Welcome to the PRISMA® PVT Knowledge World. Here you will find concise answers to frequently asked questions. Discover content that is clearly presented and helps you to easily and comprehensibly grasp the full potential of hybrid PVT systems.
PRISMA® PVT - Products
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Frequently asked questions
Yes, in many cases, using a PVT system is worthwhile – especially when on the
The property requires both electricity and heat. With PRISMA® PVT combine
Photovoltaics and solar thermal in one module, making double efficient use of your roof space.
This allows:
– Heating + hot water off 100% cover
– a significant proportion of the Power consumption generate them yourself,
the Increase self-consumption in conjunction with a heat pump and thus significantly reduce energy costs in the long term.
Another advantage: PRISMA® PVT achieves in the...
Comparison to conventional PV modules higher current yield, especially with
summery temperatures.
Whether a PVT system pays off in your specific case depends, among other things, on the
Roof area, orientationthe Primary energy requirement of the building and the available
Support programmes BAFA and KfW offer various funding programmes that
Significantly reduce acquisition costs.
The yield of a PRISMA® PVT The system depends on several factors – for example, the location, roof pitch, orientation, and system size. Nevertheless, typical values can be stated:
electricity yield:
One PRISMA® PVT-System with e.g. 10 modules (450 W) can annually generate around max in Germany.
4,500 to 5,000 kWh Generate electricity – dependent on solar radiation and roof orientation.
Heat yield:
At the same time Approx. 2,000 to 3,500 kWh thermal energy is generated – ideal for
Domestic hot water preparation with insulated modules or as a renewable source for a heat pump.
Thanks to the active cooling the PV cells Can PRISMA® PVT on an annual average 5–10 % more power
produce than conventional PV systems.
Cooling with PRISMA® PVT This is achieved via an integrated, water-cooled duct system on the rear of the modules. This system absorbs the heat generated by solar radiation and transfers it to the source side of the heat pump or releases it via a heat exchanger to
a buffer tank out.
This so-called Active recooling has two main advantages:
More electricity yield through cool PV cells
Photovoltaic cells lose efficiency when exposed to heat - the warmer they get, the lower their output. Active cooling ensures that the cells work at the optimum temperature. The result: Up to 10 % more electricity yield compared to conventional, uncooled PV modules - especially on hot summer days.
Simultaneous heat utilisation
The heat extracted is not wasted but used purposefully – for example, for hot water preparation, for heating support, or as an efficient energy source for a heat pump. This way, surplus heat is turned into a valuable benefit.
Cooling is therefore a central element of PVT technology: it improves the Electricity production,
increases the Overall efficiency and enables a Dual utilisation of solar energy – on the same
Roof area.
Yes, the PRISMA® PVT Collectors are designed to fit flexibly into existing heating systems can be integrated. It is suitable for both New buildings as well as for the Retrofit in existing buildings.
Typical applications:
Combination with brine heat pumps
The PVT system supplies the heat pump with source energy all year round.
Connection to buffer storage or stratified storage
The heat from the PVT modules can be fed directly into a storage tank and used as needed – for example, for hot water or to supplement heating.
Supplement to existing heating systems
Even in conjunction with gas or pellet heating systems, PRISMA® PVT can contribute as a regenerative heat source to reduce fossil fuels.
The energy distribution for a PRISMA® PVT Installation is carried out in two separate but coordinated systems: for Electricity and for Heat.
1. Electricity distribution (photovoltaic share):
The solar power generated is converted into standard household alternating current via an inverter and then:
- used directly in the household (e.g. for lighting, household appliances, heat pump),
- cached in a power storage device (if available),
– or into fed into the public gridif more is generated than required.
An intelligent energy management system can optimise self-consumption by, for example, specifically activating consumers when there is sunshine.
2. Heat Distribution (Thermal Component):
The heat generated from the modules is utilised via a Water-based pipework system to a Buffer storage tank or Stratified storage in the house. From there, the heat is utilised as follows:
To Hot water preparation (e.g. for shower or kitchen),
– or as Heat source for a heat pump.
A control system ensures that the energy is distributed efficiently and used as required - depending on the time of day, outside temperature and consumption profile.
In short:
The electricity flows into the house's power grid like with any PV system, while the heat is
hydraulically integrated – e.g. in a storage tank, heat pump or heating circuit. Both energy flows
work parallelbut Intelligently coordinated, to make the best use of the energy
PRISMA® PVT Modules are extremely Easy to clean and for a Long-term, low-maintenance operation designed. Both the photovoltaic and the thermal part of the module work reliably for many years - with minimum effort.
What you should know:
Low-maintenance hydraulic system:
The integrated water system is closed, pressure-tested, and made with high-quality materials. With professional installation, it only requires low control.
Long-term security:
The modules are designed for a service life of 25 years and more designed. The function remains even after decades – provided the system is operated in accordance with the manufacturer's specifications
As a rule No manual snow clearance required. The PRISMA® PVT Modules have several properties that a Rapid snowmelt promote:
Why snow usually melts by itself:
Heat dissipation at the module surface:
As the PVT modules not only generate electricity, but also heat, they give off heat even at low levels of solar radiation. heat to the module surface. This significantly accelerates the melting of snow - often even in daylight.
Glass-glass surface with low adhesion:
The smooth, high-quality glass surface ensures that snow sticks less well and slips off more easily – particularly on roof pitches of approximately 20 degrees or more.
Optimised arrangement:
Due to the installation in an inclined position and the heating from the inside to the outside, snow often slides off by itself - much earlier than with conventional PV modules.
When does an eviction make sense?
Only for longer periods of heavy snowfall and persistently low temperatures it can be useful in rare cases to remove snow manually – but only with appropriate aids (e.g. telescopic, soft snow shovels) and without damaging the modules. In most regions of Germany this is not necessaryas the thermal effect of the modules ensures a Automatic defrosting provides.
No, that the PRISMA® PVT The modules work absolutely silently.
No noise on the modules:
There are no active components on the roof - there are Neither whirring fans nor humming motors.
Noise only possible in the plant room (as with any heating system):
Only in the Hydraulic unit or in the area of Heat pump Depending on the system, low flow or pump noises may occur. However, these are at the level of conventional heating systems and are not in the living area.
Especially suitable for quiet residential areas or where there is no space for an outdoor unit of a conventional air source heat pump:
Thanks to its silent function, PRISMA® PVT is also ideal for Detached houses,
Terraced houses or buildings with high Sound insulation requirement.
The economic efficiency of a PRISMA® PVT The system depends on several factors, including your Electricity and heat consumptionthe Size of the systemthe Locationthe Energy pricesthe available Support programmes and how you operate and use the system.
Typical amortisation period:
In many cases, a PRISMA® PVT system already pays for itself after 5 to 8 years – partly also considerably faster if high self-consumption rates are achieved and state funding (e.g. BAFA subsidy) is used.
Why PRISMA® PVT can pay off particularly quickly:
– Dual use of the roof area (electricity + heat)
– Increased self-consumption = lower energy costs
– Higher electricity yield through active cooling
– Independence from rising energy prices
– Eligible through various programmes
– Regeneration of Earth probes
In most cases no planning permission requiredwhen the PRISMA® PVT Attachment on a pitched roof is installed. Like photovoltaic or solar thermal systems, it is then considered a Project without authorisation according to the respective state building regulations.
What you should bear in mind:
Roof mounting (standard case):
Installation on the roof of the house is usually licence-freeas long as there are no listed building or special structural requirements.
Flat roofs, garages, outbuildings:
Here too, permission is generally not required – unless special conditions apply, e.g. in the development plan or in protected areas.
Ground-mounted systems or large commercial projects:
Here you can Building or nature conservation licences be necessary. The same applies to installations on listed buildings.
Mandatory reporting:
Regardless of the requirement for authorisation, every electricity-generating plant must be registered with the Network operator and in the Market Master Data Register (MaStR) be registered with the Federal Network Agency. This also applies to PVT systems
Yes, in most cases it is even implemented that way. Fortunately, we at TWL-Technologie GmbH offer visually identical PV modules to match our Prisma PVT collectors. This means it is not only technically sound, but also aesthetically uniform.
A PVT heat pump uses that of PVT hybrid collectors provided environmental energy to Heating of buildings and for Hot water preparation. The collectors simultaneously generate electrical energy from sunlight and heat from the ambient air and solar radiation.
The recovered heat is via a closed brine circuit transported to the heat pump. There, a thermodynamic process raises the temperature level so that the energy can be used for heating and hot water.
Unlike conventional air-source heat pumps, no separate outdoor unit required. Energy is absorbed via the PVT collectors on the roof, while the heat pump itself inside the building is being installed. This eliminates fan noise in
exterior area, which can be particularly advantageous in densely built-up residential areas.
That means: The PVT collectors supply electricity and heat, while the heat pump makes the captured environmental energy usable for heating and domestic hot water.
Click here for our List of PVT-ready heat pumps.
So that a PRISMA® PVT system can operate optimally and be installed safely, your roof should meet certain structural and technical requirements.
1. Load-bearing capacity
The roof must bear the additional load of the modules (Kerb weight approx. 33kg per module) and the substructure be able to bear it. The structural suitability is checked in advance by the installation company. PRISMA® PVT Modules are thanks to the glass-glass construction and the absorber heavier than pure PV-
Modules, but remain within the usual load range.
Orientation & Tilt
Optimal: South-facing with approx. 30-45° inclination
Well suited: South-east or south-west orientation
East, west or even north-facing installations can also be used, albeit with a slightly reduced yield.
3. Roof area
For a standard module (approx. 1.76 m × 1.10 m), depending on the planned system size, you will need sufficient contiguous space. We recommend approx. 2 modules per kW of heating load.
4. Roof skin & condition
The roofing (e.g. tiles, slate, metal) should be in good condition be. With older roofs, it can be sensible to renew the roof cladding prior to installation.
Almost every sturdy detached house roof can be used for a PRISMA® PVT system – the decisive factor is a thorough planning of the conditions.
These key figures describe the Efficiency of heat pumps. They show how much heat from a deployed kilowatt-hour (kWh) of electricity can be generated.
COP (Coefficient of Performance)
The COP value describes the efficiency of a heat pump under specified laboratory test conditions. It serves primarily for comparing different devices.
SCOP (Seasonal Coefficient of Performance)
The SCOP looks at performance over an entire heating season and takes into account different outdoor temperatures. As a result, it is more practical than the COP value.
SPF (Seasonal Performance Factor)
The annual performance factor indicates how efficiently a heat pump actually operates over the course of a year. It is determined using real operating data and takes into account, amongst other things, the heating system, the building characteristics and user behaviour.
SCOP (Seasonal Coefficient of Performance)
The system annual performance factor considers not only the heat pump itself, but the entire heating system. This can include, for example, heat sources, pumps, thermal stores, control technology or other system components. The SAPF therefore provides a particularly realistic picture of an installation's overall efficiency.
As a general rule:
The higher the COP, SCOP, JAZ or SJAZ to be cancelled, the more efficiently the system works and the less
Electricity is needed to provide heat.
Potential disadvantages:
– Higher investment costs than a purely photovoltaic system.
– Even lower market penetration than classical PV systems.
– Additional components such as pipework, hydraulics or storage cylinders may be required.
Common myths:
❌ „PVT only works when the sun is shining.“
✔️ PVT uses ambient heat in addition to solar radiation.
❌ „PVT is loud.“
✔️ PVT modules operate without a fan and do not cause any operational noise on the roof.
❌ „PVT does not supply energy in winter.“
✔️ PVT can also generate heat at low outside temperatures.
❌ „PVT requires more roof space than PV.“
✔️ PVT uses the existing roof space twice for electricity and heat generation
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Conclusion
A decision that pays off
A PVT system such as PRISMA® makes optimum use of the existing roof area of your detached house - and reliably supplies electricity and heat from a single source. This not only improves the energy efficiency of your home, but also permanently reduces CO₂ emissions and makes you less dependent on rising energy prices. The technology is manufactured in Germany, designed for durability and comes with a 25-year performance guarantee on the PV. In combination with a heat pump, storage system and state subsidy, the result is a well-thought-out solution - for greater self-sufficiency, greater cost-effectiveness and greater security for the future.
Please note!
As a manufacturer/wholesaler, we only supply the specialised trade and craftsmen.
If you are a private customer and would like a quote, please send your request for a quote to your local installer.
However, we are happy to offer you as a private customer an initial consultation or information by e-mail.
