The energy requirements for a Plus+energy house
Plus+energihuset fra Træhuse Nordsjælland er at finde blandt de allerbedste producenter indenfor lavenergi byggeri i Danmark
De offentlige myndighederne i Danmark og EU stiller stadig større krav til, hvor stort det årlige energiforbrug maksimalt må være i et helårshus bygget på en helårsgrund. Kravet står beskrevet i Bygningsreglementet BR18, og omfatter energi til opvarmning, varmt vand og tekniske anlæg, driften ved brug af ventilationsanlæg, displays, pumper, automatik og andet energiforbrug til driften.
Energy framework
Plus+energi huset complies with the energy framework, which does not, however, set a standard for how much of this framework can be used for heating in the home. But there is a standard for how much heat loss there is on the climate screen, i.e. all exterior walls, floor and roof construction, total glass areas, and exterior solid doors. The energy framework calculation is part of the energy supply form called the energy factor. Electricity, gas, and district heating are included with a factor relative to 1 kWh at the time of calculation, and please note that the calculated energy requirement is not the actual consumption.
Low-energy class BR18
Homes are divided into different low-energy classes, e.g. low-energy class BR18, which are homes where energy consumption for hot water and heating, including technical installations, is max. 75% of the energy framework specified in the building regulations. As our Plus+ energy houses are highly insulated in their standard design and come with low-energy glass, a heat pump and, where applicable, a solar cell system with batteries, the Plus+ energy house will meet the energy consumption requirements for a low-energy construction class in accordance with Building Regulation BR18, depending on the number of windows and doors in the home.
The Plus+energy house from Træhuse Nordsjælland is unrivaled in its class
Energy demand is the total energy consumption of the home for hot water, heating, ventilation, operation of technical systems including displays, pumps, free heat from
sunlight, people, pets, standby functions, chargers, TV, lighting, freezers/refrigerators, and household appliances, etc.
Energy-efficient buildings
Standard low-energy wooden houses and Plus+energy houses are both energy-efficient buildings, but there is a significant difference between the two. A standard low-energy wooden house is a building that produces as much energy as it consumes on an annual basis. This means that the total energy bill for a standard low-energy wooden house is theoretically zero. To achieve this, a standard low-energy wooden house uses a range of energy-saving technologies and strategies, such as effective insulation, high-performance windows, solar panels, and heat pumps. This type of building is still connected to the energy supply system, but energy consumption is reduced to a minimum.
Solar panels and battery packs
A Plus+energy house from Træhuse Nordsjælland also uses energy-saving technologies and strategies to reduce energy consumption, but it also produces energy using solar panels or other technologies. While a standard low-energy wooden house has a zero energy bill, a Plus+energy house produces more energy than it consumes and can even earn money by selling surplus energy back to the energy supplier.
Surplus energy
A Plus+energy house is a building that produces more energy than it consumes over the course of a year. In other words, the surplus energy produced by the building is greater than its total energy consumption over the year.
The above energy requirements are approximate figures and should be viewed in relation to the size of the house, the number and location of windows and exterior doors, and the use of the house. Some families will achieve lower consumption, while others may achieve higher consumption.
Heating & ventilation
A Plus+energy house is primarily heated by a ground source heat pump or an air-to-water heat pump system, a pellet boiler, or a district heating system supplemented by solar cells as needed. Gas boilers are also an option, but are often not chosen. Wood-burning stoves with fresh air intake from outside or other types of bio-stoves, etc., can also be used as secondary heating.
Heating in floor areas
Plus+ energy house® from Træhuse Nordsjælland is equipped with underfloor heating throughout, downstairs and upstairs. An individually dimensioned underfloor heating system is installed. This is available with many options.
Ground source heat pump or air-to-water heat pump
Our Plus+energy houses® are built with a high-quality heat pump system from a total supplier who delivers the entire system, from pipes in the ground to the system installed in the utility room, with an efficient Danish service organization. The ground source heat pump system heats the home and produces hot water for domestic use. The heat comes from the 200-300 m of ground pipes buried horizontally on the property.
Mechanical ventilation
All Plus+energy houses are ventilated with a top-quality ventilation system with a heat exchanger, i.e., a controlled air exchange of approx. 0.5 times per hour. Once you have experienced the air exchange and the resulting increased comfort in the house, you will never want to be without it again.
Natural ventilation
All modern houses must be well ventilated, but not necessarily with a mechanical ventilation system. With so-called natural ventilation, where air exchange takes place through ventilation grilles in walls and windows or man-made ventilation, there is often a significant drop in temperature and discomfort associated with it. Therefore, a mechanical ventilation system is clearly preferable.
Solar cells & Plus+energy houses go hand in hand
Solar energy in the form of solar cells is an integral part of today's construction. A super low-energy house with solar cells on the roof is equivalent to a Plus+energy house. The solar cell system can be installed on a garage or the main house, after which it is connected to the electricity meter. If the house uses less electricity than the solar cells produce, the surplus electricity is sent to the grid, or first to a battery backup and then to the grid. Due to higher electricity prices, solar cell systems are in high demand, and you can therefore make a reasonable profit by installing a solar cell system.
's own energy production Virtually all of Træhuse Nordsjælland's customers will eventually have solar panels installed on either their main house, carport, garage, or outbuilding. The desire to live in a Plus+energy house with its own energy production is highly valued by many customers. The Plus+energy house from Træhuse Nordsjælland is the most future-proof type of home that can be built today, and also the best investment for the future.
Construction
Unique wooden construction
The Plus+energy house from Træhuse Nordsjælland consists of very strong 45 x 245 cm construction timber in high-quality wood with special joints in the outer walls and rafters, which are adapted and assembled on site to form a completely unique wooden construction. The house is built from several patented materials. These modern houses can be supplied with different roof pitches and rafter types of 24°, 30°, 36°, 45°, 48°, and 50°. Houses with a 25° roof pitch are supplied as standard with scissor rafters, while the rest of the rafter types mentioned are typically with or without collar beams but with skunk posts.
Insulation in the Plus+energy house
The ceiling consists of between 400 and 600 mm of insulation (available as mineral wool or wood fiber). The exterior wall consists of approx. 300 mm of insulation (available as mineral wool or wood fiber). The floor consists of between 300 and 400 mm of insulation, depending on class/quality. U-values vary according to insulation quantities, qualities, and materials.
Untreated wood vs. pressure-treated wood
In the very humid Danish climate, pressure-treated bottom rails and facade cladding are a technically sensible solution, but by no means a necessity. Several professionals actually advise against the use of pressure-treated wood, and a responsible construction company will try to avoid using pressure-treated wood in the future. The frame construction and rafters are, of course, supplied in natural wood for the sake of the environment, sustainability, and responsibility. There is no particular risk of condensation when the house is built correctly, and rot damage in the structure is typically only found in houses that have been poorly constructed.
If you want to ensure that your wooden house has the longest possible lifespan, you should choose a modern wooden house where both hidden structures and exterior cladding are built correctly with ventilation and without sloppiness. Pressure-treated wood must be used with care and is not suitable for structures that are built-in and already protected.
Glass areas
The windows in the Plus+energy house are supplied as standard with triple-glazed low-energy glass with argon gas, warm edges, and a U-value of 0.5 W/m²K. The elements feature wood/aluminum profiles from an approved supplier in the best energy class.
floor separation The floor separation in the Plus+energy house from Træhuse Nordsjælland consists of very strong 2 x 10” construction timber in high-quality wood every 50 cm, with special joints in the outer walls and insulation cladding and coverings, which make this structure particularly rigid and significantly better than our competitors. This is a conscious choice on our part, as we base our decisions on our own experiences, dreams, and ideas – quality pays off.
Concrete roof vs. clay tile roof
All our roofs are laid with beautiful red or black clay tiles with a good underlay. This is a conscious choice, as we base our decisions on our own dreams and ideas when it comes to choosing quality materials and beautiful designs. A widely used roofing material is concrete, which is one of the cheapest options, and this is naturally one of the reasons why many construction companies choose it. But another advantage of concrete is that it is available in many colors. However, concrete is artificially colored, with a high probability that the color will fade under UV radiation.
Algae, moss, and patina
Concrete typically lasts for at least 20-30 years and is quick to install because the material is more dimensionally stable—i.e., uniform in shape. Concrete is not resistant to algae, moss, and patina, and you should expect the roof to be severely affected after less than two years. Please note that several large timber house companies supply concrete roofs without underlay as standard, solely to maximize their profits.
clay tile roof Tiles are often the architect's own choice, a beautiful, environmentally friendly, and well-known natural material that also has a Danish identity. Tiles are made from real clay, fired at temperatures above 1,050 degrees Celsius. As the genuine clay color does not fade or change under the sun's rays, the color remains beautiful for a long time. It is said that brick ages gracefully because it develops a natural patina. Another advantage of brick is that the material is highly resistant to algae and moss, as it only takes eight days for a brick roof to dry after 100% wetting. By comparison, the figure is 28 days for concrete. Brick typically comes with a 30-year warranty against frost damage, etc.
The roof is the most important part of a house
Since the roof is the most important part of a building, it is important not to compromise on quality. Quality can be linked to price, but not always. We know that price is an important factor for many people. However, if you choose the cheapest concrete roof solution, you risk it becoming very expensive in the long run, and not looking so good in both the short and long term.
FACADE CLADDING
Create your dream home with the right wood cladding – Træhuse Nordsjælland gives you the freedom to choose
When building a new house, every solution must make sense – functionally, aesthetically, and sustainably. The façade is the first impression of your home and must both express your style and withstand the Danish climate for many years to come. At Træhuse Nordsjælland, we build individually designed, newly constructed wooden houses of uncompromising quality. We place great emphasis on personal service and take the time to listen to your wishes and needs, so that your house becomes a true extension of you and your everyday life. That is why we collaborate with one of Denmark's leading suppliers of wood cladding, which offers one of the market's widest ranges of facade profiles. This gives you access to over 1,000 combination options – and thus the freedom to create exactly the style you dream of.
Express your style – with technical freedom
Whether you dream of a modern, architect-designed look or a classic, charming facade, we offer wood solutions to match. The cladding can be customized with the following technical options:
Profiles
We offer a wide range of facade profiles, including:
• Clinker profile – classic and suitable for a lively, traditional look.
• Double rebate with or without grooves – provides a more modern, clean-lined look.
• Offset cladding or vertical moldings – popular in minimalist new construction.
• Special profiles – can be designed and customized for a completely unique look.
Installation direction and appearance
• Horizontal installation supports the traditional building style.
• Vertical installation gives a modern, streamlined facade appearance.
• Tongue and groove joints ensure concealed installation and a streamlined appearance.
Wood types and treatment
Our wood supplier offers, among other things:
• Heat-treated pine (ThermoWood®) – chemical-free, dimensionally stable, and durable.
• Siberian larch and cedar – naturally robust and beautiful in both color and structure.
• Nordic spruce – light, easy, and suitable for surface treatment.
Ready for color selection – even before installation
A particular advantage of our solutions is that all our facade cladding is delivered dry and therefore ready to be painted, treated, or stained before installation.
This ensures
• A uniform finish and optimal adhesion of paint or oil.
• Far better protection of the wood from day one.
• The ability to choose exactly the color and surface that suits your home.
Not everyone in the industry offers this quality as standard – often the wood is delivered with high moisture content and must be dried further on the construction site, which can lead to uneven paint absorption and an increased risk of cracking. At Træhuse Nordsjælland, we do not compromise: we ensure that the wood is technically ready when it is delivered – and thus one step ahead, both aesthetically and practically.
Modern and romantic – whatever your style
If you want a modern look, we offer facade solutions without visible flashings, so that the wood cladding appears clean and unbroken. With concealed fastenings and straight lines, we create an exclusive, architectural overall impression.
Classic and detailed
If you prefer a romantic and traditional style, we can instead highlight frames, corner moldings, and flashings that frame the house and give it character and warmth. With painted wood and fine carpentry details, we create a new house with soul and history.
Long service life – without toxins
We never use traditional pressure-treated wood. This type of wood contains heavy metals and environmentally harmful substances that are both harmful to nature and difficult to dispose of.
Instead, we work with:
• ThermoWood® – heat-treated wood without chemicals, but with high resistance.
• Naturally durable wood types such as larch and cedar.
• Environmentally approved surface treatments that protect and preserve the appearance of the wood.
This gives you a facade with long durability, low maintenance, and a clear conscience.
A wooden house created with you and for you
At Træhuse Nordsjælland, you don't get a standard house – you get a personalized project from start to finish. We combine architectural freedom, technical knowledge, and personalized advice so that you can confidently create the home that suits your style and values.
With us, you get
• Individually designed houses of uncompromising quality.
• High technical standards and professional responsibility.
• Materials you can vouch for – both aesthetically and environmentally.
• A partner who listens, advises, and follows you every step of the way.
A wooden house is not just a home – it is a choice of quality, thoughtfulness, and beauty.
Thermowood Facade
The advantages of ThermoWood
ThermoWood cladding offers many advantages over pressure-treated cladding, and at Træhuse Nordsjælland we are proud of our collaboration with ThermoWood. Let's explore the advantages of ThermoWood and the disadvantages of pressure-treated cladding.
Advanced heat treatment
ThermoWood undergoes an advanced heat treatment that significantly increases its durability and dimensional stability. This treatment ensures that the wood can withstand external influences and retain its shape and structure over time.
Impressive durability
Due to the heat treatment, ThermoWood has impressive durability and dimensional stability. This means that it can withstand the challenges posed by outdoor conditions such as sun, rain, and wind without losing its quality.
ThermoWood is naturally resistant to rot and wood-destroying fungi. This property ensures that your house remains healthy and free from damage caused by fungal attacks.
Specially designed for outdoor use
ThermoWood is specially designed for outdoor use as a facade material. It can withstand varying weather conditions and is ideal for protecting your home from the elements. One of the biggest advantages of ThermoWood is that it is an environmentally friendly alternative to pressure-treated wood.
Free from harmful chemicals
ThermoWood treatment is free from harmful chemicals, allowing you to choose a sustainable and safe solution for your home. The heat treatment of ThermoWood improves the natural structure of the wood and highlights its growth rings. This gives the wood a unique and aesthetic appearance that will enhance the look of your home.
Minimal maintenance
ThermoWood requires minimal maintenance and will develop a beautiful patina over time, taking on an elegant silver-gray hue. If you prefer to preserve the brown hue, the surface can be treated with a colored or pigmented wood preservative with a UV filter.
certified wood In general, ThermoWood® requires only occasional maintenance to minimize the risk of cracks and splinters. ThermoWood is certified wood that meets strict standards and environmental targets. These certifications prove that ThermoWood® is a reliable and sustainable choice for house cladding.
Durability, aesthetics, and environmental friendliness
Both pine and spruce are popular choices for ThermoWood. Pine has larger and more scattered knots, while spruce has smaller and darker knots. Both options offer unique properties and aesthetics for ThermoWood house cladding.
Overall, ThermoWood cladding is an ideal choice that combines durability, aesthetics, and environmental friendliness. At Træhuse Nordsjælland, we are proud of our collaboration with ThermoWood and recommend it as a reliable and long-lasting solution for cladding our luxury wooden houses in Denmark.
Choose ThermoWood to ensure a beautiful and durable facade material for your house.
For those who want to know more
Indoor climate - Allergies & asthma
Being able to breathe freely
Owning a home where you can breathe freely without worrying about allergies or asthma is crucial for many people in today's society. In Denmark alone, more than 250,000 children and adults, or approximately 4% of the population, suffer from allergies or asthma, and it is a serious challenge for this population group to find a place to live where they can avoid the triggers for respiratory problems.
Relative humidity
Fortunately, there are steps you can take to reduce the risk of allergies and asthma in your home. One of the most effective ways is to keep the relative humidity in your home at an appropriate level, typically between 35 and 50%. This can be a challenge in traditional brick houses or houses with inappropriate wooden structures, where the relative humidity can rise to dangerous levels above 50-60%, allowing dust mites to thrive and cause allergies.
Wooden houses with customized vapor barriers
It is important to choose a high-quality building with highly insulated wooden structures that are only partially impregnated or made from environmentally friendly natural wood. Wooden houses North Zealand is known for building houses with customized vapor barriers that are placed inside the structure so that installations such as pipes and wires do not destroy the vapor barrier. This ensures that the relative humidity is kept down and that house dust mites cannot thrive in the home.
Plus+energihuset from Træhuse Nordsjælland offers an even better solution for people with allergies or asthma. These houses are equipped with a mechanical and well-balanced ventilation system, typically in the form of a counterflow heat exchanger, which effectively removes moisture and odors and keeps the relative humidity below 40-50%. In addition, almost exclusively wood paneling is used on floors, ceilings, and walls, which also contributes to a healthy and allergy-friendly indoor climate.
Reducing the amount of pollen in the house
Mechanical ventilation is an automated process that uses fans and heat exchangers to ventilate and create a fantastic indoor climate. This system is also effective at reducing the amount of pollen in the house and is easy to maintain with regular filter changes. Once you have experienced the freedom and security that comes with living in a house with mechanical ventilation, it will be difficult to do without. Overall, Træhuse Nordsjælland's Plus+ energy houses are the ideal solution for anyone looking for a healthy and safe home without allergies or asthma.
Storms, Earthquakes & Tremors
By choosing a Plus+energy house from Træhuse Nordsjælland, you can be sure that you are investing in a home that is designed to withstand natural disasters such as earthquakes and other tremors caused by storms and hurricanes, for example, and provide a safe and secure environment for your family. The Plus+energy house has the advantage of being able to absorb energy because the connections that hold the house together are both elastic and flexible. Neither brickwork nor concrete has this property. The lightness of wood is also a big advantage, because the lighter the houses are, the less they are affected by vibrations.
Earthquakes and tremors in Denmark
Studies in earthquake zones have demonstrated the many advantages of wooden buildings. For example, a systematic study was conducted of the damage caused by the earthquake that struck California in 1989, measuring 7.1 on the Richter scale. The conclusion was that even near the epicenter, where damage to buildings made of other materials was extensive, no wooden houses built in accordance with current regulations suffered catastrophic damage. Studies conducted in Denmark by Geus have recorded earthquakes since 1930. Since the beginning of 2008 alone, more than 2,000 tremors have been recorded in Denmark.
1954: An earthquake measuring 4.6 on the Richter scale struck southwest of Thisted in northern Jutland.
1967: An earthquake measuring 4.5 struck in the North Sea west of Klitmøller.
1985: An earthquake measuring 4.7 struck the seabed north of Gilleleje in North Zealand.
2008: An earthquake measuring 4.8 on the Richter scale struck Sweden about 65 kilometers east of Copenhagen. The tremors were clearly felt throughout Copenhagen and in several surrounding municipalities.
2010 and 2012: Two earthquakes measuring 4.3 on the Richter scale struck in the North Sea west of Thy and in the middle of the Kattegat, respectively.
2018: An earthquake measuring 3.4 on the Richter scale struck West Jutland.
The five most powerful storms in Denmark
Based on wind speed and the damage they caused:
1. Storm Allan – October 2013
• Average wind speed: 39.5 m/s (142 km/h) at Røsnæs, Zealand.
• Wind gusts: 53.5 m/s (193 km/h) at Kegnæs, Als – the highest wind gust ever recorded in Denmark.
• Damage: Extensive damage to buildings and infrastructure, including destroyed S-train overhead lines and fallen trees.
2. Storm Bodil – December 2013
• Average wind speed: Up to 36.6 m/s (130 km/h) at Nissum Fjord.
• Wind gusts: Up to 63.6 m/s (229 km/h) in Scotland.
• Damage: Extensive flooding in Roskilde Fjord and along the coast of Zealand, including Jyllinge Nordmark and the Viking Ship Museum.
3. The hurricane – December 1999
• Average wind speed: Over 40 m/s (144 km/h) in parts of Denmark.
• Wind gusts: Up to 51.4 m/s (185 km/h) in Denmark.
• Damage: Extensive damage to forests and buildings, especially in the southern part of Zealand and Funen.
4. Storm Pia – December 2023
• Average wind speed: Up to 30.3 m/s (109 km/h) at Torsminde.
• Wind gusts: Up to 44.0 m/s (158 km/h) at Thyborøn.
• Damage: Moderate damage to infrastructure and buildings.
5. Storm Urd – December 2016
• Average wind speed: Up to 29.4 m/s (106 km/h) at Torsminde.
• Wind gusts: Up to 37.8 m/s (136 km/h) at Torsminde.
• Damage: Moderate damage to buildings and infrastructure.
These storms have had a significant impact on Zealand and have caused extensive damage to both nature and infrastructure. The hurricane in 1999 and Storm Allan in 2013 are particularly noteworthy for their extreme wind speeds and the extensive damage they caused.
Eurocode 8 for timber structures
In Europe, Eurocode 8 is the applicable standard for timber structures in earthquake zones. This is a comprehensive standard that ensures that timber houses meet strict requirements to protect against earthquakes.
Brick or aerated concrete houses vs. wooden houses
Earthquakes and tremors during storms can be devastating, and it is important to consider which type of house is safest. When it comes to choosing between brick houses, aerated concrete houses with brick facades, or wooden houses, it is impossible not to mention the advantages and disadvantages. Wooden houses can move with the ground, and their flexibility can significantly reduce the chances of structural damage in the event of violent tremors.
Brick and concrete houses are more susceptible to structural damage in the event of an earthquake or other tremors due to their rigid structure, which makes it more difficult for the house to withstand the tremors and can thus increase the risk of damage and collapse.
Most commonly used foundation types
The importance of having a soil analysis carried out
A soil analysis is essential, as soil varies from place to place and has a significant impact on the choice of foundation and the stability of the structure. The analysis determines the soil's bearing capacity, compression properties, and ability to resist settlement or movement. Without a proper analysis, you risk choosing a foundation that is not strong or stable enough for the specific soil conditions at the construction site. This can lead to serious structural problems and damage to the building.
Geotechnical engineers
Træhuse Nordsjælland's skilled geotechnical engineers have extensive experience with soil analyses, environmental surveys, and foundations. Supervision is carried out during construction to ensure customer safety.
Here are the most common types of foundations, along with some information about the importance of conducting a soil analysis and the possibility of conducting an environmental survey at the same time:
A standard foundation is the traditional method of supporting a building. It typically consists of concrete posts, beams, and a concrete slab that is poured directly onto the ground. This foundation is suitable for areas with stable soil and is a reliable solution for standard house construction. It prevents the building from collapsing (settling) and protects against moisture penetration into the walls of the house.
Pile-framed foundation
A pile foundation is necessary in areas with unstable soil or risk of flooding. This foundation involves the use of vertical piles or columns that are either driven or drilled into the ground. These piles support the weight of the building and prevent settlement. Pile-framed foundations provide deep and solid support for the building and are essential in coastal areas and areas with soft soil.
A bored foundation involves drilling deep holes in the ground, often using a drill, and then filling the holes with concrete. This creates a strong post or column under the building and is ideal for heavy-weight buildings or in areas with complex soil conditions. Drilled foundations prevent the building from sinking or moving due to uneven ground.
Steel screw foundations with or without concrete
New steel screw foundations use large steel screws or pins that are screwed into the ground for stability. This method can be used with or without concrete.
Steel screw foundations without concrete are suitable for light or temporary structures, while those with concrete provide extra strength and stability. They are also useful for raising buildings above ground level to protect against flooding.
Sand cushions are a less conventional type of foundation in which the building is placed on a layer of compacted sand. This method is typically used in areas with good drainage and stable soil. Sand cushions are easier to install and can be cost-effective, especially for smaller or lighter structures.
Possibility of an environmental survey of the soil
At the same time as the load-bearing capacity surveys, it is an excellent opportunity to conduct an environmental survey of the soil. This involves assessing the condition of the soil for any pollutants or environmental considerations. It may be crucial to ensure that the building is constructed in a safe and environmentally friendly manner. If contamination is found in the soil, further steps can be taken to deal with this and protect both the environment and residents.
Geotechnical engineers
With Træhuse Nordsjælland's and the geotechnical engineers' extensive experience and supervision during construction, you can feel confident that you are getting the most suitable and reliable solution for your construction project, which takes into account both the load-bearing capacity of the soil and environmental aspects.
We guide you through the process
Træhuse Nordsjælland specializes in the construction of luxury wooden houses in Denmark and guides you through the process of choosing the right foundation.
Solar cell facts
Electricity from sunlight
Solar cells produce electricity directly from sunlight and can be installed on the roof of a building or on the ground.
What are solar cells and solar cell systems?
According to DTU, the Earth receives an average of 100,000 terawatts of energy from the Sun. This exceeds the Earth's average human power consumption (approx. 15 TW) more than 6,000 times. In just an hour and a half, the Earth receives enough energy from the Sun to cover the world's energy needs for a year. We just need to learn how to use it optimally.
Solar cells are often confused with solar heating systems. But while solar heating systems produce hot water, solar cells produce electricity. Solar cells are a pollution-free energy source that produces electricity from sunlight, if you disregard the pollution caused by the production, transport, installation, and disposal of solar cells.
There are three types of systems:
• Grid-connected solar cell systems
• Grid-connected systems with buffer/backup battery
• Off-grid solar cell systems
Off-grid systems are also known as stand-alone or island-operated solar cell systems and are not connected to the electricity grid. Stand-alone systems, on the other hand, store the electricity they produce in batteries. The electricity from solar cells is direct current, and in order for it to be used in a power outlet, it must be converted to alternating current. This is done using a grid inverter, which is placed inside the house near the electricity meter. From the grid inverter, the electricity flows into the house's power outlets mixed with electricity from the power company.
solar cell system A solar cell system consists of a series of modules that are connected together. In principle, there are no restrictions on the size of the system. The desired output and the physical possibilities are decisive for the size of the system. If you have solar cells on several different roof surfaces, you should purchase several inverters, i.e. one for each roof surface, to ensure optimal utilization, as efficiency in relation to location varies depending on the time of day.
Types of solar cells
Almost all solar cells available on the Danish market today are crystalline and based on silicon. However, there are also newer types, as shown in the overview below. Research is being conducted into countless combinations and solar cell technologies, but the most common types at present are those listed below.
| Type | Utilization of solar energy | Advantages and disadvantages | Lifespan |
| Silicon-based solar cells | Up to 22% | Delivers the most cost-effective performance. Must be protected by glass. Made of silicon at 1000 degrees Celsius. Contains a small amount of heavy metals (e.g., lead) in the solder joints. | 25-50 years |
| Thin-film solar cells CIS (Copper – Indium – Selenium) CIGS (Copper – Indium – Gallium – Selenium) CdTe (Cadmium – Tellurium) | Up to 19% | The raw materials in CISG often come from recycled electronics. Can be produced in all colors, including transparent. Not shade-sensitive. Both cadmium and tellurium are toxic to humans and the environment, and there are not unlimited quantities of tellurium available – but production is cheaper and has lower CO2 emissions compared to silicon. In addition, most of the materials can be recycled. | +25 years |
| Organic solar cells (polymers and PEC) | Approximately 10% (in studies/laboratories up to 18%) | Thin and flexible. Environmentally friendly and inexpensive compared to other solar cell technologies. Available in different colors, including transparent. Made from carbon at 100 degrees Celsius. Not sensitive to shade. Can be placed on/in windows and glass sections. | 10 years |
| Perovskite-based solar cells | Up to 25% | Cheap, and materials are abundant, but have an excessively short lifespan. Contains a quantity of heavy metals (e.g., lead). | 1 year |
| Inorganic-based multi-junction panels Gallium Arsenide (GaAs) | Up to 46% | Extremely expensive and difficult to build. Currently, it only makes sense for space exploration/satellites, and not for energy production on Earth. |
Silicon solar cells
80 to 95% of the world's solar cells are based on silicon, whereas perovskite has not yet made a major breakthrough. One reason for this is that perovskite contains lead. Nevertheless, research into perovskite solar cells is continuing in the hope that they will become the technology of the future due to their simpler manufacturing process, lower costs, and greater flexibility. CIS and CISG are also gradually gaining market share, especially in integrated solutions.
Silicon-based solar cells can be further divided into three types:
Monocrystalline solar cells (c Si – black) | 20-22% utilization |
Polycrystalline solar cells (c Si – blue) | 14-16% utilization |
Thin-film solar cells/amorphous solar cells (a Si – brown/black) | 7-12% utilization |
Monocrystalline solar cells
A monocrystalline solar cell consists of a single silicon crystal. The solar cells are black as standard with a uniform surface. They are usually rounded at the corners, but if a particularly tight fit is required in the finished module, they can be cut into squares. The individual cells are mounted in a metal grid between two layers of glass or between a glass and a plastic layer. The metal grid acts as a contact network.
Alternatively, a newer technology called "shingled cell" has been invented, which means that the cells overlap each other and are electrically connected via an electrically conductive adhesive. This way, there are no gaps between the cells, and the metal grid can be omitted.
Polycrystalline solar cells
Polycrystalline solar cells contain several silicon crystals that are molded into a shape, and they often come in shades of blue. The individual crystals in the solar cell reflect light differently, creating a "living" surface. They are available with or without frames. Polycrystalline solar cells can be colored to the color specified by the builder, but coloring the solar cell will reduce its efficiency and affect the price.
Polycrystalline cells have a slightly lower efficiency per square meter than monocrystalline cells. Thin-film solar cells and amorphous and non-crystalline types
Thin-film solar cells are also referred to in some contexts as second-generation solar cells and are based on amorphous silicon. We are familiar with them from pocket calculators, among other things. Their efficiency is lower than that of crystalline solar cells, and they are therefore also cheaper. In this case, the photoactive semiconductor is amorphous silicon (formless or non-crystallized silicon), onto which a supporting substrate, usually glass, is vapor-deposited. Amorphous silicon is by far the most developed technology. Amorphous or micromorph solar cells are available in many forms.
Although the effect is not as significant on thin-film solar cells, they also have other advantages. Among other things, they can withstand significantly more heat than crystalline cells, as well as significantly more shade.
Building-integrated photovoltaics
– solar roof – BIPV
The additional cost of installing building-integrated photovoltaics compared to traditional roof and facade materials is limited. Therefore, the market for building-integrated photovoltaics is expected to grow significantly in the coming years.
Retrofitting solar cells to existing roofs with rail systems (BAPV) is not always the best solution. Solar cells can be installed to great effect in connection with new builds or renovations of existing roofs.
What can solar cells produce in Denmark?
It is best to use the electricity at the same time as it is produced. You can therefore consider placing the solar cells on different roof surfaces, if possible. This way, you will get production and thus utilization of the sun throughout the day, although not with 100% efficiency in production.
A south-facing location produces the most kWh, but east and west-facing locations produce less, meaning that more is available early in the morning and late in the evening.
In order for solar cells to be connected to the power grid, direct current (DC) must be converted to alternating current (AC) in a special grid inverter or converter, which converts the current to 230 volts.
Production also depends on the season. As a rule, electricity production peaks in May and is lowest in January.
Percentage of annual energy production from solar cells
The figure shows the percentage of annual energy production from solar cells at different angles and orientations, relative to the ideal location facing south and at an angle of 35-40 degrees.
Production in Denmark at an optimal location
| Percentage distribution of production over the year | Plant size: 3000 kWh | Daily average production (kWh) | Plant size: 6000 kWh | Daily average production (kWh) | |
| January | 1% | 30 | 1 | 60 | 2 |
| February | 5% | 150 | 5 | 300 | 10 |
| March | 8% | 240 | 8 | 480 | 16 |
| April | 12% | 360 | 12 | 720 | 24 |
| May | 15% | 450 | 15 | 900 | 30 |
| June | 13% | 390 | 13 | 780 | 26 |
| July | 14% | 420 | 14 | 840 | 28 |
| August | 12% | 360 | 12 | 720 | 24 |
| September | 9% | 270 | 9 | 540 | 18 |
| October | 6% | 180 | 6 | 360 | 12 |
| November | 3% | 90 | 3 | 180 | 6 |
| December | 2% | 60 | 2 | 120 | 4 |
What are the advantages and disadvantages of solar cells?
Advantages of solar cells:
- Solar cells are noise-free, do not pollute, and have no moving parts.
- Contributes to the green transition, where Denmark has decided that we must use 100% renewable energy by 2050.
- Solar cells have a long service life. They typically come with a 25-year warranty, and since the technology has no moving parts, it is robust and reliable with low maintenance costs.
- Solar cells can be integrated into the architecture of the building – either as a building element in roofs and facades, installed in windows, or as sunshades.
- Solar cells can replace part of the facade or roof covering, thereby saving on the cost of these building components.
Disadvantages of solar cells:
- Solar power systems typically have a payback period of 10-15 years. That's not very long, but it still requires you to think carefully before investing.
- During installation, there may be challenges in terms of both fastening and the load-bearing capacity of the roof structure.
- Solar cells only produce electricity during daylight hours, when you are not at home for most of the time anyway.
- Even small amounts of shade can significantly reduce electricity production, so it is not a good idea to have trees near the plant that could shade it.
- The yield of solar cells from hours of sunshine is limited during the winter season.
- From a purely aesthetic point of view, it can be challenging to install solar cells in a way that fits in with the architecture of the building, unless they are integrated into the building itself (BIVP).
- Solar cells can reduce the value of a home if they do not fit in with the aesthetics of the building.
Price of solar cells – is it worth it?
The price ofsolar cells has fallen over the years, so a correctly installed solar cell system typically has a payback period of 10-15 years, or to put it another way, the building owner will have a larger disposable income from the first year than if a solar cell system had not been purchased.
If you don't think you can afford to invest in solar cells at the moment, you could prepare areas on the building where they can be installed when/if the price becomes more favorable.
What should you research and consider before installing a solar power system?
Before installing a system, you must first and foremost ensure that you have a place to put it, including making sure that the roof can support the system if you want to mount it on a roof.
Sensitive to shadows
Some solar cells are sensitive to shadows, as their performance is significantly reduced. It is therefore important that there are no trees, antennas, chimneys, branches, etc. that can cast shadows over the solar cells during daylight hours. Trees grow, so think ahead before planting a small tree in your garden.
Architecturally, the biggest challenge is to adapt building-integrated photovoltaics (BAPV) to the building so that they do not appear as foreign elements that detract from the architectural quality of the building. It is a good idea to seek advice from an architect in this regard.
Installation of solar cells
It can be difficult to install solar cells on detached houses, for example, as they often have many details and protrusions that can cause unwanted shade. Often, there is also only a small total roof area on which to place the solar cells. Instead, solar cells can be installed on carports, greenhouses, and other small buildings or as freestanding structures, such as pergolas.
In our latitudes, solar cells are best placed facing south with a tilt of 30-45 degrees to achieve 100% efficiency. However, east- and west-facing solar cells also perform acceptably, but best at a tilt of 0-30 degrees, where production efficiency reaches 80-85%.
When positioned vertically (90 degrees), e.g. on a facade, efficiency is reduced by 20-40 percent, but on the other hand, efficiency is greater in autumn, winter, and spring, when the sun is lower in the sky.
Before choosing the final location for a solar power system, you should check the following:
- What does the local plan say? This applies especially in summer cottage areas.
- Is the building listed or worthy of preservation?
- Are there rules governing the appearance of the building's facade?
- What do the building regulations say about height limits (building height in relation to boundaries and neighbors)?
- Are there any trees, building parts, flagpoles, or similar objects casting shadows?
- Can solar cells bother neighbors with reflections? Solar modules don't reflect more than a skylight, but neighbors might still object, and in the worst case, they could plant a tree—which is totally legal. There are solar cells with anti-reflective coatings.
- Where is the optimal location in relation to the cardinal directions and the angle of the solar panels?
- Which location harmonizes best with the building? Get advice.
When choosing which type of solar cell to use, you should consider the following:
- What are your requirements for service life?
- Do you have any specific requirements regarding shape and color? How will they fit in with the building?
- Should the modules be installed freestanding on the ground or integrated into a building?
- If you are looking for the most sustainable solar cell, you can check the CO2 footprint of the solar panel before you buy.
In addition, there are a number of technical requirements regarding installation that you need to consider. Ask an architect or engineer for advice.
In Denmark, authorization is normally required to install solar cell systems. The Danish Energy Agency has introduced a VE installer scheme, and it is recommended that you choose a VE-approved solar cell installer.
How long does a solar power system last?
Suppliers typically provide a 15-25 year performance guarantee on the cells. However, the grid inverter or converter will not last more than 10-20 years, depending on the type and make. Therefore, you should expect to replace it during the lifetime of the solar cell system.
How much do solar cells and solar power systems cost?
Below are four price examples (2023 prices) of what a solar cell system might cost, suitable for most Danish households with an annual electricity consumption of around 6,000 kWh.
Price example 1:
A single silicon solar panel (shingled) costs approx. DKK 3,600. This can provide 400 Wp and covers an area of 2 m². To achieve an output of 6 kWp (kilowatt peak) – equivalent to approx. 6,000 kWh – you will need 15 panels/30 m² of space.
The price of the panels alone for 6 kWh production is DKK 55,000. Added to this are the costs of the inverter, cables, and mounting/rail system.
Price example 2:
Monocrystalline panels totaling 6 kWh with a 5kWh battery. Complete system with rail system, inverter, and cables = DKK 115,000 incl. VAT, excluding installation.
Price example 3:
Polycrystalline solar cells on a total 6 kWh system – including installation and connection = DKK 110,000 incl. VAT.
Price example 4:
Integrated solar cells in tiles on a 200 m2 roof surface. The price for a black 3.6 kW system (producing approx. 3600 kWh per year) is approx. DKK 175,000 incl. VAT in material costs. Of this, 36 m2 of the 200 m2 tiles are solar cells. The price does not include installation costs. The price of this type of roof is therefore DKK 800-950 per m2.
Settlement of electricity production with solar cells
When you have solar cells, you can be billed in different ways. This depends on the type of net metering you are approved for. The Danish Energy Agency determines how you, as a solar cell customer, can be billed.
There are three different types of settlement groups for selling your surplus electricity. However, if you establish a private system now, the only option is settlement group 3.
The unique GSRN number
The electricity company from which you receive your electricity bill is not (necessarily) the same as your grid company. Your grid company supplies electricity to your household and settles this with your electricity company. It is your grid company that assigns your solar cell system its unique number (GSRN number), which you must use if you want to enter into an agreement with a company that wants to buy your surplus solar cell electricity.
You can receive payment for any surplus production from a production supplier. The list of production suppliers is available atEnerginet.dk. There are currently five suppliers on the list (February 2023). You must contact one of these suppliers yourself to make an agreement.
Overview of settlement groups
Net settlement group 3 is settled on an instantaneous basis. This means that production must be used at the same time as it is produced, otherwise it will be lost to the grid. No application for approval must be submitted to the Danish Energy Agency for instantaneous settlement. The grid company must simply be contacted to agree on connection.
Net settlement group 2
It is no longer possible to apply for approval for group 2, which is hourly settlement. Plant owners who have received approval have two years to establish and connect their plants. The two years are counted from the date of approval. This means that there will continue to be plants approved for hourly net settlement until 2024, as applications for approval for hourly net settlement were processed in January and February 2022.
Net settlement group 6
Net settlement group 6 (only for installations installed no later than 2012) is settled annually and does not exceed 6 kW. Flexible settlement system owners receive monthly statements for consumption. Production is settled by another operator, and the Danish Energy Agency pays a price supplement for the number of kWh registered at the "Surplus production" metering point. On January 1, 2021, all Danish electricity customers in group 6 should have switched to flex settlement.
Battery for solar cells
If you choose to purchase a solar cell system that supplies more than 50% of the electricity you use per year, you should consider purchasing a battery system.
The battery can be charged using the output from your system or via the grid, and it will typically start charging when there is a surplus of output relative to household consumption.
Charging at night
In winter, if your inverter has the technology to do so, you can, for example, charge your battery at night from the grid, when electricity is cheap, and then use the stored energy during the day, when electricity is expensive.
In general, battery utilization is about charging your battery as cheaply as possible and using the stored energy when electricity is expensive. With this strategy, you can save money every day and turn your battery into an investment in a short time.
You should ensure that your batteries are placed as close to the inverter as possible, as there will be direct losses in the cables the longer they are.
Are solar panels environmentally friendly?
A report from Aalborg University conducted in 2021 casts doubt on whether solar cells are always beneficial for the climate. It turns out that half of the solar panels available in stores do more harm than good. The study's top performer is a system that would need to produce electricity for 48 years to generate the amount of energy used to produce the energy source itself. The panel that performed best would start producing CO2-neutral energy after just three years. However, there have been major developments in this area, and there are now several solar cells on the market with a significantly improved climate payback period since the study was completed.
This is because the CO2 footprint from production is often so large that the climate-friendly effect of producing green electricity cannot make the climate footprint positive during the expected lifetime of the solar cells.
If solar cells are produced in a country where the electricity used to manufacture them comes from environmentally harmful energy sources (coal, gas, oil), they will have a greater impact on the climate than if they were produced in a country where green energy is used for manufacturing.
It is therefore important to investigate where the solar cells are manufactured before investing in a panel – but this can be difficult for the average consumer to ascertain, as there is not yet a common system for this area.
Source: Bolius
Frequently Asked Questions
What effect does a thatched roof have on sound and unwanted heat from outside?
With their traditional charm and cosiness , thatched houses candampen sound and keep cool in summer. The thick layer of thatch provides excellent insulation against both sound and heatfrom outside, which also reduces the need for cooling systems.
How do you build a storm- and earthquake-proof wooden house?
Storm andearthquake-resistant homes often use innovative construction techniques and materials that inherently offer superior insulation properties. By focusing on structural integrity, these homes can maintain consistent temperatures, reducing reliance on heating systems while also protecting against damage from storms, for example.
What distinguishes architect-designed wooden houses from other houses?
Architect-designed wooden houses are carefully planned and well thought out in order to optimize energy. With advanced placed insulation, wind-resistant conditions, windows, doors and efficient systems minimise these home energy, while they maximize comfort and sustainability.
Why are energy-efficient luxury wooden houses being sold in Denmark?
Energy-efficient luxury wooden houses in Denmark are with technologies in order to meet high standards for comfort and sustainability. From groundbreaking insulation to smart heat– and cooling systems offer these homes both luxury and environmental responsibility.
How can a luxury wooden house in Denmark incorporate renewable energy sources?
A luxury homefrom Træhuse Nordsjælland can haveintegrated renewable energy sources such as solar panels, inverters, batteries, ventilation , and geothermal heating to increase energy efficiency and reduce environmental impact. These eco-friendly features complement the exclusive amenities and create a harmonious blend ofluxury living and sustainability.
What role do energy-efficient windows play in modern residential design?
Energy-efficient windows, such as those with super-low–energy glass and argon gas insulation, helps to minimizing heat loss and maximize natural light. By reducing the need for artificial heating and lighting contributes these windows to the total energy savings.
How do ground source heat pump systems improve the energy performance of a home?
Ground source heat pumps use renewable geothermal energy to to supply heating and cooling, which offers an highly effective alternative to traditional systems. By utilizing the stable temperatures ensures these pumps consistent comfort with minimal energy consumption.
