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Should you run your washing machine at 2 PM? And why is the government making solar panel owners install batteries? Dive into the electrifying world of prosumers, solar panels, and how our energy grid really works! Get the real scoop and some surprising physics. Subscribe for more awesome breakdowns and let us know in the comments what shocked you most! #energy #solar #science #news #renewables
👉 This channel was created in collaboration with https://www.youtube.com/@presura
0:00 - News Stories and Energy Advice
0:43 - Becoming a Prosumer: Basics
1:33 - Electric Grid Physics Explained
2:59 - Solar Panels, Prosumers, and Grid Balance
6:17 - Grid Balance Solutions Worldwide
7:56 - Inverters, Three-Phase Systems, and Batteries
10:27 - Battery Law, Costs, and Consequences
13:44 - Conclusion and Farewell
👉 This channel was created in collaboration with https://www.youtube.com/@presura
0:00 - News Stories and Energy Advice
0:43 - Becoming a Prosumer: Basics
1:33 - Electric Grid Physics Explained
2:59 - Solar Panels, Prosumers, and Grid Balance
6:17 - Grid Balance Solutions Worldwide
7:56 - Inverters, Three-Phase Systems, and Batteries
10:27 - Battery Law, Costs, and Consequences
13:44 - Conclusion and Farewell
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🗞
NewsTranscript
00:00A recent news story. The Minister of Energy is asking us not to wash our clothes in the evening because
00:05it's not good for the energy system.
00:06Friends, it's 2 o'clock in the afternoon when solar energy enters the grid. It's the right time to start
00:12the washing machine.
00:13Here's another recent news story. It seems that prosumers will be required by the state to install batteries.
00:19So, if you have a solar panel and produce excess energy, you won't be able to inject it into the
00:25power grid unless you have batteries.
00:27What's with this law? Where does the problem come from? And how is it connected to washing machines?
00:33Thinking of installing solar panels and becoming a prosumer?
00:36Here are the basic things you need to know.
00:38Dear friends, you already know that I installed my solar panel in the countryside.
00:43I even started injecting energy into the grid. It's called being a prosumer.
00:49That means I give from my surplus.
00:52But it's not as simple as it might seem.
00:54To understand this, let's go back a bit to the laws of physics.
00:58Energy is produced at the hydroelectric plant, let's say.
01:01Then the high and low voltage networks bring it to the consumer.
01:04I put bring in quotation marks because energy doesn't travel through cables, as one might think, but through the air.
01:11I learned this from Richard Feynman.
01:13However, nothing in the laws of physics prevents energy from flowing in the opposite direction using the same electricity networks.
01:21From the consumer who has solar panels and therefore produces energy, now called a prosumer.
01:27To other consumers on the same electrical grid.
01:31Nothing except practical considerations.
01:33The fact is, if the electrical grid isn't built for this from the start, the neighbor's light bulbs start burning
01:39out and the fuses blow.
01:41Why?
01:42Here's what happens in a super, super simplified electrical diagram where we have direct current and consumers placed one after
01:50another on a transmission line.
01:52In addition, we consider them placed one after another on a transmission line.
01:57U0 is considered constant.
01:59They would have had the same voltage.
02:01Look at what actually happens when we have losses on the transmission line.
02:04The electric voltage is lower and lower along the line.
02:08The electric voltage gets lower and lower when we reach the last consumer on the line.
02:14U0 is greater than U2.
02:18Basically, due to voltage drops on different transmission sections, the drop is proportional to the current passing through there.
02:26The more current the consumers draw, the more the voltage drops along the network.
02:31In practice, the generator voltage U0, which remains constant, is chosen high enough so that even the last user U4
02:40has sufficient voltage.
02:42The more current the consumers use, the greater the voltage drop across the transmission sections of the network, and the
02:48voltage at the users decreases.
02:51In this case, we have U1' less than U1, meaning the voltage at high consumption is lower than at low
02:58consumption.
02:59In this diagram, you can see what happens when the last consumer on the line turns on their solar panels.
03:05Here, I model the solar panels as a direct current source for simplicity.
03:10When the solar panels start generating current, in the morning when the sun comes up, we apply Kirchhoff's laws and
03:15see how the current coming from the grid to the consumer decreases a bit compared to what it was before.
03:21Basically, the household consumes less electricity from the grid because part of the energy used is provided by the solar
03:27panels.
03:28If the light on the panels increases as the sun rises in the sky, then the current generated by the
03:33solar panels also increases.
03:35At some point, this will equal the current consumed by the household itself and a balance is achieved.
03:41The consumer no longer draws electricity from the grid because they produce their own energy from the panels.
03:47Now it's as if the consumer has disconnected from the grid, that's why the total electricity consumption on the power
03:53network is lower.
03:54The voltage drops on the network will also be small due to resistive losses.
03:59That's why the voltages on the network for the other consumers, meaning U1, U2, U3 and so on, will now
04:06be higher.
04:07The sum of the voltages on the lines is always the same, given by the U0 source.
04:11Here you can see what happens when there is a lot of sunlight.
04:13I kept the same internal consumption for the example.
04:17Now, the electric current generated by the panels is very high, exceeding the one normally drawn from the grid.
04:23Therefore, the direction of the electric current coming from the grid changes in our direct current model.
04:30Since the model is direct current and the direction of the voltage remains the same, the power flowing from the
04:37grid reverses direction.
04:40This means that the entire household becomes a generator of energy for the grid.
04:45The current injected by the panels into the grid reaches the neighboring consumers, so the total consumption from the grid
04:51is reduced even further.
04:53This means that the electric voltage at the consumers upstream on the grid, that is, at our neighbor, will increase
04:59even more.
04:59That's where the problems start.
05:01Well, if it increases too much, their household appliances can get damaged.
05:05This is the most important thing to consider when we talk about prosumers.
05:09When they pump energy into the grid, the electric voltage increases along the distribution network and can affect other consumers.
05:18In practice, if there are many prosumers, they create imbalances in the grid.
05:22On that sunny day, when all the solar panels generate a lot of electricity, the electric voltage will increase uncontrollably
05:29in the power grid, endangering all other consumers.
05:33We call this a grid voltage imbalance.
05:35Now we understand, at least from the perspective of solar energy, why the minister says to run the washing machine
05:42during the day.
05:43By running the washing machine, we will draw more current from the grid and the electric voltage will decrease, which
05:49otherwise would have been higher due to the surplus of solar energy.
05:54In the end, the energy system remains safe.
05:57Essentially, it's a matter of balancing the energy grid.
06:00In the evening, we have a problem at the opposite end.
06:03Too much energy is consumed and the voltage ends up dropping too much.
06:07Now it's better not to use the washing machine because otherwise the electric voltage would drop even more.
06:13This is how we understand the effort involved in balancing the electric grid.
06:17Essentially, it's an old problem of Romania, which inherited an energy distribution system that is basically one way from the
06:24big producers to the consumers.
06:27What are you supposed to do with prosumers who now want to pump energy into the grid as well?
06:33In developed countries, there are mechanisms that make it easier to maintain balance in the electrical grid.
06:39Many countries offer financial benefits.
06:42If you consume energy at night when the voltage is higher because there is less consumption, you pay less.
06:48Other countries use technical solutions such as transformers with variable voltage.
06:52Of course, you've seen a transformer near high-voltage networks.
06:57Its role is to convert the electric voltage from the network, alternating, of course, into low electric voltage, about 230
07:05volts.
07:06In transformers with variable electric voltage, this low voltage delivered to consumers can be automatically adjusted depending on the user's
07:15load.
07:15If they consume a lot, the electric voltage naturally drops, and then the transformer will raise its secondary voltage.
07:23The same thing happens when the consumption decreases.
07:26The voltage would naturally increase.
07:28The variable voltage transformer measures this and delivers a lower voltage on the secondary side.
07:33Such a solution also benefits prosumers.
07:36A sunny day arrives and all the prosumers on the line deliver energy.
07:40Voltage in the networks rises, and the transformer sees this.
07:45Being variable, it will automatically lower its voltage.
07:47In Romania, however, such solutions are expensive.
07:51To protect the network, a harsh method is applied, disconnecting the prosumer.
07:56If the prosumer, by delivering too much energy into the system, causes the voltage to rise in a dangerous way.
08:03The idea is as follows.
08:04Any solar panel produces direct current voltage.
08:07To feed it into the AC grid, an inverter is used.
08:11That's why the inverters used by prosumers have a built-in safety system.
08:16They monitor the electric voltage.
08:18When a lot of energy is fed into the grid and the electric voltage increases,
08:23the inverter automatically disconnects from the grid so that the high voltage doesn't cause any damage.
08:29Prosumers who have installed a three-phase system have an advantage.
08:32They distribute the energy across all three phases of the grid.
08:36The energy delivered on a single phase will be lower.
08:40Because of this, three-phase systems disconnect from the grid less often,
08:44which benefits the prosumers who have them.
08:47In addition, when the three-phase inverter is more complex, for example,
08:50being built from three separate single-phase inverters,
08:54it is possible to deliver energy on those phases of the grid that have a lower voltage.
08:59However, there are other solutions as well, such as using batteries.
09:03This is easy to understand.
09:04If the voltage rises too much when the surplus energy is delivered to the grid
09:09and the inverter is disconnected from the grid,
09:11it can automatically connect to the batteries and charge them.
09:16The energy stored in the batteries is then delivered to the grid at the most suitable time.
09:20For example, in the evening when the panels are not charging the battery,
09:24when consumption is high and the system needs energy.
09:27In fact, with batteries, you can do something even smarter.
09:30If you automatically check the weather and see that it will rain tomorrow,
09:34it's better not to put the battery energy into the grid,
09:36but to keep it for yourself.
09:38Use it the next day.
09:39Such a smart system is installed, for example, by the company EcoSolaris.
09:43At EcoSolaris, they understand the importance of optimizing photovoltaic systems for prosumers,
09:49and we know that batteries are essential in this process.
09:52The use of batteries in photovoltaic systems brings multiple advantages,
09:57including maximizing energy efficiency and reducing dependence on the power grid.
10:02By storing the surplus energy produced during the day,
10:05batteries allow you to use it at night or on cloudy days,
10:09ensuring a continuous power supply.
10:11In addition, this solution helps save on energy costs
10:14and protects the environment by reducing carbon emissions.
10:17Investing in a battery system is a smart choice for a more sustainable and economical future,
10:22strengthening energy independence and the efficiency of the entire photovoltaic system.
10:27Visit the EcoSolaris.ro website now to find out more information.
10:31Link in the description.
10:32Batteries are good for prosumers and for balancing the energy system.
10:36This way, we can understand why the government came up with a new law
10:40that required prosumers to install batteries.
10:43But, of course, this comes with an additional cost for prosumers.
10:49The law was hastily discussed on the last day of the parliamentary session.
10:54It was not adopted.
10:55It was sent back by the president with a few observations.
10:58It would require all prosumers who have solar panels with an installed capacity
11:04of at least 10.8 kW to install batteries equivalent to 30 or 50% of the system's capacity.
11:11The average installed capacity for a household prosumer is somewhere between 5 and 10 kW,
11:16so they would seem to be excluded.
11:18On the other hand, there is an additional article in the law that can be interpreted
11:22to mean that all prosumers who have more than 3-key W of installed capacity
11:26must also install batteries.
11:28In this case, the batteries must have a storage capacity of at least 30% of the installed capacity.
11:34To give you an idea, for an installed capacity of 6 kilo dollars,
11:37this would mean a battery storage capacity of 2.5 kilo dollars.
11:41The costs for these batteries start at 250 euros per kilo dollar to which you have to add
11:46the control system and even the replacement of the system's inverter.
11:49It seems that the law would actually create a problem for prosumers who installed their
11:54solar panels through the Casa Verde program.
11:57According to the contracts, they are not allowed to modify anything in the installation for several
12:02years.
12:03If their inverter does not have the capacity to connect to batteries, which happens in many
12:08cases, they cannot replace the old inverter with a new one.
12:11That would violate the contract.
12:13What they can do is install the new inverter alongside the old one.
12:17From what I read in the draft law, the affected prosumers should also install batteries by
12:21the year 2027.
12:24Otherwise, they will no longer have the right to feed energy into the national grid.
12:28The question remains, would this law be a good thing or a bad thing?
12:32Personally, I believe the government's message is that prosumers are the ones who should contribute
12:37financially to balancing the grid, at least for the part they are responsible for.
12:41Of course, the issue is a double-edged sword.
12:44The imbalance of the energy grid is much deeper, going beyond the issue of prosumers.
12:51This can be seen these days in the high cost of electricity, which comes from large daily
12:57fluctuations in energy transactions precisely because of this imbalance.
13:02However, there are also other mechanisms for regulating the grid, such as encouraging consumption
13:07at appropriate times or building a balanced grid from the start with all its components.
13:13Hydro, nuclear, wind, and so on.
13:15If prosumers will have to pay for the batteries out of their own pockets, we might end up with
13:20the opposite effect.
13:22Due to high costs, fewer and fewer solar panel owners will want to become prosumers.
13:27As I said, the president has sent the law back to parliament.
13:31In the request for re-examination, the president emphasized that implementing this obligation
13:37would involve considerable costs for prosumers, and it could discourage investments in photovoltaic
13:43panels.
13:44And with that, we've reached the end for today.
13:47Until next time, please subscribe if you haven't already by clicking this subscribe button right
13:51now.
13:52I want to thank those who support us on Patreon and those who become channel members here.
13:57I'm Cristian Pressura, Fisica Apovestita.
13:59You're cool and I wish you the best.
14:01See you next time!
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