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HELIOS – a 2 000 m² Solar Plant for District Heating in Graz

2018-06-04T11:00:46+02:00Nov 30th, 2017|

Graz is making constant efforts to increase the share of renewable energy in the city’s district heating system. So the project ‘HELIOS’ in Graz with its 2 000 m² solar plant has been put into operation in September 2017. The thermal energy is fed into the district heating grid of Graz.

‘HELIOS’ has a 2 000 m² solar field which will be expanded to 10 000 m² at its final completion. The expected capacity at the moment is about 2,5 GWh. The plant is situated on a closed residual waste disposal site. For this reason, all solar pipelines are laid aboveground in order to be prepared for underground movements. An unpressurized aboveground storage tank holding 2 500 m³ offers the possibility of absorbing thermal power peaks. A landfill gas CHP unit with a capacity of about 120 kW (electrical) and 170 kW (thermal) is also part of the project. The electrical output is used for self-sufficiency and to run a Power-to-Heat unit. The plant is operated by ‘Energie Graz’. ‘HELIOS’ has received funding from the local state of Styria (approx. 1,17 Mio. €) and from the state of Austria, ‘K.L.I.E.N.’ (approx. 0,45 Mio €).

Good perspectives for SDH in Italy

2018-06-04T11:01:27+02:00Nov 30th, 2017|

Three installed systems and one more planned: SDH shows a few examples of operation in Italy but quite good perspectives thanks to relevant incentives and the recent inclusion in the National Energy Strategy for 2030. A workshop in Venice on 15 December 2017 will analyze the status quo and the possible developments.

Plants in operation and plans for the near future

As shown in the map below, three SDH plants are in operation at the moment in Italy. The first SDH plant has been installed in 2015 for feeding in the district heating network of Varese: 990 m² of flat plate solar collectors are used for pre-heating either the make-up water or the return line of the network. Operational results for the first year show a very good performance, with a +13 % over the expected design yield.

The second system, commissioned in 2016, has a much smaller size, with a total gross area of 63 m², and combines solar thermal with a gas-fired CHP unit for a local district heating network located in the mountain village of Sansicario, in the province of Turin. The peculiarities of this plant are the use of two different technologies, flat plate collectors and evacuated tubes, and the opportunity to test solar thermal operation at 1 600 meters above sea level.

The last example is a 200 m² solar plant connected to the district heating network of the city of Lodi in 2017. This is a case of ‘third-party access’ since the whole solar thermal production is injected into the grid and is purchased by the DH utility from the owner of the solar thermal system. Besides these installed systems, the utility Gruppo Iren has planned to install a 600 m² SDH system for its DH network in Turin by 2020.

Incentives and policies: Good perspectives

The national incentive of Conto Termico 2.0 supports energy efficiency measures and small renewable heat systems, including solar thermal plants, also for district heating applications, up to 2 500 m² gross area. The amount of the incentive, paid in five annual instalments, depends on the system size, the application and the expected collector yield. For SDH plants, this amount can range between 40 % and 60 % of the investment cost.

Furthermore, budgetary resources for this scheme are quite generous, corresponding to a yearly amount of 200 million EUR for public bodies and 700 million EUR for private subjects, and a larger portion of these resources are still available.

From a policy point of view, it is worth to mention that, thanks to a consultation comment sent by Ambiente Italia on behalf of the SDHp2m project, the National Energy Strategy, released by the Italian Government in November 2017, explicitly includes solar district heating as a viable option to ‘reduce installation and O&M costs’ and ‘particularly interesting for smart and flexible district heating network, where multiple energy sources are operating together’.

A workshop in Venice

On 15 December 2017, Ambiente Italia organized, in collaboration with the Veneto Region, a specific workshop on the use of solar thermal in combination with other renewables, especially biomass, for supplying thermal energy through small local DH grids.

More information on the event is available here.

New largest solar thermal plant in Upper-Styria, Austria

2018-06-04T11:02:10+02:00Nov 30th, 2017|

Starting in 2017, SOLID and the public utility of Mürzzuschlag developed a concept for a large-scale solar thermal plant. The new large-scale solar thermal plant on the northern outskirts of Mürzzuschlag will be built over the next 12 months and cover around 10% of the annual heat demand.

The demand for district heating has increased significantly in the Mürzzuschlag area in recent years. A solar system should supplement the already existing biomass plant (50% of the current heat demand). Consequently, the project ‘Solarthermie-Anlage Mayerhoferwiese’ was started. On the 13th of September, the public utility of Mürzzuschlag and SOLID met with the population of Mürzzuschlag in the Stadtsaal to clarify all questions and to present the new project on site. The solar plant will be funded by national Klimafonds and by the region of Styria.

The ‘e5’ municipality of Mürzzuschlag has been using district heating and renewable energies for 35 years. The new solar field is a long-term investment. It is based on the infinite availability of the sun and does not produce any CO2 emissions. Maintenance and operating costs are low, but the highly valuable contribution to a sustainable heat generation is big! The e5 program encourages Austria’s municipalities to modernize their energy and climate protection policies, to save energy and thus to save costs and to use renewable energy sources more intensively. The commitment of each individual municipality is a major contribution to climate protection in Austria, Europe and the world. Municipalities like Mürzzuschlag thus form the foundation for a global energy turnaround.

Funding opportunities for district heating with renewable energies in Thuringia

2018-06-11T14:20:39+02:00Nov 27th, 2017|

Projects dealing with district heating and renewable energies can receive funding through several subsidy programs in Thuringia. The funding programs ‘Green Invest’, ‘Solar Invest’ and ‘Klima Invest’ are focused on different aspects and actors.

Within the subsidy program ‘Green Invest’ pilot projects that contribute to a reduction of energy-related CO2-emissions through the implementation of energy efficiency measures and renewable energy technologies with multiplier effect can receive funding. Also studies, as far as they are necessary for the implementation itself or for proving the success of the demonstration project, can receive funding. Beneficiaries may be enterprises.

Investments for implementing new or expanding existing seasonal thermal energy storages can receive funding within the subsidy program ‘Solar Invest’. Beneficiaries may be municipalities and their in-house operations, administration unions, municipal enterprises, small and medium-sized enterprises, housing cooperatives, energy cooperatives, associations, charitable organizations, foundations and natural persons. There are special conditions for citizen energy cooperatives.

Within the subsidy program ‘Klima Invest’ climate protection concepts dealing with renewable energies and thermal use can receive funding amongst others. Municipalities and municipal associations, administrative districts and administration unions may be beneficiaries.

Target of these measures is the reduction of greenhouse gas emissions and energy saving as well as a sustainable energy production and usage in Thuringia.

SHC Task 55 – Large Scale SDHC

2018-06-07T13:52:12+02:00Nov 27th, 2017|

Looking closely at contributing projects and listening to outside market information is vital to the success of SHC Task 55, which deals with the implementation of very large solar thermal systems (including large scale seasonal storages, large scale heat pumps etc.) in DHC networks.

Without the right team in place, any Task and its objectives can be challenged. Because of this, the operating agent of Task 55 has connected its core expert participants, their projects and stakeholders in four dynamic Subtask teams. All actors involved have commitment to their group and share the Task 55 vision of large scale solar thermal district heating and cooling installations globally.

Thrity five experts have participated in the third Task Meeting on 27 and 28 October 2017 in Abu Dhabi, more than 60 % of the participants represent SDH industry. Researchers as well as industry partners have the same target – to enhance the market activities of large scale SDHC up to Gigawatt level.

More information: Task website, Twitter

SDH in Sweden: latest news from the Västra Götaland region

2018-05-17T16:42:59+02:00Nov 27th, 2017|

An initiative aiming at the realization of at least one new solar district heating plant in the Swedish region of Västra Götaland in 2017-2018 is ongoing within the European project SDHp2m – policy to market. Here are the latest developments.

The work to find demonstration sites where existing wood fueled district heating plants can be complemented with solar heat is ongoing in Sweden. The first step, a survey to the 49 municipalities in order to identify potential solid wood fuel plants to be complemented with solar heat was accomplished. In a second phase, the most feasible plants should be pre-designed in order to prepare a call for tenders.

There are now two feasibility studies for Borensberg and Vara on the way, and one planned for Hemse (on Gotland). Preliminary results show solar heat costs of the order of 50 Euro/MWh and one of the main focus points is to find a feasible placing of the collector arrays requiring 1 to 3 hectares land area.

Switzerland: plans for solar district heating pilot system

2018-01-09T14:33:43+01:00Oct 18th, 2017|

‘Why is there no solar district heating in Switzerland?’ Swiss scientists were asking after their visit to Denmark. Now, the Swiss-based SPF – Institute of Solar Technology has begun to work with a district heating company on giving the country its first pilot plant.

SPF had been investigating the feasibility of solar heat in district heating networks in the St Gallen canton and published a 50-page study this March. As it turns out, solar heat could be produced in several networks for 60 to 160 CHF/MWh (50 to 140 EUR/MWh). Assuming plant owners or operators could get an incentive similar to the one for small-scale solar heat systems, it would make several larger ones economically viable.

The current SPF project started with an analysis of 43 heat networks in St Gallen in east Switzerland. Data provided by Energy Agency St Gallen was used to identify the most promising ones among them. ‘Many district heating networks get their heat from waste incineration. You can normally rule those out right away, as the cost is about 20 EUR/MWh, incineration will continue throughout summer because of no space for saisonal waste storage, and the temperature in the network is around 120 °C,’ said SPF’s Igor Mojic, one of the study’s three authors. Another typical energy source besides waste is wood, for which average cost ranges between 40 and 60 CHF/MWh (35 to 70 EUR/MWh).The researchers also used the available data to estimate heat demand in summer as precisely as possible.

Grafic: levelized cost of heat for fove selected district heating networks, as per offers by collector manufacturers. Calculations assume a 25-year economic life and a 3% loan interest rate. Source:SPF

A total of 34 networks made it to the second stage, during which SPF tried to get first-hand information by sending out questionnaires and conducting interviews over the phone. It employed Polysun 9.0 to run model simulations of 17 heat networks. The right plant size was determined by assuming a system met all the demand in summer, which led to solar fractions of 10 to 32 %, depending on the consumer base. The subsequent third stage was used to perform calculations based on real-life data for five district heating networks, namely Thal, Gommiswald, Wattwil, Altstätten and Waldkirch (see the chart below). The underlying assumption was that solar collectors were roof-mounted, as ‘setting up PV systems on the ground is unthinkable in Switzerland. We were naturally assuming roof space to be used for installing the solar thermal system,’ said Mojic.

Of course, roof installations are more expensive than ground-mounted ones. Offers from six domestic and foreign manufacturers of flat plate and vacuum tube collectors showed a price range of between 70 and 140 CHF/MWh (60 to 120 EUR/MWh) for each plant. The main cost factors were the time and effort expected to be spent on installing the unit and integrating and linking it with and to central heating. If large solar thermal plants were to benefit from the same subsidy amounts as smaller versions, the cost of heat would come down to 30 to 100 CHF/MWh (30 to 90 EUR/MWh).

The figures from the feasibility study seem encouraging, but have their limitations. ‘So far, calculations have been based on real-life data, but there has been no assessment on site,’ said Mojic. The prices from collector manufacturers were only indicative – in reality, businesses might set them higher. ‘There are yet other unknowns, such as the structural limitations of the roof,’ he added.

The next step will be to find some district heating companies interested in integrating solar into their network. One operator has already partnered with SPF to take a closer look at the requirements, such as roof space availability. ‘We’re looking for other companies from across Switzerland,’ said Mojic.

SPF also calculated the cost of ground-mounting, which was 20 to 40 % cheaper. ‘So far, no one knows if and how Swiss authorities were to approve a system equipped with ground-mounted collectors and whether they would be willing to grant any subsidies. Our objective is to design an actual roof installation and apply for incentives and approval to establish a standard procedure,’ explained Mojic.

Eva Augsten

W Niemczech ogłoszono nowy program dotacji dla sieci ciepłowniczej czwartej generacji

2018-06-14T18:34:05+02:00Aug 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+02:00Jun 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):

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