The Irish Low Frequency Array (I-LOFAR) is a sensitive radio telescope located in Birr, Co Offaly. I-LOFAR is a national facility that has received over €3 million in support from Science Foundation Ireland, Enterprise Ireland, Offaly County Council, private donors and eight partner universities in Ireland and Northern Ireland. It also is a vital component of a major €150 million European radio telescope network that includes eight international partners and is in the process of applying to become a European Commission European Research Infrastructure Consortium (ERIC) project. I-LOFAR was switched on by the Minister of State for Training, Skills, Innovation, Research and Development in July 2017.
Radio astronomy involves the detection of the very weakest signals from distant astronomical radio sources, often billions of light years away.
Due to I-LOFAR’s extreme sensitivity, it is vulnerable to interference from electrical equipment such as LED lighting power converters, electric fences and wind turbines. Although such systems are not intended to be radio transmitters, they emit radio waves over a broad range of frequencies causing unwanted interference in sensitive radio telescopes. In addition, tall structures such as wind turbines reflect transmissions (from DAB radio for example) resulting in the telescope receiving transmissions that might not otherwise be received. In the worse cases, interference from such sources can completely blind a sensitive radio telescope such as I-LOFAR. Further details on the impacts of wind turbines on radio astronomy can be found in Winkel & Jessner (2018) and in this recent report.
There are a number of measures that can be put in place to protect sensitive radio telescopes, such a locating wind turbines at sufficient distances from a radio astronomy facility and/or shielding the wind turbines and associated infrastructure. In the US, UK, France and Australia, “radio quiet zones” have been created to give special protection to radio astronomy facilities.
Protection of I-LOFAR by spatial planning
We are requesting that spatial planning regulations be employed to protect this significant infrastructure as follows:
• Zone I (Protected Zone <5 km):
No large wind farm/photo-voltaic installations allowed within a radius of 5 km from I-LOFAR.
LED lighting installations to be subject to consultation with the I-LOFAR Consortium.
Consultation with the I-LOFAR Consortium on any other developments which require the use of large power inverters.
Consultation with the I-LOFAR Consortium on any proposed radio transmission systems in Zones I and II.
• Zone II (Consultation Zone <10 km):
Limitations on the turbine height for wind farms.
Consultation with I-LOFAR as to the turbine types and related equipment to be used.
Turbines from certain manufacturers are better than others from the point of view of radio interference/pollution. This should be considered.
Consultation with I-LOFAR as to equipment to be used on any photo-voltaic installations. Field tests on the equipment to determine the effects, if any, on the station should be carried out.
Equipment field tests to determine effects, if any, on the station should be carried out.
It should be noted that I-LOFAR is a designated “Radio Observatory” registered with the International Telecommunication Union (ITU) to protect the service from interference.
Further details of the impacts of wind turbines on I-LOFAR can be found in the I-LOFAR Consortium’s submissions to the first stage and the second stage of Offaly County Council’s Draft County Development Plan.