Small town supply is the world’s largest PV power plant1 January 2009
Juwi’s Waldpolenz solar park first sent electricity to the grid in July 2007. Now nearing completion, it is on target to be the largest PV site in the world, serving the power needs of two small townships in north east Germany
By new year 2009, juwi solar GmbH, based in the Rhineland-Palatinate state of north east Germany, will have constructed, near Leipzig in Eastern Germany, the world’s largest photovoltaic power station. The r130 million Waldpolenz Energy Park will comprise 40 MW of production capacity at its peak. The collector array, which will consist of 550 000 First Solar FS-265 thin film solar modules covering about half of the available area, is being built at a 220 hectare site (about 2km by 1km), a former military air base east of Leipzig in the district of Muldentalkreis in Saxony state between the small townships of Brandis and Bennewitz. The photographs on this page and on page 42 clearly reveal the site’s air base antecedents. Installation had reached the equivalent of 24 MW by August this year, and is on schedule to finish by early 2009 ahead of its original mid 2009 completion date. It will be twice the size of the largest PV plant in the world now which is about 20 MW. Its builders believe that it will produce power at a discount of 20 to 40% on the going price in Germany.
The project was initiated by the juwi group which approached the two small communities that own the site in 2005. They decided to accept its offer, resulting in the launch in March 2006 of the licensing procedure. In February 2007 juwi received the building licence. ‘Solar electricity not only protects the environment, it also creates independency from expensive energy imports and creates jobs. Ground mounted PV installations are a cost-effective market segment and an integral part of that success’ says Fred Jung, CEO of the juwi group.
As general contractor juwi is in charge of the planning and construction site management, and responsible for the operation and maintenance of the park. The inverters and sub-structures are all made in Germany.
At the end of April 2007 the first bank of solar modules was assembled and four months later the first segment, approximately 6 MW, was connected to the power grid. By February 2008 the installation had reached 12.7 MW, making it Germany’s largest such site. By then some 17 500 steel posts had been put in place and nearly 5 000 aluminum sub-structures assembled to support more than 215 000 solar modules. By late June, 2008, 350 000 of the final total of 550 000 thin film modules had been installed: by the end of August 2008 some 30 000 steel supporting posts had been located, over 9 000 aluminum frames were assembled and nearly 385 000 solar modules mounted and wired. At this time the installation's capacity reached more than 24 MW. After completion the solar power station is expected to produce 40 million kWh of solar power annually, offsetting approximately 25 000 tons of CO2 emissions.
Thin film solar modules
The solar modules predominantly come from Frankfurt (Oder), where in July 2007 manufacturer First Solar started up their biggest and most sophisticated assembly line for pv modules. The First Solar modules applied by juwi are designed for use in grid-connected photovoltaic power plants and have been adopted in commercial photovoltaic projects by several developers.
The CdTe thin film modules produce a high energy yield under a variety of climatic conditions.Cadmium telluride is a natural p-conducting semiconductor and owing to its physical and chemical characteristics appropriate for use in these kinds of cells. Based on a high capacity for the absorption of solar radiation, layers of just a few microns are sufficient. Further advantages are first-rate performance at low irradiation and an excellent temperature coefficient. The temperature coefficient indicates the efficiency decrease of a solar cell by ambient temperature. Thin film modules are superior to modules based on crystalline silicon, because efficiency losses are less sensitive to temperature rise, and exhibit better absorption of diffuse light resulting in a higher yield.
70 x 500 kW inverters by SMA Solar Technologie will be on duty at Waldpolenz, two inverters per module field. The module fields will be connected to the grid step by step. A dedicated electric power transformer substation about five kilometres away feeds the solar generated electricity to the 110 kW grid. The power plant is fitted with what is described by SMA as state-of-the-art communication and operation technology. At Waldpolenz the PV panels are assembled on the module substructure with a tilt angle of about 30 degrees and oriented towards the south. 45 panels are fitted to each substructure supported by steel posts buried 150 cm deep in the ground.
The Waldpolenz Energy Park involves investment of some r 130 million (USD 200 million). The project has been financed with equity capital and loans. About 1000 limited partners participated in the offer handled by SachsenFonds GmbH, a degree of take-up that represents a milestone in the development of photovoltaics financing. The PV power station is scheduled to operate for at least for 20 years, although a lifetime between 30 and 40 years is anticipated. Solar electricity is remunerated between 33.18 and 37.96 Eurocents, depending on the date of implementation of the field. ‘With the competitive prices of solar electricity produced at Waldpolenz we are demonstrating that there are no limits for photovoltaics’ comments juwi CEO Matthias Willenbacher. The PV industry as a whole expects solar PV power to become competitive with retail electricity prices within 8 –10 years, that is, to reach grid parity.
Finance by public offer
With its specific price of approximately r 3.250 per kilowatt (US $4.226) the power plant is expected to be around 20%–40% cheaper than the going German market price. In addition, after just a year in operation, Waldpolenz will have produced the energy needed to build it. As a general guide the cost of the power will probably work out to be between 33.18 and 37.96 eurocents per kilowatt hour.
The r130 million investment in Waldpolenzsolar was raised by a variety of means. Sachsen Fonds GmbH had been offering owner’s equity of the project in the form of closed-end funds since late summer 2007, so people living in the area also has the opportunity to participate in this unusual project with investments starting at just r5000.
The juwi group philosophy is to produce solar electricity at competitive prices as quickly as possible. ‘With the Waldpolenz station we are demonstrating that there are no longer any limits to photovoltaics’ commentsWillenbacher.