This report has been gratefully written for us by Mark Sanderson, M0IEO
A brief outline of Electromagnetic Fields (EMF) and Electromagnetic Radiation (EMR)
All electrical circuits produce radiation, from your kettle to your own body, all produce electromagnetic fields. Life itself is a balance of electromagnetic fields from individual cells to our brain and thoughts, all rely on this invisible force to exist.
Electromagnetic fields can be broken down into two categories, Ironizing radiation and Non-Ironizing radiation. Ironizing radiation is basically high frequency, high energy radiation with the ability to change molecular structure by stripping away ions in cells, typical examples being x-rays, Gamma rays and the like. Non-Ironizing radiation is low frequency low power radiation which is not able to strip ions from cells, it is found in everyday life and in small doses is deemed to be relatively harmless.
However, Non-Ironizing radiation in sufficient concentration can have an adverse effect of everyday life. In strong enough fields there can be cross contamination with electrical circuits such as TV, Radio, computers, mobile phones and in extreme cases the household electrical system itself. There are countless cases recorded in medical journals of people being hypersensitive to Non-Ironizing, low power low frequency radiation, with symptoms including but not limited to dizziness, nausea, loss of thought process and insomnia.
Can Solar Power cause Electromagnetic Fields?
Solar power can cause a rise in electromagnetic fields. The solar panels themselves do not produce EMF/EMR fields, however the associated wiring and inverters do cause considerable EMF/EMR fields.
Solar panels produce Direct Current (DC) electricity by converting sunlight into electricity using Photovoltaic (PV) cells which are the main constituent of the solar panel. The voltage of the panel is dependent on the number of PV cells on the panel which can run into thousands of cells per panel. DC current is then converted into Alternating Current (AC) using an Inverter and the AC current is then fed into the mains network as a saleable commodity. It is the Inverter which is the weak link in the process as this is where the bulk of the low power, low frequency radiation is to be found because Inverters are not efficient converters of DC power to AC power and almost always have a high loss factor which results in electromagnetic radiation.
Do Commercial Solar Power Farms use the same technology as domestic PV Panels?
Yes, they do. All solar panels work on the same principle as described above. The obvious difference being that commercial producers of solar power use bigger and more productive equipment which produces larger amounts of electrical currents and by default, larger amounts of potential electromagnetic interference.
How many panels and inverters to the acre?
Each solar panel requires its own inverter to convert DC power to AC, when thinking about commercial producers you have to accept that a large area of land is required to make production economically viable. Solar power plants require significantly larger land areas compared to conventional power plants. A 100MW thermal power plant for instance would require less than 10% of the total area that a 100MW solar PV power plant would. A simple rule of thumb is to take 100 square feet of panel for every 1kW of production, extrapolating this, a 1MW solar PV power plant should require about 100,000 square feet (about 2.5 acres, or 1 hectare). However, owing to the fact that large ground mounted solar PV farms require space for other accessories as well as access for maintenance, the total land required for 1MW of solar PV power plant will be about 4 acres. Given that a PV panel for industrial use will equate to approximately 120ft² each, that’s 834 panels per 4 acres of land and 834 inverters producing electromagnetic radiation. Also, to be taken into account are the miles of wiring needed to feed the electricity produced into the national grid, every connection, joint and radius in the cabling is a potential leak point for EMF/ EMR, thus increasing the background radiation in the area.
(CARE Suffolk note: the three solar PV developments in our area are proposing to use containerised inverters. So instead of one small inverter behind each panel changing the current from DC to AC, this process for thousands of panels is amalgamated into one of 16/17 containers around the site. This concentrates the EMF/EMR into specific locations around the sites, many of which are right next to the public footpaths you walk along!)
Do Solar Panels work all the time?
In a word, no! Solar panels rely on daylight to produce electricity, the stronger the daylight the more they will produce until the solar panel reaches it’s yield point or point of maximum production. Obviously Solar panels do not work at night and work at greatly reduced output when the weather is cloudy and/ or rainy. Modern solar arrays are switchable so that when demand drops off the panels should shut down and not produce electricity although many now have storage facilities attached to the site to store power for when electrical demand is higher. Start up and shut down of the solar panels can cause a spike in electromagnetic radiation which can result in elevated levels of electromagnetic radiation for a period of time.
Who is likely to be at risk from EMF/ EMR?
Although designated as farmland, there is still a significant population adjacent to the proposed installation at Tye Lane in Bramford, Suffolk. This comprises mainly of dwellings although there are local businesses in the area as well as water services immediately adjacent to the proposed site. The water service in the guise of Essex & Suffolk Water rely on Radio Telemetry in the lower VHF band to maintain the flow of water to the town of Ipswich. EMF radiation could have an adverse effect on that telemetry causing the service to fail to thousands of customers. Other RF spectrum users who can be affected include:
- Mobile Phone signals
- TV signals
- Broadcast Radio signals
- Domestic and commercial alarm systems
- Emergency communications systems
- Mobile communication systems
- Service provider communication systems (Gas, Water, Electricity, Police, Fire Brigade, Ambulance all rely on RF communications which could become swamped because of Electromagnetic Radiation caused by the inverters within the solar farm area)
- Aeronautical radio users (Wattisham and Hitcham Airfields have approaches passing directly over the proposed solar farm at Tye Lane, Bramford and use low frequency VHF radio as well as radio navigation for Wattisham which is the landing zone for Suffolk and Norfolk Air Ambulance)
- Local Government (Suffolk County Council Emergency Planning Office)
- Land Mobile radio users
All of the above have allocations in the HF, VHF and UHF radio spectrum and all will be susceptible to the interference from electromagnetic radiation caused by the installation of solar panels and the associated hardware to make a solar farm work.
Is Electromagnetic Interference a danger to the local community?
In a world where radio spectrum is a hotly contested commodity, its preservation and the effects of unwanted electromagnetic radiation is something that should concern everyone. I have personal experience of working with radio near a site in Manston in Kent which has now become a solar farm with acres of solar panels. Prior to the solar farm coming on line I used to be able to hear and be heard in the Far East, India, Australia, New Zealand etc at only modest output power of 100 Watts of RF output. Immediately following the solar farm switch on, I could neither hear nor be heard in these countries without being at least 5km away from the solar farm, and then only with some difficulty because of the electromagnetic radiation. Given a decay rate of V multiplied by 1/d² that would put the level of electromagnetic radiation way above any safety limit published by the Health and Safety Executive within a 1km proximity of the solar farm. It is my opinion that if you live within 2km of one of these installations you should think very seriously about your exposure to electromagnetic radiation as at the time of writing, very little has been written about the effects of this phenomenon on human beings let alone the effects on wildlife, its habitat or the surrounding countryside.
About the author of this report.
Mark Sanderson is an amateur radio user with a keen interest in the use and abuse of the radio spectrum, he holds an Advanced Licence for Amateur radio and teaches amateur radio at all licence levels under the Radio Society of Great Britain approved syllabus and is also an invigilator for the Ofcom Examination Process.
Mark has taken part in a number of investigations involving solar panel installations in the domestic environment where these have caused electromagnetic interference to both the panel user and neighbours in the vicinity of the panels. Mark is committed to ensuring that the radio spectrum is not polluted and degraded and that all spectrum users are able to use the spectrum without interference or abuse from outside users.