SERVANT OF TWO MASTERS? TRADE-OFFS FOR AGRICULTURAL BIOGAS PLANTS BETWEEN FLEXIBLE POWER GENERATION AND HEAT COGENERATION

摘要

In Germanyare about 8,000 biogas plants in operation, with an installed electrical capacity of 4.5 GW.rnWithin the amendments of the EEG in 2012 and 2014 thelegislative authority promotes a paradigm shift for biogasrnplants away from a previous and mostly current base load power generation towards a demand driven and flexiblernpower generation. This aim requires a fundamental rethinking in how anappropriate concept for biogas plants shouldrnlook like. One critical issue is how the price patterns at power exchange are in line with the demand patterns forrnconnected heat sinks. We elaborate some simulations for current-controlled and heat-controlled operation schedulesrnunder a cogeneration share of 40%. If power generation schedule doesn’t match the heatload profileheat demand canrnbe ensured by a heat-storage or/ and a peak load boiler, respectively. We figure out the combination of storage andrnpeak-load in terms ofleast cost intensive. The challenge, to find the most preferable configuration under differentrnconditions is done by a modelling with discrete input factor variation. Based on these modelling an optimal linkofrnheat-storage and peak-load boiler is calculated in regardsto investments and operating costs.