The Fuel Cell was invented by a barrister a Mr W.Grove in 1838 so the technology has been with us for some considerable time. As the 20th century advanced and both petrol, diesel and indeed steam advanced as power sources, fuel cells were just about forgotten. It was the space race that brought them back to the fore, their Low Mass and high efficiency made them a realistic alternative to batteries. Who can forget the high drama of the Apollo 13 mission to the moon when a malfunction in a fuel cell came close to wrecking the mission in deep space? The alkaline cells designed for the spacecraft were capable of producing 1.6k Wh/kg for a 200 hour mission, the best batteries at that time could only produce 0.2k Wh/kg. A bonus was the production of water as a ‘waste’ product, rather a useful function on a spacecraft.
After Apollo development and research again went into hibernation and virtually nothing new was published until 2000 when research once again took off. The Automotive Industry realising that conventional batteries would not provide the solution to the electric zero emission vehicle, has since 1997 invested huge sums into research. Ford has started limited production of a vehicle in North America; the P2000 and it may win the race to be the first mass-market vehicle completely powered by hydrogen fuel cells. Close alongside Ford, Daimler Chrysler has announced plans to market a fuel cell powered car named the NECAR 4.
The Ford system gets around many problems of re-fuelling by buying a tank of liquid or gaseous hydrogen rather than ‘filling up’ from an LPG pump as gas powered vehicles do today. Ford says the P2000 has a ‘Ballard Power System proton exchange membrane’ (PEM) fuel cell. The system comprises a stack of 400 PEM cells. The electricity generated from the cell stack is used to power the car’s electric induction/motor transaxle and electric power inverter to produce up to 90 kilowatts of power. The inverter converts the electrical current from the cell stack into A/C that then goes to power the motor. The ‘normal’ electrical system i.e. lights,radio,a/c etc is powered by a conventional battery which charges itself from the inverter. The wonderful thing about this system is the potential power output. Currently the system is producing the equivalent of 100bhp, giving the same performance as a conventional vehicle with a petrol engine producing 135bhp; the secret of course is the power to weight ratio. The fuel cell stack and electric power train is 40% lighter than the conventional unit.
Most all engines in use today on the Norfolk Broads indeed in most Marine areas are conversions of road going car or truck engines. The market is to small generally to design an engine specifically for marine use with a very few exceptions. The same will apply with mass use of electric powered marine craft. The current situation in Norfolk has proved the considerable limitation of craft deriving power from storage batteries. Electric powered craft have been around since Edwardian times and although extremely pleasant to use for an hour or so’s jaunt become a rather fraught method of transportation for any distance. The question of re-charging points the length of time to re-charge all need to go into the equation. The real killer to efficiency is the considerable power loss from the generating station, the transmission system (overhead power lines) and the massive capital cost involved getting this power to the waters edge. Aha someone cries from the gallery, what about solar
Panels and windmills (turbines if you will). I see these as for instance the Broads Authorities craft ‘Ra’ on Barton Broad, a very interesting concept and an elegant solution to a specific local problem not requiring long range or speed. You cannot economically build ‘Ra’ into a hire cruiser or a sea going boat. The demand for power in such craft is considerable and the huge array of solar cells required to feed conventional battery banks is not only expensive but also impractical. Wind turbines again very interesting concept but the power output over a season is minimal and can only be considered a back up to solar. Best left in the hands of dedicated enthusiasts. Those of us of a certain age can remember the fantastic achievements of Lotus on the racetrack, do you remember Indianapolis? The skinny little Lotus from Norfolk beating the pants off the huge American behemoths on the banked circuit; and the astounding performance of their road vehicles in the 60’s and 70’s! Engineering innovation and flair had a great deal to do with it but at the end of the day it was down to the power to weight ratio of the product. This is the real killer for today’s electric boat propulsion. The storage batteries weigh tons; the hull of a cruiser needs to be fairly beefy to carryAll this weight and weight means energy required to drive it, the power to weight ratio is hopeless and we are stuck in the loop and cannot significantly move forward.
The Holy Grail then for us broads boaters is one or two electric motors preferably installed in 360 deg. Swivelling pods beneath the hull (no rudders or thrusters required and little appendage drag from sterngear). A transplanted automotive hydrogen/oxygen fuel cell stack giving 90 to 120 kW and a Ford style re-fuelling method of plug in tanks (rather like the Calor gas bottle). Couple this with a suitably designed low wash lightweight hull and Bingo we have the basis of a silent non polluting craft that because of its power to weight ratio could with the correct hull design be a high speed planning hull as well as a low speed plodder. With easily available fuel, range limitations on a par with conventional craft.
The current work going on with fuel cells, not only with Automobile manufacturers but with the worlds armed forces proves to me that if the bigger bangs for less bucks brigade are using them then the technology will improve and rapidly. Navies have a keen interest in an all-electric ship with low or nil emissions ‘stealth’ is one of the buzzwords. At Expo 2000 in Hanover the MS Weltfrieden was fitted with a 10kw Proton Exchange Membrane Fuel Cell and the Hydrogen was stored in metal hydride. In the US the Coastguard is planning to replace a diesel generator set with a 2.5Mw molten Carbonate Fuel Cell. The plan is to install a reformer (extracts hydrogen from diesel fuel. Reformer technology a major field on its own) The US Navy is developing a 2.5Mw Fuel Cell with a reformer, the idea is to be able to use low sulphur Nato standard F-76 Fuel. The aim is to achieve this using commercial technologies. Sea trials of a 625kw demonstrator planned for 2006. The Royal Netherlands Navy is using a unit designed by Renault to use in a car, it produces 1Kw and the Italian navy has a 1Mw molten carbonate fuel cell in use.
What is this you say, the Military using Fossil Fuels to drive fuel cells, that’s not green why are they not using hydrogen? The answer is simple, the Military is awash with fairly basic standard fuel and most of the kit used by Nato forces is designed to run on anything from creosote to Aviation Spirit and it makes sense to design new kit
To run on the same fuel. Hence the need to incorporate a ‘reformer’ into the system to extract hydrogen from whatever fuel is being used. So we can agree that the Military aside most of us will want cells powered with convenient, clean, renewable non polluting and preferably a safe fuel. At the moment although cells can be powered by a whole variety of fuels from wood alcohol to Aviation Fuel the hot contender for us mere civilian’s looks like a gas and that gas is hydrogen.
Hydrogen is made from separating water into Oxygen and Hydrogen by electrolysis. The challenge is how to produce shed loads of electricity without burning coal, natural gas or having lots of pressurised water reactors (Nuclear Power Stations). A glimmer of hope is on the horizon and somebody has been thinking laterally. In 1999 The Icelandic Hydrogen and Fuel Cell Company Ltd was formed with the express idea of producing Hydrogen using ‘free’ hydroelectric and geothermal energy. The Icelandic Government is considering converting to a hydrogen economy and converting its fishing fleet over the next twenty years. Iceland has abundant natural power supplies but negligible amounts of fossil fuels. Hydrogen produced this way is still slightly more expensive than shipping fuel in from the gulf but primary cost is not the way to calculate energy cost, you need to consider the energy content. When the relative efficiencies of an internal combustion engine burning petrol and a hydrogen fuelled Fuel Cell are taken into consideration then the costs are about the same but the cost of fossil fuel will keep on rising and geothermal should remain fairly constant. The Shareholders of the Company are of interest other than the Icelandic holding company they are Daimler Chrysler, Shell International BV and Norsk Hydro ASA. I wonder if other Countries with large amounts of geothermal energy will go down this path, New Zealand for instance.
A Fuel Cell works by using electrodes (solid state electrical conductors) in an electrolyte (an electrically conductive liquid or molten medium). By supplying hydrogen to the negative electrode and oxygen to the positive electrode a fuel cell will generate a voltage between the two electrodes. The molecules of the hydrogen and oxygen are combined chemically with water as the ‘waste product.’ (Some thermal activity may also take place). Although the chemical process of a fuel cell is similar to the way a battery produces energy, a battery has to be recharged or replaced but a fuel cell can keep running as long as it is supplied with hydrogen and oxygen. If the hydrogen is extracted from natural Gas, there is a small amount of carbon dioxide as a by-product, but fuel cells emit far less pollution those traditional energy sources. It is perfectly feasible to build a cell stack to generate three to five kilowatts and as a by-product produce enough thermal energy to heat hot water.
So is it time to throw away the shore support lead and dump the generator over the side? I will not be getting rid of mine just yet, but already small units are available to use as charging units for conventional lead acid batteries. Very practical for caravans or yachts without auxiliary power. A bit expensive though at around £2,000 per 12 volt cell but with 100 amps available every 24 hours you can see the potential. Forecasting is best left to Mystic Meg but once stacks of cells from motor cars are available at around 100kw, it will not take long for somebody to hook it up to an electric motor, throw away the diesel tanks fit in plug in Hydrogen and you are in action. The availability is dependent on the speed fuel cell cars reach the market, the technology is there now but we cannot buy the interesting bit yet. My guess is we will see them within the next five or six years.
My own dilemma is do I fit an electric motor to our ‘Macushla’ now and put up with the awful lead acid traction batteries and the limited range or do I wait to get my hands on one of Fords Proton Exchange membrane Fuel Cells in five or six years time.
All I have to do is sit back in my chair, imagine the sun beating down on my face, hear the gurgles from aft as the wake leaves my transom as Macushla slips through the water with just a muted whirr from below. It is no good - I cannot wait five years, I will fit the wretched batteries and hope they last until the PEM Ford Fuel Cell is on sale at the local dealers.