Introduction

Herne – Sordingen lies in the centre of the Ruhr. The training centre was built on the site of a former coalmine, Mont Cenis, and is one of the prominent architectural features of the IBA-Emscherpark project. The French architect Jourda settled for a box within a box principle: all accommodations are under a glass cover.
Management of the interior environment takes more or less the same form as in the buildings with double-skinned facades. In summer, warm stale air rises and escapes through openings in the roof. This out flowing airstreams produces under pressure in the glazed hall, so that fresh, cool air is drawn in through louvers in the side walls. Shade-giving ‘perspiring’ plants and evaporating pools combine to lower the internal temperature.
Besides, solar cells were integrated into the facade and roof glazing in a special pattern that provides sufficient shading from solar radiation but still admits sufficient daylight.

Objectives and target audience

Environmental concept in this building a main and prominent issue. And so this category will be a little bit heavy in proportion.
We can divide the strategy into several streams as follows:
1. Rain water system;
2. Climate Concern;
3. Solar Power Station;
5. Cogeneration.

Financial Resources and Partners involved

The overall cost of the PV-system was DEM 15,7 Million (€ 8,0 million).
A cost for a system that is roofing, facade, shading and solar generator in one.
Solar-Modules: DEM 11,1 Million (€ 5,67 Million)
Inverters: DEM 1,2 Million (€ 0,60 Million)
Switches, cabling, etc: DEM 0,6 Million (€ 0.31 Million)
Planning and engineering: DEM 1,1 Million (€ 0,56 Million)
Mounting: DEM 1,7 Million (€ 0,86 Million)
Maintenance (total estimated): DEM 30 000 € 15 300
Costs per kWp: DEM 15 700 (€ 8 000)

Process

The former mine site is to be converted into a park connected to the town centre to the south and extended to the north by the open green space.
To the north of this park leads to an urban square. This is bordered by the new extension to the existing shopping centre which will include a shopping mall. The car parking will be reorganised.
The park will be reached by a gently climbing stairway, enclosed on the east and west side by linear buildings. At the top of these stairs a large building is sited which contains the “academy”(education centre) and public buildings. This building will be a dominant landmark in the landscape. This, the heart of the project, is placed in the oval cleaning of the new park.
Besides, a specially chosen dry vegetation will give this area a particular character, corresponding to its situation. New pathways crossing the site will create a new public space on land which had previously been inaccessible. In the zone which is landscaped with trenches and embankments these pathways will be raised wooden walkways.
Building materials and building elements were selected on the same criteria of environmental protection as the overall objective of the building itself. This resulted in a limited range of materials, mainly timber, glass and concrete.
The timber elements of the structure make use of local wood sources. The main columns of the glass envelope structure consist of the trunks of 130 year old pine trees which were felled more than one year ahead of construction from a first less than 100km from the site.
The photovoltaic panels were also manufactured locally at Germany’s largest photovoltaic assembly plant 15 km from Herne.

Results

Rain water system.
Rainwater falling on the large expanse of roof is collected via a symphonic rainwater which minimizes pipe diameters.
The transparent and photovoltaic roof glazing elements are cleaned by an automatic cleaning system employing recycled rainwater.
Rainwater is collected in an underground storage cistern, filtered and also reused for watering and maintenance of plants within the glass house.
Rainwater slide down from surrounding down into the site and collected in the pool marked blue and then drain away from the site.
Climate Concern.
A detailed study of the climatic effects of the glass envelope has been carried out by the architects and engineers of this project in 1994. The education centre will be the first project to apply the results of this research.
The glass envelope creates a climatic shift. It creates a climate close to that of the Mediterranean.
In winter the interior temperatures are less severe, its users will be sheltered from rain and wind. The climatic conditions of the interior buildings is reduced. It is not necessary for the interior buildings is reduced. It is not necessary for the interior buildings to be completely watertight.
In summer, to avoid overheating, certain elements of the facade will be opened and the glasshouse will be ventilated. The vegetation and refreshing effects of the basin will cool the space. In order to cool the interior buildings, fresh air will be drawn in by tunnels from external zones.
Solar Power Station.
The glazed roof of the building incorporates 10.000m2 of photovoltaic modules providing 1MW Solar Power Generation Sattion.
Forming clouds patterns, the photovoltaic modules provide shading and protect from glare and direct solar radiation. The density of photovoltaic cells per panel vary from 58 to 86% and thus their energy production varies accordingly from 192-416Wp per panel. Solar panels are also incorporated into the west facade of the envelope.
600 inventers transform the DC current to AC current which can be fed back to the general grid. The energy generated is far in excess of what is required by the building itself (750.000Kwh).
Technical details:
Total roof area: ca12.600 m2
Photovoltaic area: ca. 8.400 m2
Standard photovoltaic roof panel: 116m x 278 m
Standard photovoltaic facade panel: 116m x 240 m
Number of roof panels: 2.802
Number of facade panels: 280
Electricial power of each panel: 192-416 Wp
Incline angle of roof panel: 5 degree
Incline angle of facade panel: 90 degree
Number of converters: ca.600
Total electrical power: 1 Mwp
Energy production: ca.750.000 kwh
Congeneration.
Beside the solar power generation station, a complex system using a number of environmentally friendly energy sources is erected.
The former mine pitheads on the site release more than one million cubic metres of gas per year containing 60% methane. This gas fuels two co-generation units, producing both electricity and heat.
The electricity is fed into the public power supply system. The heat is used for the academy, new surrounding housing and a near-by hospital.
Exploiting the mine gas will avoid the release of methan into the atmosphere, this will reduce the emission of CO2 by the amount of 12.000 tons per year.
A 1,2 MW battery plant stores the electricial power, balances fluctuations in AC energy production and reduces peak loads. All 3 projects together set up the energy park Mont-Cenis, pointing the way to an ecological generation of energy.
Technical details:
Compact thermic station – Mine gas
Mine gas capacity: ca. 1,000.000 m/a
Methane content: ca. 60%
Power (electricity): 506 kw
Power (heating): 756 kw
Energy (electricity): 2.000.000kwh/a
Energy (heating): 3.000.000 kwh/a
Reduction of CO2 emission: ca. 12.000 t/a
Battery Storage energy: 1.200 kwh
Battery Storage power: 1.200 kw

Critical Success Factors / Challenges

23% less energy than buildings with the same insulation standard – 18% less CO2 emissions – Electricity production: approx. 600.000 kWh /year.