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Decarbonising district heating with solar thermal energy

2018-06-07T13:47:15+02:00May 3rd, 2018|

The 5th International Solar District Heating Conference presented technical solutions as well as trends for district heating with solar thermal. Best practice examples serve to demonstrate their potential.

While Denmark is the pioneer country in terms of solar district heating, Graz has become a pioneer city for solar thermal energy in district heating. The project ‘BIG SOLAR Graz’ achieved a major milestone: the land for the construction of a large-scale solar thermal storage with a technical building as well as a relevant part of a future 450 000 m² solar collector field have been secured. Graz is also home to the largest solar thermal plant in central Europe (5,4 MWth) which has been operating for a while now as well as to new flagship projects such as, for example, the ‘HELIOS project’; a large-scale thermal storage built on a former domestic refuse landfill and fed by three different heat sources: a solar thermal plant, a power-to-heat module and a CHP plant powered by landfill gas. This is the reason why the second biggest city in Austria was chosen as the venue for the 5th International Solar District Heating Conference. 350 scientists as well as industry, community and utility representatives and decision makers from 33 countries met here on April 11th and 12th. The number of participants doubled compared to the conference two years ago which is a clear sign for the high interest in this technology and its implications for the decarbonisation of district heating. The conference leaders Christian Fink from AEE – Institute for Sustainable Technologies and Thomas Pauschinger from the Steinbeis Research Institute Solites in Stuttgart both see this as a very positive sign for the application of the solar thermal technology in district heating.In the European Union there are close to 300 systems over 350 kWth in size, feeding into district heating. The total capacity installed amounts to 1 100 MW. At the conference Werner Lutsch, president of the European district heating association Euroheat&Power and director of the German district heating association AGFW called the combination of solar thermal and district heating a ‘very good solution’ for reducing CO2 emissions as well as for reaching the EU goal which calls for an 80% reduction in CO2 emissions by 2020 compared to 1990 (Heating & Cooling strategy). Regarding its advantages, he pointed out that ‘solar thermal energy is CO2-free, solar energy is available everywhere and the heat generation costs are predictable for the coming 25 years. Furthermore the technology is fully developed and mature’.

However, he also admits that there are challenges to overcome when implementing such projects. The biggest hurdle stems from the space required for renewable energy such as solar thermal. In order to keep costs to a minimum, they need to be installed close to the heat consumers. Yet, land in or close to urban areas is usually limited and expensive. Lutsch added ‘Furthermore it is still a niche technology and the knowledge about it is not yet wide spread’. In addition, there is cost competition with other heat generation technologies, for example with cheap natural gas. Nevertheless, nowadays solar thermal plants can achieve a solar fraction of up to 50% in district heating. The generation costs are around 30 to 50 €/MWh. For this year market researchers predict that solar thermal plants in Europe will already contribute one terawatt hour (= 1 billion kWh) to the district heating supply.

Best practice examples

The conference participants took part in excursions where they were able to have a close look at how projects can be implemented successfully. One of the destinations was the above mentioned HELIOS plant, a project by Energie Graz. During the first construction phase last year, 2 000 m² of flat plate collectors with a 2 500 m³ heat storage were installed on a domestic refuse landfill in the city area of Graz. Heat is also generated by a power-to-heat module with a capacity of 90 kW as well as a 170 kWth CHP plant powered by landfill gas. The feed-in capacity to the district heating amounts to up to 10 MW. An intelligent storage management system ensures that peak loads in the heating network are diverted, so that heat from renewable sources is prioritized. The system has been in trial operation since November. Energie Graz is planning to expand the collector area to 10 000 m².

Another destination was the district heating Puchstraße where already today 7 750 m² of solar collectors are feeding into the district heating system of Graz. About 5 000 m² of collectors were installed as roof-mounted systems in 2007 and 2 750 m² were added on the ground by the heating plant in 2014. Currently the operator S.O.L.I.D. is adding another 500 m² of solar collectors. In this system, where the collectors are also ground-mounted, collectors from different manufacturers are tested for their application with district heating.

The second excursion lead to the community Eibiswald, where a 1 250 m² solar collector field and a 105 m³ heat storage have been supplementing the biomass heating plant since 1997. At that time the solar thermal system was able to cover 90% of the local heating network’s demand in summer. By adding new customers the yearly heating demand increased to 8 GWh in 2012 and the network grew to 10 000 m in length. This is why an additional 1 200 m² of solar thermal and a 70 m³ buffer storage were installed. The solar fraction is now 12%. The majority of the heating demand is covered by two woodchip boilers with 2.3 MW and 0.7 MW capacity. Thanks to the solar thermal plant the boilers can be taken out of operation entirely during the summer. According to Christian Fink ‘this is a very common combination of two renewables in rural areas in Austria’.

In total there are about 35 MWth (ca. 50 000 m² of collector area) of solar thermal feeding into district heating systems in the region around Graz and in Styria. The city of Graz is planning to completely decarbonise its heat supply in the medium term and has chosen solar thermal to be one of the main technologies in order to achieve this. In its final expansion stage the plant ‘BIG SOLAR Graz’ will provide 20% of the district heating demand and will entirely heat about 4 400 buildings.

Growing market in Germany

There is also progress in Germany. There are about 25 large-scale solar thermal plants with integration into district heating in operation. More systems with a total capacity of ca. 40 MWth are in the planning and preparation stage. Currently the strongest market segment is made up of energy villages (‘Energiedörfer’); five plants are going to start operating this year in Randegg and Liggeringen (both in Baden-Wuerttemberg), Mengsberg (Hesse), Ellern (Rhineland-Palatinate) and Breklum (Schleswig-Holstein).

Utilities in urban areas are also actively involved, as is evident by the biggest network-integrated solar thermal plant in Germany in Senftenberg in Brandenburg and a new pilot plant by the municipal utility in Duesseldorf. Pauschinger says that ‘we expect the collector area of large-scale systems in Germany to double within the next years. The majority of the currently planned systems are in the segment of urban district heating’.

Denmark, however, is still way ahead. By now there are more than 110 systems with about 700 MW of thermal capacity. The reason why Denmark was able to take the leading position lies also with the political and infrastructural circumstances. On the one hand there are high taxes on fossil fuels like oil and gas. On the other hand district heating is very widely spread in Denmark.

The Danish examples show very clearly how renewable energy and CHP can be combined in a ‘smart’ way on a local scale by deploying large heat storage units. They allow CHP plants and power-to-heat systems to operate optimally.

A new generation in district heating

The above mentioned project examples show trends. Christian Maaß, director of the Hamburg Institute, says the ‘new generation in district heating’ has begun. ‘District heating networks will be the platform for different heat sources: solar thermal, biomass, industrial waste heat, waste incineration, geothermal and heat pumps’.

Simona Weisleder from the Hamburg Institute demonstrated that there are various options for installing solar thermal collectors. She pointed out that there is a lack of willingness to provide agricultural land for large-scale solar thermal plants and presented alternatives. At the ‘Energy Bunker’ in Hamburg-Wilhemsburg, for example, the solar collectors are mounted on an old bunker. They can also be installed on car park buildings, greenhouses, industrial or multifamily buildings, decommissioned landfills, next to wastewater treatment plants and on noise protection walls. Other options include installations along streets or elevated above agricultural land, a concept already being tested in so-called agro-photovoltaic systems, for example. She reported that ‘during workshops we identified a huge interest in win-win solutions’. Participating representatives of state institutions from Styria, Thuringia and the French Auvergne-Rhone-Alpes region presented their initiatives for improving the legal framework in this matter as well as for making land more readily available for renewable energy.

The bottom line of the conference was that the technology is ready to be used today. The speakers in the final discussion round called for a stronger political commitment to introduce policies for reducing CO2 emissions. Considering that the prices for fossil energy sources are very low, incentives are necessary to make renewable energy more attractive. One option could be a CO2 tax. In closing, Maaß called upon the industry to remain confident and implement projects despite the less than ideal political circumstances. ‘We have all the good reasons on our side.’

Pictures: Energie Graz (HELIOS), Guido Bröer (Fernheizwerk Puchstraße)


Solar and biomass – a winning solution for district heating

2020-04-03T16:14:26+02:00Apr 27th, 2018|

Biomass may be cheap and carbon-neutral, but a solar upgrade of biomass-fired district heating could further improve efficiency and reduce local emissions. For example, solar heat helps avoid having to start up and shut down wood-chip boilers or operate them at partial load. It can even replace backup fossil fuel systems, which provide district heating networks with energy in summer.

During a December 2017 webinar, held as part of the Horizon 2020 project SDHp2m…From Policy to Market, experts from Sweden and Austria showed promising case studies for a clever combination of biomass and solar thermal in district heating.Jan-Olof Dalenbäck, Project Manager at CIT Energy Management and Professor at Chalmers University of Technology in Sweden, explained that a small pellet-fired DH network, below 1 MWth of capacity, was usually not the best candidate for solar integration, since it can be shut down and restarted while retaining high levels of efficiency. ‘If you then add a solar array, including storage – typically the best solution for biomass plant integration – you can’t get relevant benefits from shutting down the boiler. Emission and cost savings are negligible or, at least, not worth it because of the investment needed,’ he added.

Biomass boiler in Sweden benefits from 10 % solar fraction

Larger biomass systems, for instance, between 1 and 100 MWth, have the advantage that their boilers run on wood chips. They take more time to be shut down and restarted, while a partial load results in reduced efficiency, for example, below 20 % of nominal power. To prevent partial loading, the systems are usually equipped with a smaller fossil-fuel boiler or buffer storage. Of course, an alternative solution is the integration of a solar thermal field, which can provide a significant boost to boiler efficiency, reducing emissions and costs.

One such biomass-solar system in Sweden is the DH network set up in 2010 in Ellös, in the Västra Götaland county. It consists of 4 MWth of biomass boilers, a 1 000 m2 solar array and 200 m3 of buffer storage. The average annual solar fraction is around 10 %, and the main benefit of solar integration is the option to switch off the biomass boiler in summer, except for a few rainy or cloudy days in a row. The size of the solar system is planned to be scaled up to 2 000 m2 soon.

Austria: High potential for solar upgrades of DH plants

Solar-assisted biomass DH was quite common in Austria, Moritz Schubert from Austrian-based S.O.L.I.D. said. Sixteen of the 32 SDH plants in operation across the country have been combined with a bio-energy system. Their solar arrays range from 100 m2 to 7 000 m2.

One factor encouraging these kinds of developments is the national subsidy programme for large solar thermal plants above 100 m2. Launched in 2010, it has recently been extended to include plants of up to 10,000 m2. It provides 40 % of the investment cost, and both SMEs and designers of innovative systems can get another 5 % on top. Two new SDH systems of between 7 000 m2 and 8 000 m2 are planned to be set up this year.

Schubert also mentioned a biomass-solar DH system in Mürzzuschlag, a town in the northeast of Austria’s Styria region. The plant has solar-based production costs of 35 EUR/MWh, which is slightly below the biomass values of 37 to 38 EUR/MWh.

Over the last 20 years, Austria’s countryside has seen the installation of more than 2 000 biomass DH networks, which makes it quite difficult to find a suitable location for a new grid. Instead, solar collector suppliers should focus on solar upgrades of existing biomass DH. ‘Moreover, some of them have 20- to 25-year-old boilers,’ Schubert said, ‘which should be replaced to meet new efficiency requirements. Some also no longer benefit from CHP feed-in tariffs, so I see great potential for integrating solar arrays into existing networks.’

Replacing fossil fuel boilers for DH summer load

Samuel Knabl from Austrian Institute AEE INTEC said that a survey among DH utilities analysed the main reasons for integrating solar thermal into biomass DH. His interview partners emphasised that solar could replace backup fossil fuel boilers used exclusively in summer to avoid partial load operation. The DH utilities added that solar thermal could also reduce local emissions, such as dust and nitrogen oxides, created during biomass combustion, which would increase public acceptance of biomass DH.

Additionally, Knabl underlined that Austria had a programme to recover up to 35 % of the investment in a biomass DH installation. The incentive required that overall network efficiency exceeded 75 % – not an easy objective for small networks in areas of low population density, where long pipes are necessary. Solar thermal could help meet the target. In that case, the biomass incentive could serve as indirect support for SDH systems.

Riccardo Battisti (Text and Foto)

CIT Energy Management

Solar district heating market grows by 35 per cent

2018-06-04T09:54:45+02:00Apr 11th, 2018|

Graz, 11 April 2018. The 5th International Solar District Heating Conference in Graz starts with record attendance. Inspired by an annual market growth of 35 per cent in Europe, 350 experts have come together in Graz, Austria, for the 5th International Solar District Heating Conference. On 11 and 12 April 2018 the scientists and market stakeholders discuss the state of the art and strategies for the further development of the solar district heating market.

The branch looks forward to a bright future for their business field. Werner Lutsch, president of the European district heating association Euroheat&Power, expects that solar thermal will – for the first time – contribute more than 1 terawatt hour (1 terawatt hour = 1 billion kilowatt hours) to the district heating supply this year. According to market evaluations the solar thermal capacity connected to district heating will rise up to 240 terawatt hours in 2050. This will represent 15 per cent of the European district heating demand.Considering the average market increase in the last five years of 35 per cent annually, Lutsch is confident that the solar thermal and district heating industries will achieve this goal. Particularly as both industries work together to achieve this goal, said the president of the association at the conference. ‘The solar thermal and the district heating industries have established a reliable cooperation.’

Not only Denmark, the forerunner in the field of solar district heating, makes progress. In Denkmark there are more than 100 cities and communities with solar district heating plants – mostly with shares of 15 to 60 per cent of the local district heating supply. However, other countries like Austria, Germany, France and Sweden catch up. The well-proven solar district heating technology is being more and more applied in these countries – with a broad variety of scale: There are installations which supply solar thermal heat for urban quarters, there are so called bioenergy villages where solar thermal plants supply the entire heating demand in summer time, and there are huge plants built on fields with up to 100 megawatt thermal capacity as in the Danish city Silkeborg.

Compared to the previous conference in Billund, Denmark, which took place in 2016, the number of participants is twice as high this year. The 350 participants come from 33 countries. The conference managers, Christian Fink from AEE Institute for Sustainable Energy (AEE INTEC) in Graz and Thomas Pauschinger from the Steinbeis Research Institute Solites in Stuttgart, Germany, judge this a very positive signal for the use of solar thermal in local and district heating networks. Pauschinger emphasized that the EU commission reliably supports this kind of international cooperation for the further development of solar district heating. ‘We have been able to successfully develop this conference also due to the support of the EU commission, starting in 2009 and lasting until today.’ Fink said: ‘It is the goal of the conference to bring together business experts and decision makers who are interested in using the technology and to make use of this impulse for new projects.’

Two excursions on Wednesday afternoon to solar district heating plants in the Graz area were an appreciated opportunity for networking and discussions. It is not by accident that Graz was chosen for the conference this year. The second biggest city in Austria plans to completely decarbonize its district heating network. For a CO2-neutral supply a project called ‘Big Solar’ is in preparation. 450 000 square meters solar collectors shall be installed. Christian Purrer, board speaker of Energie Steiermark emphasized at the conference: ‘It is our goal to significantly increase the share of renewable energy in the heat supply in the coming years in order to combine security of supply with even more sustainability. Solar thermal in combination with big thermal storage tanks, as in our project Big Solar, play a leading role in it.’

Fotos: Energie Graz (HELIOS Anlage), Guido Bröer (Fernheizwerk Puchstrasse Anlage)


Solar district heating on the roof of the world

2018-06-07T10:27:18+02:00Mar 13th, 2018|

A contract to set up a solar district heating network in Langkazi county in Tibet has been awarded to Arcon-Sunmark Large-Scale Solar Systems. The Chinese-Danish joint venture signed an agreement with the local government of the autonomous region of 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, 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 China’s central government. ‘Tibet has double the radiation found at most central European cities and enjoys similar levels of sunshine each month,’ Jiao Qingtai, Vice President of the Sunrain Group, said of the region’s solar potential during a presentation at the Task 55 meeting in Abu Dhabi, UAE, in November 2017. With average temperatures of below zero in northern and around 8 °C in southern Tibet, there is large demand for heating all year round.

Langkazi county, which is surrounded by tall mountains on all four sides, is in the southeastern part of Tibet, an average 4 500 metres above sea level. Up here, the boiling point of water is as little as 85 °C, a great challenge for anyone designing district heating systems. Qingtai said that the town’s advantage was a lack of heating equipment in its building stock. It meant that new space heating units could be adapted to accept a fairly low supply temperature, 70 °C to be exact. Hydraulic adjustment inside the buildings would then lead to a rather low return temperature of 40 °C. The solar system is part of a larger project to develop renewable heating in Tibet. Feasibility studies were conducted in more than 20 of the region’s counties and cities and Tibet’s local government has approved funding for five of them. The county of Langkazi has already completed its tender process, awarding the contract to Arcon-Sunmark Large-Scale Solar Systems. The joint venture is now in charge of the entire Renminbi (RNB) 122 million investment (USD 19.26 million), including the construction of the seasonal storage, collector field and district heating network.

Organisations mentioned in the article:


RES with heat storages replace coal in polish DH systems

2020-04-03T16:09:43+02:00Feb 28th, 2018|

Elaboration of the new subsidy program for RES to heat, including solar thermal and wind power to heat, is the main conclusion of the conference – ‘District heating systems with renewable energy sources and seasonal heat storages’, held in Warsaw, at the National Fund for Environmental Protection and Water Management (NFOŚiGW), on January 17, 2018.

Nearly 130 people took part in the conference. The event, co-organized by the Institute of Renewable Energy (IEO), initiated the work on new priority projects in this area in Poland. Zbigniew Kamieński – adviser to the President of the NFOŚiGW Management Board was opened and led the conference.Grzegorz Wiśniewski, President of the Board of IEO, in the introductory ‘District heating systems with renewable energy sources and seasonal heat storages’ drew attention to of the role of variable RES (solar thermal and wind) in the district heating systems (DHS) integrated with short and long term thermal storage. Solar assisted DH are already in use in dozen Polish cities and need to be scale up and market push, however the opportunity of usage of 6 GW wind power in Poland for heating and its balancing is not used yet. He emphasized the specifics of the operation of the competitive electricity market and the increasing impact of renewable energy on electricity prices, in particular on the concept of green electric heating – (Green Power-to-Heat) and integration of heating and electricity sectors. The key to introducing renewable energy for heating and integration of district heating with power engineering would be seasonal heat storage. Energy storage in hot water is still the cheapest technology that also allows long-term storage of surplus generation.

The Danish example of investment in DHC renewable energy sources and seasonal heat storages was presented by Per Kristensen from Planenergi, Denmark. Per Kristensen said, the key to effective and rapid transformation of heating is the implementation of solutions improving energy efficiency, which reduce the temperatures of water in the district heating networks.

Modern fourth generation (4G) district heating infrastructure should be based on smart low temperature networks. Seasonal heat storage combined with solar district heating systems coupled with the electricity market was presented by Professor Jan-Olof Dalenbäck from Chalmers University of Technology and CIT Energy Management AB, Sweden. Professor Dalenbäck said, the use of solar heat has many advantages that put them over the use of the biomass. First of all – fixed and long term guaranteed heat cost. The cost of solar heat is independent of the rising prices of energy resources or prices of CO2 emission.

In addition, in order to obtain the same amount of heat from biomass, it is necessary to use raw material collected from the cultivation area many times (30-50 times) larger than the surface of the solar collectors area in a solar district heating system. SDH systems are functioning and mature technology, which should be taken into account, and its development must be supported by a change of approach in creating the state energy policy, both at the political and investor level.

In the second part of the conference, two panels of experts took place. The first of the discussion panel, titled ‘The use of renewable energy installations and heat storage – new challenges for district heating companies and housing cooperatives’ was led by Zbigniew Kamieński. Panel participants were: Wojciech Ignacok – President of the Board Geotermia Podhalańska S.A., Dariusz Marczewski – President of the Board District Heating Company in Płońsk, Konrad Krzysztof Nowak – President of the Board District Heating Company in Olsztyn, Krzysztof Rodak – President of the Board District Heating Company in Tarnów, Jacek Szymczak – President of the Board Chamber of Commerce Polish District Heating, Tomasz Wilczak – Member of the Board – PGNIG Termika. The panelists, in their statements concerning proposed establishment of the National Fund of a new support program found that this proposal could be a chance for the modernization of the Polish district heating system. The implementation of the project must be adapted to the specifics and needs of potential beneficiaries in Poland.

The second of the discussion panel titled ‘Does Poland is a market for intelligent systems cooperating with the heating-weather-dependent renewable energy sources, seasonal heat storage and electricity market?’ led by Grzegorz Wiśniewski. Panel participants were: Roman Majnusz – President of the Board Ensol, Małgorzata Mika – Bryska – Director in Veolia Energy Poland, Andrzej Rubczyński – Director of District Heating Strategy, Forum Energii, Tadeusz Skoczkowski – Warsaw University of Technology, Witold Rożnowski – Director of the Research and Development Center in Rafako S.A. , Małgorzata Mika-Bryska – Director of Regulation and Public Relations , Veolia Energia Polska, Roman Majnusz – President of the Solar Power Management Board ENSOL, Andrzej Rubczyński – Director of Heat Engineering Strategy, Energy Forum , Profesor Tadeusz Skoczkowski – Head of the Department of Rational Energy Use at the Warsaw University of Technology. The panelists of the second discussion panel stated that without the introduction of renewable energy sources into district heating systems, it will be not possible to obtain by DH companies the status of the ‘effective district heating system’ (according to the EU energy efficiency directive) and to fulfill the RES targets for Poland for 2020 (according to the EU RES directive).

Summing up the conference, Zbigniew Kamieński stated that the proposal of a new subsidy program RES for DH is worth attention and implementation. Kazimierz Kujda, President of NFOŚiGW confirmed that NFOŚiGW is prepared for financing of a series of pilot RES to heat projects for the polish district heating industry. The undertaken work on new subsidy program will be finished in a few months. IEO is collecting and analyzing good examples of policy measures and subsidy programs for promotion of RES and heat storage for DH systems in other counters. The conference was organized and the new subsidy program are preparing with the support of SDHp2m project.

Aneta Wiecka

Presentations of experts from the conference are available on the NFOŚiGW website


Guarantee of SDH yield in Châteaubriant, France

2018-06-04T10:27:05+02:00Feb 6th, 2018|

15 December 2017 saw the inauguration of the first installation supported by the subsidy scheme for large-scale solar thermal projects in France. The 2 340 m2 collector field by German manufacturer KBB Kollektorbau has since been feeding into a biomass district heating network of Châteaubriant, a town in western France.

The municipality of Châteaubriant was the sole provider of funds for the EUR 1.25 million (530 EUR/m2) endeavour, having received a EUR 875 000 subsidy from ADEME. ADEME’s grant covered 65 % of the project costs and another 5 % were added from the so called AFR fund to boost economy in designated regions in France. The primary objective of the Châteaubriant project has been to reduce the heat price for consumers by 2.5 % after taking into account a carbon tax increase planned by the French government.The French energy agency emphasised that the large subsidy amount would allow each stakeholder to accumulate experience and lower the risks involved. The investor in the project did not choose a turnkey contractor, but asked French engineering companies Girus and Tecsol to supervise the project as independent businesses. Several contractors were chosen to work on different aspects of the project, such as the solar field, the support structure, civil engineering and hydraulics. The solar district heating plant was included as an independent unit in the existing district heating contract hold by French utility Engie Cofely, the operator of the biomass plant. The contract for the solar heat delivery was revised by the Austrian company S.O.L.I.D..

The solar system is planned to deliver 900 MWh/year to the heat network (385 kWh/m2). This equals 5 % of the annual demand and 70 % of the one in summer. An important difference to other projects is that an agreement signed by Eklor, which represents the collector field supplier KBB in France, Cofely, which operates the plant, and Tecsol, which oversaw completion of the project, guarantees the delivery of a certain amount of solar heat. Another innovative approach is the payment of an incentive if heat customers connected to the district heating network reduce their return temperatures.

Organisations mentioned in this article:
KBB Kollektorbau
Girus Engineering

photo: ADEME

Kyrgyzstan’s capital sees 0.5 MW SDH plant being built

2020-04-03T16:02:27+02:00Feb 6th, 2018|

In September 2017, the then deputy PM of Kyrgyzstan, Duishenbek Zilaliev, attended the inauguration of a 0.5 MW solar district heating plant in the capital Bishkek. The press release– published by the media and communications department of Bishkek’s city hall – also mentioned the operator of the solar field, the Bishkekteploenergo municipal utility, the largest thermal energy provider in the city.

The media and communications department of Bishkek city hall quoted the deputy prime minister as having said that ‘this innovation should be introduced into other regions, and the government will take every measure to support such a revolutionary step.’ Kyrgyzstan is a small central Asian country with a population of 6 million, neighbouring China, Kazakhstan and Tajikistan. The national Environmental Protection Fund supported the project financially by offering a grant of Kyrgyzstani Som (KGS) 10.6 million – 72 % of the total investment costs of KGS 14.8 million (around USD 212,000).According to Bishkekteploenergo, the solar plant feeds into the return line of the existing district heating network, which supplies a day care, a school, residential housing units and 4 student buildings. The solar heat system was designed and installed by the municipal utility. Its 364 Chinese-made flat plate collectors have been the only parts imported from abroad.

Bishkek city hall estimates the natural gas cut-down to be around 124,800 m3 a year, which will save KGS 2.2 million annually, based on current tariffs. The State Agency for Environmental Protection and Forestry issued the grant as special funding, not as part of a regular solar thermal support scheme. Bishkekteploenergo has since announced plans for a second solar district heating installation in Bishkek’s Orto Sai suburb.

Organisations mentioned in this article:
State Agency for Environmental Protection and Forestry
Report on Bishkek

Solar District Heating: how to tackle land use issues

2020-04-01T17:05:34+02:00Oct 17th, 2017|

Usually, solar district heating (SDH) plants require large fields for collector installations, which has raised concerns at local level because of competing land uses and a system’s potential visual impact on the surroundings. One way out of this dilemma is to combine heat generation and fruit and vegetable harvest.
As part of SDHp2m…From Policy to Market, a Horizon 2020 project, some regions are looking to create regulations based on best practice examples of land use or spatial heat planning. This article will present showcases from the Styria region in Austria, Hamburg in Germany and Valle d’Aosta in Italy.In the metropolitan region of Hamburg, several SDH projects have failed because of a lack of suitable areas or because they lost out against residential buildings, roads, nature habitats or industrial, agricultural or commercial facilities. The Hamburg Institut Research (HIR) is now developing best practice guidance and policy recommendations to tackle this barrier. It established five main categories:

• large roof spaces
• polluted or contaminated areas
• zones along traffic routes
• agricultural plots
• double use for both SDH systems and nature conservation

In the second category, Hamburg shows large application potential in areas storing sewage from the Elbe river. For example, the fields covered in sludge at the port of Hamburg-Altenwerder could provide enough space for about 40 000 m² of solar collectors, with some challenges remaining, such as the lack of a nearby district heating network and a legal permit for SDH systems on these hills. Potential site for SDH plant on sludge fields at Hamburg-Altenwerder port in Germany

In the Austrian region of Styria, almost all DH networks which require significant hot water amounts in summer are in urban areas, where land is quite expensive. Additionally, the owner of the property expects its value to rise, which usually leads to higher rental costs and sale prices and threatens the economic viability of SDH plants. Together with Austrian-based research institute AEE INTEC and system supplier S.O.L.I.D., the regional government has been trying to rectify the situation by devising new policies which would allow the installation of SDH systems in agricultural priority areas and green zones. The first step has been to establish a broader consensus about the future need for energy supply mainly from local renewable sources, essentially by evaluating energy demand in spatial planning. There will be one pilot study each about three municipalities to analyse the situation.

The case of Italy is a rather peculiar one, as the main competitor for land use is photovoltaics. The widespread and mostly unchecked deployment of large ground-mounted PV plants because of generous feed-in tariffs has prompted a quick and harsh response by many regional administrations, leading to stringent rules on new ground-mounted solar systems. Even though these requirements make no explicit mention of solar thermal collectors, the technology falls within their scope automatically.

To counter this unfortunate development, Ambiente Italia has been cooperating with the Valle d’Aosta region in northwest Italy and other local stakeholders, such as district heating utilities, to find a solution based on a multi-level approach:

  •   ‘We are different from PV’: SDH plants usually require a smaller piece of land and are placed in industrial and residential, not in heritage areas.
  •  ‘We are different from Denmark’: Danish SDH systems typically have large fields of collectors thanks to a low population density and very inexpensive plots; In Italy, the average SDH plant size ranges from 1 000 to 2 500 m².
  • ‘We need a showcase’: An SDH system in operation would show all stakeholders that there is zero impact on the

Riccardo Battisti
See also our factsheets on regional activities within SDHp2m

Three pilot case studies in the Auvergne-Rhône-Alpes region

2018-05-03T11:12:31+02:00Jul 19th, 2017|

Three pilot case studies in the Auvergne-Rhône-Alpes region
The solar thermal industry needs a second wind in France. This is the challenge of the European project SDHp2m, of which the Regional council of Auvergne-Rhône-Alpes, RAEE (regional energy and environment agency in Auvergne-Rhône-Alpes) and CEA INES (research institute, department of the French national institute for solar energy) are partners. The aim of the project is to develop the integration of solar thermal energy in district heating systems. In the region, the potential is very significant: indeed, from 400 000 m² to 1 600 000 m² of solar thermal collectors could be integrated into district heating systems.
Last February, a call for proposal was launched. The idea was to find three suitable pilot sites that would allow the study of several possible configurations of solar thermal integration, being the most representative in the region. Twelve applications were received and three laureates selected:

The district heating system of Clermont Ferrand (Puy-de-Dôme), La Gauthière area

The operating company Clervia, subsidiary of Dalkia, operates this 5 km district heating system. It provides 38 140 MWh of heat per year of which 65,5 % comes from biomass and 34,5 % from natural gas with a part of cogeneration. This heating network is part of a blueprint process initiated to study development paths such as increasing the share of renewable energy, extension or interconnections with other systems. The case study for the integration of solar thermal energy in this heating network, proposed within the SDHp2m project, totally fits in within the development approach already initiated.

The district heating system of Chambéry (Savoie)

The operating company SCDC, subsidiary of Engie Réseaux, operates this district heating system of 51 kilometers. It provides 208 836 MWh of heat per year of which 28 % comes from biomass, 27 % from the energy recovery unit and 45 % from natural gas. The area selected for the case study is the neighborhood of « Croix Rouge » equipped with its own biomass and gas heating plant providing 32 GWh/h of heat (not connected to the energy recovery unit) . This study strengthens the TEPOS (Positive energy territory) approach in which one of the strategic axes is the development of district heating systems using renewable energy.

The district heating system of Pelussin (Loire)

The SIEL, Territoire d’Energie Loire (trade union for energies that operates throughout the Loire department), is responsible for the management of biomass district heating systems for local authorities. The SIEL is in charge of the studies, invests and maintains all the equipment. The local authority reimburses the investment in the form of a rent and is responsible for its biomass supply. The district heating system of Pélussin, operating since 2009 is 1,8 km long. It supplies public buildings as well as individual and collective housing on a ZAC (joint development zone). The 450 kW heating plant provides 1 000 MWh per year (88 % of heat coming from biomass and 12% from propane). Private housing requires an important supply of domestic hot water during the summer, which is essentially provided by an auxiliary propane boiler. The use of thermal solar energy could significantly reduce the consumption of this non-renewable energy.
In 2014, the SIEL has implemented on behalf of the municipality a second biomass district heating system, with equivalent power, to supply about 20 000 m² of public buildings in another area. In the Loire department, the SIEL has already implemented 46 biomass district heating plants. The feasibility studies will be carried out during the summer and the first results will be available in September 2017.

District heating operators who are interested in the topic of solar thermal energy integration can contact the SDHp2m team for a first level of information and referral. Furthermore, ADEME (The French Environment & Energy Management agency) can also finance these case studies.

Mathieu Eberhardt – RhônAlpEnergie Environnement
Alexis Pellat – Region Auvergne Rhône Alpes
Cédric Paulus – INES CEA

New subsidy program for 4th generation district heating in Germany

2018-06-11T14:22:58+02:00Jul 19th, 2017|

The German Ministry for Economic Affairs and Energy launched a new subsidy scheme for ‘District Heating Pilot Projects 4.0’ on the 1st of July. In order to get funding, district heating networks have to cover at least 50 % of the annual heat consumption from renewable energy sources or waste heat.

A district heating network 4.0 has a maximum supply temperature of 95°C. Innovations like long-term thermal energy storages or coupling of the electricity and heat sector via large heat pumps or electric boilers are promoted. Via a fundamental orientation towards low-temperature district heating networks, the German Federal Ministry for Economic Affairs and Energy aims at enabling a large range of technologies. Support is foreseen for so-called cold district heating networks with 20°C supply temperature as well as for classic district heating systems as long as the supply temperature does not exceed 95°C. However, no more than half of the renewable heat supply should be generated from biomass. Therefore, most of the projects realized so far with 20% of solar heat and 80% of biomass wouldn’t be eligible as pilot project in the framework of this new funding guideline.The objective at political level is to prove the economical and technical feasibility in at least twelve cases thanks to feasibility studies. Moreover, at least six district heating networks should be built or fundamentally transformed by 2020. The district heating networks should have at least 100 connections or a minimum heat supply of 3 GWh per year.

Cost efficiency has high priority: The heat supply from supported networks should be as competitive as heat supply from fossil fuels. Support is foreseen for new construction or transformation of existing networks but low-temperature sub-networks are also eligible. Two stages are planned. In a first step, feasibility studies are supported up to 60%. In a second step, the realization of the networks can be financed up to 50 %. In addition, an allowance up to 80% for information activities to potential users is foreseen, in order to reach a high connection rate. Moreover, the participation of local research organizations is sponsored up to 100 %.

The gradation of the subsidy is new. The district heating grid gets a subsidy of 20 % (or 30 % if the applicant is a Small or Medium Enterprise). In addition, there is a ‘sustainability bonus’ of up to 10 percent: One can receive 0,2 % for every full percentage point of renewable energies or waste heat fraction exceeding the minimum requirement of 50 %.

Another innovation is the ‘cost efficiency bonus’ for especially low heat prices. If the heat price falls below 10 cents per kilowatt hour, this bonus increases step by step. For a heating price of only 5 cent the maximum subsidy of 10 % of eligible costs would be reached. Long-term thermal energy storages are considered standard for district heating networks 4.0 unless it can be demonstrated that their implementation in the system is not economically feasible.

The previous KfW subsidy program for renewable district heating networks is not replaced by this new program and is still valid. A combination of both programs is despite a general non-combination rule possible, if a project is split in several subprojects.

Guido Bröer

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