Tuesday, February 6, 2007

Our Energy Future

By Capt. Dallas

These are exciting times. Political, economic and technological conditions have combined to create a true opportunity for advancing our energy choices. Fossil fuels price will fall back some but our vulnerability as a nation to “black” mail will drive continued alternate energy development. The “black” being black gold controlled increasingly undesirable nations.

Everyone has his or her own opinion of the right way to approach changing our energy economy. Being pragmatic, I try to look at all the options. Of all the options we have, each has benefits and each has disadvantages.

Bio-fuels are the greatest example of the conundrum we face. Alcohol fuel is made from renewable resources. It is clean burning and works with our internal combustion engines. Big benefits! Alcohol has only 75% of the energy of gasoline, it takes energy to produce, it is a solvent that reduces engine life and food/feed crops have to be diverted for it to provide a significant portion of our energy needs. Pretty big disadvantages!

The biggest disadvantage of bio-fuels is the last, competition with our food sources. Biomass is non-competitive to a point, but eventually energy producing acreage will compete win food production acreage.

Solar energy has the advantages of being clean and renewable. The disadvantages are less obvious but are there. Solar energy using photovoltaic panels has over thirty-five years of history and is only now reaching 20% efficiency in conversion. Like other electronic technologies, solar cell efficiency and prices will change dramatically. Investing billions into huge solar energy plants will be a hard sell. With a recent record of a PV cell reaching 40.3 percent efficiency, more than twice the efficiency of available mass produced cell it is a harder sell at this time.

One good thing about the new high efficiency PV cell is that solar technology is close. Since 40% is approaching maximum efficiency reducing chances that radically higher efficiencies will be available any time soon. Price reduction of the higher efficiency cells should still be a concern of energy investors.

Wind power has made great leaps in efficiency in the past twenty years. Windmills rated for five Mega Watts (MW) each are in production. These new windmills or wind-turbines if you prefer can produce energy at lower wind speeds extending their useful range. With current power outputs and useful life spans of twenty-five to thirty years they are a good investment. While wind power technology is sure to improve the cost per MW is low enough with current technology to pay for the investment. All great advantages for wind power. The disadvantages are really only two. The not in my back yard (NIMBY) mentality, that limits areas where it can be used and wind power needs wind to work. In conjunction with other power plants wind can provide a large portion of our power needs but not own its own.

Tidal and wave power, the most over looked of the alternate power sources have quietly proven themselves and are poised to be energy players. Tidal has forty years of proven reliable service at the La Rance power station in France. Wave power has less of a track record but has proven reliable in initial smaller scale tests. The advantages of tidal and wave energies is that they are very cost effective. The disadvantages are they can effect the environment and hinder shipping in some applications. Further disadvantages are that acquiring ideal lease for areas are difficult and there is only a limited selection of ideal area to be considered.

Nuclear power technology has improved over the years as well. Nuclear power’s advantages are clean, reliable, stable and cost effective power. The disadvantages are catastrophic disaster (low probability but a big concern), security and waste disposal. Due the first list disadvantage the NIMBY crowd are highly vocal.

Hydrogen, which is not really a source of energy just a medium of storing energy, has the advantages of being clean and versatile. Hydrogen can fuel a large variety of existing engines and heat sources. It is perfectly suited for fuel cells which is a much more efficient method for using this fuel. Disadvantages are it takes energy to produce, is more difficult to store and it is explosive as all hell.

Now is the fun part of this article for me! Expressing my option. Despite its disadvantages hydrogen will be the portable fuel of our future. Hydrogen is a far to efficient and clean a fuel to be ignored. Safe, reliable storage systems for hydrogen are developing rapid because of its potential. Hydrogen also will extend the useful areas for wind and tidal/wave power generation. Areas remote from civilization and electrical grids can be used to produce hydrogen. Hydrogen will also increase the overall efficiency of nuclear power plants and other manufacturing processes with waste heat. Thermolysis, a heat and chemical hydrogen manufacturing process is perfectly suited for using the waste heat of various processes.

Hydrogen stored in plentiful energy times can be used to make energy produced by wind, solar and tidal/wave stand-alone power sources. For example: in a solar home, hydrogen produced in the day will produce electricity at night through fuel cell conversion. Think of hydrogen as the near ultimate battery. While a solid-state battery would be a huge boon to mankind a gaseous/liquid state battery ain’t all that bad!

Our energy future will require various sources and responsible application to maintain a healthy economy and meet our goal of energy independence. These are the most exciting times of our energy lives.

Sources: www.wikipedia.com
http://www.reuk.co.uk/La-Rance-Tidal-Power-Plant.htm

Just for Something a Little Different

As a charter captain and avid fisherman alternate fuels and power plants for the boating industry is a major consideration. Since Fuel Cell Vehicles (FCV) will probably rule the roads, what about the waterways?

Boats have different power needs that cars. A boat run at or near maximum horsepower anytime they are running, cars can coast a bit using gearing. Also boats live and work in a far more inhospitable environment than cars. Electricity and salty, high humidity environments don’t play well together.

This makes using electric power propulsion systems in boat a little more complicated but not impractical. So to continue my optimistic green power theme I would like to present my concept boat of the future.

The boat is based on a 26 foot Panga style hull design, as this style hull is very energy efficient. Pangas can be inboard or outboard powered. To simplify design let’s use an outboard configuration.

The power plant for the concept boat is in two parts, the fuel cell and the electric power motor. To equalize weight load distribution, the fuel cell will be mounted forward to offset the aft engine weight.

For the outboard motor a 90-horsepower Mercury midsection and lower unit is used (Mercury just to keep it made in America as much as possible). The internal combustion engine is replaced with a 125KW electric motor weighing just over 100-pounds. So the net weight of the aft portion of the power plant is roughly the same as normal outboard motor. To have the roughly the same performance as a typical gasoline powered Panga twin engines will be installed.

This electric motor was selected for its lightweight, compact size and high efficiency. The motor is water-cooled allowing for complete sealing of the motor for protection against the marine environment. Adaptation to the outboard midsection should be simple and the power head portion would have a much lower profile. (See http://www.premag.com/products/autod.htm)

The fuel cell adds about 460 pounds to the concept boat. A considerable amount of added weight, but much less than you were probably expecting. The fuel cell selected has maximum continuous output of 210KW (based on estimates using modified stacked Honda V flow fuel cells, weight estimates may be a little low see http://www.nuvera.com/markets/androm.php).

Fuel storage will have to be liquid hydrogen to provide acceptable range in a reasonable space. With the increase efficiency of the fuel cell/electric power plant and the higher energy content of hydrogen, the fuel storage space requirement is rough the same as for gasoline.

Allowing for fuel tank insulation and the added weight of the fuel cell, the boat deck height should be raised approximately 2 inches. If not the boat would tend to be wet footed. If you are designing a concept boat may as well make it comfortable.

Now for the good part, performance! With a continuous 210KW output equal to approximately 160 horsepower at the prop, the FCV Panga should cruise at a respectable 24 knots. Fuel efficiency would be on the order of 6 miles per gallon in gasoline equivalent terms. Not bad at all!

With newer fuel cell designs that are increasing efficiency and reducing weight, even better performance can be expected in the not so distant future. Safety considerations using hydrogen are of course a major concern. So I won’t be building this concept boat this weekend. Still the fuel cell powered small fishing boat doesn’t seem as for off in the future as it did just a few years ago.