The Hydrogen Economy, Hydrogen Sources, and the Science Behind These

The hydrogen-filled Hindenburg in 1936 or 1937. Photo from DeGolyer Library at Southern Methodist University.

THE HYDROGEN ECONOMY

The hydrogen economy is a hypothetical future in which energy can be bought, sold, stored, and transported in a currency of hydrogen, much like today’s energy is often exchanged in electricity. Because hydrogen doesn’t need to be attached to the electricity grid, it can be used in forms of transportation like buses and cars.

The end-user of the hydrogen, for example an automobile driver, doesn’t experience significant pollution beyond the formation of water from burning the hydrogen.

For more details about the hydrogen economy see here.

Hydrogen, a gas, isn’t a fuel like gasoline or coal; hydrogen is a way to store and transport energy made from other fuels, like a battery or electricity. Unlike fossil fuels, pure hydrogen isn’t stable, so forming hydrogen in the first place requires energy and produces carbon dioxide, and storing hydrogen involves special considerations because this light gas is very flammable and also quickens rust and oxidation in pipelines and storage containers.

HOW HYDROGEN IS DIFFERENT FROM FOSSIL FUELS

Allowing hydrogen (a gas) to burn in the presence of oxygen releases that stored energy in the form of heat. Hydrogen can also be reacted in a fuel cell to produce electricity. In either case, electricity or heat can then be used to power cars or any number of other devices. Gasoline, biofuels, wood, and other carbon-based fuels all produce carbon dioxide when they are burned, and rising carbon dioxide levels are widely implicated in climate change. Burning hydrogen produces energy, water and a few trace compounds, but it doesn’t produce carbon dioxide.

2 H2 (hydrogen gas) + O2 (oxygen gas) = 2 H2O (water vapor) + energy

It’s unclear what widespread emission of water vapor could do. According to recent published estimates, atmospheric water vapor is responsible for 75 percent of the greenhouse effect. However, water vapor can condense, and it’s naturally-occurring in the atmosphere. It is much easier to trap and transform to liquid than the carbon dioxide normally emitted by burning gasoline. Carbon dioxide won’t form a liquid at atmospheric temperatures and will solidify into dry ice only below -108.4 Fahrenheit, so proponents say it can be easier to trap the vapor in hydrogen-powered machines.

If the energy used to generate and purify and store and ship hydrogen doesn’t require emitting greenhouse gases or toxics, proponents argue that hydrogen is a clean alternative.

SOURCES OF HYDROGEN: THE UNFORTUNATE REALITY TODAY

Hydrogen, not carbon, is the most prevalent atom in the human body. There are two hydrogen atoms in every water molecule, and as many as hundreds of hydrogen atoms on the basic building blocks of life, from DNA to plant fibers. Nonetheless, harvesting the hydrogen atoms out of any of these structures to make hydrogen fuel isn’t easy because hydrogen likes to be bonded to carbon or oxygen; it doesn’t like to be elemental gas.

To produce pure hydrogen today, industries use primary fuel source like petroleum, natural gas, coal, or biomass. Through chemical processing, the hydrogen atoms are stripped from the fuel by way of an input of energy from electricity (more than 80 percent of which comes from fossil fuels in the United States). Furthermore, the leftover material from the stripping is carbon dioxide, the same carbon dioxide that would have been produced if the fuel was burned in an engine.

The reactions for various fuel to hydrogen conversions can be found on the U.S. Department of Energy website here.

Hydrogen can also be produced, at great energy loss, through the electrolysis of water: using electricity, water is divided into its constituents, hydrogen and oxygen. However, water electrolysis is the least carbon-neutral hydrogen production method, and it is very expensive ($3 to $6 per kilogram instead of a little more than $1 in the case of using coal for hydrogen), according to the U.S. Energy Information Administration. All hydrogen production methods result in a net energy loss.

 

 

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Major sources of energy/their advantages and disadvantages

There is no easy answer to what is the best source of energy or electricity. Is the priority reliability, affordability, the economy, international human rights, limiting greenhouse gas emissions, preserving environmental resources, or human health?

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It’s undeniable that today — whether we like it or not — humans worldwide are overwhelmingly dependent on fossil fuels: coal, oil, and natural gas. Everything eaten, worn, lived in, and bought is tied to availability of fossil fuels. Even if 100 percent of politicians were determined to stop using them today, society has neither the electricity grid nor the vehicular and industrial technology to sustain the current American lifestyle on non-fossil sources of energy. Yet.

When comparing sources of energy, it’s easy to forget how universal fossil fuels are. These sources continue to dominate for reasons that are difficult to measure, like political influence, advertising clout, and control over energy infrastructure. Other sources have disadvantages purely because they don’t fit in as well.

Volume brings another difficulty in comparing sources of energy. There is so much more fossil energy, and it’s been used for a long time, so we know a lot more about its hazards and benefits. More modern technologies are harder to quantify. Some are renewable but still pollute (biofuels), some are very clean except in accidents or waste disposal (nuclear). Most electricity sources (renewable or not) use steam turbines, and all the water to make steam has to come from somewhere, but how important should that factor be?



Clicking the graphic above will give an abbreviated chart comparing sources line by line, but that doesn’t provide anywhere close to the whole story.

Each of the following topics compares the major sources of energy  through a different lens. Though environmental and local issues may seem the most important to those of us who don’t own power plants or utility companies, the cost of energy drives which sources are actually in place today and which sources will see investment tomorrow.

 

 

 

 

 

 

 

 

 

 

 


Source: U.S. Energy Information Administration

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The Electricity Marketplace

Boulder Dam wires. Photo by Ansel Adams, from U.S. National Park Service.

Electricity has to be produced within moments of its use. Its markets are bound tight to the paths electricity can take – the geography of power lines – and how much towns and cities need at any moment. And yet, intentionally, the retail electricity prices that we pay are buffered from the wholesale marketplace.

Gasoline is an example of where we energy consumers can see the market forces at work. The price of gasoline sways with the crude oil market, usually somewhere between $70 and $100 per barrel. Those swings are reflected back at the pump, a place any driver is familiar with. No one is surprised by a nickel’s worth of change here or there, but when prices increase by enough, some people actually reduce their driving.

Electricity doesn’t really work that way. The prices in the electricity market can easily double or more, routinely, every single day, and consumers like you and me will never know. (See figure below). The rate that we users pay is tightly regulated by regional authorities, which themselves vary depending on where you are (and not only by state).

Furthermore, we’re insulated from the market because, from our perspective, supply is virtually bottomless. We don’t sign a contract in advance that says we’ll receive a certain amount of electricity and no more. We never hear from the utility saying, we can’t give you that power you wanted, we’re out. We go straight from experiencing bottomless supply, to blackout, and we have no control over either case. And unlike the gas pump, we can’t choose where we buy: a monopoly.

 
And yet, the power plants, the fuels markets and the power companies are a competitive, by design.

The figure, from a few days in June 2011, shows average prices. They are aggregated from the hourly prices at the various distinct places within Maine, which themselves are based on mathematical algorithms and what they predicts is the logical price. However, though these prices matter, no one really pays these average prices. Some power plants are paid by node – a theoretical geographical point  – so they get paid according to the price at that hour at their location. Some power plants get paid by zone, a larger geographical area encompassing nodes. The actual market prices and settlements happen in a market that’s administered by a company, not the government. In Maine’s case, the state participates in a larger, regional market moderated by the New England Independent System Operator, a non-profit company. However, the power lines in Maine are joined in a vast network of power lines all the way across the Eastern seaboard, in the Eastern Interconnection. Therefore, market participants in New England can buy and sell electricity outside of New England too.

Further complexity arises because utilities enter long-term contracts with power plant owners for electricity at a particular cost, years ahead of time. They also enter short-term contracts, and they can buy energy on the spot market, right before they need to deliver it.

To see average prices of electricity by state here.

 

MEETING DEMAND: BASE AND PEAK LOAD

A lot of planning goes into making sure there’s enough electricity at any particular moment, making the most of the type of power plants available: sort of like a symphony of different players at different geographic locations.

Many large power plants, nuclear and coal plants particularly, can produce huge amounts of energy. However, to turn on and ramp up these plants to full capacity takes time and costs a lot of money, even though once the plants are running, producing energy is relatively cheap. Instead, these kinds of plants are applied to the base load, or the minimum amount of energy needed. They run all the time and shut down only for special reasons like maintenance.

At the same time, other kinds of power plants are applied to the peak load, the maximum amount of energy needed. Usually powered by natural gas, they are called peaker plants, and though the electricity they produce is generally more expensive, they can be turned on and ramped up or down quickly and for far less cost than the base plants.

American electricity infrastructure developed regionally, in a slowly filling patchwork of power plants, power lines, and power authorities. Each region of the United States has its own market, with its own, vastly different rules.

One example of diversity in market rules is how to manage payments. The organizations responsible for reliability on the grid and administering the electricity market aren’t allowed to make a profit. At the same time, electricity itself can’t really be tracked, the electrons have no name tags. So even though utilities sign long-term contracts with power producers, there’s no way to guarantee if a power plant in West Texas generated the electricity that it sold to a utility in North Texas. Instead, the market’s moderated through the transmission authorities, who get the money from the utility, and pay the money out to the power plants.

As with the stock market, electricity markets have different products and ways of investing, but every region has different rules about which ones are allowed and how they should be bought and sold.

To really complicate things, market rules don’t even apply to whole states! Take a large state like California. It has its own stringent environmental laws, it has a public utilities commission and an energy commission, and it has its own electricity market and administrator, the California Independent System Operator. However, some parts of Northern California participate in the Northwest power market instead. And there are six small regions in the state of California that are their own balancing authorities, including Los Angeles Department of Water and Power and the Sacramento Municipal Utility District.

 

For descriptions of U.S. markets see here, as expressed by the Federal Energy Regulatory Commission.

For a map of which states have restructured (deregulated) their energy markets to allow for retail choice, see here.

 

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Basics of Electricity and Circuits: How Energy Moves Through the Home

A BRIEF HISTORY OF ELECTRICITY

The first major use of electricity began in 1879, when Thomas Edison began installing incandescent lighting in notable locations like Wall Street in New York City. Edison wasn’t alone in his pursuit of electricity development, but he was the first to install integrated systems in conspicuous places.

At that time, Americans used various other light sources, like oil lamps, candles, and fires. A candle gives off only around a single watt’s worth of light. Calcium (or lime) lights could provide a lot of light, but it was a harsh light and reserved for conditions like the theater, hence the term in the limelight.

Most lighting was very poor – and often dangerous – in comparison to fluorescent bulbs, and electricity became popular quite quickly. By the turn of the century, other electric devices began to become available, and by the 1920s, Americans could purchase electric refrigerators, dishwashers, and washing machines.

The first electrical systems depended on extremely local power plants, within a few blocks, or even within the building. As time passed, electricity development became a regional responsibility, and today, the United States is split into many different systems of electricity distribution, including both regulated municipalities and for-profit utilities.

 

WHAT IS ELECTRICITY?

Electricity isn’t merely the existence of electrons but the flow, and it is their flow that provides power. It’s a little bit like gravity and the flow of water downhill. Water will move spontaneously downhill because of gravity. Electrons (like other charged particles) move spontaneously when they are in electric fields. An electric field is generated when there’s a difference in electric potential – called a voltage – just like a hill exists when there’s a difference in altitude.

Electricity is the flow of electrons, which themselves are small charged particles associated with atoms. Under neutral conditions, electrons stay with the atom or group of atoms that make up a compound. However, one electron is indistinguishable from another and can move from one atom to an adjacent one if the atoms make up a conducting material, like various metals.

Voltage can be thought of as the height of the hill. The bigger the voltage, the more electrons want to move, and the more power can be delivered.

Cataract Falls, Mount Tamalpais, California

Electrons moving can be diverted to do work, sort of in the same way that water traveling downhill can be diverted to run a mill or turbine.

The water’s kinetic energy is lost as it is used up in the turbine. Likewise, the electrons’ kinetic energy is lost when they are put to work in a device. The electrons don’t get destroyed in the process of losing energy, just as the water wouldn’t be destroyed.

 

ALTERNATING CURRENT

When you plug in something like a light, electrons flow from the plug, through the light, and back out through the plug. However, it’s not that simple, since we use what’s called alternating current, or AC, which means that the electrons flow one direction and then reverse direction. Alternating current makes it easy to change from a high voltage to a lower voltage. This change is made through a transformer.

 

ELECTRICITY IN THE HOME

Today, inside the home, electricity powers computers, televisions, telephones, lights, refrigerators, heaters, air conditioning, healthcare-related devices, video games, rechargeable toys, stereos, alarm systems, garage doors, ovens, stovetops, dishwashers, clothes washers, routers, can openers, DVD players, DVRs, and countless rechargeable devices like phones and electronic tablets.

Computers, televisions, and handheld electronic devices have become increasingly popular, while refrigeration, heating, and cooling have become more efficient. These recent trends in home electricity use have shifted the greater part of home energy needs from climate control to electronics.

 

A FUTURE FOR TELEVISION?

Today, most households have more than two televisions, with 88 percent of homes have two or more televisions in 2009. The average household had 2.5 televisions. In the same year, 79 percent had DVD players, 43 percent had DVRs, and 86 percent of households had one or more computers. Nielson reported in May, 2011 that for the first time in 20 years, television ownership is slightly down, perhaps in part because computers may be replacing the use of televisions, DVDs, VCRs, and video games.

 

More about home energy in the energy efficiency section.

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Petroleum, Natural Gas, and Coal

The world depends on fossil fuels for its energy, and the United States is no exception. The vast majority of U.S. energy — more than 80 percent in 2009 — comes from burning fossil fuels. (more…)

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