ᐅ Roof Covering and Choosing a Solar Installer – Making the Decision?
Created on: 10 Aug 2022 18:21
E
Elias_dee
Hello everyone,
I am about to decide whether to hire a solar installer. I am building a turnkey single-family house with a general contractor in the 84xxx area, featuring a gable roof with a 25° pitch, oriented north/south. There are no skylights, chimney, or other obstructions on the roof, so conditions are optimal.
I am having some difficulty even requesting quotes and now have at least two offers. I would appreciate help evaluating and choosing between them (both the company and whether to include the north side). I have not asked for a battery system but might consider adding one later if it becomes more affordable.
So, first I am facing the question: include north side or not? I can fit about 25 modules on each side, resulting in roughly 10 kWp. PVGIS estimates around 10,000 kWh for south and about 7,000 kWh for north.
Offer 1 comes from a solar installer with many years of experience, who not only works on single-family houses but also builds large-scale systems in the megawatt range. My general contractor, who is building the house turnkey, also has long-standing experience with this installer and recommends them.
Offer 1 details:
- 20.5 kWp
- 50 x Q-Cells Q-Peak ML G10 410 heat pump compatible modules
- 50 x SolarEdge Power Optimizers, S440 Worldwide (v1)
- SolarEdge StorEdge three-phase inverters: SE10K-RWS-EU-APAC/AUS (v1) and SE7K-RWS-EU-APAC (v1)
- SolarEdge Smart Meter for self-consumption monitoring
- All other materials, installation, and commissioning services included
- Cost: €31,980 net, which equals approximately €1,560 net per kWp — reasonable for today, not really cheap but not very expensive either
Now to Offer 2. This offer is from a very small and new electrical company I found through a neighbor's recommendation. The company does not even have a finished website yet because it is so new, but they have already done electrical work in the development area (not sure about PV though). Two different neighbors have told me this company is good.
Offer 2 details:
- 20.9 kWp
- 51 x JinkoSolar Tiger NE HC N-Type black solar modules JKM410N-54HL4-B
- 2 x SMA inverters STP10.0-3SE-40
- 1 x SMA Sunny Home Manager HM-20
- Other materials are not specified here, but all installation, planning, and commissioning services are included
- Cost: €25,570 net, equaling approximately €1,223 net per kWp
My questions now:
- What do you generally think about the materials used?
- Are the SolarEdge power optimizers in Offer 1 really necessary? I expect practically no shading from trees, chimney, or anything else given the location
- Company 2 is probably a bit risky, but the price is really attractive. Is it worth taking the risk here?
- Does installing modules on the north side make sense at all in the case of Offer 1? If I calculate north and south separately, south obviously makes sense in both cases. North seems worthwhile (based on my calculation) only with Offer 2... with Offer 1 I would be running at a loss.
I would be very grateful for a brief assessment!
Best regards
I am about to decide whether to hire a solar installer. I am building a turnkey single-family house with a general contractor in the 84xxx area, featuring a gable roof with a 25° pitch, oriented north/south. There are no skylights, chimney, or other obstructions on the roof, so conditions are optimal.
I am having some difficulty even requesting quotes and now have at least two offers. I would appreciate help evaluating and choosing between them (both the company and whether to include the north side). I have not asked for a battery system but might consider adding one later if it becomes more affordable.
So, first I am facing the question: include north side or not? I can fit about 25 modules on each side, resulting in roughly 10 kWp. PVGIS estimates around 10,000 kWh for south and about 7,000 kWh for north.
Offer 1 comes from a solar installer with many years of experience, who not only works on single-family houses but also builds large-scale systems in the megawatt range. My general contractor, who is building the house turnkey, also has long-standing experience with this installer and recommends them.
Offer 1 details:
- 20.5 kWp
- 50 x Q-Cells Q-Peak ML G10 410 heat pump compatible modules
- 50 x SolarEdge Power Optimizers, S440 Worldwide (v1)
- SolarEdge StorEdge three-phase inverters: SE10K-RWS-EU-APAC/AUS (v1) and SE7K-RWS-EU-APAC (v1)
- SolarEdge Smart Meter for self-consumption monitoring
- All other materials, installation, and commissioning services included
- Cost: €31,980 net, which equals approximately €1,560 net per kWp — reasonable for today, not really cheap but not very expensive either
Now to Offer 2. This offer is from a very small and new electrical company I found through a neighbor's recommendation. The company does not even have a finished website yet because it is so new, but they have already done electrical work in the development area (not sure about PV though). Two different neighbors have told me this company is good.
Offer 2 details:
- 20.9 kWp
- 51 x JinkoSolar Tiger NE HC N-Type black solar modules JKM410N-54HL4-B
- 2 x SMA inverters STP10.0-3SE-40
- 1 x SMA Sunny Home Manager HM-20
- Other materials are not specified here, but all installation, planning, and commissioning services are included
- Cost: €25,570 net, equaling approximately €1,223 net per kWp
My questions now:
- What do you generally think about the materials used?
- Are the SolarEdge power optimizers in Offer 1 really necessary? I expect practically no shading from trees, chimney, or anything else given the location
- Company 2 is probably a bit risky, but the price is really attractive. Is it worth taking the risk here?
- Does installing modules on the north side make sense at all in the case of Offer 1? If I calculate north and south separately, south obviously makes sense in both cases. North seems worthwhile (based on my calculation) only with Offer 2... with Offer 1 I would be running at a loss.
I would be very grateful for a brief assessment!
Best regards
R
RotorMotor15 Aug 2022 17:12Elias_dee schrieb:
A different question. If everything is installed but the utility company has not yet completed the grid connection, can I still use my own electricity inside the house? I'm mainly thinking about the floor heating warm-up program... (this is a new build). It would probably be ideal if the air-to-water heat pump runs on photovoltaic power right away (even though in November/December there likely isn’t much solar output). Oh, you’re opening a much bigger can of worms than you might realize. 😉
This topic often causes major misunderstandings with electricians and utility providers.
Especially regarding feed-in tariffs, it has been a recurring issue.
To my knowledge, the utility provider’s approval is not required for the photovoltaic system’s commissioning (though many providers see it differently and it can lead to very difficult discussions).
Some even ask for payment for this...
It’s a different story with your main electrical connection.
Snowy36 schrieb:
Can someone explain to me how this is possible if this law exists? It seems to have been around a while, so shouldn’t new TVs and espresso machines be covered by it? You’re saying yourself that these are older devices.
Maybe the devices are simply on rather than in standby mode.
Another question is how you’re measuring, as some meters do not correctly measure real power consumption.
S
SaniererNRW12315 Aug 2022 17:16Snowy36 schrieb:
When I add everything up, the consumption becomes clear to me.No, the total for you so far is 2 kWh in standby per day. So you would need five times as many high-power devices. You are still far from 10 kWh per day.I’m clearly referring to the two new devices—the OLED and the portafilter espresso machine.
Please explain how to put a TV into standby mode other than turning it off until the little red light is on. A super-automatic coffee machine also only has one power button. What do you understand by standby? For example, a printer goes into standby automatically, I don’t have to press anything. It has a power on/off button on the side, but I don’t press it to ensure it uses zero power. So I also don’t toggle a switch on the TV—do you? And that old Samsung TV that’s at least 10 years old can do this too. I turn it off, and it uses only 0.x power.
Please explain how to put a TV into standby mode other than turning it off until the little red light is on. A super-automatic coffee machine also only has one power button. What do you understand by standby? For example, a printer goes into standby automatically, I don’t have to press anything. It has a power on/off button on the side, but I don’t press it to ensure it uses zero power. So I also don’t toggle a switch on the TV—do you? And that old Samsung TV that’s at least 10 years old can do this too. I turn it off, and it uses only 0.x power.
SaniererNRW123 schrieb:
No, your total standby consumption so far is 2 kWh per day. So you still need five times as many high-power devices. You are nowhere near 10 kWh per day yet. No, it’s 4 kWh in total. I still need 3 kWh more, including all the other devices that are there. Difference: 3 kWh that I am still looking for.
Snowy36 schrieb:
So, I’m not really sure what to make of your comments. I’ll leave that up to you.
RotorMotor schrieb:
And another question is how you are measuring, because some "meters" don’t measure real power accurately. Exactly, very few energy monitors costing around 10€ can do that…
R
RotorMotor15 Aug 2022 17:36Snowy36 schrieb:
The OLED and the portafilter machine.The OLED definitely does not need 40W in standby mode. As I said, it can sometimes use that much power right after being turned off or occasionally in between to refresh the OLED screens, but not continuously.
I can’t say what’s up with the portafilter machine.
You should ask the manufacturer or contact consumer protection.
But first, please check your measurement method. 😉