Expensive plus energy house with great "plus" | enbausa.de

What do you get if you put everything in a massively built single -family house that is available in energy technology today?- a fairly expensive plus energy house with a fairly large "plus".So one could summarize the result of the final report for a project in the Upper Bavarian Burghausen.

According to the plans of Sonnenhaus alter Georg Dasch, the brick company Schlagmann and the Baywa construction and energy group built a classic KfW efficiency house 40 with expanded gable roof and had been measured by the TH Deggendorf for two years from February 2014, funded by the Federal Ministry.

The brick walls are filled with the volcanic insulation material, allow a U-value of 0.14 W/m²K and enclose a heated living space of 176 m².A heat pump works in the basement.Unusual: the large hot water tank, which, with its 48 cubic meters, takes around a third of the basement alone and above all supplies the underfloor heating with heat - but also drinking water tapping points, flushing and washing machine and the dryer.

A lithium iron phosphate battery is also installed, which is designed as a daily memory with 10.8 kWh capacity.103 m² of photovoltaic modules are laid on the roof of the house and garage, plus 51 m² thermal solar collectors.There is also component activation and a ventilation device with heat recovery in each room.What the house cannot absorb the house goes into a partial electric car or the public network.

Final energy surplus in electricity and heat

From the data of the final report, the average of both measurements can be calculated that 31 each.047 kilowatt hours (kWh) produces heat and electricity, but only 19.269 kWh were used up.Over the entire time, the final energy surplus was 61 percent - corresponding to 66.9 kWh/m².About twice as much energy came from the solar collectors as from the solar modules.A surplus was also reached separately after electricity and heat;also related to primary energy.

Nevertheless, due to the unequal of production and consumption, only a solar heating of 94 percent was achieved in the second year, with the current of 61 percent (self -consumption).In July 2015 almost 1.057 kWh of electricity can be fed into the network;Nevertheless, even this month with the highest photovoltaic yield (1.528 kWh) almost 15 kWh can be obtained from the network.In February 2015, when the heat pump needed over 378 kWh of electricity, the solar modules still delivered 434 kWh - but apparently not always on the days when they were needed: additional 597 kWh had to be removed from the network.

High additional costs for extensive equipment

The house cost around 850.000 euros.This is hardly more than the most expensive of the prefabricated houses in the efficiency house plus program, building in wooden frame construction.However, if you pull the additional costs towards a house that receives the electricity from the network and is heated with a gas boiler, the abundance of the additional equipment is noticeable.The final report estimates the difference in the investment with almost 102.000 euros, also 580 Euro/m².In contrast, the additional costs for the nine other single-family houses of the Efficiency House Plus program were only between 230 and 325 euros/m².

The additional costs at a prefabricated house of Elbe-Haus in Brieselang near Berlin, which is most comparable to its solid construction (aerated concrete stone) and photovoltaic plus solar thermal system, were 378 euros/m².Of course, the Endergie-Plus at the building in Burghausen with 66.9 kWh/m² is more than the factor of 6 higher than that in Brieselang, where only a balance of 10.8 kWh/m² was achieved.Half of the fairness, it should also be mentioned that the memory battery in Burghausen alone is 22.000 euros gekostet hat - ein Betrag, der inzwischen wesentlich niedriger wäre.

More warmth than usable

If you go through the thermal monthly balance sheets, it becomes clear that thermally there is also a lot of energy at the wrong time.Especially in July and August, the solar collectors provide so much warmth that the memory can no longer absorb them despite its remarkable size.In the course of 2015, the amount of heat that had to be released back to the surroundings over the roof added to 3.488 kWh.

The fact that the house is designed for four people is caused by frowning.Three people not only need significantly less electricity and hot water, but also less heating energy in doubt.On request, Raphaela Pagany, one of the three report authors of the TH Deggendorf, stated: "The consideration of the consumption per person was not part of the funding project."A correction factor is superfluous.The second children's room was used as an office by the tenant."He worked full -time there and the room as well as the other rooms heated."

In the appendix to the report, however, monthly funds for the room temperature are documented for the measurement year 2015/16, which fall below 20 ° C in three months.In addition, the report says: "Likewise, the consumption of the office (lighting and electrical appliances) does not flow into the evaluation, since it is used by the tenant only for professional purposes full -time."Sabine Heinrich-Renz, responsible for press work, noted that in other houses of the Efficiency House Plus program, only couples would have lived.Apparently it cannot hurt to focus more on "understaffed" test houses in the future.By Alexander Morhart