ABB factory in Finland unveils largest solar power plant in Nordic countries

Thursday, Jul 01, 2010
The largest grid-connected solar power plant in the Nordic countries, built on the roof of an ABB factory, has been powered up during an inauguration ceremony attended by Finland’s Minister of Economic Affairs and dignitaries from academia, industry and business.

The 181 kilowatt (kW) solar power system is on the rooftop of ABB’s low voltage AC drives factory at Pitäjänmäki, in Helsinki, Finland. The electricity it generates is to be used for charging the batteries of the factory’s fork lift trucks, and for cutting energy consumption peaks at the factory.

The solar power plant is the first in Finland to use ABB’s recently introduced string inverters together with a central inverter, both of which are designed and manufactured at the Helsinki factory. The ABB solar inverters are used for converting direct current, generated by solar panels, into high-quality alternating current that can be fed into the power network.

The use of several smaller inverters helps overcome the non-uniform shading across the solar array which is the result of obstructions on the roof and neighboring buildings. As such, ABB string inverters*, rated from 4 to 8 kW, and one 120 kW ABB central inverter** are used in the 1,200 square meter solar module area. All the inverters are connected to the building automation system and can be monitored remotely.

Cutting the peaks
“This system is a good example of the benefits of decentralized electricity production near the place of consumption,” says Antti Suontausta, senior vice president, ABB low voltage AC drives. “Photovoltaic electricity gives added value for users, especially in commercial and industrial buildings where peak consumption can be cut by using electricity generated by a solar power system.”

While Finland is not renowned for its abundance of sunshine, the 181 kW solar power plant is expected to generate about 160,000 kWh per year and will benefit from the region’s long summer days. The electricity generated is equivalent to the annual energy consumption of about 30 residential homes (without electrical heating) and is fed directly to the grid within the factory for powering the battery chargers of the forklift trucks. Any excess electricity is used by other loads within the factory grid.

“Our decision to locate the solar power plant on the roof top of the factory is particularly effective as no additional land is used,” says Jyrki Leppänen, ABB’s market director for solar inverters. “ABB in Finland is globally responsible for the development, production and marketing of solar inverters within the company. With this power plant we get the opportunity to test our inverters with solar modules in cold weather conditions. Furthermore we will be able to test the products compatibility with a building automation system.”

Valuable lessons
The project, which costs approximately 500,000 euros, is partly funded by Finland’s Ministry of Employment and the Economy from its renewable energy system investment fund that invests in future and renewable technologies as part of its strategy to create new technologies and jobs within these sectors.

The system, and the ABB central inverter in particular, is providing ABB with valuable information about the behavior of such plants within Nordic climates which experience cold weather, low sunlight levels and slow night-to-day change over.

The solar modules and a new type of flat roof installation system were supplied by Naps Systems Oy, and its partner Purso Oy which provides the profile system for the module mounting structure.

ABB’s Pitäjänmäki factory is globally responsible for the product development, manufacture, sales and marketing of the solar inverters. It is also home to the world’s leading range of variable speed frequency converters, wind turbine converters and large machines.

*Transformerless, single-phase ABB string inverters feed power collected from solar panels into the grid. They are suitable for small and medium-size photovoltaic systems connected to the public electricity network. The ABB string inverter features a high conversion efficiency, which means more electricity is fed to the grid for higher revenues and a faster return on investment; inbuilt protection, which reduces the need for costly external devices; a compact design that frees-up space for other equipment; and an intuitive and easy-to-read control display that can be mounted within the inverter enclosure or remotely.

**Transformerless, three-phase ABB central inverters feed solar energy into conventional power grids. They are suited for large to medium-sized photovoltaic systems, as well as solar power plants from 100 kW to several megawatts (MW).