Mott's Blog

I have put together this interesting graphic to depict what the different assumptions about support mean in the new Polish law being debated now. This does not reflect the value of heat sales or support for co-generation, which are critical to having a profitable project. It does show the relative inefficiency of smaller projects. The graphic also clearly illustrates the problem of buying substrates (such as grain or silage) and their very high contribution to the end price per kWhr. The values used cover a variety of scenarios. The 1.4 correction factor was the original Ministry of Economy proposal. The 2 factor is slightly lower than the IEO report recommended last year. The auction value would be the reference price (maximum in the auction) which will be lower somewhat, but not significantly since there will be too few projects below 1 MW to create real competition in the bidding as the proposal now stands. It is questionable whether the Polish proposed auctions can be approved ...

News that the peak market prices are getting out of hand in Poland raises the issue of using more means to balance energy production. The 24 hour cycle seems to be getting worse. Energy storage over a short span of hours seems to be an attractive idea. While there are a number of energy storage solutions using batteries to store electricity, or devices to store kinetic energy to produce electricity later, one of the renewable energy sources itself has the potential to provide output matched to the 24-hour demand cycle - biogas, All biogas plants have biogas storage in some form. The most common is shown below: One biogas vendor explained one of the advantages of gas storage:   " Since the gas-store can hold several hours of gas, the CHP unit can be turned down during off-peak generating times without loss of biogas. The stored biogas can then be burned during high-peak electricity demand hours to maximize revenue efficiency. In addition, the gas store provides a steady s...

   The impetus for Polish policy supporting biogas has been almost entirely from the stand-point of agriculture (narrowly defined). The Ministry of Agriculture has been the only Ministry taking biogas seriously (the Ministry of Environment seems to forget that biogas has a critical organic waste management role). The vision of the Ministry of Agriculture (until recently anyway) was for small farm-based biogas plants averaging 250 kW in capacity. Ironically, while sacrificing every other biogas application to this vision, the current proposed law does little to help farmers get into the biogas business.    Every serious discussion of biogas policy needs to start with how much it actually cost. The Institute for Renewable Energy documented the cost of biogas last July in their report to the Ministry of Economy using multiple sources. Their data were realistic and no one has seriously questioned their conclusions: biogas requires substantially more support than the fl...