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Hitokiri-19784 Jul 2022 13:08Hello everyone,
We recently selected a building plot in a new development area during the allocation appointment in our home municipality near Munich. I won’t even start talking about the problems and frustrations this topic will continue to bring us for years to come—otherwise, I might as well do a dive off the 10-meter (33-foot) platform into an empty pool. So, let’s just leave it at that.
My main concern is the photovoltaic system that is supposed to be installed (with battery storage + heat pump) or on the (semi-detached house). I have to say that the development plan isn’t very well thought out and specifies a shed roof (mono-pitched roof) facing north-north-east for our house and the five other semi-detached houses on the side street. I have seen from various tables that a 12° (12°) roof pitch combined with a north orientation is quite poor for photovoltaic system yield. And if I am already investing a lot of money in such a system to make the heat pump pay off, it really should operate at maximum efficiency.
According to the municipality, which will discuss this in its building committee on Tuesday, it is not yet clear whether they will approve a 180° rotation of the roof orientation (then facing south-south-west). It is also uncertain whether this would be required only for the directly attached neighbor or for all six semi-detached houses in that row, due to the requirement for uniform profiles.
Two questions on this:
1. How do I find providers with a good price-performance ratio for photovoltaic systems (with or without storage? pros and cons)? I think there is hardly any other technical system about which I have less knowledge than photovoltaic systems. I know more about sewing machines and construction machinery, even though I neither sew nor dig deep holes. 😀
2. From a construction point of view, I see two possibilities:
a) Do nothing, which means I would have a photovoltaic roof system facing north. How much output can I expect from 0° flat-hung balcony panels or wall-mounted panels? It probably looks awful and what about the yield?
b) Rotate the roof by 180°, and raise it overall by about 50cm (20 inches), which would automatically exceed the maximum allowed height according to the development plan. The roof pitch would be flattened from 12° (12°) to 7° (7°) (so that rain can still provide self-cleaning) to prevent the sloping side from extending too far over the south-facing balcony below. The balcony forms the bay window for the first floor and ground floor.
I would like possible providers to calculate both scenarios, but how do I find reasonable, reliable, and capable photovoltaic system providers? Many thanks.
We recently selected a building plot in a new development area during the allocation appointment in our home municipality near Munich. I won’t even start talking about the problems and frustrations this topic will continue to bring us for years to come—otherwise, I might as well do a dive off the 10-meter (33-foot) platform into an empty pool. So, let’s just leave it at that.
My main concern is the photovoltaic system that is supposed to be installed (with battery storage + heat pump) or on the (semi-detached house). I have to say that the development plan isn’t very well thought out and specifies a shed roof (mono-pitched roof) facing north-north-east for our house and the five other semi-detached houses on the side street. I have seen from various tables that a 12° (12°) roof pitch combined with a north orientation is quite poor for photovoltaic system yield. And if I am already investing a lot of money in such a system to make the heat pump pay off, it really should operate at maximum efficiency.
According to the municipality, which will discuss this in its building committee on Tuesday, it is not yet clear whether they will approve a 180° rotation of the roof orientation (then facing south-south-west). It is also uncertain whether this would be required only for the directly attached neighbor or for all six semi-detached houses in that row, due to the requirement for uniform profiles.
Two questions on this:
1. How do I find providers with a good price-performance ratio for photovoltaic systems (with or without storage? pros and cons)? I think there is hardly any other technical system about which I have less knowledge than photovoltaic systems. I know more about sewing machines and construction machinery, even though I neither sew nor dig deep holes. 😀
2. From a construction point of view, I see two possibilities:
a) Do nothing, which means I would have a photovoltaic roof system facing north. How much output can I expect from 0° flat-hung balcony panels or wall-mounted panels? It probably looks awful and what about the yield?
b) Rotate the roof by 180°, and raise it overall by about 50cm (20 inches), which would automatically exceed the maximum allowed height according to the development plan. The roof pitch would be flattened from 12° (12°) to 7° (7°) (so that rain can still provide self-cleaning) to prevent the sloping side from extending too far over the south-facing balcony below. The balcony forms the bay window for the first floor and ground floor.
I would like possible providers to calculate both scenarios, but how do I find reasonable, reliable, and capable photovoltaic system providers? Many thanks.
1. In my opinion, such a development plan would not hold up against legal challenge. However, from a practical standpoint, this doesn’t help much since the process is lengthy and the outcome uncertain.
2. For that reason, I would simply mount the photovoltaic panels at about a 30° angle (unless that is also prohibited). This provides an acceptable tilt (which is commonly done on flat roofs, where 12° is not far off).
P.S. Many heat pumps also work without photovoltaic systems; with photovoltaics it’s just more enjoyable — if you can get a heat pump nowadays 😳
2. For that reason, I would simply mount the photovoltaic panels at about a 30° angle (unless that is also prohibited). This provides an acceptable tilt (which is commonly done on flat roofs, where 12° is not far off).
Hitokiri-1978 schrieb:That is a very good question, but unfortunately you will probably share the fate of many others currently searching for photovoltaic systems (unless you suddenly receive top recommendations from relatives or acquaintances). You have to contact or write to every supplier you find somewhere and wait weeks or even months for responses. Sort out the unreasonable offers (currently about 95%). Choose a supplier. Wait a year or longer for components and installation. Then, at some point, finally be happy and enjoy every day how efficiently the photovoltaic system runs.
...but how do I find reliable, reputable, and readily available photovoltaic system suppliers? Many thanks.
P.S. Many heat pumps also work without photovoltaic systems; with photovoltaics it’s just more enjoyable — if you can get a heat pump nowadays 😳
i_b_n_a_n schrieb:
2. I would simply tilt the photovoltaic panels by about 30° (unless this is also prohibited), which gives you an acceptable angle (we often do this on flat roofs; 12° is not far off). Mounting frames are usually installed on the south to southwest/southeast sides. On the north side, it’s better to keep the panels relatively flat if the roof orientation remains the same. (I mean this to allow more sunlight exposure from east and west). A quick online search will also quickly provide relevant statistics.
Do you have any requirements to install the system along with the construction? Or is this more of a hobby for you?
A north-facing roof would work too, but you would need more panels to achieve a similar output. South-facing is better, of course.
The costs for a system of this size are roughly 800-1000 euros per kWp (kilowatt peak), plus 5,000-6,000 euros for the inverter, electrician, scaffolding, and miscellaneous expenses, plus the battery if desired. You should be able to get reliable offers in this range currently. These are net prices.
Are you building the semi-detached house with a developer? Then ask the roofer if they would install the mounts and panels on the roof for you. Just installation. You can connect them to each other up to the edge of the roof yourself. That way, you’ve already completed the most complicated part, and the scaffolding would already be in place.
You can have an electrician install a conduit from the roof to the utility room (HAR) and ask them if they would also handle the inverter and system connection. Otherwise, check with a solar specialist if they would take care of this part in the utility room. They wouldn’t be involved in the planning or installation of panels on the roof, which increases the chance of getting a quick appointment that can be fitted in easily.
There are also online forums dedicated to photovoltaics (which cannot be named here) where you can get help with planning and panel selection.
A north-facing roof would work too, but you would need more panels to achieve a similar output. South-facing is better, of course.
The costs for a system of this size are roughly 800-1000 euros per kWp (kilowatt peak), plus 5,000-6,000 euros for the inverter, electrician, scaffolding, and miscellaneous expenses, plus the battery if desired. You should be able to get reliable offers in this range currently. These are net prices.
Are you building the semi-detached house with a developer? Then ask the roofer if they would install the mounts and panels on the roof for you. Just installation. You can connect them to each other up to the edge of the roof yourself. That way, you’ve already completed the most complicated part, and the scaffolding would already be in place.
You can have an electrician install a conduit from the roof to the utility room (HAR) and ask them if they would also handle the inverter and system connection. Otherwise, check with a solar specialist if they would take care of this part in the utility room. They wouldn’t be involved in the planning or installation of panels on the roof, which increases the chance of getting a quick appointment that can be fitted in easily.
There are also online forums dedicated to photovoltaics (which cannot be named here) where you can get help with planning and panel selection.
Ysop*** schrieb:
Is battery storage mandatory for you? Otherwise, I would reconsider that. We will have one, but economically it's quite an expensive matter ;-) Exactly: first, fill the roof with as many solar panels as possible — and if there is still money left, get a small battery (typically 5 kWh) to cover the night and some cloudy periods. More rarely pays off, and a larger solar array allows the heat pump to run longer throughout the year using solar power. On the other hand, the heat pump won’t run on battery power!
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