Microbial fuel cells (MFCs) have the potential to generate electricity while simultaneously providing secondary treatment to wastewater. In a typical application, a microbial fuels cell converts chemical energy to electrical energy via electron exchange between two chambers, the anode chamber and the cathode chamber. In the anode chamber, oxygen-starved organic material (for example, wastewater) is oxidized by naturally occurring bacteria. This process releases protons and electrons, from which the fuel cell extracts electrical power. This electricity can then in turn help power the wastewater treatment facility, or be used for other purposes. In this way, a microbial fuel cell can serve two important environmental functions: treating wastewater while simultaneously generating electricity from a renewable energy source.
It would seem that a technology as massively useful as MFCs would represent a virtual slam-dunk commercialization opportunity. However, a number of significant challenges must be addressed before MFCs fulfill their potential as a multibillion dollar global market.
Perhaps the most significant risk to the successful commercialization of MFCs is technical: bluntly stated, can this technology produce electricity at a sufficiently high rate to provide at least a significant portion of the power needs of a large wastewater facility? This is a known issue in this niche, one to which significant recent R&D has been devoted. The second risk is related to the first: MFC systems have yet to be widely demonstrated at full scale operations. Currently, MFC demonstration projects tend to be small, and expanding the MFC reaction to industrial operation will likely involve significant technical challenges. To bridge the gap between laboratory demonstration and commercial scale operation, a new MFC startup may first develop a detailed computer simulation prototype. This can serve as a model from which the company can gather data and make design improvements. It may also help convince potential early adopters of this technology to give it a try. An MFC company may also consider developing a prototype in a Third World location where clean water is scarce, or in a military application such as a Navy vessel. This could provide an intermediate-scale site that could help generate visibility within the general market.
The third risk we see for MFCs is material cost. Finding the right combinations of materials to overcome the risks of low energy production and scalability may drive up the cost of MFC components such as anodes, cathodes, and membranes. Thus one may need to remain open to using low-cost materials whenever possible, while simultaneously stressing the performance advantages of the system should the price of materials rise.
In spite of these risks, a number of companies are actively looking into building a business around MFCs. To gain some insight into the best ways to do this, we recently spoke with two industry experts. The following summarizes their views on things a new entrant to the MFC market may want to consider when devising a commercialization plan, especially one that requires attracting a partner or investor.
For instance, major players in the wastewater treatment industry typically look for an exclusive license, with interest dropping off markedly when non-exclusive deals are proposed. However, non-exclusive deals do happen, particularly when the technology is seen as especially interesting. In considering terms for a license, companies typically consider the following:
- Does it work?
- Who will buy it?
- Are their IP issues?
The last item is of particular importance. If there is any question about IP, companies will sometimes license a technology they might otherwise acquire, in order to minimize risk. When this happens, upfront money is minimal. Therefore, it is likely that a licensor will need to have their IP story in order to maximize the chances of obtaining favorable licensing terms.
Licensing royalties for MFCs fuel cells can be based on several different metrics:
- Cubic meters of wastewater: This pays a royalty based on the amount of wastewater treated. Although this is a relatively simple metric to measure, it does not take into account the fact that different volumes of wastewater can vary significantly in the amount of dissolved waste they contain. Thus this may not be a true measure of how effective the fuel cell is (or phrased another way, how much “work” it performs) and by extension, how much value it is bringing the treatment site.
- Kilogram of BOD (biochemical oxygen demand): This measures the amount of oxygen required to break down the organic material dissolved in the wastewater, which is indicative of the “strength” of the effluent. A royalty paid on this metric would award more for the treatment of water with high waste content than for low waste content. This is probably the most commonly used metric upon which to base royalties in wastewater treatment.
- Kilogram of COD (chemical oxygen demand): This is similar to BOD, but applies to the organic chemicals dissolved in the wastewater.
- Kilowatt hours: This measures the amount of electricity produced by the MFC. This is a very easy metric to measure accurately, and is generally more precise than measuring BOD or COD. However, it is subject to end-user misuse; if site operators are more concerned with wastewater treatment than energy generation (and the large majority of them will be), the energy generated may not accurately reflect the effectiveness of the fuel cell. A royalty of one-half cent per kilowatt hour may be typical in this industry.
It also may be possible to base royalties on more than one metric, for example both BOD and kilowatt hours; but given the emerging nature of the industry, this might be hard to determine for certain. Therefore one suggestion would be to initially basing royalties on BOD.
Other factors that would impact licensing terms would be whether or not the licensor is licensing a part of the technology (for instance the electrodes) or finished MFC units. Since the market for MFCs is currently very small, it would likely be difficult to find a company that would incorporate the electrodes into its MFC products and provide meaningful revenues anytime soon.
Overall, substantial upfront money in the wastewater treatment market is rare. When it is given, it is usually on the order of $5,000 to $10,000 and intended only to cover the cost associated with processing the licensing deal, not as money to be used for further development of the technology. From an energy production standpoint, industrial wastewater may be a better market for this technology than municipal wastewater, since the former typically has far higher contaminants in it (and thus greater energy generation potential). In general, companies are seeking to license (or acquire) more commercially developed technologies over early stage technologies. On the plus side, there appears to be growing interest in MFCs recently; and with the entry of Emefcy into the market, interest may continue to grow.
Clearly, any technology that proposes to solve two very large problems simultaneously — wastewater treatment and sustainable energy production — is worth considering. Equally obviously, a great deal remains to be done before microbial fuel cells deliver on this promise, and thereby create a viable and reliable market opportunity.
Dick McCarrick is an analyst with Foresight Science & Technology.