16
SAVING ENERGY Sunny future for solar PV
It has taken a long time for solar panels to finally become a - financial – practicality for the Dutch mushroom sector, but we seem to have a reached a breakthrough. This article presents the initial practical experiences on two farms equipped with solar panels– one mechanised and one that picks by hand. The power generated by the panels is renewable and for self-consumption.
By Jan Gielen, DLV Plant Mushrooms Manager / Climate & Energy Specialist
j.gielen@
dlvplant.nl
When energy awareness started to kick in at the end of the 1990s, growers gradually began to pay more attention to energy saving measures – also partly motivated by rising energy tariffs. One of the questions most raised was the use of solar panels to generate power particularly to run cooling units. Despite this being a technical possibility at the time, the high costs of solar panels and the impossibility of earning back the investment within an acceptable time scale made this an unrealistic option until quite recently. As the price of solar panels fell, they moved within the financial reach of more growers. The first solar panel electricity systems, also known as solar PV, have been installed on mushroom farms in the Netherlands since 2011. Two of these farms, Willems BV in Kessel and van Nieuwenhoven in Ospel, share their experiences with us.
Willems BV, Kessel On Maurice and Roger Willems’ farm the mushrooms are harvested mechanically in 24 growing rooms of 1478 m2 in total. Each week, they fill five growing rooms and harvest two flushes. This converts to 20 rooms using a five-week cycle, and four rooms with a four-week cycle. The climate installation has indi- vidual climate units with the customary technology such as cold water cooling, high-efficiency boilers and a steam boiler that is only used for cook out. The company participates in energy monitoring. Despite the fact that no specific energy saving technology
was used, the energy efficiency in 2011 was no higher than 4.37 MJ/kg. That means that 4.37 MJ of primary energy is required to produce one kg of mushrooms. That is 12 % less than the average figure on mechanical picking farms, at 4.95 MJ/kg in 2011. Due to the larger scale and the higher production per m2/year, the energy efficiency on mechani- cal farms is always higher than on farms that pick manually.
Spacious roof space Maurice Willems made sure he was well informed before committing to solar PV. The guiding princi- ple was the expectation that energy was certain to become more expensive (namely due to rising taxes on energy) and that investing in solar PV would be good for the pocket and for the environment. As the buildings have relatively shallow-sloping north and south facing roofs, both were suitable for solar PV to be installed. For the time being, a planning permit has only been applied for – and granted – for the south facing roofs (1300 kW peak rating). In 2013, 741 kilowatts peak (kWp), or 5200 m2 crystalline solar PV was installed (3152 PV panels of 1.65 m2 of 235 kWp), which also makes this one of the largest solar PV arrays in the country! On an annual basis, the system generates approximately 575,000 kWh, which is equivalent to around 230 households, and provides a quarter of the electricity needed for the farm. The initial experiences indicate that the power generated is actually higher than assumed at first.
Cumulative kWh generated in January and April 2013 at Willems.
Investment and payback The total investment made by Willems BV in the PV installation was in the region of € 1 million, excluding VAT. Investments naturally become more attractive if they are eligible for subsidies. In the Netherlands, a financing mechanism is in place for non-domestic in- stallations based on the amount of renewable energy the installation generates. In this case, a subsidy is granted of 0.048 € per generated kWh, and fixed for a period of 15 years. In addition to this rene- wable energy subsidy, a tax provision has also been utilised, whereby companies that make a profit and invest part of this revenue in energy saving or rene- wable energy measures can enjoy tax benefits of up
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44
