The Danish town of Silkeborg now holds the record for having the world’s largest solar heating system. The SDH plant of 156,694 m² (110 MWth) came online as scheduled in December 2016 after only seven months of construction. Municipal utility Silkeborg Forsyning intends to use the harnessed solar energy to meet 20 % of the annual heating demand of the 21,000 plant-connected users. The solar field was divided into four subfields to make it possible to set up the installation and hydraulics systems on this irregularly shaped piece of land (see photo). The former record holder is another installation in Denmark, in Vojens, boasting 70,000 m² (48.90 MWth) of installed solar thermal capacity. Both plants were turnkey deliveries from Danish collector manufacturer Arcon-Sunmark.
“Large-scale solar thermal systems in the GW range – an insignificant niche market or the future for solar thermal?” was the official title of a panel discussion at the Gleisdorf Solar conference in Austria in early May. The most important question was: What will be next for the planned 350 MWth solar district heating system called Big Solar in the Austrian city of Graz? “The challenge was to adapt the Danish district heating solutions to Austrian conditions,” emphasised the project’s initiator, Christian Holter (right), Managing Director of S.O.L.I.D. Meanwhile, Christian Stadler (left), Managing Director of one of Arcon-Sunmark’s subsidiaries, Arcon-Sunmark Germany & Austria, represented the company that has stated his own interest in realising Big Solar.
The Austrian municipality of Graz is preparing for the post-fossil fuel heating era: On 27 February, the front page of national newspaper Kleine Zeitung (copies sold each day: around 300,000) read “Graz plans largest solar storage worldwide”. According to the news article, regional energy provider Energie Steiermark and Austrian solar thermal system supplier S.O.L.I.D conducted a feasibility study for a huge solar district heating plant called Big Solar – with promising results. The study and the news article both references the world’s largest collector field in Danish Vojens with 70,000 m² (49 MWth) as a successful example of how to undertake such a large project. At the beginning of April, Energie Steiermark confirmed the plans for Big Solar’s realisation in a press release about 2015’s annual financial statement.
Graz, the capital of one of Austria’s federal states, Styria, and a city with a population of 276,000, is planning to increase the share of solar thermal in its district heating grid by 20 %. The regional utility Energie Steiermark and the Austrian turnkey provider S.O.L.I.D. agreed in June to carry out a feasibility study for a collector field of up to 500 MWth with a matching seasonal storage. The proof-of-concept study will be a joint project of regional energy providers, S.O.L.I.D. and outside specialists. The photo shows the four collector fields with a total of 7,400 m2 partially belonging to the AEVG, the municipal waste disposal company in Graz, operating since 2007, and to Energie Steiermark, operating since 2014.