The smart concept of SAILWIND
What used to be the miller's job when setting or rolling the sails in his mill is now done by servomotors of SAILWIND. Sails are automatically rolled and trimmed depending on the wind speed. Of course, the gondola is also turned into the wind by a motor (Yaw control). Everything with the most modern features of today's electronics: data transmission from the rotor, remote monitoring of the operating status of the entire wind turbine and self-optimizing control in the Maximum Power Point. SAILWIND runs completely automatically and does not require any human supervision and control during operation.
Smart in the energy optimum
Every SAILWIND is programmed for self-optimization of its performance. Depending on the location, the optimal control parameters and map data of the rotor for wind strength and wind direction are determined and automatically adjusted, so that the machine is always set to the optimal, local wind conditions. Self-optimizing (adaptive) control loops guarantee, that SAILWIND always operates at the Maximum Power Point.
SAILWINDs in a network
SAILWIND systems are particularly interesting as a network of individual systems or entire wind farms, because they exchange data with one another. This is made possible by higher-level control algorithms, so that, on the one hand, the operational reliability of the individual systems is increased, but above all, the energy efficiency is increased. Changes in wind direction and wind strength, for example in the event of gusts, are recorded by the SAILWIND system in windward direction, which processes the data predictively for other machines lying downwind. The higher-level control has an intelligent algorithm to dynamically identify, which system in the network is currently upwind from the wind field. The other machines are aligned accordingly. This is also how it is done today with offshore wind farms. We thereby increase the operational safety and efficiency of the individual machines in the network. SAILWIND are fully automatic, powerful wind turbines that are in no way inferior to large wind turbines. There is no other small wind turbine on the market like this!
Condition monitoring and predictive maintenance
In principle, all operating and status data of a machine are not only stored on site, but also wirelessly transmitted via GSM to a central web server and stored on a cloud-server. This is used for seamless condition monitoring, data of events in the past can be called up at any time. Events of the past can be retrieved at any time. A large number of sensors record the load of the machine. With regard to "preventive maintenance", remote maintenance and supervision is applied. Artificial intelligence-based diagnostic models increase the operational safety and availability of the machines. In this way, the time periods between mandatory maintenance cycles of the machine are extended. If a call for service or repair is required, a message will be automatically sent to the nearest service point.
Optimization potential of SAILWIND
In ancient times, sails were smooth, flat and sometimes cut in one piece. Definitely without a belly. The performance was accordingly low. High-performance sails with the most modern, flow-optimized sail cuts, as they are used on sailing yachts today, offer great potential for increasing the performance of sail windmills compared to previous times. We already know from CFD simulations ,that sail cuts of boats cannot be transferred directly to SAILWIND. Sails optimized for SAILWIND must look different. The reason is quite simple: the sail moves faster outside than inside. It's just different from sailing on ships.
In addition, new micro-structured materials and flat seams generate less turbulence in the direction of flow. An important topic for SAILWIND sails!
The modular design of SAILWIND
SAILWIND has a modular structure and can be adapted to the existing style of a sail windmill. SAILWIND's smart technology includes the rotor, the nacelle with generator, the electrical control and inverter with a control cabinet. Cladding, aesthetics and structural designs are variable and on-site options. For restorations or new construction of towers for SAILWIND systems, planning support for a cost-effective construction method can be offered.
Depending on the circumstances the tower might have to be entirely reconstructed in the historical model. The old construction materials (fieldstones etc.) can be of course reused, especially for the visible external cladding. The price of the, widely common in Mediterranean countries, concrete made frame structure is reasonable - also good against earthquakes. The reinforced, modular ready pieces of concrete will be delivered to the construction site, assembled to framing and molded on site. The empty rooms between the concrete parts will be invested with tiles or stone.
Well-preserved or already renovated towers for SAILWIND
Even towers in a visually acceptable condition usually have to be reinforced from the inside due to the high wind loads. This must be checked. A concrete ring and concrete platform at the top of the tower (so-called ring anchor) are required to accommodate the nacelle (gondola) bearing. The tower construction work must be planned individually with an architect on site. He will also check whether the conversion into a holiday apartment with windows is an option. High-strength precast concrete elements can be used for the internal reinforcement of the towers.
The sustainable concept of SAILWIND
SAILWIND systems are built to be stable, robust, protected against dust and corrosion for operation in sea air. They are designed for a long service life of at least 20 years and high operational reliability with minimal maintenance. SAILWIND systems are specially designed for regions with strong winds, such as the Greek Aegean. However, they can also be operated very effectively in less windy locations.
SAILWIND on holiday apartments
The optimal aerodynamic design along with the trimming of the sails lead to a smooth operation of the machine and minimize noise emissions and vibrations. This means that SAILWIND systems can easily be operated in residential areas, settlements and villages, as was often the case with sail windmills in the past. SAILWIND machines can also be installed on the roofs of residential buildings, hotels, restaurants and office buildings. A special nacelle bearing minimizes the transmission of structure-borne noise into the building. The mill towers are suitable as a holiday home. SAILWIND is therefore ideal for sustainable tourism for hotels, restaurants and apartments with their own energy supply.
Security, Certificates and Approvals
SAILWIND systems are of course tested and approved according to the state of the art in order to meet international requirements. CE label and national approvals (type tests) are mandatory. Certifications according to the rules for small wind turbines (e.g. German FGW) and other common regulations, as well as field measurements are on the plan. These things are very expensive but essential. Therefore, we look forward to any support so that SAILWIND becomes a success.
The rotor and the nacelle can employ electro-hydraulic brakes. The overall function of the system, even in the event of a power failure, is ensured by separate buffer batteries especially in off-grid operation. An onboard diagnostic system monitors all functions. Malfunctions are reported to a web server. In the worst case, the system is shut down in a controlled manner and brought to a standstill.
The electrical components (generator, inverter, servo motors) are of high quality from European production. It goes without saying that the modern inverter meets European standards for feeding energy into local power grids. In addition to on-grid operation, we also support hybrid solutions, because that means the share of self-consumption generated energy can be increased.
SAILWIND on roofs
Taller buildings, in particular the newer ones, are suitable for installation of SAILWIND units on the roof if the statics allow it. Energy-self-sufficient buildings (including PV) are a trend in modern architecture. SAILWIND on roofs are an eye-catchers, visible from a distance.
In addition, SAILWIND can also be installed between taller buildings, depending on the orientation to the main wind direction. Everyone knows the phenomenon: in alleys and aisles between rows of houses it can blow very strongly. They name it the nozzle effect: if the wind is dammed up against obstacles, the wind speed increases between the obstacles. However, these locations require very precise clarification, possibly with CFD flow simulations.
SAILWIND 12
has a rotor diameter of 12 m. Estimates in the scientific literature as well as our own CFD calculations have shown that around 50 kWp output can be expected at 14 m/s wind speed. However, SAILWIND should also be able to operate at higher wind speeds. To do this, the sails are being rolled more and more. With a reduced sail area, the output is kept constant at 50 kWp. Between 22 and 25 m/s wind speed, i.e. a storm force of 9 Bft., the sails are fully furled and the operation will be stopped by brakes.
When the wind speed is below 14 m/s, the sails are fully rolled out. The same applies here as a sailor does on his ship, setting the sails at the correct angle to the wind. This trimming of the sails is used to optimize performance in weaker winds to increase effectiveness. By the way: it is typical for flat wind turbines like SAILWIND that they start turning with only very little wind.