Photovoltaic hybrid system with fuel cells as a guide for off-grid power systems
Solar generator on the lodge Rappenecker
The power of Rappenecker hut with one of the landmark renewable energy projects in the early history of the Fraunhofer Institute for Solar Energy Systems ISE. In 1987, the Freiburg researchers are installed on the network remotely located Wandergasthof a photovoltaic (PV) hybrid system, which is not only a practical solution for owners and tenants, but also a research station for off-grid power systems has been.
With the aim to come to a completely environmentally friendly energy supply, the plant underwent successive enlargements. In 1990, to a wind turbine, a fuel cell in 2003, the use of fossil diesel generator component could be reduced still further. On 27 July 2012 celebrates the Rappenecker hut not only their 350-year anniversary, but also 25 years of successful photovoltaic history.
Today, the development of PV-hybrid systems beyond the individual home care, the focus is primarily on larger island networks in developing and emerging countries. "In remote rural areas with solar coverage rate of over 80 percent, we can today in electricity generation costs compared to a diesel generator, depending on boundary conditions even in half," explains Dr. Matthias Vetter, Head of PV-grid systems and battery management systems.
"Here on the Rappenecker hut we have 100-percent renewable energy supply made available, as the last element missing is the step of producing hydrogen on site," adds Director Prof. Eicke Weber to supplement and builds a bridge for network-integrated PV: "Even in grid-connected region of the solar power today costs much less than the electricity from the socket. In addition, we can make the good news that the modules have the Rappenecker hut after 25 years well over 80 percent of its original power. "
Installed 25 years ago, the EU supported PV system (3.8 kWp) on the roof of the barn Rappenecker hut was, she made the popular hiking destination Rappenecker hut to the first alternating current produced by solar powered restaurant in Europe. In 1990, the solar gain of a wind turbine (1.8 kW), funded by the Federal Ministry of Research. 2003 was a further step was taken towards sustainable energy supply. With funding from the Innovation Fund of the regional energy supplier Badenova a fuel cell could be installed. With high electrical efficiency, locally emission-free and silent, was installed with the hydrogen-fueled polymer electrolyte membrane (PEM) fuel cell is a pioneering technology of the future, so that the use of the diesel generator (12 kW) could be further reduced. Again took the Rappenecker hut was a pioneer and trailblazer for systems in the world.
To celebrate 25 years of solar power on Rappenecker hut the company Futuree 2012 represents a new fuel cell (4 kW), including peripherals available for free. With an efficiency of 55 percent of the fuel cell system is much more efficient than a diesel generator, which reached a maximum of 15 percent. The primary energy use can be more than halved. Fuel cells are very low maintenance. Thus, the high costs for the maintenance of diesel generators. Moreover, especially in ecologically sensitive mountain regions, the reduction of groundwater and environmental hazards caused by the leakage of diesel in transport especially important. When used herein fuel cell hydrogen from gas cylinders (energy content of a bottle 26 kWh) is used. Since 2003, the company basi Schöberl the hydrogen charge. The diesel generator is the emergency reserve in the system.
In a fuel cell, hydrogen and oxygen controlled and converted into electricity with high electrical efficiency, whereby the resulting heat can be used. The PEM fuel cell runs on pure hydrogen and oxygen. For the longer term option and need to make hydrogen available from renewable energy sources and thereby reduce emissions of climate-damaging substances to zero.
Today, the annual electricity consumption of 4000 kWh of Rappenecker hut, which is closed during the winter months, to cover about 65 percent of the photovoltaics. The share of wind power is about 10 percent and fuel cells share about 25 percent. Interested hikers and mountain bikers can use the combination of photovoltaic system to know, wind turbines and fuel cells in "glass" technology rooms with explanatory panels.
