ᐅ Operating a heat pump independently with a photovoltaic system.
Created on: 18 Dec 2015 19:51
I
Inotsara
Is there a photovoltaic expert here? Preferably an engineer specializing in this field? I am an electrician myself but have not yet had any practical experience with photovoltaic systems. So far, I only know about them theoretically and am very enthusiastic. I want to dive deeper into this topic and prepare myself for practical work. Recently, I have been looking into inverters and especially battery storage. The more I read, the bigger the gap I feel needs to be filled.
Currently, I am working on a project involving my parents' air-to-water heat pump. It’s a newly built house with two living units. The combined electricity consumption of both units is about 2200 kWh. Additionally, the pump consumes approximately 6600 kWh per year. Naively, I assumed my parents could invest around 25,000€ in a 9 kWp photovoltaic system and achieve a self-sufficient setup with very low electricity costs (about 30€ per month instead of 180€).
But that’s not the case. Firstly, a single-phase storage system is not an option because, due to the technology and grid regulations, the pump relies on the other two phases and will ALWAYS draw power from the grid. Even with a three-phase battery storage system, this problem would only be theoretically circumvented but not completely solved. Especially in winter, the pump runs at 80%-100% capacity while a photovoltaic system generates only about 30%-35% of its output in winter. In summer, the situation is almost exactly the opposite. This means we would underproduce in winter and overproduce in summer. On top of that, a three-phase battery system costs twice as much, and the number of manufacturers offering this option is very limited.
So, my question to the real experts: Should I just discard the idea of making the heat pump fully independent, or have I missed something?
I have gained a lot of knowledge in recent days through phone conversations with an engineer who is also a salesperson. However, I feel a bit uncomfortable bothering him further. He has already explained a lot to me. Also, information in written form is always better because you can look things up repeatedly and add to your knowledge. Therefore, it would be great if we could share our knowledge here together =)
Currently, I am working on a project involving my parents' air-to-water heat pump. It’s a newly built house with two living units. The combined electricity consumption of both units is about 2200 kWh. Additionally, the pump consumes approximately 6600 kWh per year. Naively, I assumed my parents could invest around 25,000€ in a 9 kWp photovoltaic system and achieve a self-sufficient setup with very low electricity costs (about 30€ per month instead of 180€).
But that’s not the case. Firstly, a single-phase storage system is not an option because, due to the technology and grid regulations, the pump relies on the other two phases and will ALWAYS draw power from the grid. Even with a three-phase battery storage system, this problem would only be theoretically circumvented but not completely solved. Especially in winter, the pump runs at 80%-100% capacity while a photovoltaic system generates only about 30%-35% of its output in winter. In summer, the situation is almost exactly the opposite. This means we would underproduce in winter and overproduce in summer. On top of that, a three-phase battery system costs twice as much, and the number of manufacturers offering this option is very limited.
So, my question to the real experts: Should I just discard the idea of making the heat pump fully independent, or have I missed something?
I have gained a lot of knowledge in recent days through phone conversations with an engineer who is also a salesperson. However, I feel a bit uncomfortable bothering him further. He has already explained a lot to me. Also, information in written form is always better because you can look things up repeatedly and add to your knowledge. Therefore, it would be great if we could share our knowledge here together =)
toxicmolotow schrieb:
In the end, the question in X years will be: How much do I have to pay monthly for heating energy?
It doesn’t matter whether it’s 100 euros for electricity or 100 euros for gas, wood, or whatever. Exactly. It’s better to build as efficiently as possible with a photovoltaic system and live off your own electricity. That is significantly cheaper than 100€ per month.
T
toxicmolotof9 May 2016 16:18I haven’t read the entire thread, but operating a heat pump solely with photovoltaic power (off-grid) is quite experimental. Collector, buffer storage, and heat pump all need to be generously sized for winter to make it even remotely practical. And then you are far from being economical.
toxicmolotow schrieb:
I haven’t read the entire thread, but running a heat pump solely on photovoltaic power (off-grid) is quite experimental. The solar collector, buffer tank, and heat pump all need to be generously sized for winter to even come close to working properly. And then you’re far from being cost-effective. Not necessarily off-grid. It depends on your budget. But on average, €240 (approximately $260) in electricity costs per year is better than €200 (approximately $215) in two months.
T
toxicmolotof9 May 2016 16:37And what does this system cost monthly? How about taxes?
In the end, it doesn’t get cheaper, but it also doesn’t get more expensive. Initially (without storage), it’s basically a matter of paying out of one pocket and into the other... And after 10-14 years, we can then talk about it being "worth it."
In the end, it doesn’t get cheaper, but it also doesn’t get more expensive. Initially (without storage), it’s basically a matter of paying out of one pocket and into the other... And after 10-14 years, we can then talk about it being "worth it."
toxicmolotow schrieb:
And what is the monthly cost of this system? How about taxes?
In the end, it’s not cheaper, but also not more expensive. (Without storage) it’s basically just moving money from one pocket to another... And after 10 to 14 years, we can start talking about it being “worth it.”But it definitely is worth it. Many people overlook factors like rising electricity prices, etc. I have spent a long time researching the storage systems available on the market and have calculated all the costs thoroughly. I will put this together soon and share the link here. It is more worthwhile now than ever before...T
toxicmolotof9 May 2016 18:32Then get ready...
I predict that electricity costs with storage (all in) will currently be around 35-40 cents per kilowatt-hour.
As long as these prices are not consistently undercut by grid power, you will be paying that.
I predict that electricity costs with storage (all in) will currently be around 35-40 cents per kilowatt-hour.
As long as these prices are not consistently undercut by grid power, you will be paying that.
Similar topics