Saturday, July 27

Some Solar Farm myths busted

It seems that in Hampshire solar energy farms are the main renewable energy projects that are currently being planned. Since this is the case, I thought it is worthwhile listing a few popular lies and myths regarding solar energy farms of the photovoltaic variety.

They are noisy

Photovoltaic solar panels don't make any noise, they produce direct current (DC) which doesn't cause any vibration in electrical equipment and hence doesn't produce noise. Invertors and transformers may produce some vibration, however sound insulation is used to eliminate such problems. Engineers are paid to solve these issues, so it isn't generally a problem. The other point of course is that vibration and noise are energy losses, so any modern equipment is generally designed to minimise such noise.

I recently visited the solar farm at Clanfield and despite it being in a quiet rural location, I could hear nothing other than some workmen talking and passing vehicles. My visit highlighted the obvious, that existing technology based on fossil fuels is inherently noisy and modern technology such as solar PV panels should help to reduce the noise levels around us. If you want noise, just build a busy road near your home.


They produce glare

This of course is a logical fallacy and is a product of poor analysis of what a solar panel is designed to do.
If you want to capture as much sunlight on a flat panel as possible, the last thing you would do is make it shiny. You would design the panel to absorb as many frequencies of electromagnetic radiation as possible, including those in the visible range.
If glare were a major problem, then airports wouldn't invest in solar panels to produce energy, such as Birmingham airport which has solar panels installed on the terminal roof, the Denver Colorado Airport solar farm, or Gatwick, which has them installed next to the main runway.


They produce electromagnetic radiation or fields (EMF)

This is one of those memes that gets spread by conspiracy theorists. Electromagnetic radiation and fields are around us all the time, produced by mobile phones, TVs, cars, computers and many other systems.
PV panels themselves won't produce anything significant because they are direct current, the biggest DC electromagnetic field is Earths. We are bathed in Earths field 24/7, we would all be dead without it.
Invertors and transformers produce confined fields but regulations require equipment to be shielded and tested for any leaks. Many people already live near large electricity transformers and invertors or similar equipment, in fact much of it is located close to homes, hidden away behind fences and locked gates, home owners don't generally have a problem with it.


They industrialise farm land

Farm: low biodiversity and industrial
Farmland is already industrialised! How many documentaries does someone need to see about modern farming, tractors that use GPS to navigate around fields, robots that milk cows, loss of biodiversity and bees poisoned by pesticides?

Why do people living in a house next to a field that probably work in an office in a city, think a field full of crops sown by a mechanical vehicle is anything but industrialisation? Not only that, but the field is beaten up like this on a yearly basis. It's called agriculture and it's primary purpose is to serve humans.

But if some inert solar panels are stuck in a field, sitting on frames, then plant some wild flowers, trees and hedges, then leave them be for 25 years to produce energy. Apparently that is called industrialisation! It is far more natural to leave the ground alone for 25 years than to plough it regularly and grow mono-crops.


The manufacturing carbon footprint is large

This is typical cherry picking and/or a fallacy.
Every single technology used to produce energy has a high carbon footprint at the manufacturing stage. We are animals that live for periods of time, our impact on the planet and on other people is measured over that time, it isn't just measured when we are born.
The same principle is applied to energy production, so the carbon footprint of different sources of energy is calculated over time, or per unit of energy. Hence any carbon emissions from the solar farm are calculated on the basis of it's total life time, which is approximately 25 years.
On this basis, we know that electricity generated via gas has an approx carbon footprint half that of coal and solar PV energy has a footprint between 14 and 20 times lower than coal.


During winter they only produce 8% of their annual output

Read that statement very carefully and think about it. The method of obtaining the percentage is misleading. Typically in winter PV panels produce about 20% of what can be produced in the summer. Of course comparing Winter output with the whole year would give a misleading small figure! Lets choose a nuclear power station and say winter is three months, that means in the winter the power station only produced 25% of the annual output! When you compare that with 8%, it means the solar panels are producing a third of the full output possible, approximately 33%. Not bad for a dull winter!


After 20 years, performance drops by half

Kyocera tested some old panels last year that had been installed for 20 years in France, they found the panels had only degraded by 8.3%, no where near a half!
Typically many solar panel manufacturers guarentee 80% output after 25 years

See also: http://info.cat.org.uk/questions/pv/life-expectancy-solar-PV-panels

Some more points...
How many technologies last for 25 years with little maintenance and are still 80% efficient or even still work at all?
Because of the solid state nature of solar panels, even after 25 years they can still be used in the second hand market. In many places around the world solar energy is welcome because it replaces dangerous kerosene lamps. So second hand panels that are still functional are valuable pieces of kit.





2 comments:

TheVille said...

Comment removed.
Reason: although the question was a legitimate one, it was off topic and information on the subject could probably be found on many other more suitable web sites and forums about roof top solar energy. I do not have an answer to the question asked.

Craig Chance said...

Good read. Informative