ᐅ Roof Covering and Choosing a Solar Installer – Making the Decision?
Created on: 10 Aug 2022 18:21
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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
E
Elias_dee27 Mar 2023 12:24Bookstar87 schrieb:
I just calculated it with an electricity price of 35 cents. My system breaks even after 9.8 years, with yours it would be 14 years. Both are decent figures, but proper design plus a battery is key.
Emergency power backup is a personal choice, but in these crazy times, in my opinion, it’s a must-have. Ok, thanks for the feedback. Have you also done the calculation with and without energy storage? I’d be interested to see the difference.
PS: Yes, these are crazy times, but at least for us, there hasn’t been a power outage since the war started.
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Bausparfuchs27 Mar 2023 13:44Of course, that’s possible.
I installed a Huawei system. It includes a backup box that takes over within milliseconds during a power outage and simulates an existing grid for the inverter. It can then either use photovoltaic power or power from the storage.
This works perfectly even without mains electricity. It is therefore black start capable.
I installed a Huawei system. It includes a backup box that takes over within milliseconds during a power outage and simulates an existing grid for the inverter. It can then either use photovoltaic power or power from the storage.
This works perfectly even without mains electricity. It is therefore black start capable.
Bausparfuchs schrieb:
Of course it’s possible.
I installed a Huawei system. It includes a backup unit that kicks in within milliseconds during a power outage and simulates an existing grid for the inverter. The system then runs either on photovoltaic power or energy from the battery storage.
This works perfectly even without grid power. So it is black start capable. Do you ever listen to yourself? In this case, your system is black start capable. Most inverters, including yours, cannot do this without an additional backup unit. Saying “of course it’s possible” is, as often with you, a statement to take with caution because it is not accurate in such a general way. If you want an emergency power function for longer grid outages, you need to pay close attention to these details.
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Bookstar8727 Mar 2023 20:58Well, my Fronius Gen24 also supports black start capability without any additional installation.
Without a battery, I estimate about 12 years. If you have an electric vehicle, you can of course also use its battery to increase self-consumption.
Without a battery, I estimate about 12 years. If you have an electric vehicle, you can of course also use its battery to increase self-consumption.
Actually, black start means that the device can restart without a battery. Otherwise, the battery would be drained after 1-3 days. The Symo GEN24 cannot do this either, at least I researched extensively last year and couldn’t find this function anywhere. However, I am happy to be proven wrong.
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