Last year was a record-breaking one for new solar district heating (SDH) installations in Denmark. With 31 new SDH systems and 5 plant expansions, the newly installed collector area grew at double the rate of 2015 and totalled 495,226 m² (347 MWth). The year prior saw 15 plants built and three expanded, while collector area increased by 250,161 m² (175 MWth). Almost all plants newly installed or expanded in 2016 were equipped with flat plate collectors, except for the 18.9 MWth parabolic trough installation in Brønderslev. The annual statistic on SDH installations is maintained by Daniel Trier from Danish consultancy PlanEnergi and starts with the very first large SDH plant in 1988. Trier said that at the end of 2016, there had been 104 SDH plants in operation with a combined collector area of 1.3 million m² (911 MWth).
During the last seven years, a group of scientists has monitored selected large solar thermal installations in Austria on behalf of the Austrian Climate and Energy Fund. The gathered data confirms that these plants have been reliable and produce satisfactory yields. Particularly the new generation of large-scale medium-temperature collectors either with a foil or with a second glass cover shows remarkable results in district heating use. The 2,490 m² solar field (see photo) which has fed heat into the district heating network of Graz, Austria, reached a yield of 489 kWh/m².
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.
The ranking of the largest flat plate collector manufacturers is headed by the same four companies as last year: Greenonetec from Austria, Fivestar from China, Soletrol from Brazil and Bosch Thermotechnik from Germany. But aside from the continuity at the top, last year shows what different paths some markets have taken. Whereas Australian-based Solahart, one of the pioneers of global solar collector trade, as well as Soletrol, the largest Brazilian manufacturer, have lost ground, several others – such as Sunrain from China, Hewalex from Poland and Eraslan from Turkey – were able to report above-average growth for 2015 and rise through the ranks. The produced collector area of the overall 21 companies added up to 4,212,462 m². The number was 21 and not 20 because the last and second-last spot were occupied by companies with equal production output.
The Solar Keymark Network (SKN) discussed and approved new complaint procedures during its most recent meeting on the Greek island of Crete in mid-October 2016. Action had to be taken, as the first series of complaints filed in late 2015 against Swedish test lab SP about the certificates of Danish collector manufacturer Arcon-Sunmark was not resolved to the satisfaction of all parties involved. The results of the October meeting are described in a publicly available draft of the minutes on the SKN webpage.
Arcon-Sunmark has announced the completion of a second solar-heated copper mine project. In September 2016, the Danish company installed a 6,270 m² collector field (4.4 MWth) at La Parreña in central Mexico. A 30 September press release said that the solar field would cover 58 % of the mine’s demand for heat. The field consists of 456 components of nearly 14 m² each and a storage tank of 660 m³. The first project of its kind, a field of 39,300 m² (27.5 MWth), was completed with a joint-venture partner at the Gabriela Mistral mine in Chile in 2013. Being the world’s largest solar system for process heat application, it had produced 142,000 MWh in the first 35 months of operation, the press release said. This corresponds to a specific yield of 1,112 kWh per m² and year.
Pampa Elvira Solar (PES) operates the largest solar process heat installation worldwide, a 27.5 MWth collector field at the Gabriela Mistral mine in Chile. “It´s an every-day, every-hour struggle to harvest the sun and earn our wages, so we may continue the very humble – and much too often neglected – business of running a solar heat-delivering system in the middle of the desert,” said Ian Nelson, General Manager of Pampa Elvira Solar. Solarthermalworld.org spoke with him about dust problems, the opportunities of concentrating collectors, the challenges of ESCO operation and improved copper cathodes. Five-and-a-half years ago, the engineer started at Energía Llaima, an independent producer of hydro and solar thermal solutions. PES, which was founded in 2012, is a consortium of Danish company Arcon-Sunmark and Energía Llaima.
This July, SP issued new Solar Keymark certificates for four Danish Arcon-Sunmark collectors after the Swedish test lab and certification body had retested these four systems in April. The retesting had been necessary, as SP had received six complaints because of a lower-than-expected c1 (heat loss coefficient) value on certificates issued in November 2015. At first, it looked like a case closed, but the stakeholders who submitted complaints are now calling for a reform of the complaint procedures and tolerances established by the Solar Keymark Network (SKN).
While the solar thermal industry has had a difficult time in several EU countries, the solar district heating (SDH) community is still growing: 180 participants from the EU, South Korea and China attended the 4th International Solar District Heating Conference, which was held at quite the peculiar location this year – Denmark’s Legoland – and was organised under the auspices of the Horizon 2020 project SDHp2m…from Policy to Market. The introductory session of the conference was really inspiring. Thomas Pauschinger, Project Coordinator of SDHp2m, underlined how Denmark’s construction of plants in the 100 MW range was proof of the country’s solar thermal strategy of “think big”. Impressive results, even more so if one takes the statement by Kim Behnke, Deputy Director General of Dansk Fjernvarme, the Danish District Heating Association, into account that “the Danish solar dream started just ten years ago”. Denmark’s solar installations have become so famous that they have even been turned into brick models at Legoland. The photo shows the 13 MW solar field in Braedstrup, Denmark.
On 13 July, Arcon-Sunmark, the Danish large-scale solar heating specialist, officially announced that as the chosen turnkey provider, it was beginning construction on the 156,694 m² solar district heating system (110 MWth) on behalf of the Danish city of Silkeborg and its district heating company Silkeborg Forsyning. The plant is scheduled for completion by the end of the year and will then be the largest solar district heating system worldwide.