The Danish Industry is running a web system pointing at energy solutions, companies involved, projects, including solar thermal. You can find the map at http://www.energymap.dk. You find the Marstal Central Solar Heating Plant, their contact company and other information on the direct link http://www.energymap.dk/Profiles/Ramboll/Cases/Large-Scale-solar-heating-in-Marstal.

Any Danish owner of a plant or a company is invited to contribute to the common resource. Please do so.

Through a research and development support of 11.9 mio. DDK, the Danish government pushes for CSHP with seasonal storage. In charge for the project is Planenergi, the most active consulting company in the business together with the plant owner, Dronningelund District Heating. The overall concept will be to use solar heating in combination with a large scale thermal storage and a heat pump. The collector area is planned to be approx. 35,000 square metres, a storage volume of 60,000 m³ and a heat pump with 3 MW effect.

The seasonal storage is planned as a pit water storage with floating lid, a well-known solution applied in the past.

The overall budget for the project is 80 mio. DDK or approx. 10.1 mio. Euros.

We keep an eye on this project at this blog.80

You are able to follow actual production data from large scale solar heating plants through at homepage. This gives you an idea of the performance for different plants at the same time, in real time . The texts are in Danish – however, the first value shows the actual production in kW, the second value shows the production per area and the third shows the actual solar irradiation.

You find the site at http://www.solvarmedata.dk/.

The CSHP in Brandstrup is one of the very large plants at this time. The solar heating plant is connected to a co-generation plant, whereas other plants are connected to district heating plants with no production of electricity. Therefore the results of this plant is rather interesting to see.

The plant is presented at http://www.braedstrup-fjernvarme.dk/side1298.html (in Danish). The plant was taken into operation in 2007. It consists of 8,000 m² of solar panels. Guests are invited to visit the plant where a rest area is prepared to them.

The 14th and 15th of January 2009, there was a workshop at the Technical University of Denmark, Lyngby with aims described by the workshop title “How ambitions can we be in contributing to the worlds energy needs with wind, solar and bio energy. – And what role does energy storage play?”

This was certainly a very interesting place to be and listen to experts, politicians and industries. At the workshop “solar energy” the experts in CSHP, Jan-Olof Dalenbäck, representing amongst other the European platform ESTTP (http://esttp.org), representatives from universities and two major players from industries Sten Beltman Jørgensen, Sunmark A/S (http://www.sunmark.com) and Jes Donneborg Arcon Solvarme A/S (http://www.arcon.dk). Backed up by others the target was to be defined for “solar thermal” including large solar.

Some remarks from the discussion show that even though CSHP have just a share of 1% of the collector area, the production share is at 9%, a Factor 9. This is due to size, efficiency and storage.

According to figures by Jan-Olof there are 30 central plants and 120 block and “small” plants at current times. As you will find in the coming future there are a number of plants under construction and planning.

It was discussed that subsidies schema do not support large-scale solar heating while supporting the small systems. It can be argued that subsidies are not necessary for CSHP due to the cost effectiveness for commercial plants. See the VEKS post below.

It was mentioned that there is a new project founded by the EU “SDH Take-off” probably Solar District Heating (SDH). You will find more on that topic later in this blog. (I could not find any through Cordis or Google – please help).

The method of the workshop was to define an ambitious target, uncover challenges which lead to a number of actions and from here a road map could be drawn. This work, over 2 days let to the following conclusion which was presented at the workshop: (my interpretation)

Pro-solar arguments are that you need 1 hour collection of all solar energy to supply the world with the total energy necessary. This ought to be possible. Solar produces 30-40 times the energy per area as biomass. The ambitious goal was defined at he the COP14 in Poznan, Poland to 50% of all heat demand must be supplied by solar heating in 2050. This target was than distributed over the period, not referred here.

The road map was laying out that all actions ought to start as fast as possible. Politicians ought to adopt the target (which they did i Poland). Next step ought to be public investments into maximum application of solar heating in public buildings, which would result in a) a stable marked condition for the industries and b) a critical mass for the production lines, assuming that marked conditions will lead to price-performance and competitiveness that brings along sustainability for the branch. A very important goal is than to increase the solar fraction of the technologies by improving/increasing the storage technologies. As another effort solar cooling would be investigated.

Please not that the workshop was also working with targets for other solar technology, education, wind and bio energy, plus energy storage.

I hope that other participants will be able to support by their descriptions and comments to this post or we will be able to supply with a proceedings or official summary by Risø. DTU, the organizers. Thanks to them. You may probably find it at http://risoe.dtu.dk

Next step will be COP15 – see http://www.cop15.dk/en

At the Eurosun 2008 in Lisbon, the thematic of large scale thermal storage was part of the topic range. Per Alex Sørensen from Planenergi, Denmark did provide me a copy of three papers that I refer here. Unfortunately, it seems that one cannot get the proceeding online. (This ought to be changed for any renewable energy and environmental conference, where proceedings ought to be open access and free for reading).

T. Schmidt and D. Mangold from the Steinbeis Research Institute, Stuttgart, Germany mailto:schmidt@solites.de did present a paper including three thermal storage projects, a 5,700 m3 water tank i Munich, a borehole storage 37,500 m3 volume in Crailsheim and a 4,500 m3 pit storage in Eggenstein.

F.Ochs, J. Nussbeicker-Lux at.al. presented the following abstract to their paper “Solar assisted district heating system with seasonal thermal energy storage in Eggenstein-Leopoldshafen” with the following abstract:

The solar assisted district heating system with seasonal thermal energy storage in Eggenstein-Leopoldshafen (Germany) is the first system realized with existing renovated buildings. The system consists of 1600 m² flat plate collectors and a 4500 m³ gravel-water thermal energy store (TES) for seasonal thermal storage. Experiences gained within the BMU-project “Further development of the pit heat store technology” contributed to the design of the seasonal TES. This paper focuses on the design and construction of the gravel-water store. The monitoring concept of the solar assisted district heating system with focus
on the gravel-water TES is presented.

Per Alex Sørensen, mailto:pas@planenergi.dk, from PlanEnergi, Leo Holm and Niels Aage Jensen from Marstal Fjernvarme, Denmark presented a paper “Water Storages, Solar thermal and Heat pumps in District Heatin” with the following abstract:

In 1996 Marstal Fjernvarme (Marstal District Heating) established 8.000 m2 solar collectors that covered 13% of the yearly consumption. The solar fraction in later built district heating plants goes up to 25% covering the total summer load, but several district heating companies especially natural gas fired combined heat and power plants want a higher solar fraction in order to replace expensive natural gas. Therefore new projects with solar fractions of 50% are designed and are expected to be implemented  in 2009. Design calculations show that the production price for heat from solar thermal plants with 50% solar fraction can compete with heat prices from natural gas fired CHP plants.

Congratulations to Samsø Green Island pioneer Søren Hermansen. He’s one of the “Heroes of the Environment 2008″ by Times Magazine. Source: http://www.time.com/time/specials/packages/article/0,28804,1841778_1841782_1841789,00.html.

One of the achievements are the central solar heating plan in Nordby. The solar plant of 2,500 m² solar collector supporting a chip wood plant with a 800 m³ thermal storage. You find more information on the plant and all the many other efforts on the Green Island at http://www.energiakademiet.dk/front_uk.asp?id=73.

Congratulation to the whole community of Samsø – well done.

The Technical University of Denmark does research in large-scale solar collectors.

Abstract from DTU-homepage regarding the conference publication:

The test method of the standard EN12975-2 (European Committee for Standardization, 2004) is used by European test laboratories to determine the efficiency of solar collectors. In the test methods the mean solar collector fluid temperature in the solar collector, Tm is determined by the approximated equation where Tin is the inlet temperature to the collector and Tout is the outlet temperature from the collector. The specific heat of the solar collector fluid is in the test method as an approximation determined as a constant equal to the specific heat of the solar collector fluid at the temperature Tm. The power produced by the solar collector during a test period is determined by the product of the specific heat, the mass flow rate and the temperature increase of the solar collector fluid. The solar collector efficiency is in the standard determined by measurements at different temperature levels. Based on these efficiencies, an efficiency equation is determined by regression analysis. In the test method, there are no requirements on the ambient air temperature and the sky temperature. The paper will present an evaluation of the test method for a 12.5 m² flat plate solar collector panel from Arcon Solvarme A/S. The solar collector panel investigated has 16 parallel connected horizontal absorber fins. CFD (Computational Fluid Dynamics) simulations, calculations with a solar collector simulation program SOLEFF (Rasmussen and Svendsen, 1996) and thermal experiments are carried out in the investigation. The investigations elucidate: • How the mean solar collector fluid temperature Tm is underestimated by the approximated equation in the test standard and how the collector efficiency equation is influenced by the underestimation of Tm. The dependence of the volume flow rate is shown; • How the use of the approximated specific heat of the solar collector fluid is influencing the collector efficiency expression; • How the temperature levels used is influencing the collector efficiency expression; • How the measured collector efficiency is influenced by the weather conditions such as the ambient air temperature and the sky temperature. Based on the investigations, recommendations for change of the test methods and test conditions are considered. The investigations are carried out within the NEGST (New Generation of Solar Thermal Systems) project financed by EU.

For the first time, a major district heating company is planing to adopt the concept of central solar heating. The company VEKS, distributing heat in the western part of the Copenhagen area is aiming at a CSHP with a solar collector size of 20,000 m2, placed along a main highway. The plant will match the current record of the Marstal plant, also placed in Denmark. The plant will deliver approx. the heat of 5-6,000 single family houses.CEO, Lars Gulev, of the “Vestegnens Kraftvarmeselskab” district heating company estimates the plant to produce 10 GWh heat to the district heating system. The goal is to get the plant into production before the International Climate Conference in Copenhagen, 2009, where the expectations are to replace the Kyoto-protocol with a more ambitious protocol.

It is expected that the application of central solar heating is a factor 4 more cost efficient compare to single family housing solar installations.

Relevant is to mention, that the company is expecting lower production prices for the solar plant compared to the traditional co-generation plants due to the facts that solar prices are reduced as conventional heating prices are increased during the later years.

“In the first place, the solar heating plant is planed due to commercial reasons. Getting reduced CO2 pollution is a environmental side effect.” says Lars Gulev.

We hope others will take this considerations up and CSHP will play a more dominant role in the future of district heating. It would be interesting to see, if surplus heat from the power production will be cooled into the see due to this investment.

You find information on VEKS’s homepage on http://www.veks.dk (in Danish), where you change to English and will be presented for general information on the district heating system of Copenhagen. The solar plant is presented at the location http://www.veks.dk/Artikler/Seneste%20nyt/Solvarme.aspx

The Danish Engineering Newspaper did present the following news about a new very large CSHP plant:

Place: Denmark, Brænderup (near Horsens), at the mainland.

Size: 8.000 m² solar collector field, sized to deliver 10% of the district heating demand.

Of the 13 million total cost, the 3.5 millioner DDK are funded by a public body, Energinet.dk, that last year did analyse solar and district heating lead to positiv economical results. This analysis pointed out that this is due to the fact that the heat- or power plant can be turned of for some periods, where the price for power is too low to produce.
The maximum effect is estimated to 6 MW heat, with an annual production of approx. 4,000 MWh heat, leading to a yearly emission reduction of 4,300 tons CO2. The plant is designed by consultant company Planenergi and Ramboll, Denmark with Arcon solar collector producer, the same companies as involved in most of the plants in Denmark.