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

166 Conclusionthe plant economy further. Opposite to the BPO-system, heat pumps in general have anegative impact on the individual power plant economy – except for condensing units,which are likely to experience a revival if this scenario is implemented. Units with amore heat-producing purpose however (such as backpressure- and boiler units) will beeconomically harmed the most, as they are being completely replaced by the heat-supplyof heat pumps – this, of course, when optimizing from a system point of view.When observing the total system costs, the increased wind penetration is shown havingdifferent impacts in relation to reduction in total system costs, when comparing the reference,heat pump and the bypass scenarios. Differences existing therein that the totalcosts of the reference system were highly insensitive to the increasing wind capacity of2017 and 2025, while the heat pump and BPO systems experienced reduced total costs.It was found that the key factor for reducing the total costs given increased wind capacity,is increased flexibility plus the possibility of letting the electricity (and thus the REproduction) gain impact on the rather constrained heat-supply of today. As both BPOand heat pumps raises the electricity price (while lowering the heat price), the two instrumentshave an indirectly positive impact on the value of wind power – an economicgain indicated by a change in the shadow prices.When it comes to the environmental impacts – which can be said to be of most relevanceto the purpose of increased wind power – it is found that if no means are taken, the increasein wind capacity alone will only result in a slight increase in the share of renewableenergy when it comes to power generation, but none, when it comes to heat production– an increase, which is higher in both the heat pump and the bypass scenario.However, the total CHP efficiencies of the heat pump scenario will drop as a result ofincreased demands for condensing electricity, which ultimately worsens the CO2 factor –relatively seen. Nevertheless – as the heat pumps scenario has a significantly lowerCHP-production on a total basis (due to improved wind integration and large import ofhydro power), the total CO2 emission from the heat pump system still has been foundlower than in the reference and BPO system. Moreover, the CO2 emission in the windyfull-scale bypass scenario is slightly greater than in the reference scenario, as a result ofcoal-based extraction units replacing the gas-fueled boiler capacity. Finally, a furtherstudy of the environmental impacts from heat pumps was suggested since the low valueof hydro assumed in this model is likely to have covered up a potential increase in coalrelatedpower generation.It was generally found in the results, that heat pumps have a positive effect on the environmentalimpacts of increased wind penetration as well as on the prices on heat andelectricity and on the production patterns. So does bypass operation (except from when itcomes to CO2 emission) and it has therefore been argued that flexible production, in theshape of optional bypass and heat pumps, are good instruments for meeting the challengesof 50 % wind power. Furthermore they are simple alternatives to flexible consumption,which depends on consumer behavior plus an advancement of the technologicallevel of the power system.The formulated unit commitment model is not to be regarded as a exact approximationof the West Danish energy system, but an approximation to a system with similar characteristics,and the results are thus to be interpreted with awareness of the dynamics ofthe energy system of today, as well as of the system with increased wind power, and thus

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