With more than 1,700 realised buildings, SolarActiveHouses are no longer a marginal phenomenon. What has been missing so far is a scientific evaluation of this heat supply concept. To this end, researchers have measured nine solar houses over several heating periods. The responsible project manager Gerhard Stryi-Hipp presented the interim results at the OTTI symposium "Thermal Solar Energy".
Read more in the BINE-Projektinfo from 13.05.2015
(BINE-Info was discontinued at the end of 2020)
Hamburg (8 July 2017). In Hamburg, 19 heads of government from the largest economies jointly reaffirmed their commitment to the swift implementation of the Paris Climate Agreement and rejected US President Trump's attempt to undermine the Paris Agreement.
According to the leaked results, the final declaration sets out the differences between the USA and the other 19 partners on climate protection. The 19 emphasise the irreversibility of the agreement, commit to rapid implementation and adopt a detailed climate and energy action plan. "The action plan is the most concrete result on climate policy that the G20 has ever produced," explains Christoph Bals, Political Director of Germanwatch. "It shows that it is no longer just about reaffirming the Paris Agreement, but about taking steps to implement it."
In the document, the 18 states plus the EU emphasise, among other things, the importance of long-term climate protection strategies, which are to be presented by 2020. They commit to aligning development aid and infrastructure investments with climate targets and specify steps that can be taken to encourage companies and investors to disclose their climate strategies. Bals: "We welcome the fact that the 19 partners are also recognising their responsibility for the poor and those particularly vulnerable to climate change and are launching a global partnership for financing and climate insurance solutions."
The US government's attempt to obtain a free pass for fossil fuel exports was curbed as the US accepted the UN's global Sustainable Development Goals as a framework for the energy transformation in the joint section of the G20. "This means they accept that the share of renewable energies will grow substantially by 2030 and that the pace of energy efficiency improvements will double," explains Bals.
Chancellor Merkel is criticised. She cannot "put the phase-out of coal, oil and gas on the international agenda by the middle of the century and refuse a plan at home for the rapid, socially acceptable phase-out of coal," emphasises Bals. "It cannot push ahead with plans to accelerate the international climate transition and at the same time have no strategy in Germany for the transport sector, which still has emissions as high today as they were in 1990."
Good news for the PV industry: The solar cap will be abolished and solar expansion will be further promoted. The photovoltaic potential in Germany is enormous - especially when it comes to using roof space on new buildings. The new LichtBlick SolarCheck now shows in detail how well the 14 largest German cities are currently exploiting this potential. Enormous differences are revealed: While Nuremberg (49.1%) and Hanover (46.8%) exploit almost half of their potential, Munich and Düsseldorf do not even reach the 10 percent hurdle. The absolute taillight: the Hanseatic city of Hamburg with only 7.2 percent - one more reason for the solar obligation for new buildings planned by the mayor's office.
To calculate the solar potential of the individual cities, the newly built roof areas were put in relation to the newly installed photovoltaic systems in the respective cities in 2018 (most recent figures). The result: the PV potential on roofs is barely exploited in most metropolitan regions in Germany. Yet every new roof without a solar installation is a wasted opportunity for climate protection and a consumer-oriented power supply. The vast majority of people in Germany want solar power from their roofs*.1
In view of the sobering results of the SolarCheck, Ralph Kampwirth, Head of Corporate Communications at LichtBlick, said: "We must finally bring the energy turnaround to the big cities - and the best way to do that is with solar power from the roof. Discussions about distance regulations for wind power or the use of agricultural land for PV plants show that the responsibility should not only lie with the rural population."
Converted to German households (average consumption 3,000 kWh), the possibilities of the individual cities become apparent: If Munich had fully exploited the potential of the new building roof areas, you could have supplied more than 10,000 households with solar power with the new solar areas built in 2018 alone, Hamburg around 11,500 households, in Berlin it would be 16,200 households." Especially in the megacities, only a small fraction of this is developed, as the SolarCheck shows.
About the research method: The market research company Statista determined the number of newly constructed residential and commercial buildings in 2018 for the 14 German cities with more than 500,000 inhabitants on the basis of data from the State Offices for Statistics and calculated the respective roof areas using scientifically based conversion factors.
Timber construction can be cheaper than standard construction - At the same time significantly better CO2 balance
MNP Architects Munich, School Wangen
Current comparative calculations based on realized new buildings in timber construction show: Building with wood does not have to be more expensive than the standard construction method. This result is surprising, as it contradicts the common perception that timber construction is more expensive. At the same time, the CO2 balance of timber construction is significantly better; as a result, its CO2 avoidance costs are very favourable, in some cases even negative. An expansion of timber construction would therefore be climate protection at comparatively low cost.
The architect and developer of the Legep construction software, Holger König, has balanced the construction costs and CO2 emissions for the production of five public and private timber buildings and compared them with the results that would have been produced for the same buildings if they had been built in the conventional way. Legep can be used to calculate the manufacturing and life-cycle costs, energy requirements and environmental impact of buildings. In this case, König only looked at manufacturing. For the prices, he used current sirAdos data, which represent the market very realistically. He then went to the trouble that many architects, civil engineers and building owners shy away from: He modeled the buildings with the same area and cubature and the same energy standard, but replaced the wooden components with conventional materials - depending on the building project, solid masonry in brick, sand-lime brick or aerated concrete, or a column-beam supporting structure made of reinforced concrete. He used reinforced concrete for the floor slab, cellar, ceilings and flat roofs, mineral wool or polystyrene for the insulation, and plastic or aluminum frames for the windows. König explains the fact that four out of five buildings in timber construction cost less or the same as in standard construction with the industrial-technical development that many timber construction companies have undergone in recent years. Two of the timber buildings even achieved a negative CO2 balance in the manufacturing phase due to the large amount of renewable raw materials used, which act as carbon stores. In the other three buildings, a slightly higher proportion of non-wooden components, which every timber building also contains, caused the slightly positive CO2 balance.
If one relates the difference in CO2 savings to the difference in construction costs, one obtains the CO2 avoidance costs of timber construction. Negative abatement costs here mean that the builder has saved costs with timber construction compared to standard construction and at the same time protected the climate.
By increasing the proportion of timber construction, more climate protection can be achieved at low or even negative costs, while at the same time strengthening rural areas. The green-red state government in Baden-Württemberg has recognised this and created more favourable framework conditions for the building material in its state building code, which was amended on 1 March (information here). In contrast, some state building codes still contain legal obstacles to building with wood.
The city of Munich also wants to convince more builders to use timber construction: as part of its "Munich Energy Saving Promotion Programme", it has been granting a CO2 bonus for the use of timber and other renewable raw materials in building construction of 30 cents/kg since 2013 (information here).
A high insulation standard with insulating materials made from renewable raw materials is also a contribution to climate protection. The plant raw materials from which the insulating materials were obtained have bound CO2 from the atmosphere, which is now stored in the building material for long periods of time. And finally, heating based on renewable energies also reduces CO2 emissions.
The Agency of Renewable Resources (Fachagentur Nachwachsende Rohstoffe e.V.). (FNR) funded the determination of LCA baseline data for the Legep programme with funds from the Federal Ministry of Food and Agriculture (BMEL) between 2004 and 2006.
Contractor: Joachim Eble Architecture, Rolf Messerschmidt, Tübingen
EGS-Plan engineering company for energy, building and solar technology mbH
IER Institute for Energy Economics and Rational Use of Energy, University of Stuttgart
Results: When analysing the total annual costs, the running costs and revenues in the utilisation phase are taken into account in addition to the capital-related investment costs. The result of this full cost calculation is a relatively homogeneous cost level for all building energy standards examined. Due to the subsidies for the better standards, lower energy costs and the use of subsidies, the cost level remains relatively constant among the building energy standards. Thus, higher building energy standards up to the "KfW 40 Plus Standard" are already economically attractive today.
The influence of building energy standards can be classified as subordinate when considering total consumer spending.
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With more than 1,700 realised buildings, SolarActiveHouses are no longer a marginal phenomenon. What has been missing so far is a scientific evaluation of this heat supply concept. To this end, researchers have measured nine solar houses over several heating periods. The responsible project manager Gerhard Stryi-Hipp presented the interim results at the OTTI symposium "Thermal Solar Energy".
Hamburg (8 July 2017). In Hamburg, 19 heads of government from the largest economies jointly reaffirmed their commitment to the swift implementation of the Paris Climate Agreement and rejected US President Trump's attempt to undermine the Paris Agreement.
