Frequently Asked Questions: Q: What is a fuel cell? A: A fuel cell is a device that converts fuel directly into electricity, via a flameless electrochemical reaction. Hydrogen fuel cells are the most widely-known type, and methanol fuel cells are very similar in operation (liquid methanol contains a lot of hydrogen) plus have some distinct advantages. The most common PEM type fuel cell (such as the EFOY Pro) basically has a stack of membranes that strip the electrons from the hydrogen atoms, allowing only the hydrogen ions (missing the electron) to pass thru. This forces the stripped electrons to travel the long way around through the load (i.e. charging batteries) in order to meet on the other side. When they meet again, oxygen is taken from the air and used to form water (H20). In the case of a Methanol fuel cell, there is also a carbon atom to deal with, so it forms CO2 (very small amount). Some produced water is recycled internally, but most is exhausted. Q: How effiecient are fuel cells? A: Direct Methanol Fuel Cells are about 25-30% efficient. This means that 25% of the possible energy in the methanol fuel ends up as electricity in your batteries. This compares very favorably to other generators such as thermoelectric (TEGs) which are only about 2-3% effiecient. Q: How clean are they? A: Very clean. Usually less CO2 emissions than a typical person creates when he/she breathes. Much less than a TEG unit. Q: How much power can they put out? A: The three sizes of EFOY Pro fuel cells (600, 1600, and 2200) represent the maximum output in watt-hours per day. Divide by 24 hours per day and you get 25, 67 and 92 watts respectively. This doesn't sound like much until you consider that they can actually do this for up to 24 hours per day, unlike solar panels. For example an EFOY Pro 2200 can put out the same amount of power as TEN 135W solar panels during an average winter day in central Alberta. Without the concern for periods of "worse-than-average" weather. Q: OK then, what exactly is a "watt-hour"? A: A watt-hour is a measure of total energy produced or consumed. Example: a 10 watt load running for 1 hour uses 10 watt-hours of energy. A 5 watt load running for 2 hours also uses the same 10 watt-hours of energy in total. Q: How do I determine what size of EFOY Pro fuel cell, and solar panels, and batteries that I will need? A: It starts with an estimate of your expected average load, in either watts or else watt-hours per day. Average is the key word, since your batteries will typically take care of short peak loads that may be significantly higher than average. We just want to be able to replace the energy that your load takes out of the batteries before they are empty. Add up all of your equipment power loads (watts) x hours of "on-time" per day. A sizing spreadsheet is provided for estimating purposes, or you can just request a quote with your conditions. Q: How much fuel does it use? A: Actual fuel usage is variable, since it depends on electrical load, and solar ouput (i.e. weather conditions). The typical value for estimating is 1100 Wh/L (watt-hour per litre). For example, some Oil & Gas well-sites (SCADA power, hybrid with solar) can last a full year on the (2) 28L size cartridges (= 61,000 watt-hours total) and only need to re-fuel once per year by using the DCS accessory. A sizing spreadsheet is provided for estimating purposes, or you can just request a quote with your conditions. Q: How difficult / dangerous is it to handle / install the fuel cartridges? A: Handling the fuel cartridges is simple and safe. They are designed with built-in check valves to prevent spillage if tipped over while the cap is off. They have internal plumbing to permit operation in almost any orientation. The operator simply screws the end of the fuel hose onto the cartridge. There is no need to shut off the EFOY Pro during this procedure (the EFOY Pro has a small internal resevoir). It only takes 1 minute to remove and replace a fuel cartridge, and no tools are needed. Methanol is both flammable and toxic. More info including an MSDS safety sheet is available here. Q: When do I need a Power Pod versus just the EFOY Pro? A: If you already have a heated building (always above zero degrees C) and the interior of it is considered to be non-hazardous (by electrical code classification standards) then you can just install the EFOY Pro inside it. But most remote off-grid sites don't have any heated buildings. Or if they do, they may be considered hazardous classification (Class 1 Zone 1, etc) due to possible existing combustable gas mixtures, such as typical for Oil & Gas well-sites. So for most sites, you need a Power Pod to allow the EFOY Pro the best chance to survive winter conditions without freezing. Q: Can the EFOY Pro freeze? A: Yes it is possible, but not generally expected (if installed properly). There are several layers of defences that combine to prevent freezing of the EFOY Pro. Evergreen's patent-pending Power Pod system has an insulated enclosure with HVAC designed to retain waste heat that is produced by the EFOY Pro (i.e. the other 75% loss after the 25% efficiency is complete). Plus the Power Pod has a thermostatically-contolled exhaust tube heater assembly and exhaust tube configuration designed to avoid water collection and freezing in the exhaust. Also the EFOY Pro has a built-in antifreeze mode that is designed to keep the unit warm even if the load is turned off (i.e. batteries do not need to be charged yet). Q: What happens if the EFOY Pro freezes? A: If the EFOY Pro does freeze, then normally the unit will require to be thawed out at room temperature for up to 24 hours prior to re-starting without damage. This would mean removal of the EFOY Pro from the Power Pod enclosure (a simple, 1-minute task without tools) and possibly swap-out with another EFOY Pro in the meantime. Occasionally, damage from freezing will require the unit to be sent off for repair by SFC. Q: How can I control & communicate with the EFOY Pro? A: There is a simple user control panel that displays some information and has input buttons for direct control at the location. Also, with the optional interface adapter accessory, you can plug into the serial port of your laptop PC and use a program like HyperTerminal to access more features and settings. It is also possible to remotely control and communicate with the EFOY Pro using additional modems and/or Modbus SCADA adapters. Even to set up automatic alarms for low fuel and status. Please ask us for more details. Q: How do I install / operate the various EFOY Accessories (DCS and FS1, etc)? A: Please see the EFOY Pro Accessories page for more info, including downloadable manuals (bottom of page) and Evergreen's Operating Tips . Q: How does it work with Solar? A: Very well. The EFOY Pro only goes from standby into charging mode IF the battery voltage drops below a pre-set level, which is much lower than a typical solar controller. So this means the solar is used as much as possible until it can no longer keep up, then the EFOY Pro kicks in automatically. NOTE: there are some very important criteria to meet when selecting a solar controller to work with the EFOY Pro (and not damage it). The solar controllers that we supply are proven compatible. A: Yes, the EFOY Pro fuel cell can also be integrated with micro wind turbines instead of (or in addition to) solar panels. Since the wind and sun are not continuously reliable sources of power, the EFOY Pro can help "fill the gaps" in power output. Q: How can I get one? A: Contact us by phone or email with some information about your project, and we will be glad to provide sizing assistance and a quote. |
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