Off-grid systems: Solar energy replaces fossil fuels

Sun, 01/10/2017 - 00:00

A mountain lodge, a remote part of the country or maybe a comfortable mobile home - sometimes it is difficult or even impossible to connect to the public electrical grid. Then, this is the time for off-grid systems capable of operating independently. The german company enerquinn Energiesystemtechnik GmbH is an experienced full service partner for off-grid systems. In addition to the individually optimized planning and concept design of off-grid PV systems, they also take care of installation, commissioning and training of the operators or their customers.

Off-grid systems

These are small photovoltaic systems. The electrical consumers are supplied with 230 V AC current via an inverter. During the day, the consumers are supplied directly with solar energy; during the night, electricity is provided by the battery. If the battery capacity is insufficient, a back-up electric generator can be actuated. Off-grid systems are dimensioned in such way that these diesel generators are only switched on in exceptional cases and are not needed most of the time.

Micro-grid systems

These systems basically work according to the same operational principles as off-grid systems. However, it is also possible to feed for example solar or wind energy into the grid on the AC side, i.e. the consumer's side in the same way as the large electricity grids.

The product components of the enerquinn off-grid PV plants are photovoltaic systems or photovoltaic modules, charge regulators, storage batteries (lithium-ion batteries) and PV-and grid forming inverters.

Microgrid systems with lithium-ion battery storage for the Maldives

In 2016, enerquinn planned, installed and commissioned a microgrid system on Rakeedhoo, an island in the Indian Ocean, located about 100 kilometers south of the Maldivian capital Male. The result: More than 50% of the energy required for Rakeedhoo now comes from self-generated solar energy. In addition, CO2 emissions were reduced by 50 tons per year.

On the island Raakedhoo live about 90 people in 46 households. There are seven public buildings and two radio masts for telecommunications. The annual energy consumption is about 100 megawatt hours. This demand was met by two gensets, which burnt about 40,000 liters of diesel a year. In order to reduce energy costs and environmental pollution, enerquinn installed a micro-grid system (plant size: 30 kWp PV, battery storage 60 kWh) which can now be used as a natural source of energy. The same is true for the island of Dhidhoo, on which a similar system from enerquinn (plant size: 45 kWp PV, battery storage 90 kWh) has also been put into operation in 2016.

"The lithium-ion battery packs used offer a whole series of essential advantages," says enerquinn CEO and project manager Stefan Oexle. "They are not only durable and highly efficient but also very easy to maintain – and hence the perfect choice for applications in the framework of technically challenging pilot projects required to operate reliably in the long run also."