Hello from North of Europe

[Joukahainen]

Greetings from the wild north. Well, actually there is nothing wild here because I live in a suburb in the south of Finland. I have a small detached house and an 8 kW geothermal heating system (Nibe F1255). The geothermal well is 180 m deep. The geothermal well is also used to cool the house with a ducted radiator in the ventilation duct. The cooling is controlled by a Simene RLU200 series controller. The energy consumption for heating is 3000 kWh/year. The electricity consumption is about 7000 kWh/year. I am a plumber by profession but an engineer by education.

Since the price of electricity has risen dramatically I am thinking about installing solar panels. I am most interested in microinverters because they have Rapid Shut Down. Microinverters are not very popular in Europe, especially in Finland. So I thought I would ask here for a different opinion on solar power plants.

Microinverters European market share in 2028

Micro-inverter Market Size & Share | Growth Trends 2028

The micro-inverter market size surpassed USD 1.54 billion in 2021 and is projected to grow at a CAGR of over 9.8% between 2022 and 2028, driven by surging need for clean & sustainable energy on account of rising concerns regarding destructive GHG emissions.

www.gminsights.com

 

[houseofancients]

Greetings from the wild north. Well, actually there is nothing wild here because I live in a suburb in the south of Finland. I have a small detached house and an 8 kW geothermal heating system (Nibe F1255). The geothermal well is 180 m deep. The geothermal well is also used to cool the house with a ducted radiator in the ventilation duct. The cooling is controlled by a Simene RLU200 series controller. The energy consumption for heating is 3000 kWh/year. The electricity consumption is about 7000 kWh/year. I am a plumber by profession but an engineer by education.

Since the price of electricity has risen dramatically I am thinking about installing solar panels. I am most interested in microinverters because they have Rapid Shut Down. Microinverters are not very popular in Europe, especially in Finland. So I thought I would ask here for a different opinion on solar power plants.

Greetings from the wild north. Well, actually there is nothing wild here because I live in a suburb in the south of Finland. I have a small detached house and an 8 kW geothermal heating system (Nibe F1255). The geothermal well is 180 m deep. The geothermal well is also used to cool the house with a ducted radiator in the ventilation duct. The cooling is controlled by a Simene RLU200 series controller. The energy consumption for heating is 3000 kWh/year. The electricity consumption is about 7000 kWh/year. I am a plumber by profession but an engineer by education.

Since the price of electricity has risen dramatically I am thinking about installing solar panels. I am most interested in microinverters because they have Rapid Shut Down. Microinverters are not very popular in Europe, especially in Finland. So I thought I would ask here for a different opinion on solar power plants.

@upnorthandpersonal i think this gentleman is up in your neck of the woods, and could do with your advise, wisdom and experience

 

[upnorthandpersonal]

Tervetuloa forumissa @Joukahainen

If you have a decent roof with little or no shading, you should be fine with a normal string inverter. It's what most installations right now do anyway here in Finland, and opting for microinverters will make it harder to get going/find installers, equipment, etc. I don't really see what the benefits are since they are likely resulting in higher costs, and you introduce more points of failure (winter with all the cold, moist, etc. isn't really a nice environment for them). The only reason to use them would be if you're dealing with shade, but even then I think the advantage is minimal compared to the cost and potential failures.

I'm off-grid here and use a battery inverter with stand alone MPPT charge controllers, with a series of solar arrays installed around the property, often in sub-optimal locations (I'm surrounded by forest and the sea). Even with the shading, power generation is perfectly fine and not worth the expense of adding e.g. optimizers (basically DC versions of micro inverters) on the panels.

 

[Sverige]

Welcome to the forum @Joukahainen. I’m across the water in Sweden and have a pretty similar setup to you - a Thermia geothermal heatpump and 176m of borehole just because that’s as far as they got before there was water blowback out of the hole! But they say that’s good as it brings free energy into the borehole ?

Our annual consumption is around 5,500-6,000 kWh and I’ve lowered that to around 3,500 with the use of my off grid solar system which charges a 4kWh lithium battery and runs a couple of off grid inverters. Then we just switch appliances between solar and mains depending how much solar we have available. The heat pump will only ever run from mains though as it will not run on single phase electricity which my inverters make. So the heating and hot water system runs three phase mains electric and is our biggest source of consumption of course. I only spent around 20,000 Swedish kronor in putting my system together and with the recent rise in the price of electricity my breakeven point when it’s paid back in savings on our electricity bill should come in around 4 years.

None of which really helps you with your question of course - sorry for that! I would trust the advice of @upnorthandpersonal who is one of the most clued up guys on the forum, so if he says micro inverters aren’t the best idea then it’s worth reconsidering your plan. Alternatively you could explore a DIY off grid system for which there is tons of info on this forum, which will cost you a lot less money than hiring a company to install a grid connected system, but you’re likely to run into the same limitation i have with not being able to run the geothermal heat pump on solar that way.

 

[upnorthandpersonal]

Alternatively you could explore a DIY off grid system for which there is tons of info on this forum

The problem with that is Finland has strict rules on what electrical work one can do on their own as a layman. You would have to find a qualified electrician at the minimum who is willing to sign off on the DIY work. This is not easy. The reason I was able to build my DIY system without issues is because I've been an electrician in another EU country and the local electrician has no issues with me doing my own work - he signs off on it. It also helps my set-up is in the middle of nowhere and the house is not at all connected to the grid in any way (there is no grid coming to my place).

Depending on where OP is exactly, this is not going to be as straight forward. The rules in and around Helsinki are in practice a lot more strict than some place in the middle of nowhere village with 500 people living.

 

[Joukahainen]

Tervetuloa forumissa @Joukahainen

If you have a decent roof with little or no shading, you should be fine with a normal string inverter. It's what most installations right now do anyway here in Finland, and opting for microinverters will make it harder to get going/find installers, equipment, etc. I don't really see what the benefits are since they are likely resulting in higher costs, and you introduce more points of failure (winter with all the cold, moist, etc. isn't really a nice environment for them). The only reason to use them would be if you're dealing with shade, but even then I think the advantage is minimal compared to the cost and potential failures.

I'm off-grid here and use a battery inverter with stand alone MPPT charge controllers, with a series of solar arrays installed around the property, often in sub-optimal locations (I'm surrounded by forest and the sea). Even with the shading, power generation is perfectly fine and not worth the expense of adding e.g. optimizers (basically DC versions of micro inverters) on the panels.

I have received the same advice before and I understand the downside of micro inverters. Thanks.

In Finland - and Europe - micro-inverters are not popular and there is limited support available. That's really why I'm here. I was thinking of installing the panels myself and hiring an electrician to install the grid part. I'll buy the stuff from Germany or Holland. The price is about 50% more expensive than a similar Fronius based system and the yield is not that much better, +3% according to some tests. According to the same tests the Fronius is able to handle shadows as well as the iQ7. But as I said, I am interested in safety and above all Rapid Shut Down, especially when I install the panels myself. Installation prices in Finland are quite high, in practice well over a hundred euros per hour (1). Since I have a geothermal system that I installed myself after building it, I can get a subsidy for installing the panels for about 25% of the total cost (ARA).

But I'm still in the planning phase and waiting for the market to calm down a bit.

1) The law on electrical work in Finland is indeed strict. According to the law, I am not even allowed to install DC cables in a system with more than four panels. However, you can install microinverters as long as they have connectors and I believe that this is where you save money compared to a normal inverter. Only the grid part has to be done by a legitimate electrician.

 

[upnorthandpersonal]

I was thinking of installing the panels myself and hiring an electrician to install the grid part.

If you install the panels as a regular string, you get to account for high voltage DC, and you probably won't be allowed to do it yourself. If you use micro inverters, you work with 230V AC at the output, and you likely also won't be allowed to do it yourself. As far as I know the law on this, you have to have a permit for electrical work (and thus has to be done by a qualified electrician), no matter which way you go. You might be able to only install the panels, just not wire them up. In that case, it's easier with a string inverter as well since all the electrician has to do is connect MC4 connectors from panel to panel.

I am interested in safety and above all Rapid Shut Down, especially when I install the panels myself.

You can add rapid shut-down to strings using an MLPE from e.g. Tigo: TS4-A-F.

 

[Joukahainen]

If you install the panels as a regular string, you get to account for high voltage DC, and you probably won't be allowed to do it yourself. If you use micro inverters, you work with 230V AC at the output, and you likely also won't be allowed to do it yourself. As far as I know the law on this, you have to have a permit for electrical work (and thus has to be done by a qualified electrician), no matter which way you go. You might be able to only install the panels, just not wire them up. In that case, it's easier with a string inverter as well.

The law is not clear on this point. However, I don't see any problem because Enphase's cables are pre-assembled and the work is no more demanding or dangerous than installing a light fitting. Any on-site connections I can have done by a normal thread fitter.

You can add rapid shut-down to strings using an MLPE from e.g. Tigo: TS4-A-F.

I know. This is another option I'm looking at.

 

[upnorthandpersonal]

The law is not clear on this point.

I know. It depends on where you are and what your local electrician will want to deal with or not.

In any case, it feels to me you already made up your mind. If you don't mind the extra expense, go for it. Both systems work fine; you just have more options with string inverters since everyone uses that over here (and most of Europe as you already know).

 

[Joukahainen]

In any case, it feels to me you already made up your mind. If you don't mind the extra expense, go for it. Both systems work fine; you just have more options with string inverters since everyone uses that over here (and most of Europe as you already know).

Not really. Enphase microinverters also have their drawbacks, such as 50% higher cost, limited supply of inverters and limited software. I'm building up a component list for both systems and will explore the software while the market bubbles.

 

[Danke]

If you install the panels as a regular string, you get to account for high voltage DC, and you probably won't be allowed to do it yourself. If you use micro inverters, you work with 230V AC at the output, and you likely also won't be allowed to do it yourself. As far as I know the law on this, you have to have a permit for electrical work (and thus has to be done by a qualified electrician), no matter which way you go. You might be able to only install the panels, just not wire them up. In that case, it's easier with a string inverter as well since all the electrician has to do is connect MC4 connectors from panel to panel.



You can add rapid shut-down to strings using an MLPE from e.g. Tigo: TS4-A-F.

I paid slightly more than those Tigos and get the Optimizer function with RSD.

Enteligent

Enteligent offers state-of-the-art PV module rapid devices (RSD) and maximum power point tracking (MPPT) power optimization

enteligent.com

 

[Joukahainen]

I paid slightly more than those Tigos and get the Optimizer function with RSD.

Enteligent

Enteligent offers state-of-the-art PV module rapid devices (RSD) and maximum power point tracking (MPPT) power optimization

enteligent.com

No Europe shop?

 

[MattiFin]

1) The law on electrical work in Finland is indeed strict. According to the law, I am not even allowed to install DC cables in a system with more than four panels. However, you can install microinverters as long as they have connectors and I believe that this is where you save money compared to a normal inverter. Only the grid part has to be done by a legitimate electrician.

First step is to call to half a dozen electricians and probe them on what you can "pre-install" and what they want to do by themself.

 

[Danke]

No Europe shop?

Can’t they just ship it to there? Mine are being shipped to me.