As part of our new build, we plan to install a photovoltaic system on the roof. The roof area is approximately 160sqm (1,720 sq ft), with a pitch of 25 degrees, a gable roof with one side facing northeast and the other southwest. Since we are both civil servants and income from photovoltaic systems requires approval and may later be counted towards our pension, feed-in is not an option for us.
The system is intended solely to reduce our electricity consumption. We will have a ground-source heat pump with a borehole, a 300l (80 gallons) hot water storage tank, and a ventilation system for heating. The house is designed to meet KFW 55 standard (higher efficiency is no longer possible due to the basement).
Since I am home starting at midday, appliances such as the washing machine, dryer, dishwasher, and others will mainly be used during the day.
Additionally, we live in an area with above-average sunshine and fewer cloudy days, even in winter.
We do not want a battery storage system yet, even though this means we will occasionally export surplus electricity. Once batteries become more affordable, we plan to add one later.
How should the system be sized for our needs?
The system is intended solely to reduce our electricity consumption. We will have a ground-source heat pump with a borehole, a 300l (80 gallons) hot water storage tank, and a ventilation system for heating. The house is designed to meet KFW 55 standard (higher efficiency is no longer possible due to the basement).
Since I am home starting at midday, appliances such as the washing machine, dryer, dishwasher, and others will mainly be used during the day.
Additionally, we live in an area with above-average sunshine and fewer cloudy days, even in winter.
We do not want a battery storage system yet, even though this means we will occasionally export surplus electricity. Once batteries become more affordable, we plan to add one later.
How should the system be sized for our needs?
T
toxicmolotof2 Mar 2017 21:30Are you referring to our roof, Alex85? No, we are not getting a flat roof and have a roof pitch of 25 degrees. The roof orientation cannot be changed due to the building regulations. It wouldn’t make sense for our house either.
PVGIS provides an annual value of 927 per kWp for the southwest side and 736 for the northeast side at our address.
PVGIS provides an annual value of 927 per kWp for the southwest side and 736 for the northeast side at our address.
ehaefner schrieb:
Are you referring to our roof, Alex85?No, I meant toxicmolotow
T
toxicmolotof4 Mar 2017 12:49@Alex85
Even though many sellers claim that east-west orientation is the latest trend, it doesn’t make any mathematical sense for a flat roof on a single-family house with a system size below 10 kWp, unless you want or need to use every square centimeter.
Even though many sellers claim that east-west orientation is the latest trend, it doesn’t make any mathematical sense for a flat roof on a single-family house with a system size below 10 kWp, unless you want or need to use every square centimeter.
@toxicmolotow
Okay, so you decided against it consciously? On a flat roof, you usually have the option.
The idea is to compensate for the lower yield from east/west orientation by increasing self-consumption. But, of course, this always relies on assumptions that it will actually be worthwhile.
Okay, so you decided against it consciously? On a flat roof, you usually have the option.
The idea is to compensate for the lower yield from east/west orientation by increasing self-consumption. But, of course, this always relies on assumptions that it will actually be worthwhile.
Similar topics