Integration of 50 % wind power in a CHP-based ... - Ea Energianalyse

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Integration of 50 % wind power in a CHP-based ... - Ea Energianalyse

114 Model resultsWhen analyzing the hours with critically low electricity prices, it is shown that theseprices occur during hours with increasing demands, as a result of the increasing windcapacity, and so do the amount of spilled wind production. The result of the optimizationvaries a bit from the real data though, in that the modeled central units was found respondingtoo well to low prices compared to the West-DK 2004-2009 production. The levelof export, observed in the hours of critically low prices, is higher in the model than inWest-DK as well, which could indicate a worse management of congestions in the realsystem.When it comes to electricity production in the bypass scenario, it was shown, that in acold month like January, switching to bypass mode is generally more attractive than cogeneration(in the windy 2025 scenario), whereas co-generation can be more efficient inNovember. Compared to the reference scenario, it was shown that the greatest differenceon a total basis is the reduced exported power in the BPO scenario. Last but not least itwas argued, that the bypass system is suitable for cold and windy times.With regard to the heat pump scenario, this system differs from the reference scenario inthat the decentralized power generation almost is completely superseded from the optimizedheat- and electricity production, plus electricity production from condensing unitssuddenly takes place. This give rise to full internal utilization of wind power (which havedisplaced a great part of the power generation from extraction units), negligible electricitygeneration from decentralized units, “full steam” on condensing units during dailypeaks, a great amount of import and increased electricity consumption from the electricalheat pumps. When subjected to the 2017 and 2025 wind scenarios, it is shown, thatthe power generation from extraction units decreases further, and in 2025 electrical spilloveroccurs even within the low consumption periods. Finally it is shown, that heatpumps with a COP value of 300 % efficiency are the most economic variable alternativeout of the producing alternatives as long as hydro or wind power represent the marginalutility.Overall, the production patterns regarding electricity, changes significantly as the windcapacity increases, almost eliminating power generation from centralized extractionunits in the reference scenario as well as in the bypass system, and from decentralizedunits in the heat pump scenario.When it comes to the production of heat, it has been shown that in the 2008-referencescenario, heat produced on extraction units is the most economic option - excepts whenthe electricity price drops to a critically low level. As the wind capacity increases thispicture reinforces, and in the 2025-reference scenario a complete down-regulation – andin some periods even a complete de-commitment – of extraction units occur in the periodswith critically low prices. At least this is the case when looking at the three Januarysamples. The January samples are quite extreme though, regarding the level of bothwind capacity and heat demand, and when looking at the average over the years, theonly real development as the wind capacity increases, is an increased production fromboilers in the central distribution areas. However, when focusing solely on the hourswith critically low price, it has been shown that the heat production from extractionunits gradually decreases while production from boilers increases as the wind capacityincreases. Simultaneously, the decentralized heat production decreases as a result of the

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