I install balcony solar panels at home.
They work.
They reduce my electricity bill.
They make a lot of sense.
They also taught me something essential about housing renovation and the energy transition.
When we speak about decentralized energy,
we often describe it as simple.
Plug in the panel,
produce electricity,
become a prosumer,
contribute to the grid,
gain autonomy.
In practice,
even a small installation reveals something
More complex.
It asks questions.
Who coordinates the electrician?
Who explains the tariff structure?
Who answers when the installer disappears?
Who ensures the mounting is safe in a multifamily building?
Who carries the learning curve?
In plain policy language,
it means consumer protection.
Who carries liability?
Who guarantees safety?
Who provides redress?
Decentralized energy.
can't rely on goodwill.
It requires enforceable clarity.
Over the past few days,
I've been in Vilnius with two projects working precisely at this intersection.
Balcony solar,
storage,
and multifamily housing.
Laboratories,
production lines,
demonstration buildings,
policy discussion,
technical standards,
one-stop shops.
The technology is evolving quickly.
Panels are becoming lighter.
Batteries are modular.
Standards are being formalized.
Legal barriers are being removed in some countries and reinforced in others.
And yet,
every time solar approaches a multifamily building,
governance enters the room.
Ownership structures,
homeowner association,
municipal rules,
grid constraints,
sufficiency debates,
renovation targets,
energy parity.
60%
of people in Central and Eastern Europe live in multi-apartment buildings.
These buildings are where climate ambition meets collective decision-making.
They are also where energy vulnerability concentrates.
Balcony solar,
on the other hand,
look individual.
Housing renovation is collective.
Storage might connect both the grid.
Each layer introduces coordination.
So this episode asks a simple question.
When decentralized energy scales,
who carries the responsibility for making it work?
From plug-and-play to trust and repair,
this is a story about housing,
governance,
and the quiet infrastructure that makes the energy transition livable.
From wellness,
this is energetic.
Christian
Offenhussel of the German Association for Plug-in Solar.
It's not only that people have solar panels on their roof,
you know,
and on their balcony,
because we have the luxury issue now in Germany that we have over 60%
of renewable energy in the grid,
a lot of it being solar,
which means we have a lot of peaks during noon,
and prices drop below zero on the stock exchange.
So that means that we have to do something against that,
because otherwise it's very expensive for the society as a whole.
Yeah,
the famous duck curve.
Yeah,
exactly,
the duck curve.
And this is why we also realize that we have to...
Well,
with balcony soil,
it's not that much of a contributor to that because,
first of all,
we have many of them on the balconies are 90%
angle,
so they go straight downwards,
right?
And this means in wintertime,
they produce more than in summertime.
Oh,
wow,
okay.
It can happen,
right?
And also they're not all facing south.
Some of them face west or east,
other than,
let's say,
big solar installations that mostly face south,
because this means more profit for them,
right?
So it's more distributed production curve,
which is good for the grid as a whole.
But we want to do more.
We want to do more.
We realize that this huge potential that we can not only contribute to energy production,
but also to a more levelized energy distribution.
It means that we can also add batteries and program them in a way so that they do the valley filling and peak shaving that is necessary to have a levelized energy production.
Johann Strese of
IWO. Give people the chance that they can install something in their flat area.
In this case,
it is the balcony.
Not all flats have balconies,
but those who have,
and ideally in the direction south,
west or east.
and you can produce your own energy and without any big equipment you buy the balcony PV plug-in equipment it's in Germany you can get it already for 300 euros and
you can produce your own energy you plug it in in your flat it's really easy to mount and it's easy to install and to run and the project started in
Lithuania
in both Bulgaria and in North Macedonia.
A representative of ProTech.
The main goal is to develop the residential battery based on sodium ion technology and equipped with all the intelligent and smart solutions,
including the energy management system,
which allows not only to store energy,
but provide flexibility service,
etc.
So maybe why sodium ion?
Now the mainstream is lithium-based technologies.
It could be NMC technology,
it could be LFP technologies and different things.
But sodium-lime is quite,
how to say,
a magic technology.
And the main advantages,
I would say,
is the price.
It's cheaper than lithium-ion.
Everything sounds ready.
Panels are lighter.
Batteries are modular.
Standards are emerging.
And yet,
when I installed my own balcony solar panels,
readiness did not feel like simplicity.
Because technology scales through deployment.
Trust scales through coordination.
So I come here with a very open mind,
but I also have this mixed experience with developing solar technology.
And since,
you know,
these two days we'll visit Mariby about that,
I thought,
OK,
maybe it's like a good angle to start with.
like I'm
Of course,
an early adopter,
and I'm happy about that.
Still,
I've seen that there were things that didn't deliver that much.
Because the situation is extremely different in Italy.
There are only a few requirements,
like you can't install more than three standard panels,
basically.
But up until three,
you are really ready to go.
Like I'm talking about the size of really the standard panel.
And it's considered a furniture.
So there are no,
like the condominium management and your neighbors cannot prevent you from installing them.
You need to present a project,
but then you're basically ready to go.
So it's extremely easy.
But let's say that there are not as much innovation on the type of panel.
To give you an example,
the ones that I have are
1,70 m long and about
1,20 m large.
So they are much bigger,
much,
much bigger than me.
So for someone like me,
they are definitely not plug and play.
I need professional help to install them.
They are heavier and larger than me.
So we are very far from a plug and play system,
flexible system that I move in and out.
Now they are installed.
I don't think I would ever be able to remove them.
After a few months,
I had this kind of very bad experience with the solar panels because there were the installers and the companies that installed them and that sold them and that installed them were nowhere to be found.
And that creates quite a problem of mistrust.
That is a consumer protection issue.
When after sales disappears,
early adoption becomes reputational risk for the entire sector.
One of the things that I didn't get was a system to monitor if they were actually producing anything.
And that was extremely frustrating because,
of course,
I've been working on demand-side flexibility.
I'm a huge advocate for flexibility.
And the panels basically need to know when they produce in order to use the electricity produced.
I was doing a very empirical technique,
looking at the panels,
checking if the sun was shining on the panels and so on.
Flexibility policy assumes information symmetry,
but without visibility,
flexibility remains completely theoretical.
My experience?
I suspect it was not unique,
but it was very structural.
Across Europe,
the same pattern appears.
Housing associations hesitate.
Legal frameworks diverge.
Grid rules shift.
Early adopters,
like me,
carry uncertainty.
This friction might be way more institutional than properly technical.
This is a very important development here because we see that apartment owner associations,
they sort of create...
barriers to not have to deal with this,
to not allow single apartment owners of tenants to install their own installation.
They produce big catalogs of requirements that they have to fulfill,
cost thousands of euros,
statistical calculation for the balcony railing,
if it could take such crap,
right,
really.
But it's all just aversion politics to not have to deal with it.
And we're working on this.
This is the biggest issue right now that we do not...
get to the cities where it's actually supposed to be,
the balcony solar,
that's the potential of the balcony solar,
is to be in the cities.
Ida Wanger of the Josef Aras municipality in Hungary.
The plug-in TV panels that we worked with in sunbots and sunrises before in Hungary,
they are completely forbidden.
You cannot install them.
It's not legal.
It's basically for business.
Explicitly the legislation forbids it.
When rooftops are blocked by heritage rules or collective ownership,
households invent you
workarounds,
but workarounds do not scale.
institutions do.
Julius
Sarkalov-Skaz, the CEO of Solitech.
My example,
I live in the central part of the city and cannot install solar tunnels on the roof because not allowed,
no,
architecture,
other.
But
I bought a piece of remote.
I know where,
approximately,
but never saw.
And we have
8 kilowatts.
And it is interesting that in our case,
you see,
producing,
you have to pay for grids that they transmit from that part to me.
But
I can pay,
not by money,
but for electricity.
I leave
30% of electricity for the grids.
end.
I pay,
sorry,
I remember one or two euros per month for electricity only for the administration.
And
I receive electricity for free.
It's possible for
Lithuania and before.
Barriers reveal maturity gaps.
Maturity requires structure.
This is where projects like Sunbox
and come activate intervene.
They work on standards.
They clarify mounting systems.
They build one-stop shops.
They support homeowner associations.
Overall,
they reduce the coordination burden.
The main part of the new standard is threefold.
One,
it regulates,
of course,
the power limits and the limitations of the number of modules as well.
Not the number,
but the power the modules can produce.
and other technical areas that are covered by this like rapid shutdown and discharge and stuff like that on the second part it for the first time gives out standard or requirements for the mounting system because
with let's say rooftop solar you are on the roof of your own building and if it falls down in your garden well okay that's your problem but if we are talking about multi-apartment buildings and Thank you.
It's out on the balcony and there's a walking way underneath it.
It can fall down and fall on someone,
right?
So we have to have standards that the mounting system have to adhere to.
And that's what a standard does as a second part.
And the third part is the documentation.
Because the people have to exactly know who to contact in case of a problem with the product.
What to do if one component breaks or...
the smoke there or whatever.
And they also have to have all the information about how do I register it?
How do I connect the different plugs with each other?
And so on and so forth.
So these are,
I think,
the basic requirements that are in there that are covered by the standard.
It's a rather large document and very specific in all of those three parts.
Commactivate is a project that aims to battle energy poverty in the multifamily apartment building context in Lithuania,
Bulgaria and Hungary through one-stop shops that provide advice to citizens on renovation but also through the introduction of the concept that tries to go beyond the energy efficiency and that is the energy sufficiency.
So how can citizens also become...
not just to consumers of energy,
but also producers.
In some contexts,
this is a very new concept idea.
How do we even translate it into reality?
The renewables play a big role.
It could be the first step how you very easily become a producer just as well as just a consumer.
Balcony solar empowers individual households.
Renovation transforms entire buildings.
When insulation
Heat pumps and rooftop PV align.
The energy balance changes structurally.
That requires collective governance.
It requires long-term planning.
It requires public support.
Balcony solar can be an entry point.
It's renovation that defined this trajectory.
For those who know buildings,
you can see what was the building.
Pottery area,
20 flats.
Before they used liquid gas.
But you have to bring time to time,
not by tubes,
but by car.
And now consumption of heating.
And electricity and annual consumption of heat,
and you see that consumption of heat decreased twice after insulation of the building.
For heat pump,
it was decided to make heat pumps,
heat pumps but geothermal.
And not one but two,
because heat pumps are very,
how to say,
good work.
Sometimes they have problems.
Before we suggested to make two heat pumps,
inter-volume heat pumps,
but mainly it is to receive cheap electricity.
Then one constructed solar power plant on the roof.
29 kilowatts and was enough for heat pump for this house.
For decades,
multi-family apartment buildings and renewable energy have circled around each other from a distance.
They share the same roofline,
they face the same sun,
they live under the same climate commitments,
yet they have struggled to connect.
Multi-apartment buildings are complex.
60%
of people in Central and Eastern Europe live in them.
They carry the legacy of rapid privatization in the
90s. They are governed by home owners'
associations,
tight budgets,
fragmented responsibilities,
and often deep energy poverty.
Yet,
they are the heart of our cities and also the hardest place to renovate.
Renewable energy,
on the other hand,
has moved very fast.
Lithuania,
as we heard,
is aiming for climate neutrality by 2050.
More than 170,000 consumers already generate electricity.
12%
of the electricity production in 2025 came from consumers.
2 gigawatt more are planned by 2028.
The ambition is clear.
The technology is ready.
The policy instruments are evolving.
And yet,
when solar...
approaches a multi-apartment building,
something awkward happens.
Yes,
the energy transition advances through hardware,
but it stabilizes through institutions.
Because when coordination is predictable,
adoption feels safe.
When responsibility is clear,
trust grows.
Scaling decentralized energy depends on the invisible architecture around it.
And that architecture is governance.
Over these past days,
we have walked through laboratories and production lines.
We have stood inside renovated buildings.
We have listened to engineers,
municipalities,
researchers,
community organizers.
And yes,
the technology is progressing.
Panels are lighter.
Batteries are modular.
Standards are taking shape.
Connection rules are becoming clearer in some countries.
There is movement,
definitely.
And yet,
every time solar approaches a multifamily building,
coordination begins.
Someone must inform the homeowners association.
Someone must clarify fire safety.
Someone must explain grid rules.
Someone must translate subsidy schemes.
Someone must stay available when something...
does not work as expected.
And housing renovation amplifies this dynamic.
Balcony solar can be installed by one household,
but deep renovation requires collective decision.
Heat pumps alter building systems.
Insulation changes long-term performance.
Storage interacts with the grid.
So each layer increases interdependence.
What we've seen here in Vilnius is that scaling decentralized energy requires more than equipment.
It requires institutions that are ready to absorb friction.
Sandbox works on standards,
testing and regulatory clarity.
Comactivate strengthens local resource centres and homeowner associations.
One addresses the technical pathway,
the other strengthens the social pathway.
And both together reduce uncertainty.
And uncertainty is exactly what slows adoption.
In Lithuania,
We heard that 50%
of neighbors must agree for shared solar on their common roof.
That number is not technical,
it's relational.
It reflects trust,
negotiation,
and collective confidence.
We also heard about limits,
lower budgets,
partial targeting of vulnerable households,
grid reforms that change economic assumptions.
Ambition do exist.
but implementation varies.
For households living close to energy poverty,
it's a 20%
reduction in electricity costs matter.
It affects food,
medication,
dignity.
It affects whether the transition feels protective or demanding.
Balcony solar alone will not decarbonize Europe's housing stock.
And there are the revised Energy Performance of Building Directive member states must you
accelerate renovation of the worst performing buildings.
Multi-apartment housing is really central to that mandate.
And the upcoming citizens energy package is aiming at defining how consumers energy sharing and consumer protection are to be implemented in practice.
If coordination fails at the building level,
these frameworks will remain only paper ambitions.
Numbers guide policy.
but trust guides participation.
My own balcony solar panels now operate smoothly.
They reduce my bill quite consistently.
They connect me more consciously to my consumption.
But they also revealed how easily coordination can slip onto households.
If decentralized energy depends on exceptional motivation like mine,
it will scale unevenly.
If renovation depends on perfect consensus,
it will stall.
Ever.
Multi-family buildings are the proving ground.
They test whether consumer protection is real.
They test whether governance can absorb friction.
They test whether climate ambition survives collective complexity.
When residents feel supported,
adoption accelerates.
When rules are stable,
investment follows.
When institutions remain present,
trust accumulates.
From plug-and-play to trust and repair,
this is the real work of the energy transition.
From wellness,
this is Energetic.
Energetic explores the people,
policies and institutions shaping Europe's and the world's energy transition.
I am Marine Cornelis.
If you found this conversation valuable,
you can share it with colleagues working on housing,
governance and consumer protection.
You will find references and further reading in the show notes.
Until next time.