How Many Windmills Does It Take?

In the last post, we estimated that the U.S. would need to double (more or less) the electric generating capacity, 1,000,000MW, in order to power a fleet of 135,000,000 electric cars. Remember, we left out trucks and buses.

Currently, at the end of 2007 there was about 15,600MW of wind generating capacity. Let's estimate, for argument's sake, that at the end of 2008 there was 20,000MW of wind capacity in the U.S. So how many windmills would it take to charge 135,000,000 automobiles?

Let's orient ourselves with some criteria. There are a number of wind turbine sizes available from manufacturers but for our purposes let's assume that we use the largest size--2.5MW. We also assume that each of these wind turbines is running full tilt (no pun intended) during the six hours we're charging the fleet. The fleet is charged at the same time of day, let's say overnight, and that there is sufficient wind to run the turbines at maximum output. None of this is realistic but we're trying to estimate an order of magnitude.

So, how many? Simplistically: 1,000,000MW divided by 2.5MW per turbine results in 400,000 new wind turbines. If we assume our existing fleet were composed of 2.5MW turbines (which it is not), we would have approximately 8000 wind turbines (20,000 divided by 2.5). There are more wind turbine units in the country because the original sizes were smaller, so it could be 2 or 3 times that number. A truly national study of the number of units required might be significantly larger to account for all of the changing variables.

The point is this: there is no time soon or possibly ever that the U.S. will increase the number of wind turbine units by one or two orders of magnitude. Not feasible.

Of course, one could argue that wind turbines are only one source of renewable energy that could be used, and I concede that. But we could make similar calculations for all of the renewable energy sources combined--and as much as we all would like it to--it's just not going to get us there. Moreover, as I argued in a previous post, electric cars are too inefficient and the infrastructure to support them too capital intensive to pursue this ill advised course. It's not sustainable.

The realistic solution in a future post.

Electric Cars: The Electric Infrastructure Required

My literary agent passes on articles to me (She's really helpful.) from time to time and I like to comment on them here. I do this to illustrate and quantify people's qualitative assessments. Back in February I wrote a post about electric cars and suggested that the electric generating infrastructure required should be examined very carefully. So let's do a little quantitative examination of the infrastructure required.

First, let's establish some facts. There are 17,342 electric generators in the U.S. and they have a nameplate capacity of approximately 1,000,000 Megawatts. A Megawatt equals 1,000,000 Watts or 1000 kilowatts. There are 244 Million motor vehicles in the U.S., 135 Million cars and the rest are trucks and buses.

Let's set some design criteria to size our infrastructure. First, I want my infrastructure to be built in phases. So I'm only going to design and build enough power plants, transmission lines and distribution lines to charge and power 135 Million automobiles. We'll deal with the trucks and buses later. In addition, let's size the electric car's motor and let's be realistic. A Honda Civic has a 140 horsepower engine which amounts to a 104kW electric motor. That's realistic. Phoenix Motorcars of Ontario, California provides its SUT/SUV vehicle specifications that I think are realistic. The top speed is 95 miles per hour; it can travel 100+ miles per charge; in can go 0-60 in less than 10 seconds and it requires 6.6 kilowatts for a five to six hour charge. The motor is 147 horsepower or 110 kW. Torque is 369 ft-lbs.

So how much additional power would the U.S. require to instantaneously power all of these vehicles. The utilities that provide electricity to each of us must design and build enough power stations to supply the peak load plus a reserve or capacity margin. The margin is an amount of oversupply in case power plants have an unanticipated outage and avoids blackouts. It's why power in the country is available virtually continuously.

Let's calculate the instantaneous additional power required:

135,000,000 x 6.6 kilowatts = 891,000,000 kilowatts or 891,000 Megawatts.

When one adds a 15% capacity margin, the figure increases to 1,024,650 Megawatts, doubling existing electric generating capacity in the U.S. I have personal, hands-on experience as an engineer and a banker in the construction of power plants. It is a vastly massive undertaking. The people who do it routinely in this country are unknown and unsung . . . except by me, of course, and I have high respect for them and high regard for their skill.

Of course this is an instantaneous figure. It assumes we're all plugged in at the same time. It does not account for time zones, different driving characteristics, different characteristics of the many utility service territories in the country, different size vehicles, different battery technology, and the current overall utilization rate of existing power plants, etc., but it is in the ballpark. One can argue one way or another that it's three quarters of that figure or 50% greater. But it is huge. It is extremely costly. And I haven't begun a discussion of the transmission lines, and the opposition to building them, that would be required as well.

In the next post, we'll take a look at how many power plants would be required and how much electricity renewable energy would need to generate to power the theoretical electric vehicle fleet of the future.

Fuel Cell Catalysts: The Inexpensive Alternative

My literary agent was kind enough to send me an article on the potential replacement of platinum as a reactive catalyst in fuel cells, replacing it with an iron and carbon-based alternative. Commercialized, this would be an extreme breakthrough in the state of the art of the fuel cell. Since I am currently writing the chapter on fuels cells for my book (Energy: The Primer How to Distinguish a BTU From a BLT), it was apropos.

A fuel cell creates electric energy without combustion. Rather, a chemical reaction breaks apart the fuel, likely hydrogen, although other fuels can be used, and sends the electrons through an electric circuit. This can drive a car motor or any electrical device. The electron then recombines with its hydrogen nucleus and air, forming water out the tail pipe.



Source: http://www.p2sustainabilitylibrary.mil/issues/emergeoct2005/index.html

There are two important points about fuel cells: (1) They create little or no pollution and (2) They are much more efficient than the internal combustion engine. A Proton Exchange Membrane (PEM) fuel cell, like the one pictured above, can achieve efficiencies of up to 45%, nearly twice that of the internal combustion engine. PEM fuel cells operate at low temperatures, 150 to 200 degrees Fahrenheit. Other types of fuel cells operate at temperatures up to 1800 degrees, making them candidates for combination with a steam cycle (rankine cycle, similar to today's combustion/steam turbine combined cycle power plants) and achieving efficiencies of 60% to 80%.

The fuel cell is not new but it is our future. It is the reason people can travel through and live in space because it provides electricity and water. It's applications are endless from locomotion to distributed generation to stationary power plant applications. It will reduce pollution dramatically and fuel consumption in all applications by 50%. Imagine, a fuel cell propelled car routinely getting 40 to 50 miles per gallon and power plants with twice the efficiencies they average today.

This is where U.S. energy policy should lead us. If I were president . . . .