The sun is a precondition for all life on earth and provides an incredible amount of energy, far more than what is commonly known. Only one hour of solar radiation is enough to meet the global energy consumption for a whole year. Solar energy is being received without any costs and the transformation phase to electricity or heat it is completely eco- and climate neutral. Sunrays hits the user directly and is being delivered without intermediaries. Solar energy is simply quite superior as a carrier of energy!
A common perception is believing we're getting too few hours of sun in Norway. Fact is that we have solar radiation far exceeding our energy consumption throughout the year. If 2 per mille of Norway's land area were covered with solar collectors and solar panels, it'll be equivalent to the entire country's annual energy consumption.
A typical roof in Norway receives annually 4-5 times more solar energy than the household consumes in a year. In other words, it is quite possible using solar energy to create good conditions for zero-energy or even plus-energy houses!
Solar radiation hitting the earth's surface can be used for a lot of things. We are talking primarily about solar collectors for heating and hot water preparation and solar panels for production of electricity. But now it is even possible to get both electricity and heating from the same panel, so-called hybrid panels (PV/T). Solar radiation may also be used for passive heating and daylight through windows besides this.
In a HYSS system, the free converted solar heat is used to generate heat that is either passed directly to the storage tank or helping to increase the heat pump efficiency. The operating energy (electricity) needed by the HYSS system can advantageously be supplied by solar cells.
It is common to assume annual solar radiation of 1000 W for 1000 hours per m² horizontal surface in Norway. This implies solar radiation equivalent to 1000 kWh / m² per year. If the surface are facing south and tilted 30º the efficiency will increase approximately by 25%. From southern to northern latitudes along the coast, we substantially have the same amount of annual solar radiation. In the north there are more solar radiation during the summer and less in the winter compared to the southern part of the country.
Hybrid panels are now included in Free Energy's product range. In a hybrid panel, the solar cells are cooled by a liquid-borne circuit to increase the efficiency. The heat transported away from the solar cells is used by the HYSS system to increase the heat factor in the heat pump. This allows HYSS to make full use of the PV/T technology.
Thermal solar collectors (T) for solar heat in general have an efficiency up to 50-70% depending on the operating conditions. This means that solar collectors can contribute a maximum power subsidy of 500-700 W/m² and produce between 500-700 kWh/m² per year.
Silicon solar cells (PV) generally have efficiencies ranging between 15-20%, depending on whether they are polycrystalline or monocrystalline. Solar cells based on thin film technology generally have slightly lower efficiency (just below 10%). This means that solar cells can contribute an additional power of up to 150-200 W/m² and produce up to 200 kWh/m² per year depending the technology being used.
Hybrid panels (PV/T)) generates both electricity and heat from the same panel. As the solar cells are cooled down by a liquid-borne circuit, the production of electricity increases up to 15% per year compared to conventional solar cells. The HYSS system's controller function can optimally utilize the heat from PV/T which makes the combination of PV/T and HYSS unique in the market. In normal operating conditions, a hybrid panel generates 186 kWh of electricity and 800 kWh of heat/m² per year, at 10 degrees operating temperature. The hybrid panels have the same dimensions, appearance and the same mounting system as the PV panels which simplifies the installation and provides for a homogeneous and appealing appearance.
Solar collectors are about 3-4 times more area efficient than solar cells. This means that the solar heat provides 3-4 times the power and at least 3-4 times the energy conversion per unit area. Thus, not said that one technology is better than the other. The key is to determine what the energy will be used for and then choose the technology with the greatest potential. If the intention is to produce hot water using the sun, it will be far more cost- and area efficient to choose solar panels than solar cells.
In cases where the solar heat integrates with a HYSS system and is used for heat pump efficiency, an extremely high SCOP (annual heat factor) for the heat pump is achieved. In addition, the season for solar heating is significantly extended. For each kWh electricity the heat pump consumes, it returns up to 5-7 parts heat and hot water.
With hybrid panels (PV/T), a more aesthetic adaptation of solar cells and solar heat is obtained as the energy is extracted from one and the same panel. The installation is simplified and the total additional cost of getting both solar heat and solar cells is reduced. The greatest advantage by combining PV/T and HYSS is that the heat pump, in addition to free added energy, will have significantly better operating conditions. This is due to both higher incoming brine temperatures and recharging of the borehole or ground loop. This combination is especially interesting for buildings who wants to achieve zero or plus energy standards. By adding PV- or PV/T- panels, the supply of electricity increases. Because both panels have the same design it simplifies installation and provides a more aesthetic and appealing look.
The need for added energy is significantly reduced by using a HYSS system with solar heating for heating and hot tap water. A combination of HYSS, solar heat and solar cells increases the possibility of creating a house with self-sufficient, clean, persistent and free flowing energy
Free Energy's solar collectors come from one of Europe's most innovative and leading manufacturers. Due to the manufacturer's quality requirements and certifications, we offer a 10-year product warranty on the solar collectors.
Free Energy's hybrid panels come from one of the world's most innovative and leading manufacturers. Due to the manufacturer's quality requirements and certifications, we offer a 10-year product warranty on the hybrid panels (PV/T) and up to 20 years product warranty for the solar panels (PV). In addition, there is a 25-year performance guarantee on solar electricity production for both PV/T and PV panels.
Free Energy's solar panels come from the same manufacturer as the hybrid panels and have the same design and offers a uniform appearance. The monocrystalline solar cells have one of the best levels of efficiency on the market. The product warranty is up to 20 years and the performance guarantee is 25 years.
Solar collectors and solar panels can vary considerably both in tilt angle and direction without losing too much efficiency. At Nordic latitudes the deviation in efficiency will be less than 10% if the solar collectors are mounted in directions between southeast (135°) and southwest (225°) with tilt angle between 25° and 65° relative to the horizontal plane.
The efficiency for collectors facing west or east will be less affected if the tilt angle is lower.
Illustration shows that tilt angle of 40° from the horizontal plane facing south will provide the best preconditions. Solar collectors facing east, with the same tilt angle, will decrease in efficiency by approximately 20%. Solar collectors facing east or west, placed vertically, will loose efficiency of approximately 45% compared to optimal placement. These values should not be seen as absolute because it will depend on the latitude.
Best angle of incidence are achieved throughout the year if solar collectors are mounted with 10° lower angle than the operative unit's latitude. It is however important to realize that optimal placement will have little impact on the overall performance. It’s more important to avoid all kinds of shadow and subsequently ensure a robust installation to create good working conditions (correct flow and low temperatures) in the solar circuit. In the vast majority of cases it is easiest and most cost efficient to follow the roof angle and furthermore aesthetically and architecturally beneficial.
It’s important to remember that the performance of a solar heating system is affected by many factors. An important parameter for good utilization is the operating preconditions. If the solar circuits temperature can be kept low (as in a HYSS-system) the heat loss will be reduced and efficiency will increase.
A point in this context is that HYSS comes with pre-programmed software that makes it possible to manage groups of collectors with different directions to optimize heat production. Solar collector plants with groups facing east and west can be optimized for heat production both morning and evening, i.e. when a household normally has its most intense hot water consumption.
HYSS generates more solar heat during the summer months than what’s consumed in the house in the period. When the hot water tank is fully warmed by the sun, excess heat is being dumped in the energy storage (usually in a borehole or ground loop). By using continuous recharging from solar energy, Free Energy has initiated a collaboration with ASES (Active Solar Energy Storage) which has developed a patented method for storage of thermal energy. ASES is the most energy efficient way of seasonal storage of solar heat and is constructed under the building's concrete slab for new buildings. The excess heat in the summer, and otherwise throughout the year, are stored in ASES geothermal storage for later use and mostly during the winter months. HYSS in combination with ASES heat storage provides a remarkable low energy consumption and an unmatched annual efficiency, SCOP Combi*, of up to 8!
With ASES geothermal storage and HYSS’ unique control system, the solar heat is utilized maximum throughout the year giving an annual efficiency for heating and hot water (SCOP Combi*) of up to 8. This means for every added kWh of energy to the heat pump you’ll get up to 8 times in return as heating and hot water. The geothermal storage for a new building is constructed under the buildings concrete slab (base plate). If the trenched soil has the proper quality, up to 85% may be recycled for the establishment of the ASES storage and thus reduce costs. Constructing of ASES under the concrete slab (base plate) or foundation, avoids buried tubes in the ground outside the house. This increases the freedom to construct swimming pool, garage, shed or other in the future. It is also possible to place ASES heat storage outside the house, eg. under another unbuilt part of the plot. This alternative is generally more expensive than constructing the heat storage in conjunction with building a new house placing the storage beneath the house.
* SCOP Combi specifies annual efficiency for heating and hot water.
HYSS utilize solar energy to the maximum. The solar heat is primarily used for direct heating of the storage tank. This will save operating time for the heat pump and reduce the heat output from the borehole or ground loop.
Even at low temperatures solar heat is being utilized to increase water temperature thus significantly improving the heat pump efficiency. Solar collectors in HYSS is being utilized far more hours per year than conventional solar heating systems and increases the efficiency even at low temperatures in the solar circuit. HYSS can also with great advantage, utilize solar energy (solar cells) to run fluid pumps, compressor and other electricity-driven components in the system. It is far more easy to achieve a zero-energy or plus-energy house since the amount of energy are less to handle.
To achieve extremely low energy consumption it is important to identify how the households (or house) energy consumption is allocated. A common household, consisting of 4 persons, heating and hot water represents 80% of the households total energy consumption. The real major savings potential is to enhance the efficiency and reducing energy consumption for heating and hot water.
Allocation of energy consumption in a house
Heating and hot water represents 80% of the energy consumption in a house while remaining household accounts for 20%. Major savings is achieved by reducing the energy consumption for heating and hot water if the objective is to reduce your total energy consumption. To invest in HYSS is an unique opportunity to really cut your energy costs!
Solar collectors are more efficient than solar cells
If solar radiation is 1000W per m² then each m² of solar cells provides 150W power output with 15% efficiency of the solar cells. A solar collector of the same area provides a power output of 600W by the efficiency of 60%. If both units are operating for 1000 hours during one year the solar cells will generate 150 kWh/m² and the solar collectors 600 kWh/m².
The real major advantage of solar heat is accomplished when used in a HYSS-System. Due to the great interchange in the HYSS-system you get 5-7 times in return as heating and hot water for each part supplied energy (electricity) to the heat pump.
Annual efficiency (seasonal performance - SCOP) increases to 5-7 with HYSS
For a conventional heat pump powered by solar cells the utilization from the solar cells will increase with the heat factor of the heat pump, normally between 3-4. This means that you'll get 3-4 times in return for each part supplied energy (electricity) as heating and hot water. Solar heat is utilized by solar collectors in HYSS which are significantly more area efficient than solar panels. Solar heating will additionally provide free hot water and improve the heat pump efficiency meaning for each kWh supplied to the heat pump it generates 5-7 parts of heating and hot water.
Solar collectors becomes an unbeatable investment in this comparison, both technically and economically, in terms of reducing the need for purchased energy for heating and hot water. Solar cells have their advantages naturally by providing electricity to the electrical components in HYSS. By utilizing both solar and solar heat this becomes the ultimate combination!
HYSS makes it easier to acheive the standard of a zero-energy house
By using HYSS the need for added energy for heating and hot water supply is reduced. With solar cells it also becomes easier to manage the supply of electricity. Through combination of HYSS and solar electricity, the possibility to create a self-sufficient house increases with clean renewable and free flowing energy.
Solar radiation can be transformed into heat or electricity or naturally both. The greatest potential for reducing energy costs is to utilize solar heating because the largest part of the energy consumption in a household is heating and hot water supply.