OK Las Vegas; worst case scenario – or in your case, what will eventually happen. Sooner or later, for one reason or another, Las Vegas may have to face the fact that even with all the water they may take from Rural Nevada and Utah, there won't be enough. What will you do then? And, very importantly, what will you do if this happens sooner than we expect?
We all know that no matter how big Las Vegas gets; there will always be people who will want to keep it growing. Inevitably, they will be powerful people. They'll want answers... And we won't want to disappoint them, now will we. What are you going to do? What will you do when you start thinking about all that water being used for coal fired power plants – just being wasted? You're going to think of another way. Yeah, that's right. Sooner or later, Las Vegas is going to be considering shutting down the coal fired power plants for the water. All that would have to happen is that Las Vegas run out of water again in the next 50 years. Gee... how likely is that?
Consequently, whatever they're telling you the coal fired power plants will cost, they will likely cost more – simply because it isn't very likely that the utilities will be able to keep them running for their full operational life. There are multiple reasons the utility companies may not be able to profitably operate coal fired power plants for 50 years. Potential carbon taxes, the rising price of coal, regulatory changes, and the decreasing costs of alternative generation are all working against coal fired power. If the coal fired power plants are actually more expensive than we think, alternatives may be a better idea after all.
Let's consider hydrogen power:
As you probably already know, burning hydrogen doesn't produce even a fraction of the pollution of burning coal. So, it is a potential environmentally responsible alternative – if we can make it work at a reasonable price.
Hydrogen has the highest energy content per unit of weight of any known fuel; 52,000 Btu/lb. Anthracite coal only has 12,000 Btu/lb. This means that, by weight, only 23% of hydrogen is necessary as coal to get the same energy.
The coal fired power plant planned by Sierra Pacific, near Ely, Nevada, is expected to generate 1.5 GigaWatts of power by burning 10,000 tons of coal a day. If we assume similar efficiencies, hydrogen power would only require 2,300 tons of hydrogen a day.
If we were to talk volume, however, the situation is more like comparing apples and oranges. 10,000 tons of coal a day is more than a trainload of coal every day. But, hydrogen wouldn't be delivered by fleets of smoky old trains. To be cost effective, hydrogen would have to be delivered by pipeline.
In other applications, hydrogen has had to be pressurized to fit in the pipe. This would add significantly to the cost of the pipeline. However, my calculations (rough estimates, actually) show that pressurizing hydrogen to lower it's volume is not absolutely necessary (the calculations are at the end of the article):
By running at atmospheric pressure, we could eliminate the need for most all of the pumps – and the associated power use.
Hydrogen is about 1/14 as dense as air, which means hydrogen will flow uphill in a pipeline. Unlike water, pumping costs from the coast inland could be insignificant. Better yet, a pipeline full of hydrogen will flow over hills and back down the other sides, as long as the exit is at a higher elevation than the entry (utilizing a siphoning effect).
But there's more. When hydrogen “burns” to generate power, the byproducts are heat and water... that's right, fresh water. By piping in hydrogen from the sea, one can effectively get water to flow uphill! And the heat released can be used to cogenerate electricity.
Yes, there's even more. Hydrogen's atomic weight is 1. Oxygen's atomic weight is 16. In the chemical reaction that makes water from hydrogen and oxygen:
2H + O → H2O
the atomic weights are:
1 + 1 + 16 = 18
Therefore: for every ton of hydrogen burnt, 9 tons of water is produced. So, burning 2,300 tons of hydrogen a day would result in 20,000 tons of water a day.
20,000 tons/day X 2000 pounds/ton
X 3.06888 X 10-6 acre feet/gallon
= 15 acre feet/day
15 acre feet/day X 365 days/year = 5,000 acre feet/year
5,000 acre feet/year X 5,000 dollars/acre feet
= $25,000,000 per year
The expected lifetime of a coal fired power plant is about 50 years. If hydrogen were burnt instead, the water sold could amount to:
50 years X $50,000,000 = $1,250,000,000
Which, of course, means that a utility company could spend $1.25 billion more on hydrogen power generation and a hydrogen pipeline to Las Vegas, and still come out even. Well, even... if you ignore all of the external costs and collateral damage that coal fired power plants would cause.
As mentioned earlier, what if this $5 billion coal fired power plant only gets to operate for 25 years? That means that the utility companies construction costs were twice what they expected. Which makes hydrogen look even better.
Unfortunately, our utility companies tell us that we don't have the option for hydrogen power now. It's just too expensive. (Too bad they don't say that about their executives' paychecks.) The truth, however, is that it just may be too expensive. The electrolysis of 800 million cubic feet of hydrogen a day, admittedly, will be very expensive (if we make hydrogen from fossil fuels, we'd still have a CO2 problem).
Making 2,300 tons of hydrogen a day may seem like a monumental task, but remember that digging up 400,000,000 tons of coal (literally a mountain of coal) is no easy task either. The manpower and heavy equipment costs will be huge. The loss of ranch land to mines will also be a substantial cost to our economy. Over the course of 50 years, there will be over 20,000 train loads of coal that will have to be delivered for round trips of over 1000 miles each. Just the fuel costs for the trains will make these Nevada coal fired power plant units among the least profitable in the West. There's the expense for water – enough water to support 100,000 people (or in this case, whole ecosystems). Then there's the cost of the power line from Central Nevada. Moreover, there is the expense of dealing with all the pollution from burning all that coal. The coal fired power plants will leave behind a toxic sludge pile that will cover 1500 acres – for future generations to deal with. And hundreds of tons of toxic chemicals will blanket the earth for hundreds to thousands of miles downwind. Just the health care costs will be astronomical. Of course, costs to society and the environment aren't calculated into Sierra Pacific's bottom line. But, these “external” costs had better be a concern for us.
Not to mention, there is one very important point that we have to remember. Eventually you're going to have to pay for both coal fired power and some form of alternative power generation. Hey wait a minute, both are always more expensive than either.
It may be a stretch to start construction of hydrogen power generators now. But, it may be a stretch that will be worth it in the long run.
We could construct a fleet of hydrogen generators operating offshore, powered by wave energy. The technology to make hydrogen from seawater already exists. If the hydrogen generators are built small enough, their processes shouldn't effect localized ocean salinity. Being small means that each hydrogen generator will not be extremely expensive. And starting small means that we can start right away – and not have to finance the effort (which would add to the cost).
Building a pipeline to Las Vegas might not be such a good idea until the hydrogen generators and power generators are fully functional. However, prototypes could (temporarily) use one of the natural gas pipelines that stretch from LA to LV.
Fuel cells would be the ultimate goal for any type of hydrogen generating power in Las Vegas. But until then, we may be able to retrofit an idle natural gas power generator – and utilize the water byproduct in the steam turbines.
The truth is, sooner or later, we will have to build alternative power generators anyway. So, why not consider starting now. It might actually be cheaper in the long run. It definitely will be far cleaner and less destructive.
Below are the calculations for a hydrogen pipeline operating at atmospheric pressure:
Hydrogen's density is 0.09 g/l.
0.09g/l X 0.062 g/l
= 0.0056 lbs/cu ft
so, 2,300 tons of hydrogen would be:
2,300 tons X 2000 lbs/ton
0.0056 lbs/cu ft
= 800,000,000 cu ft
If the hydrogen were not pressurized, this 800,000,000 cu ft would have to travel in the pipeline per day.
800,000,000 cu ft/day
24 hours/day X 3600 sec/hour
= 9,500 cu ft/sec
A 8 foot diameter pipe has the area (πR2) or 50 ft2
The velocity of the hydrogen would then be:
= 190 ft/sec
190 ft/sec X 0.682 miles/hour
= 130 miles per hour
...which might be an acceptable velocity, since this is a gas. Of course, pressurization might be more cost effective. Further study is necessary.