Stock image. (source: Pixabay)
The energy crisis is favourable to renewable sources of energy. While the government is still looking for ways to mitigate the impact of the crisis, suppliers of photovoltaic panels and heat pumps are having a good time.
Most have seen interest in the technology increase tenfold, leaving many unable to fulfil all orders.
For whom are photovoltaic panels and what should one consider when choosing a heat pump? Does it make sense to consider photovoltaic panels for apartment buildings? How effective is it to lower the radiator temperature and instead use an electric heater or warm air conditioning?
Slovak Innovation and Energy Agency (SIEA) expert Michal Ilovič offers answers to these questions and more.
House
1. For whom are photovoltaic panels the most suitable?
They are especially suitable for households with high electricity consumption, in other words 5,000 kilowatt hours per year. However, this limit will probably change over time in direct proportion to how the unit price of electricity rises.
"It may happen that in the future such a solution will be beneficial even for a household that consumes 1,000 kilowatt hours a year," says Ilovič.
2. What do you need to consider before installing photovoltaic panels?
Check to see if you have any reserves in your current consumption that could be removed. Energy leaks occur even in houses that are insulated and have new windows.
The SIEA offers free advice in this regard, contacting energy auditors is another option.
Subsequently, you have to decide whether your photovoltaic system will only serve to heat your water and power household appliances, or whether you will connect it to the public distribution network. Only then does it make sense to contact potential suppliers, choose the most suitable offer, or ask a distribution company to be connected.
3. Can I install panels with any output?
When it comes to households, the output cannot exceed 11 kilowatts. At the same time, however, it can be a maximum of 1.5 times the normal consumption of the given household.
In an extreme case, however, it may happen that a distribution system operator rejects the request for connection, even if the household output is within the limit. "It depends on the technical conditions of the connection in the given area," explains Ilovič.
4. How can I make money from unused electricity?
If the generated electricity can be immediately consumed and you don't want to sell it, you can use the so-called virtual battery service. In this case, the unused electricity goes into the distribution network, but the operator will return it to you later, or deduct its price from the invoice.
According to Ilovič, there is a risk that a provider can decide at any time to end the service or change its conditions, including prices. In the future, there might be the possibility to sell unused electricity within an energy community, or communities producing energy from renewable sources.
This principle is quite common in western EU countries, with projects being prepared in the Czech Republic. For example, the city of Prague founded the Prague Renewable Energy Community, which helps people with the installation of panels on apartment building roofs and wants to buy unused electricity from them in the future.
In Slovakia, there is a legal basis for such a solution, but the details are still being fine-tuned. Therefore, if you want to make money from photovoltaic panels, it will be best if you wait until the rules are precisely defined.
5. I want to apply for a subsidy from the Green Household scheme. However, I am afraid that the installation will take a long time and I will lose the support. How should I proceed?
The right to support does not arise upon registering, only when your supplier requests the subsidy. The supplier should do so only if they are sure that the device can be delivered within 90 days from making the request.
At the same time, it is possible to apply for the subsidy more than once. "If the subsidy was issued, but due to relevant reasons it is not possible to meet the set deadline, the applicant can proactively request the cancellation and submit a new application," explains Ilovič.
In addition, the support of renewable energy sources for households is also covered by the new European funds available to Slovakia for the next seven years.
6. I want to replace the gas boiler with a heat pump. I heat with radiators. Is it worth it?
If we are talking about a new construction or a sufficiently insulated renovated building, then yes. However, if you have radiators with a small heating surface, you will probably need a high-temperature pump that can heat water to more than 60 degrees.
Until recently, the Green Household scheme did not support such devices. However, according to Ilovič, they are gradually being taken into account.
It is easier for households with floor or ceiling heating, or radiators with a sufficiently large heating surface. In their case, a low-temperature pump that heats water up to 60 degrees is sufficient.
7. To what extent does the subsidy cover the initial investment?
The limit is 50 percent of total eligible costs for delivery and assembly, including accessories such as water tank, circulation pumps or expansion vessels, and possibly also testing.
However, the maximum amount of support is €3,400 for an output of 10 kilowatts. How powerful a pump you need depends on the energy demand of the house itself.
"Since most equipment is financially expensive, the subsidy most often covers a little over forty percent of the investment," adds Ilovič.
Apartment building
1. We live in an apartment and together with our neighbours are thinking about photovoltaic panels. Does it make sense in an apartment building?
Currently, not very much. Each apartment has its own power take-off. It would be possible to use photovoltaic panels only in common areas in the corridors or in the elevator.
However, even in this case the timing of consumption and production would be difficult. While the elevator and light in the corridors are used mostly in the morning and evening, photovoltaic panels produce the most electricity during the day.
It is currently not possible to transfer unused electricity to individual apartments. The solution will be the introduction of energy communities.
2. I live in an apartment building. With other owners we would like to reduce costs. Is installing solar collectors for water heating worth it?
Yes, if your apartment building is not connected to a central heat source, but has its own boiler room. In the case of a central heat source the law does not allow the installation of equipment that would reduce consumption without prior agreement with the heat supplier.
If the building has a boiler room, this no longer applies. The hot water produced by the collectors during the day can be stored in storage tanks until the evening, when the residents of households usually use it. So there is no mismatch between production and consumption.
"When it comes to gas boilers, we are talking about reducing gas consumption for heating water by up to 40 percent," adds Ilovič.
3. I want to save on gas. Is it a good idea to buy an electric radiator?
You need to make calculations. Not only gas bills, but also electricity bills are expected to go up. In addition, the bill for central heating in an apartment building consists of a basic and consumption component. If you decide to reduce your consumption, the basic component can still make up to a few dozen percent of the bill and you have to pay for it.
4. If I want to reduce gas consumption, should I heat with an electric radiator or air conditioning?
Definitely air conditioning as it is an air-to-air heat pump. In other words, it uses significantly less electricity than a radiator to deliver more heat.
5. Will I have time to install photovoltaic panels or a heat pump this winter?
Probably not. Before the pandemic, when there were enough goods and no outages in supply chains, the delivery of the mentioned systems took a month, two at most.
At present, however, the situation is completely different. Parts are missing and demand is huge worldwide. "If you order a heat pump today, it will arrive in six or eight months," says Ilovič.
6. Are there any inexpensive solutions that I can apply now?
Yes. In the case of heating, Ilovič recommends monitoring air humidity. If it reaches 30 percent at temperature of 23 degrees, the thermal comfort is the same as at a temperature of 21 degrees and a humidity of 60 percent.
"If humidity is low, it is worth increasing the heating more than turning up the radiator header," he says. You can use a diffuser or place wet towels on the radiator to increase humidity.
At the same time, it is not necessary to turn off the heating completely, otherwise the household will become hypothermic. You should also regularly service the boilers and regulate the entire heating system.
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