanical, or thermal.
This article takes a look at renewable storage systems for electricity generation from dams to molten salt and hydrogen. Some promising systems already have cool acronyms. They hold degrees of promise to reap and store intermittent renewable energy and spread nature’s bounty throughout the day.
Hydropower is the king of renewables for one reason. It is largely based on dams that work like huge batteries. They allow for storage of water and thus energy produced from uneven snowmelts and rainfalls, to be released when needed. While perhaps the most reliable renewable, hydroelectricity too has limitations, suffering from drought years, snail-darters, sedimentation, mercury contamination, not to mention relocating communities and drowning natural wonders.
Pumped storage systems were first developed in Italy and Switzerland in the 1890s. Today, these systems are large and proven effective, rising water to an upper lake during low power use periods and then “spilling water” during peak periods. In the 1930s, reversible hydroelectric turbines advanced these systems. About 80% of the energy used to pump water uphill is regenerated downhill.
Currently there is about 21.5 GW of pumped storage capacity in America. (A gigawatt is 1,000 megawatts, about the size of a large nuclear reactor.) This most advanced renewable energy storage system capacity represents about 2.5% of U.S. base-load capacity. In the European Union, there is 38.3 GW of pumped storage capacity. A new form of “hydroeolic” capacity will use wind or solar to pump water.
Thomas Edison tried his hardest to maximize the power density of batteries. His focus was getting the maximum amount of power stored in a metal. The lead acid battery he developed is still the standard. Many off-grid solar and wind systems still rely on lead acid battery banks.
But they are too heavy and require too much care: Today the focus of advanced battery research is on a cost-effective, intensely dense battery. We know that electricity can be stored in light weight and small spaces (witness cell phone batteries), but the cost is high.
Significant federal and corporate funding continues to flow into this heretofore clunky and century-old storage device. Someday, cars that sit idle in parking lots during peak periods, might collectively shore up the grid as load management devices, earning money, or at least offsetting parking fees.
Flywheels maintain rotational energy, a spinning disc with a fixed axle, energy stored in the rotor as kinetic energy ready to be released. Flywheels have been used and contemplated for greater use for centuries. Among the early flywheels was the potter’s wheel. James Watt reportedly linked flywheels with steam engines. In the 1950s flywheel powered buses known as gyro-buses were used in Yverden, Switzerland.
Subways that make frequent stops are perfect candidates for flywheels, storing momentum for minutes until the train leaves the station. British Rail’s Class 70 train has a flywheel that carries the train over the third rail. A 133 kWh flywheel pack developed by the University of Texas at Austin can take a train from standing to cruising speed.
Flywheel Energy Storage (FES) now benefits from advanced materials that allow flywheels to operate at very high speeds. They are built with high-strength carbon filaments, suspended by magnetic bearings in vacuum enclosures. They spin at 20,000 – 50,000 revolutions per minute. They are already in use combined with batteries in uninterruptible power supplies. Someday they may augment or replace batteries in electric vehicles.
Beacon Energy has recently received funding the Advanced Research Project Agency of the U.S. DOE to advance its flywheel technology for renewable energy integration. Currently Beacon’s flywheels are being used for frequency regulation on power grids. The goal of the ARPA contract is to store four times the energy at one eighth the cost of currently available flywheels.
Compressed Air Energy Storage (CAES) is another option with potential where unused natural gas wells and salt caverns exist. Currently there are two CAES plants in commercial operation, one in McIntosh, Alabama and the other in Huntorf, Germany. These systems can store compressed air for hours – even days – and then release it to spin turbines and generate electricity at optimal times. Compressed air has also been used to run locomotives in mines due to explosive gases and to maintain air quality.
An interesting marriage between CAES and wind is being explored. Developers are building compressors into the nacelles of wind turbines. The Iowa Stored Energy Park plans to meld compressed air with the wind farm anticipated to be on line in 2011.
Storage is being developed that uses molten salts as heat batteries. EcoMotion visited one of the world’s first solar/molten salt systems in Spain two years ago. Molten salt is used as a form of thermal energy storage, holding a thermal reserve in an insulated repository for future use. (EcoMotion tours visited geothermal systems in Iceland that used major insulated tanks to feed the varying demands of heating districts.)
Molten salt systems use a 60:40 mixture of sodium nitrate and potassium nitrites, non-flammable and non-toxic. Salt melts at 221 degrees C (430F). In molten salt storage systems, liquid salt gets heated to 566 degrees C (1,051F), and held in a hot storage tank with minimal losses for two days.
Hydrogen holds such great promise as a storage medium for energy that some Princeton researchers even labeled the next energy era the solar/hydrogen era, replacing the fossil era. Hydrogen is not a source of energy, it is a fuel, and it holds great potential for at least two key reasons: First, it can be produced by electrolyzing water. When used, its emission is water vapor. Second, a renewable source like solar or wind can be used to take an intermittent renewable used only for electricity, converting it to hydrogen fuel suitable for transportation energy. Email EcoMotion for an e-copy of The Results Center Special Report, “Hydrogen: The Invisible Fire.”
Big Solar for California
Brightsource Energy has cleared the final permitting hurdle now cleared and expects to begin constructing the Ivanpah Electric Generating Station in the next few weeks. The US Bureau of Land Management approved the project to be located in remote San Bernardino County near the Nevada border. Brightsource also received a $1.37 billion loan guarantee from the US Department of Energy to finance the project. President Obama has praised the project, noting that with these kinds of projects, “we are staking our claim in the new global economy.”
The solar power plant will be really big, a 370 MW installation. Its 173,500 mirrors will focus solar power on central receiving towers that will create steam and drive turbines. California’s large investor owned utilities, PG&E and SCE, are lined up to divide the plant’s output. The plant is slated for completion in 2013; at its peak it will employ 1,000 workers.
Big Solar for California
EcoMotion has the pleasure of working for the City of Santa Monica. We developed and have managed the Solar Santa Monica program for the past four years, a program that is a unique blend of marketing and outreach with technical services and advocacy, a form of programmatic acupressure.
Proud of our results there, EcoMotion is proud of the City of Santa Monica’s broad and admirable accomplishments with sustainability. Some might take exception to the word “sophisticated” in this article’s title. Perhaps all forms of sustainability today are rudimentary, at best crude representations of our best shot given how little we know! But EcoMotion happily takes a relative perspective.
Santa Monica’s Sustainable Cities online newsletter is a rich resource for Santa Monicans. It reflects a community on the go, going green. Witness the titles alone in the current edition!
To tune in to one leading city’s initiatives, contact Sustainable Santa Monica, www.sustainablesm.org