ᐅ Issues with the installation alignment of our planned solar power system
Created on: 1 Feb 2018 21:10
L
Lobster
Good evening,
Our building permit / planning permission has already been approved, and the final planning is underway.
Now we have a problem with the solar system for domestic hot water.
The roof ridge runs almost exactly from north to south. This means we only have space on the east and west sides of the roof. The energy consultant ran the calculations and concluded that neither side provides enough capacity to meet all requirements.
Simply rotating the house is not an option, and of course, we had a reason for placing it as we did. However, we did not anticipate these issues.
One initial idea was to install the system on the carport roof at home. However, this is not directly attached to the house, so a distance of about 6–10 meters (20–33 feet) would need to be bridged to the utility room.
Does anyone have experience or ideas? We would really appreciate it.
Our building permit / planning permission has already been approved, and the final planning is underway.
Now we have a problem with the solar system for domestic hot water.
The roof ridge runs almost exactly from north to south. This means we only have space on the east and west sides of the roof. The energy consultant ran the calculations and concluded that neither side provides enough capacity to meet all requirements.
Simply rotating the house is not an option, and of course, we had a reason for placing it as we did. However, we did not anticipate these issues.
One initial idea was to install the system on the carport roof at home. However, this is not directly attached to the house, so a distance of about 6–10 meters (20–33 feet) would need to be bridged to the utility room.
Does anyone have experience or ideas? We would really appreciate it.
Mastermind1 schrieb:
Unfortunately, solar thermal systems are often sold by developers at a certain price and technically poorly installed... You notice this when the appropriate protective measures don’t work during summer when there is too much hot water, or the circulation is so poor that the pipes are stressed to their limit... In the end, the system breaks down after just a few years (it barely survives the warranty period). Then it becomes a money pit.Speculations...
Mastermind1 schrieb:
I’m just assuming there’s no heating load calculation either, since the heating system (gas/oil) is massively oversized. Comment on that: we always install those...You’re most likely on the wrong track there...
Mastermind1 schrieb:
P.S. a domestic hot water heat pump also works without photovoltaic panels. But photovoltaic is even more suitable in this case.Why? Because it will end up being a money pit just like the solar thermal system?
Mastermind1 schrieb:
By the way, photovoltaic pays for itself.Hmm, sure...
Mastermind1 schrieb:
With solar thermal, I save a bit on hot water costs for the regular heating system.Yes, for about half the year, and on sunny days the tank can reach up to 70°C (158°F), which even allows you to “heat” the pool at no extra cost if needed.
Mastermind1 schrieb:
With photovoltaic, I save electricity and even get paid for any surplus... But: there’s some paperwork involved (tax office/distribution network operator...)You do have to invest much more money upfront for it to be worthwhile—or at least to break even after a couple of decades.
Mastermind1 schrieb:
I’d be interested in the costs for solar thermal.They are generally at a similar level as the cost of a domestic hot water heat pump—so roughly 1500–2000.
Installation usually takes about 3–4 hours with 2 technicians.
You see... regardless of which backup system you choose to meet the requirements, the costs for solar thermal or a domestic hot water heat pump are the same. But with solar thermal, you get hot water when the sun shines without extra costs.
With a heat pump, you either need grid electricity or an additional photovoltaic system on the roof, which adds more cost and effort (second meter, business registration, etc.).
M
Mastermind13 Feb 2018 09:56Mycraft schrieb:
Speculation...
You’re most likely on the wrong track...
Why? Because it will end up being just as much of a money pit as solar thermal (ST)?
Hmm, yes, exactly...
Yes, roughly half the year, and on sunny days, temperatures in the storage tank can reach up to 70°C (158°F), allowing you to use it to "free" heat the pool if needed.
However, you have to invest much more for it to be worthwhile or at least break even after a few decades.
Costs are generally at the same level as those for a domestic hot water heat pump, so around 1500-2000.
Installation typically takes about 3-4 hours with 2 workers.
You see... regardless of which system you choose to meet the requirements, the costs for solar thermal or a domestic hot water heat pump are about the same. The advantage of solar thermal is that you get hot water during sunny days without extra costs.
With a heat pump, you either need electricity from the grid or an additional photovoltaic system on the roof, which involves extra costs and effort (separate meter, business registration, etc.). I find it very unlikely that a developer has your best interests at heart. Ultimately, they purchase services as cheaply as possible to secure their margin, and on top of that, they have to factor in a certain percentage for warranty coverage. In the end, everyone has to decide what suits them best.
A photovoltaic system still makes financial sense.
You just need to compare quotes (as with many things). When you reach a net price in the range of 1100-1250€ per kWp, such a system pays off by about 7-8 years with a 30% subsidy. After 5 years, you can switch to the so-called small business regulation with the tax office, meaning your self-consumption is no longer subject to tax.
Contrary to common myths.
I’ve had a photovoltaic system for 1.5 years. A neighbor is now installing one as well. In our residential area, many people have added them in the last 5 years, and recently there are again some who installed them during new construction.
P.S. The first neighbor is removing his solar thermal system (tube variant) after almost 7 years. Warranty expired, tubes leaking, spare parts no longer available (manufacturer bankrupt), alternatives only if the entire modules are replaced...
What’s going on the roof now? A photovoltaic system.
From a purely technical perspective, it is still possible to install one collector each on the east and west roof, switching between them with a diverter valve on the return line. However, based on 25 years of professional experience in this field, I can tell you that such small solar thermal systems rarely pay off and are mostly useful for meeting requirements or for peace of mind. They can save a few operating hours of the main heat generator from May to September, which slightly extends its lifespan. Overall, in my opinion, if financially feasible in the long term, a photovoltaic system combined with a domestic hot water heat pump would be a better solution.
@Mastermind1
No one doubts that it works for you. However, this helps the original poster very little, especially with east/west orientation. What is implied between the lines is: How can I meet the energy saving regulations with the least possible time, money, and planning effort?
And the answer is definitely not to add more unnecessary technology inside or on the house. Rather, it is to slightly enlarge the planned system or simply have it recalculated.
No one doubts that it works for you. However, this helps the original poster very little, especially with east/west orientation. What is implied between the lines is: How can I meet the energy saving regulations with the least possible time, money, and planning effort?
And the answer is definitely not to add more unnecessary technology inside or on the house. Rather, it is to slightly enlarge the planned system or simply have it recalculated.
Although this deviates somewhat from the main issue, I find the discussion that has developed very interesting. Even if it may be unclear to some, I will briefly share our side of the story.
My wife and I both work in business-related fields, so we are completely unrelated to the construction industry and, being under 30, have very little private experience in these areas. Our parents built their houses more than 20 years ago, so that doesn’t help much either. This means the whole subject is completely unfamiliar to us.
For this reason, last year we consulted 5-6 selected construction companies. The offerings ranged from complete solutions including photovoltaic systems, heat pumps, controlled residential ventilation with heat recovery, various KFW packages, and so on. We decided on the developer with the best recommendations from our circle, where we can get everything but are not obliged to accept everything. The companies for the trades they don’t do themselves (electrical, heating, windows) all come from the local area and are well known.
I like to engage with certain topics and, out of personal interest, I also like to get other opinions—such as here in this forum. What I definitely do not assume is that I become an expert in each respective area afterward, nor do I have to. I just want to make my decisions to the best of my knowledge. In the end, it is also the construction company’s job to guide me or us in the right direction. I chose a different profession, which I do well, but housebuilding is not part of it, so I have to rely partly on those who do it every day.
If I didn’t trust the builder and thought it was only about “the simple solution with the highest profit margin,” then I would have already made a mistake in the initial selection. For example, the chosen company has no catalogs or website and relies entirely on recommendations—they have a lot to lose with us and will be very mindful of that.
In the end, we decided on an option that is probably very straightforward to many of you: a gas condensing boiler and underfloor heating. Plus good windows with a 0.6 UG value, properly insulated slab and facade, and the described solar system to support hot water. The selected components are nothing special but proven and of high quality within their respective fields.
Besides the fact that we tend to think more conventionally and some of the modern technologies did not convince us, the budget certainly played a role. There may be people who pay off half a million euros with 1% repayment and don’t worry about everything around it. We are far from that and feel very comfortable with our decision.
Now small issues like this orientation problem arise, which we will solve. I’m grateful for the suggestion that the planned system might be expandable in area to meet the requirements. Early next week, the builder will present his solutions—we are looking forward to it and may have some ideas to incorporate by then.
I will gladly report back on the results 🙂
My wife and I both work in business-related fields, so we are completely unrelated to the construction industry and, being under 30, have very little private experience in these areas. Our parents built their houses more than 20 years ago, so that doesn’t help much either. This means the whole subject is completely unfamiliar to us.
For this reason, last year we consulted 5-6 selected construction companies. The offerings ranged from complete solutions including photovoltaic systems, heat pumps, controlled residential ventilation with heat recovery, various KFW packages, and so on. We decided on the developer with the best recommendations from our circle, where we can get everything but are not obliged to accept everything. The companies for the trades they don’t do themselves (electrical, heating, windows) all come from the local area and are well known.
I like to engage with certain topics and, out of personal interest, I also like to get other opinions—such as here in this forum. What I definitely do not assume is that I become an expert in each respective area afterward, nor do I have to. I just want to make my decisions to the best of my knowledge. In the end, it is also the construction company’s job to guide me or us in the right direction. I chose a different profession, which I do well, but housebuilding is not part of it, so I have to rely partly on those who do it every day.
If I didn’t trust the builder and thought it was only about “the simple solution with the highest profit margin,” then I would have already made a mistake in the initial selection. For example, the chosen company has no catalogs or website and relies entirely on recommendations—they have a lot to lose with us and will be very mindful of that.
In the end, we decided on an option that is probably very straightforward to many of you: a gas condensing boiler and underfloor heating. Plus good windows with a 0.6 UG value, properly insulated slab and facade, and the described solar system to support hot water. The selected components are nothing special but proven and of high quality within their respective fields.
Besides the fact that we tend to think more conventionally and some of the modern technologies did not convince us, the budget certainly played a role. There may be people who pay off half a million euros with 1% repayment and don’t worry about everything around it. We are far from that and feel very comfortable with our decision.
Now small issues like this orientation problem arise, which we will solve. I’m grateful for the suggestion that the planned system might be expandable in area to meet the requirements. Early next week, the builder will present his solutions—we are looking forward to it and may have some ideas to incorporate by then.
I will gladly report back on the results 🙂
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