astra with photovoltaics

Everyone planning to build a new house or to renovate an old one has to opt for a heating system. There is a multitude of different possibilities. In terms of investment and operation costs, the astra natural stone heating in combination with a photovoltaic installation is an advantageous alternative to other heating systems.  
The energy generated by the photovoltaic installation is not only used for the heating but also for the household electricity. Thus, when looking at the energy costs, the total energy demand has to be taken into account that means energy for household electricity, heating and warm water.
In the following example we have calculated the investment and operation costs of an astra natural stone heating combined with a photovoltaic installation.
The calculation is based on a newly built family home with 146 sqm of heated surface.

trenner

Investment costs

All prices including 19% VAT

astra natural stone heating, including installation,
ready to use
10.700 €
Warm water, 300 l stand-alone water tank,
ready to use
2.000 €
Photovoltaic installation, 5.35 kWp, ready to use 10.000 €
Total 22.700 €

 

Looking at the investment costs of an astra natural stone heating, they will be approximately 4,000 to 6,000 € lower than with a ready to use heat pump. In order to measure up to the investment costs of a heat pump, it would be possible to install in addition an energy storage device.


Our calculation of the total energy costs for a newly built family home with 146 sqm of heated surface is based on the following values:

Average heat requirement 50 W/sqm
Total heat requirement 7.28 kW
Annual energy requirement for heating and warm water 8,760 kW/h
Annual energy requirement for household electricity 3,500 kW/h
Costs per kW/h for heating electricity (special rate HT/NT) 0.20 € incl. VAT
Costs per kW/h for household electricity 0.26 € inkl. VAT
Buyback price per kW/h 0.124 € incl. VAT

Consumption costs

Electricity gene-
rated per day by PV installation kW/h

Electricity generated
per month kW/h

Requirement heating, warm water and
household electricity
per month kW/h

Covered by PV installation
per month in %

Electricity costs per month
with PV installation

Electricity costs
per month without PV installation

January  4.16  129  1,757  7  %   342 €  396 €
February  8.82  247  1,758  14 %   317 €  396 €
March  14.39  446  1,241  36 %   170 €  266 €
April  20.83  625  892  70 %   59 €  196 €
Mai  21.48  666  741  90 %   17 €  166 €
June  23.40  702  292 Überschuss  -51 €  76  €
July  21.71  673  292 Überschuss  -47 €  76  €
August  19.16  594  552 Überschuss  -5 €  128 €
September  15.80  474  741  64 %   60 €  166 €
Oktober  9.90  307  991  31 %   149 €  216 €
November  5.17  155  1,241  12 %   234 €  266 €
December  3.32  103  1,758  6  %   347 €  369 €
Per year    5,121 kW/h
 12,256 kW/h
    1,592 €  2,663 €

trenner
Conclusion

 

With a 5.35 kW/p photovoltaic installation it is possible to save approximately 40 % of the annual energy costs. An additional energy storage device or a bigger PV installation will even increase the savings.
Comparing the annual energy costs of 1,600 € for household electricity, heating and warm water as well as the low additional costs (operating costs) with other heating systems and acting on a 20 years run-time, the astra natural stone heating system combined with a PV installation is one of the most advantageous, future-oriented and healthiest heating systems on the market.