Electricity, Energy and Global Warming By the Numbers, Part 2

Numerous factors contribute to climate change. In Part 2, we explore remedies, and the merits of each.

Part 1 covered recent developments in energy production, and the science behind global warming. In part 2, I'll discuss techniques for fixing the problem, focusing on the facts, in what I consider an unbiased manner.

The U.S. EIA (Energy Information Administration) is responsible for calculating the costs of different energy sources. The costs specified in this article are from EIA, and scientists consider EIA the most reputable source of energy data. These numbers are valid for 2015, but they could be different several years from now because of new research, changing commodity prices (e.g. natural gas price), and changing interest rates (which determine the cost of capital to build new power plants).

Fixing it
The average kWh (kilowatt-hour) cost in the USA is $0.12. Americans are not inclined to spend much more. We see how they respond when a politician advocates higher taxes on gasoline or natural gas to reduce consumption—the measure typically doesn't pass. Yet Americans do want to solve the global warming problem. So the question becomes, "How can we economicallysolve the global warming problem?" I'll now explore each option and their merits.

Improve efficiency and save money
This is where you get paid to reduce global warming, literally. You spend money to reduce energy consumption, and the saved money pays for the initial investment in a reasonable period of time.

For example, if you replace a 60 W incandescent light bulb with a $10 LED bulb (Figure 1), you'll break even in less than one year (i.e. the cost of the electricity needed to power a 60 W incandescent bulb for six hours per day, at $0.12/KWh is $16). After breaking even, the bulb is paid for and the profit is $13 per year until the LED bulb fails, perhaps in year 14 (30,000 hours at 6 hours per day). Here, you reduce global warming and get paid to do it.

Figure 1. LED lighting can reduce energy consumption and save money.

Below are several areas where you can often make money and reduce global warming at the same time:

• Better insulation in homes
• Paint roofs lighter colors that reflect more sun
• LED light bulbs instead of incandescent
• More efficient appliances

If you have a hot water heater, refrigerator, furnace or air conditioner that is more than 30 years old, it is often in your best financial interest to replace it, if you can afford the upfront cost.

The newer, central HVAC units have variable speed fans instead of one-speed on/off fans. Thus they can run at 10% power and put a trickle of heat or cold into your home. This saves energy and also increases comfort since you have less temperature fluctuation between the unit being on and off. In other words, you get more comfort, reduce global warming, and save money; all at the same time.

Numerous factors contribute to climate change. In Part 2, we explore remedies, and the merits of each.

Reduce global warming by spending money
This is where you spend money to reduce global warming, yet the spent money does not reduce energy costs.

An example is CCS (carbon capture and sequestration). This involves burning natural gas or coal to produce electricity, capturing the carbon, and storing it. The EIA estimates future CCS to cost an additional $0.03/kWh of electricity (e.g. $0.15 instead of $0.12 to the consumer). CCS is, however, a new technology, and its cost and feasibility has yet to be verified.

Burn Natural Gas instead of Coal to Produce Electricity
The world has a love/hate relationship with coal. It's disliked because of its association with air pollution and excessive global warming. But, it's affordable, especially in poor countries with local coal mines.

One hundred years ago, the United Kingdom had one million coal miners. For many years, coal powered factories, residential heating, residential cooking, and steam locomotives. Coal was king, and still is, to some extent. Today, 40% of the world’s electricity is generated by burning coal.

The world is, however, running out of easy-to-access coal. Many of the world's coal mines are running dry. China is expected to reach peak coal production per year sometime within the next 15 years. After that, Chinese coal production per year is expected to decrease. As coal runs out, the world will be forced to move toward alternatives (e.g. nuclear, natural gas, oil, wind, solar).

Burning natural gas instead of coal to make electricity, reduces carbon output two-fold for each unit of electricity produced. This is because coal is mostly carbon, and when it burns, most of the energy comes from burning carbon with a CO₂ byproduct. Alternatively, when one burns natural gas (mostly CH₄), half the energy comes from burning hydrogen (H₄) with a 2H₂O byproduct, and the other half comes from burning carbon (C) with a CO₂byproduct.

Natural gas is less costly at $0.066/kWh when compared to coal's$0.095/kWh. Therefore, shifting from coal to natural gas is a case where one is paid to reduce global warming. Subsequently, many governments considered it the low-hanging fruit of global warming policy (i.e. easiest first).

Squeeze electricity from the sun
Solar does not contribute to global warming, yet is a costly way to produce electricity. Electricity generated from PV (photovoltaic) panels in a sunny area cost approximately twice as much as burning natural gas. Many people don't want their electric bill increased dramatically, and therefore are not willing to pay for it.

Researchers are making great progress at reducing the cost of PV silicon, as shown in the below graph. The graph doesn't include the cost of mechanical support hardware, conversion electronics, installation labor, maintenance labor, and land use; all of which sum to a cost much greater than the PV silicon component (Figure 2).

Figure 2. The cost of electricity from solar cells has dropped, but is still too expensive.

Solar cells produce no electricity at night and little on cloudy days. Subsequently, they're more economical in sunny areas, such as the southwestern United States.

Solar is a great way to obtain surge power for air-conditioning because it produces the most when A/C units are running the hardest. If one can defer from building that additional power plant to cover surges on hot sunny days, then they can save money on a plant that is not widely used.

There are primarily two kinds of solar: photovoltaic (PV) and thermal. Thermal involves concentrating sun via reflectors to produce heat, and then converted that to electricity. Electricity from thermal is twice as costly as PV, and therefore less popular.

Squeeze Electricity Out of Wind
Generating electricity from land-based windmills doesn't contribute to global warming and its $0.080/kWh cost is a little higher than that of natural gas, which is $0.066/kWh. However, electricity cost from sea-based windmills (near land) is three times higher than land-based, due to the difficulty of building and transmitting in the ocean.

The big issue with windmills is they need high-velocity wind to produce electricity inexpensively. Power from wind increases with the cube of the wind velocity. For example, you get 64 times more energy from 20mph (9meters/second) wind than from 5 mph wind (20³ / (5³). To get fast wind, you need a tall windmill (e.g., greater than 20 stories high) in a windy area. Highest winds exist off the coast in the ocean, and in the middle of the country, as shown in the below map of wind velocities at 80 m (260 ft.) above ground level (Figure 3).

Figure 3. Wind velocities in the U.S. are highest along the coasts and in the plains east of the Rockies. Click here to enlarge. Source: National Renewable Energy Laboratory.

Windmills can extract 30% to 50% of the energy that passes through the circle covered by the blades because the blades move fast and touch the wind that appears "in between" the blades. Obtaining the right to build transmission lines to windy areas is one obstacle to wind energy. Farmers and ranchers that own land between cities and windy areas tend to demand top dollar to use their land for power lines.

Squeezing electricity from wind isn't expensive in a windy area on land with a tall windmill, so long as reasonable right-of-way exists between windmills and consumers.

Numerous factors contribute to climate change. In Part 2, we explore remedies, and the merits of each.

Nuclear Power
Nuclear power (Figure 4) doesn't contribute to global warming and produces electricity at a reasonable $0.096/kWh. Yet, we have seen several severe nuclear disasters and the public is therefore concerned about safety.

Figure 4. Nuclear power plants don't contribute to global warming, but do have risks.

Figure 4. Nuclear power pants don't contribute to global warming, but so have risks.

In 1986 a nuclear reactor at Chernobyl exploded and released radiation into the atmosphere. The accident induced cancer in approximately 24,000 people over many years.

In 2011, a tsunami at the Fukishima nuclear power plant caused it to release a moderate amount of radiation into the environment. The tsunami initially removed power to pumps that circulate cooling fluid through the reactor. The system switched over to battery backup, yet the batteries depleted 8 hours later. Subsequently, nuclear fuel melted through the reactor vessel steel onto the containment building concrete floor where it now rests. There are more modern designs that circulate cooling fluid via convection with no power, and these would have done much better. Also, diesel-powered generators with plenty of fuel and switching electronics in hardened buildings would have been helpful. Such generators and electronics were on site, yet not in hardened areas.

The long-term solution is to build nuclear power plants that inherently cannot melt down due to their design. This is sometimes referred to as "passive safety" or "intrinsically safe." An example is the use of nuclear fuel that turns off if it gets too hot (i.e. as temperature increases, the interaction between atomic particles changes and energy release decreases). Research is progressing in the area of safety, and several countries are already building nuclear power plants that employ passive safety.

Two important issues with nuclear power are the storage of spent nuclear fuel and the risk that nuclear fuel will be captured by terrorists, refined further, and turned into a nuclear bomb. Nuclear scientists are currently working on developing a nuclear reactor that does not create spent toxic fuel and does not use fuel that can be further refined to make a bomb. This research could possibly solve our long-term limited fossil fuel problem and global warming problem. Don't be surprised if an exciting development occurs sometime over the next 20 years. An example is controlled fusion where we detonate tiny specks of hydrogen 1000 times a second to create heat via Einstein's famous energy transference equation E=mc². The laser that does this is not large enough to denote more than a speck. There is no nuclear fuel and no possibility of meltdown. Scientists are working on this, and other technologies, to create energy safely and without global warming. Yet a solution might still be 10 to 50 years away.

Transportation
Automobiles can be powered by gasoline, natural gas, or electricity. Many taxis and buses are powered by natural gas since the resulting cost-per-mile is less than gasoline. The disadvantage is the fuel tank must be three times larger for the vehicle to achieve the same range.

Thanks to our new techniques for squeezing gasoline and natural gas out of the ground, we could go either way in the foreseeable future, if we were not concerned about global warming.

Hybrid gas-electric cars are cost-effective since their battery is paid for with better gas mileage. Their batteries are relatively small. For example, the Prius can only move 10 miles at 25 mph on electricity alone. This is good, because it means the battery cost is not too high and can be paid for with money saved from using less gas. The reason hybrid cars use less gas is because they capture energy when they brake, and they use the electric motor when they accelerate. And accelerating with gas-only is inefficient relative to electric (i.e. more energy is lost to heat).

All-electric cars that plug into the wall and run only on electricity have a higher cost-per-mile, as shown in Table 1 below. This table shows the cost-per-mile as a sum of three components: gas ($2.50/gallon), electricity ($.12/kWh) and battery replacement.

The battery replacement issue is interesting. Batteries lose their ability to hold charge after multiple charge cycles; therefore, all-electric vehicle total range decreases over time (i.e. number of miles one can drive before recharging batteries decreases each year). The table assumes the Tesla and Leaf owners replace their batteries after 100,000 miles. If the all-electric owner is willing to have total range decrease significantly (e.g. focus on shorter trips), then cost-per-mile improves. Alternatively, if the owner is not willing to accept range degradation and replaces the battery more often, cost-per-mile increases.

The cost of gas has a big effect as well. If its cost doubles, for example, the gas-only vehicle cost-per-mile also doubles.

The numbers in Table 1 are relevant for today, yet the cost of gas, cost of electricity, and cost of battery replacement are changing; and five to ten years from now, this picture could look quite different.

Over the next 20 years, expect to see the following trends in transportation:

• A larger percentage of drivers with hybrid, since the additional cost of the electrical hardware is paid for with saved gasoline.
• More cars powered by natural gas, since their cost-per-mile is less than gasoline.
• More small all-electric cars with low-cost batteries, with low range. These are plugged into the wall at night, and used for everyday short-range commuting and shopping.
• More families with one long-range car and one short-range car, instead of two long-range cars.

Global Warming and Energy
The world is working at a rapid pace to avert global warming related issues. It might not feel that way because CO₂ emissions increased rapidly between 2002 and 2013. Global warming-related research and programs, however, are moving forward, and this is driving down the costs of energy that emit less CO₂(e.g. solar, wind).

In the short term, we can easily reduce global warming with a shift from coal to natural gas. Natural gas is less costly, we have plenty of it, it contributes less to global warming, and the technology is verified. In the longer term, we can reduce global warming with low-cost solar, wind and safe nuclear. Moving from coal to natural gas over the next decade will give researchers time to develop less costly solar, wind and safe nuclear. Oil and natural gas are currently cheap and plentiful. They will, however, eventually deplete, forcing us to focus on geothermal, hydro, solar, wind and safe nuclear. The world does have a path forward, and we have already embarked on this journey.