Production of electricity

Production of Electricity

The new wind farm at Egmond aan Zee had its first full production year in 2007. The operationalisation of the wind farm has increased Nuon’s total wind production by about 40%.

Wind energy

Since 2005 Nuon has been seeking to upscale its production, including that of renewable energy. This is for economic reasons as administrative and maintenance costs impose a relatively high burden on small farms. In line with this policy, there were further divestments of small-scale and foreign wind activities in 2007. These were:

• Geestmerambacht wind farm (675 Kw)
• A number of stand-alone wind turbines in the province of North Holland, namely Spannenburg, Wieringen and Herbayum
• Blyth Wind Farm (4 MW)   

2007 was a good year for wind production, but a bad year for the development of wind energy in the Netherlands. The lack of subsidies and permit application problems thwarted the development of new wind projects. The Offshore Wind Farm at Egmond aan Zee was officially inaugurated in 2007, though the wind turbines already started delivering electricity to the grid in the autumn of 2006.

Several plans for large offshore wind farms had to be shelved. In the Netherlands, the development efforts were confined to projects in Oudendijk (4.8 megawatts), the start of construction work in Echteld (8 megawatts) and the initiation of the project for the replacement of the turbines on the dyke at Enkhuizen. Numerous plans, including a large project of more than 100 megawatts, are awaiting the launch of the new SDE (Renewable Energy Production Incentive) Scheme to replace the MEP. In 2007 Nuon teamed up with a Belgian investment group in the acquisition of a concession for wind turbines with a capacity of at least 90 megawatts in the port of Antwerp, where two Nuon turbines are already located. The arrangements in Belgium in the field of subsidies, sell-back rates and permits are favourable for investments in wind energy. 

In 2007 a monitoring system was introduced. With this system wind turbines can be monitored 24 hours a day, thus permitting a faster response to, or even prevention of, technical faults.

Solar energy

Nuon’s most important solar energy advances in 2007 were realised at Helianthos. This subsidiary is developing flexible laminate-shaped solar cells with a view to achieving a solar energy cost price per kWh comparable to that of conventional energy. Nuon sees Helianthos as a trail-blazer in the field of solar energy. The flexible solar cell technology will enable rooftop applications on e.g. factory halls without requiring adjustments to strengthen the load-bearing structure.

At the end of 2007 the construction of a pilot plant was started at De Kleefse Waard, an industrial estate in Arnhem. Laminates can be produced on a larger scale in the pilot plant than in the current laboratory setting. The pilot plant is expected to start producing in the third quarter of 2008. In 2007 major progress was made in improving the energy yield and stability of the laminate on larger surfaces. A larger laminate, measuring 6 metres long and 30 centimetres wide, was produced for the first time this year after a period in which exclusively smaller sizes of test laminates were made. Attempts to realise a more stable energy yield on larger surfaces were also successful. An even higher yield can be achieved on small test laminates with the aid of tandem cells.

Hydropower

A new operating system was implemented at the Maurik hydropower station (10 MW). This system optimises production by distributing the available water quantity evenly over the four turbines. In 2008 this system will also be implemented in the hydropower station in Alphen (14 MW).

In 2006 work started on the Hagesteijn hydropower station in order to make this station eligible for an MEP subsidy. Due to the discontinuation of the MEP, the work was stopped and the power station produced no energy in 2007. 

Conventional power stations

2007 was an excellent production year for conventional energy. The production of the power stations increased from 13.2 TWh in 2006 to 16.7 TWh in 2007. The capacity of the Velsen 25 power station was enlarged from 361 Mwe to 375 Mwe.  The Willem-Alexander power station in Buggenum gave an excellent performance thanks to improvement programmes.

The supply of heating from Nuon power stations is continuing to rise, particularly thanks to the growing number of connected homes in new residential areas such as Leidsche Rijn at Utrecht, Weidevenne at Purmerend and IJburg at Amsterdam. On 24 April 2007 the auxiliary heating station at Diemen (AHS Diemen) was taken into service. This auxiliary heating station produces a guaranteed heating supply for customers who have no access to back-up facilities when the basic combined heat and power station Diemen 33 is not in operation. The capacity of this AHS is currently 105 MWth and can be easily stepped up if the number of customers grows. The building for the AHS Diemen is suitable for a capacity of 175 MWth and can be expanded to 245 MWth. An increase to 175 MWth is planned for 2010. 

In 2007 the Process Management Department was able to model the first installations using the INSYP package. This makes it possible to monitor the performance of production units online and to make manual or automated adjustments where necessary. Variances between actual and optimum performance as well as the resulting lost revenue opportunity can now be made visible. Emissions monitoring has also been further refined to meet the latest regulations of the NEA (Netherlands Emissions Authority).  Monitoring is a learning process aimed at constantly improving the accuracy of the actual emissions measurements and calculations. In this year, the laboratory at the Hemweg power station was rewarded for its efforts to optimise its measurements of fuels, residual products and waste water with an NEN-EN-ISO 17025 certificate of the Accreditation Council. The laboratory of the Willem Alexander Power Station had already received this certificate which was renewed in the reporting year. As a result, both laboratories now carry the designation of Accredited Laboratory.