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New SDH installations in Tibet and Inner Mongolia

2018-10-02T08:43:09+01:00 May 29th, 2018|

China is the world’s largest market for DH, in addition to being the largest solar thermal market – a promising combination. In 2017, the Chinese central government conducted SDH feasibility studies in more than 20 counties and cities in Tibet, where many houses lack space heating, and awarded funding for two sites.

The Chinese parabolic trough collector manufacturer Vicot Solar Technology has signed a contract with the local government to install a solar district heating system in Shenzha county. The photo, taken in November 2017, shows one-third of the field’s substructure. The entire installation will have 18,000 m² of aperture area. The parabolic collector field is being installed in Shenzha county. Ouyang Cheng, Marketing Manager at Vicot Solar Technology, said that half of the collector field had already been completed in 2017 and that the remaining 9,000 m² would be set up this year. The collector field will run on thermal oil and will be connected to a district heating system. Vicot said that it planned to install a molten salt storage tank and use electric boilers for backup.

Additionally, the Chinese-Danish joint venture Arcon-Sunmark Large-Scale Solar Systems Integration signed a contract with the local government to set up a SDH heating network in Langkazi county in Tibet. The system should provide solar district heating for 82,600 m² of floor area and meet 90 % of the yearly space heating demand in Langkazi, the town sharing its name with the county. The system, planned to be set up by November 2018, will consist of a 22,000 m² collector field, 15,000 m³ of pit storage and a 3 MW electric boiler. The sponsor of the pilot project is as well the China’s central government.

Since October 2016, a 75,000 m² parabolic trough collector field for district heat seems to have been operating in Inner Mongolia, an autonomous region in China. Ruicheng Zheng from the China Academy of Building Research said that she had heard about the system, but that all the information on it was only available online. On 28 December 2017, a news article appeared on sohu.com, one of China’s largest online media companies, stating that the system supplied a shopping centre and a development project known as ZhongCheng International City in the village of HongQing De, near Baotou. The journalist who interviewed the owners of the residential buildings and the shopping centre found customers satisfied with the solar space heating that the system provides.


70% of a typical city district in Bulgaria could be heated by SDH

2018-10-02T08:36:06+01:00 May 28th, 2018|

70% of the heating and domestic hot water boiling in the ‘Kaysieva Gradina’ district in Varna, Bulgaria, could be provided by solar thermal energy by applying the SDH technology. To all the residents of Varna this is a huge opportunity to switch to clean heating, to end without using fossil fuels and to get rid of the fine particulate matter in the air. It is also crucial for achieving independence from the fuel imports. This is the conclusion of a recent survey performed by the Institute for Zero Energy Buildings in Sofia, Bulgaria. What’s more important is that the same number is relevant to all the medium and big cities in Bulgaria.

Solar district heating (SDH) consist of thermal solar collectors that produce heat for heating and domestic hot water throughout the year. This kind of installations are already very popular in Europe, especially in Denmark. ‘Today some 110 district heating companies in the country connecting between 200 and 15 000 consumers use solar district heating.’ said Per Alex Sorensen, one of the veterans of the technology, president of the FlexEnergi cluster, and a consultant at PlanEnergi, Denmark. SDH systems could function even more efficiently in Bulgaria, given the intense sunshine in the South-European country. The return on investment for a SDH system would be approximately 10 years, IZEB experts say. Its maintenance is easy and inexpensive.

The survey carried out by IZEB covers 69 residential apartment blocks build by prefabricated panels (‘panel blocks’) with a total built-up area of 285 000 square meters, located in the ‘Kaiysieva Gradina’ district of Varna. There is no centralized district heating network in this area. The main source of domestic heat are local electric stoves and air conditioners. In order to maximize the effect of the solar district heating system, thermal insulation should be applied to the residential buildings. ‘Our calculations show that, when these ‘panel’ apartment buildings have sufficient thermal insulation, thehousehold energy consumption will drop down to 85 kWh per square meter per year.’ said Dimitar Paskalev, an architect, founder and head of the Institute for Zero Energy Buildings.

Thermal solar collectors could be installed on all flat roofs of the ‘panel blocks’, where their location is most suitable considering the intensity of summer sunshine. Thermal collectors could also be integrated into the buildings’ facades. Also, these solar collectors could be a part of the thermal insulation of the residential buildings.

The heat output will reach 38 kWh/m²/a for the rooftop solar collectors and nearly 22 kWh/m²/a for the wall-mounted ones. Together, they will provide 60 kWh/m²/a. This means that district heating solar collectors can provide 70% of the annual heat consumption in the buildings. Heat energy could also be kept at seasonal storage systems placed udergroud, e.g. in the spaces between the buildings.

‘The typology of the multi-family residential appartment buildings built with pre-fabricated concrete panels is extremely popular in Bulgaria. Such type of buildings could be found both in big cities with large neighborhoods consisting of tens of panel blocks, and in smaller towns,’ said Dimitar Paskalev, head of IZEB.

At the moment Veolia Energy Varna, the district heating provider in the city, is evaluating the potential construction of a solar district heating system in Varna, the company announced. ‘We are exploring the possibilities for applying the SDHtechnology in Varna because we are trying to diversify the portfolio of energy sources we use – especially given the rising fuel prices we’re witnessing,’ said Lyubomir Kostov, Head of Customer Care and Development at Veolia Energy Varna.

The survey was initially announced during the first in Bulgaria training for design and construction of solar district systems. It took place during the ‘Black Seaside Days of Intelligent Energy’ in June 2017 at the Technical University Varna. It was organized by the Association of Bulgarian Black-Sea Municipalities and the Black-Sea Regional Energy Management Agency together with the Institute for Zero Energy Buildings, the National Association of Municipalities in Bulgaria, the Sofena Agency, the Technical University Varna and the Black Sea Research Energy Center.

The IZEB study of the potential of solar district heating in the ‘Kaysieva gradina’ district in Varna was carried out within the SDHp2m project (Solar District Heating … from Policy to Market) funded under the EU Horizon 2020 program.

Marta Stoilova

Big Solar Germany: Utility-scale solar heat at record-low 36 EUR/MWh

2018-06-04T15:39:15+01:00 Apr 20th, 2018|

Operators of several gas-driven combined cycle power plants, or CCPPs, have notified the German Federal Network Agency of their systems’ final shutdown. These plants are no longer economically viable, as they have been running ever fewer hours because of a high proportion of cost-effective renewable grid electricity. Their shutdown will create a shortage of supply in district heating networks providing thermal energy to German municipalities. Utility-scale solar thermal plants equipped with seasonal storage could help close the gap at heat prices of around 36 EUR/MWh, Christian Holter said. Holter is the Managing Director of Austrian turnkey system supplier S.O.L.I.D., which has carried out feasibility studies on behalf of several European cities.

Read the interview on solarthermalworld.org.

Solarthermie-Großanlage für die Wärme Mürzzuschlag

2018-06-14T08:28:27+01:00 Mar 26th, 2018|

SOLID und die Stadtwerke Mürzzuschlag entwickelten im Jahr 2017 ein Konzept für eine großtechnische solarthermische Anlage. Die neue großtechnische Solarthermieanlage am nördlichen Stadtrand von Mürzzuschlag wird in den nächsten 12 Monaten errichtet und deckt rund 10 % des jährlichen Wärmebedarfs des örtlichen Wärmenetzes.

Der Bedarf an Fernwärme hat in Mürzzuschlag in den letzten Jahren deutlich zugenommen. Das bereits bestehende Biomasse-Heizkraftwerk (Deckung von 50 % des aktuellen Wärmebedarfs) soll durch die Solarthermieanlage ergänzt werden. Daraus folgte das Projekt ‚Solarthermie-Anlage Mayerhoferwiese‘. Im September 2017 wurden bei einer Informationsveranstaltung für die Bürger im Stadtsaal Mürzzuschlag das Projekt von SOLID und den Stadtwerken Mürzzuschlag vorgestellt und alle Fragen der Bürger beantwortet. Die Solaranlage wird vom nationalen Klimafonds und vom Land Steiermark gefördert.Die ‚e5-Gemeinde‘ Mürzzuschlag nutzt schon seit 35 Jahren Fernwärme und Erneuerbare Energien. Das neue Solarfeld ist eine langfristige Investition und basiert auf der unbegrenzten Verfügbarkeit der Sonne und erzeugt keine CO2-Emissionen. Die Wartungs- und Betriebskosten sind niedrig und der Beitrag zu einer nachhaltigen Wärmeerzeugung ist groß. Das e5-Programm unterstützt österreichische Kommunen, ihre Energie- und Klimaschutzpolitik zu erneuern, Energie einzusparen und damit Kosten zu sparen sowie erneuerbare Energien intensiver zu nutzen. Das Engagement jeder einzelnen Gemeinde ist ein wesentlicher Beitrag zum Klimaschutz in Österreich, Europa und der Welt. Gemeinden wie Mürzzuschlag bilden damit die Grundlage für eine globale Energiewende.

W Niemczech ogłoszono nowy program dotacji dla sieci ciepłowniczej czwartej generacji

2018-06-14T18:34:05+01:00 Aug 8th, 2017|

Niemieckie Ministerstwo Gospodarki i Energii ogłosiło w dniu 1 lipca nowy program wsparcia dla projektów pt.  “Pilotażowe projekty instalacji ciepłowniczych 4.0”. Aby uzyskać dofinansowanie, sieć ciepłownicza musi dostarczać min. 50% ciepła ze OZE  lub ciepła odpadowego.

Ogólnodostępna sieć ciepłownicza 4.0 ma mieć maksymalną temperaturę zasilania 95°C. Promowane są innowacje, takie jak długoterminowe magazynowanie ciepła lub łączenie energii elektrycznej i cieplnej za pomocą dużych pomp ciepła lub kotłów elektrycznych. Niemieckie Ministerstwo Gospodarki i Energii nastawione jest na rozwój sieci ciepłowniczych o niskich temperaturach, co umożliwi wprowadzenie szerokiej gamy technologii OZE do systemu ciepłownictwa. Wsparcie przewidziane jest dla tzw. zimnych sieci ciepłowniczych o temperaturze zasilania 20°C, jak również klasycznych systemów ciepłowniczych, o ile temperatura zasilania nie przekracza 95°C.  Jednakże, aby spełnić warunek, nie więcej niż połowa odnawialnych źródeł ciepła może pochodzić ze biomasy, dlatego też większość zrealizowanych dotychczas projektów pochodzących w 20% z energii słonecznej i w 80% z biomasy nie mogą kwalifikować się jako projekty pilotażowe w ramach nowego systemu wsparcia.

Celem na poziomie politycznym jestudowodnienie ekonomicznej i technicznej wykonalności takiego systemu w conajmniej dwunastu przypadkach dzięki przeprowadzeniu studium wykonalności. Conajmniej sześć sieci ciepłowniczych należy zbudować lub  fundamentalnie przebudować do roku 2020.Sieci te powinny mieć co najmniej 100 połączeń lub minimalną ilość ciepła napoziomie 3 GWh rocznie.

Efektywność kosztowa ma priorytetowe znaczenie: zasilanie ciepłem ze wspieranych systemów powinno być tak samo konkurencyjne jak dostarczanie ciepła pochodzącego z paliw kopalnych. Wsparcie jest przewidziane na nową budowę lub przekształcanie istniejących sieci, ale podsieci niskich temperatur są również uprawnione do otrzymania wsparcia.Planowane są dwa etapy. W pierwszym kroku studia wykonalności są wspierane do 60% kosztów inwestycji. Na etapie już realizacji inwestycji, projekt jest wspierany kwotą wsparcia obejmującą do 50% całkowitych kosztów. Dodatkowo, przewidziane są działania informacyjno-promujące dla potencjalnych użytkowników sieci ciepłowniczych na poziomie 80% kosztów. Ponadto, udział lokalnych organizacji badawczych jest sponsorowany w 100%.

Gradacja  wsparcia jest pojęciem nowym. Sieć ciepłownicza uzyskuje dotację w wysokości 20% (lub 30% jeśli wnioskodawca jest właściciele małego lub średniego przedsiębiorstwa). Ponadto, system wparcia uwzględnia tzw.„zrównoważoną premię” (dodatkowe wsparcie) w wysokości 10% pokrycia kosztów: za każdy punkt procentowy w wysokości 0,2% udziału odnawialnych źródeł energii lub ciepła odpadowego w systemie posiadającym już 50% udziału ciepła z tych źródeł.

Kolejną innowacją jest “premia do efektywności kosztowej”, w przypadku uzyskania szczególnie niskich cen ciepła. Jeżeli cena ciepła spadnie poniżej 10 centów/kWh, bonus ten zwiększa się stopniowo. Jeżeli zostanie osiągnięta cena w wysokości zaledwie 5 centów/kWh dotacja może wynieść  maksymalnie 10% kosztów inwestycji. Długoterminowe magazyny ciepła są uważane za standard dla sieci ciepłowniczych 4.0, (chyba że, wdrożenie ich jest niemożliwe z ekonomicznego punktu widzenia).

Poprzedni program dotacji KfW dla odnawialnych sieci ciepłowniczych jest wciąż obowiązującym i nie jest zastąpiony nową propozycją. Mimo ogólnej zasady nie łączenia programów wsparcia, te dwa programy mogą występować razem, jeżeli projekt jest rozdzielony na kilka etapów.

Switzerland: borehole storage regeneration and solar district heating as solar thermal’s ray of hope

2018-06-14T18:32:23+01:00 Jun 14th, 2017|

As 2017 funding for solar heat incentives remains in doubt in several cantons and the priorities of the country´s energy policy haven’t been announced yet, the market outlook for solar thermal has not been very encouraging. But there seems to be a ray of hope in the form of low-temperature collectors for borehole regeneration and solar district heating.


On 24 November, the fifth Solar Heat Switzerland (Solarwärme Schweiz) conference organised by the solar industry association Swissolar, the building services association suissetec and the Federal Office of Energy was held in Lucerne, Switzerland.

The event with 130 attendees took place just a few days before the Swiss referendum on an accelerated nuclear energy exit, which gave the organisers an opportunity to highlight the sun’s role in Switzerland’s energy transformation. ‘As about 10 % of the heating energy in Switzerland comes from electricity, solar thermal can help with replacing nuclear power,’ said David Stickelberger from Swissolar. The strategy assured increased media attention for solar thermal, but interest dwindled soon after the 27 November referendum, when the nuclear energy exit was rejected by Swiss voters.

The political circumstances have cast doubt on the future of solar heat. Half a year ago, cantons Zurich and Zug had announced that they would not be able to finance solar thermal incentives in 2017. And the commitment to Switzerland’s energy strategy 2050 has been put on shaky ground. A vote is scheduled for 21 May 2017, in case opponents of the strategy can gather 50 000 signatures by 19 January next year. ‘As the political situation remains unclear, cantons are postponing their decisions,’ said Stickelberger. According to current planning, the Energy Strategy 2050 is thought to enter into force in 2018. Its aim is to increase the use of renewable energies, including hydropower and energy efficiency. The energy strategy will not permit the construction of new nuclear power plants, but will not limit the lifetime of the existing ones either. The strategy will also lower the CO2 emission limits of vehicles. The most important issue will be additional solar thermal funding from canton governments to incentivise the implementation of energy efficiency measures – including solar heat – in buildings.

Right now, solar heat is coming under fire from two sides: First, there is the cantons’ responsibility for the incentive schemes. The Harmonised Incentive Model (Harmonisiertes Fördermodell, HFM) requires that they all follow the same policy. But given budget restrictions, they have been waiting for the authors of the energy strategy to set priorities before they put aside money for solar thermal incentives. Second, the cantons have to integrate nationwide building energy standards (MuKEn). This means that cantonal law is to stipulate a certain share of renewables that needs to be met when renovating existing building stock. But like the debate about incentives, this one will only be resolved if there is a clear-cut and comprehensive energy strategy in place.

But Stickelberger also pointed to two technologies which give him hope for the future of solar thermal in Switzerland. One is the combination of solar collectors with ground-sourced heat pumps. Pumps which retrieve energy from boreholes are becoming increasingly popular across the country. The city of Zurich in particular set a 2050 target of 450 GWh/year for energy production based on ground-sourced heat pumps as part of its efficiency scenario A from the 2050 energy plan. But experiences and simulations by the Swiss-based SPF – Institute of Solar Technology show that especially in areas with high borehole density, they gradually cool the ground unless an active regeneration method is used to return heat to it in summer.

‘Unglazed solar collectors are one option to regenerate boreholes,’ explained Stickelberger. Other options are PVT collectors, which typically work at low temperatures, or conventional collectors if operated intentionally at around 25 °C. The heat pump itself can also be used for regeneration and the transfer of heat from a building or the surroundings into the ground in summer. At the conference, René Naef from Swiss engineering office naef energietechnik presented the regeneration results of nine borehole locations used to heat three multi-family properties in Mettmenstetten. After one year of operation, the temperature of boreholes using regeneration was 2 K higher than the one of surrounding buildings.

The second technology is district heating. Unlike Denmark, Switzerland has not seen much interest in district heating systems. In the cities, most networks are fed with heat from waste incineration. This type of heat is available all year round at low cost and gives solar feed-in little chance to compete. However, there are also several hundred rural district heating networks, mostly supplied by biomass boilers. At the conference, Michel Haller from the SPF Rapperswil presented a study on the potential of retrofitting these networks with solar thermal technology.
One very attractive project might be the supply of wood- and solar-based heat to the district heating network of the Beznau nuclear power plant in northern Switzerland. It has so far been powered by waste heat from one of the world´s oldest nuclear power stations. Reactor unit 1 dates from 1969 and has been turned off for safety review. After several delays in getting it back onto the grid, doubts are growing whether it will ever be operational again. Unit 2 from 1971 cannot provide enough heat for the entire year, meaning additional boilers are needed. The SPF Rapperswil and the association Wood Energy Switzerland have carried out a study to explore the options available for integrating solar and biomass into the network. “The operators have shown interest in both solar and biomass heat,” said Stickelberger.

This text was written by Eva Augsten, a German freelance journalist specialising in renewable energies.

Websites of institutions and associations mentioned in this article:
Swissolar: www.swissolar.ch
SPF Rapperswil: www.spf.ch
Suissetec: https://www.suissetec.ch/
Wood Energy Switzerland: https://www.holzenergie.ch/home.html
naef energietechnik: http://www.naef-energie.ch/
Swiss Energy Strategy 2050 (in German):