Fuel Cells for Power Generation

[TomC]

Hi,

I work for a Fuel Cell company and we've just returned from the boat show. What we found whilst exhibiting was that a lot of people did not know what a fuel cell was and that it was a good option for them.

I don't want to break any forum rules for advertising so I wanted to start this thread for anyone to ask questions about fuel cells, where one would work, or where alternatives such as solar, wind or a generator would be more suited.

To start with, a fuel cell is a device that generates electricity from a source of fuel through a chemical reaction. The reaction is silent, and the only by-products are heat and water. The most common fuel for on board generation is Methanol.

Fuel cells will produce a continuous current until the batteries are charged. They come in sizes from 25W (2.1A at 12V) to 90W (7.5A at 12V). They use about 0.9l of Methanol per kW produced. They are also small and lightweight.

Please ask any questions you might have.

Tom

 

[prv]

How much is it?

Pete

 

[Porthandbuoy]

How would they cope with heeling and violent motion?

How pure must the methanol be?

 

[Colvic Watson]

Excuse my crummy maths, but does that mean very roughly 100amps (at 12v) per litre of methanol? If so, that's cheaper than running my very frugal genny/battery charger combo.

 

[Danny]

...They use about 0.9l of Methanol per kW produced....

... per hour? (ie 0.9L per kWH)?

 

[mattnj]

... per hour? (ie 0.9L per kWH)?

does it matter?

isn't it 0.9L in an hour at 1kw output....or 0.45L per hour at 500w or 0.09L per hour at 0.1kw (100w) or 9L in an hour and outputting 10kw....etc, its all the same (ie 0.9l per KWH)
that is all assuming it operates at all those output (probably doesn't do 10kw!)

how much are they?

 

[TomC]

The prices range from £1,750 to £4,615 depending on the output.

The units can cope with 35 degrees of heal continuously and up to 45 degrees for 10 minutes. If the unit stops powering due to excess heal, it will start again once back at 35 degrees. We had one on board during the 2007 fastnet and it worked throughout the race.

The Methanol has to be pure. For the manufacturer to honour the warranty, it has to be from their sealed containers.

 

[davel]

How readily available is Methanol, in the UK and overseas?
Does the fuel cell automatically shut down when the battery bank is fully charged?

 

[TomC]

Yes, 0.9l per kWh. Take for example the most popular unit, the 65W. This outputs about 5A continuous and uses just over 1l per day.

So, 100A would use about 1l of fuel. To get this the fuel cell would run for about 20 hours.

 

[TomC]

We keep stock of Methanol which can be ordered online for next day delivery to the UK. Availability is good in Germany, France, Spain and other European countries. At this point in time you cannot buy it anywhere in the Caribbean.

The fuel cell monitors the battery voltage so will charge until it reaches 14.2V and then enter standby mode where it does not consume any fuel. It will then restart when the battery voltage reaches 12.3V.

 

[Porthandbuoy]

The prices range from £1,750 to £4,615 depending on the output.

The units can cope with 35 degrees of heal continuously and up to 45 degrees for 10 minutes. If the unit stops powering due to excess heal, it will start again once back at 35 degrees. We had one on board during the 2007 fastnet and it worked throughout the race.

The Methanol has to be pure. For the manufacturer to honour the warranty, it has to be from their sealed containers.

So, is the power quoted Net or Gross? How many amps does the unit use to keep itself going?

How long is the manufacturers warranty before we dare go and purchase 'pure' (99%? 99.99%?) methanol from a cheaper source?

Could be handy for those who have Origo cookers>

 

[TomC]

All the figures quoted are net output so 65W is 65W of charging power.

The warranty is two years that can be increased to three years (or 3,000 hours) by registering for free with the manufacturer.

 

[TomC]

Pure is 99.99% pure.

 

[Phoenix of Hamble]

How much is a litre of Methanol?

 

[TomC]

We sell Methanol in either 5L or 10L.

5L is £48 for a pack of two (so £4.80 per l)
10L is £73 for a pack of two (so £3.65 per l)

There is delivery on top of this although we can arrange for collection. There are other outlets throughout the UK, mostly camping and caravanning shops. A list is available on the manufacturers website.

 

[JerryHawkins]

24v systems

I see that these are designed for 12v systems. My electrics are 24v, do they do these or would I need 2 x 12v in series? Very expensive if even possible, and I suppose, twice the fuel consumption @ £3.65/litre (based on 2x10l containers for £73).

What is their expected service life? Are they serviceable (user-serviceable) or do you just have throw it away at the nend of its life?

Output/£ purchase/running cost doesn't seem to stack up against solar (ok it will still work when its dark!). I could have quite a large solar array for the same price and then free power for 20 years when the sun is shining.

 

[davel]

Where would a fuel cell be the optimum solution and where would alternatives such as solar, wind or a generator be more suited?

 

[earlybird]

Hi,

the only by-products are heat and water. The most common fuel for on board generation is Methanol.

If only water is produced, what happens to the carbon in the methanol?

 

[Chris_Robb]

If only water is produced, what happens to the carbon in the methanol?

That had occurred to me as well! Perhaps we need to wait till the arrival of Hydrogen for the ultimately clean fuel....

 

[TomC]

The unit I've been quoting is only for 12V systems. However, there is a unit aimed at the commercial user that is 12/24V auto sensing. Because this is for commercial use it slightly more expensive.

The running costs are more expensive than solar. However, as you say, fuel cells will produce power when there is no sun (or wind when using a turbine). They are also very compact (276mm (h) x 200mm (d) x 435mm (w))

Use solar (or wind) when cost is an issue and you have the space to install them. Also if you can guarantee the sun (or wind) is available for the output you require. If you don't mind using your engine to top the batteries up when there is not enough sun or wind then that's OK.

The carbon in the methanol combines with two oxygen to create a small (and insignificant) amount of CO2.