Strategic Research and Innovation Agenda for Renewable ... - EGEC

6Strategic Research and Innovation Agenda for Renewable Heating & CoolingDistrict Heating and Cooling876543210Marginal Distribution Capital Cost [EUR/GJ]FranceGrand totalGermanyNetherlandsBelgium0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%Share of total heat marketFigure 40: Marginal distribution costs and corresponding urban district heating heat marketpenetration in four European countries in 2008 636.1 Priorities for Solar DHCIn Europe there are around 175 large-scale solar thermal plants for heating and cooling (≥500 m²; 350 kW th ) in operation with a total installed capacity of approximately 320 MW th . Thelargest plants are located in Denmark with more than 10 plants exceeding 7 MW th(10,000 m²) of capacity, while the largest as an installed capacity of 23.3 MW th (33,300 m²).These large-scale systems are mainly used for solar district heating which, in mostcountries, is a small and undeveloped niche market.Only 1% of the solar collector surface is currently connected to district heating systems, buta couple of central pilot solar heating plants with seasonal storage - mainly built in Scandinaviaand Germany - have proved that these types of system can reach high solar fractions(approximately 50%). With the expected growth of district heating systems in denselypopulated urban areas, solar thermal systems will be able to cover a higher share of theheating demand in urban areas.ST.12ObjectiveOptimize large-scale solar collector arrays for uniform flow distribution and lowpumping powerDevelopment of large-scale collectors and advanced hydraulic concepts, which are especiallydesigned for huge collector arrays.Basic theoretical computational approaches should be developed and validated by meansof adapted methods (CFD, laboratory measurements, and measurements at large real solarcollector fields). Particularly, the flow and temperature distribution, as well as the total efficiencyand the electricity consumption of pumps and the related friction pressure loss at all hydrauliclevels have to be considered.These advanced large-scale collectors, hydraulic concepts, calculation and simulation toolshave to provide uniform flow distribution, reduced pumping power and favourable stagnationbehaviour. Furthermore also cost effective fixing systems are needed.State-of-the-artTargetsType of activityDue to their size and the need to adapt to each specific application, large-scale systems forsolar district heating, industrial process heat, agricultural and water treatment applications aretailor-made. This implies more complex design, such as planning system hydraulics. State-ofthe-artcollector fields cost around € 285/kWth (€ 200/ m²) when ground mounted and € 360/kWth (€ 250 / m²) when mounted on flat roofs. Currently, the main challenge is to achievea theoretically correct design of a large-scale collector field, as well as modelling parallelconnections comprising multiple hydraulic levels (collectors, zones, groups).Cost reduction of 50% compared to the field cost of state-of-the-art collectors.50% Research / 30% Development / 20% Demonstration.63Persson & Werner (2011).64