Sunseed News
Appropriate Technology Winter 2011/12
Sunseed’s closure for the whole winter gave us an opportunity to do major works on all the photovoltaic systems. This put Sunseed in a really low energy situation as the amount of solar energy available is lowest in the winter anyway, let alone when we were dismantling the frame of the solar panels or shut down the system to make essential modifications. We managed to deal with this situation with the introduction of Green, Orange and Red days which give clear guidelines of what appliances/services can be used on a given day taking into account the weather forecast and the actual state-of-charge of our solar battery system.
The overall aim was to optimize the efficiency of all renewable energy systems on site. Anja – a German masters student on Leonardo placement – has been a great help in achieving this and as we progressed she gained a more in-depth knowledge of photovoltaic systems in return.
We started with Isabella’s house: we had to relocate the solar modules to a more easily accessible location which also had less shading from nearby trees. The proposed new location was assessed and the optimum seasonal angles were calculated by computer simulation software: without any investment we were able to increase annual solar energy production by 18%. The failing inverter had to be replaced which gave us an opportunity to redesign the 12V system to operate on 24V, thus reducing transmission losses in cables by 75%. The new inverter was installed and the battery bank reconfigured which left only the lighting system to get a total revamp. We identified the most frequently used areas and installed low-voltage energy efficient lights (CFLs) so that they operate even when we have to switch the inverter off (this happens if we have e.g. 5 consecutive days of cloudy days). The other rooms got normal (i.e. easily available and cheaper) 230V lightbulbs. Corridors and stairs where lighting is mainly used for access, got alternating switches and LEDs installed. The reason for this is that CFLs need about a minute to warm up and get to their full brightness, while LEDs give their maximum output instantly. Overall, we reduced the electricity demand of lighting by 38% while providing 24% more light, thus increasing the efficiency of the lighting system by 52%.
We also did maintenance work on the ram pump (a gravity pump supplying the whole village with water) and the irrigation line (which provides water for our gardens), organized the workshop a bit more, repaired the solar motion-sensor floodlight and took part in many interest groups on how to improve Sunseed in many different aspects.
We also designed a DIY battery monitor/solar&wind data logger system based on the open-source Arduino platform and unconventional components. This will be installed at Isabella’s hybrid solar/wind system for us to be able to analyze the data and to see the effects of further improvements while serving as an educational tool at the same time for university students.
In the next few months we will be focusing on the optimization of the two other house’s PV systems. Starting from April, Marlene – a German MSc Process Engineering intern – will take part in designing a low-cost solar tracker (based on open-source Arduino as well) for the main house which will provide us with more electricity for the best price-performance and the least environmental impact.
If you are a university student looking for a research project or an internship in alternative technology, if you would like to get involved in specific projects or if you are simply interested in working in the AT department, please have a look at our project pack and feel free to contact Csaba – the AT coordinator.
csaba
Sunseed’s closure for the whole winter gave us an opportunity to do major works on all the photovoltaic systems. This put Sunseed in a really low energy situation as the amount of solar energy available is lowest in the winter anyway, let alone when we were dismantling the frame of the solar panels or shut down the system to make essential modifications. We managed to deal with this situation with the introduction of Green, Orange and Red days which give clear guidelines of what appliances/services can be used on a given day taking into account the weather forecast and the actual state-of-charge of our solar battery system.
The overall aim was to optimize the efficiency of all renewable energy systems on site. Anja – a German masters student on Leonardo placement – has been a great help in achieving this and as we progressed she gained a more in-depth knowledge of photovoltaic systems in return.
We started with Isabella’s house: we had to relocate the solar modules to a more easily accessible location which also had less shading from nearby trees. The proposed new location was assessed and the optimum seasonal angles were calculated by computer simulation software: without any investment we were able to increase annual solar energy production by 18%. The failing inverter had to be replaced which gave us an opportunity to redesign the 12V system to operate on 24V, thus reducing transmission losses in cables by 75%. The new inverter was installed and the battery bank reconfigured which left only the lighting system to get a total revamp. We identified the most frequently used areas and installed low-voltage energy efficient lights (CFLs) so that they operate even when we have to switch the inverter off (this happens if we have e.g. 5 consecutive days of cloudy days). The other rooms got normal (i.e. easily available and cheaper) 230V lightbulbs. Corridors and stairs where lighting is mainly used for access, got alternating switches and LEDs installed. The reason for this is that CFLs need about a minute to warm up and get to their full brightness, while LEDs give their maximum output instantly. Overall, we reduced the electricity demand of lighting by 38% while providing 24% more light, thus increasing the efficiency of the lighting system by 52%.
We also did maintenance work on the ram pump (a gravity pump supplying the whole village with water) and the irrigation line (which provides water for our gardens), organized the workshop a bit more, repaired the solar motion-sensor floodlight and took part in many interest groups on how to improve Sunseed in many different aspects.
We also designed a DIY battery monitor/solar&wind data logger system based on the open-source Arduino platform and unconventional components. This will be installed at Isabella’s hybrid solar/wind system for us to be able to analyze the data and to see the effects of further improvements while serving as an educational tool at the same time for university students.
In the next few months we will be focusing on the optimization of the two other house’s PV systems. Starting from April, Marlene – a German MSc Process Engineering intern – will take part in designing a low-cost solar tracker (based on open-source Arduino as well) for the main house which will provide us with more electricity for the best price-performance and the least environmental impact.
If you are a university student looking for a research project or an internship in alternative technology, if you would like to get involved in specific projects or if you are simply interested in working in the AT department, please have a look at our project pack and feel free to contact Csaba – the AT coordinator.
csaba