Ask G

Ask us: Solar health & safety

Tanya Ha answers your questions on the safety of solar power.

I was wondering how safe solar power is to the human body? I haven’t heard any remarks for or against its health options yet.
-Trisha Catley

Solar-home-story

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The internet has quite a bit of information – and misinformation – about the health and safety of solar panels. The most common concerns centre on the safety of the materials involved, such as cadmium telluride and potential exposure to crystalline silica dust (a carcinogen), and of electromagnetic fields (EMFs) around inverters. I ran these past materials scientist Dr Gerry Wilson and health impact assessment and public health consultant Ben Harris-Roxas.

Solar cells are semiconductor devices that convert sunlight into electricity. One commonly used semiconductor material is crystalline silicon. Cells are encased in clear, tough, inert materials, so people who have solar panels on their roofs aren’t exposed to silica dust from wear and tear, as suggested online.

Cadmium telluride (CdTe) is also a commonly used semiconductor. Elemental cadmium is nasty, but the compound CdTe is quite different. In solar cells, CdTe is the jam in the middle of a glass sandwich, so it’s not exposed. There have also been lab tests of CdTe cells in fire conditions, which found the glass plates seal during a fire and don’t allow cadmium release. First Solar, a major producer of CdTe solar panels, has a pre-funded recycling program for their panels and solar panel recycling is underway in Europe (www.pvcycle.org).

Cadmium concerns aside, tellurium is a rare metalloid, so CdTe has a limited future. The good news is solar research is hot right now! There are efforts afoot to develop alternative semiconductors that are ‘earth abundant and non-toxic’, such as Copper Zinc Tin Sulphide.

On to EMFs, all electric devices have associated EMFs and there are natural sources, too. Their strength decreases quickly with increasing distance from the source. There has been much debate about the safety of EMFs, particularly those associated with large, strong fields. However, EMFs of a size warranting concern are rarely encountered in the typical home. The current scientific consensus is that there’s no casual relationship between exposure to low-level power frequency EMFs and adverse health effects, but research is continuing. The World Health Organization has more info: http://www.who.int/emf

There’s a real danger in over-estimating risk and causing worry. The ‘Nocebo Effect’, the evil twin of placebo, occurs when people experience real debilitating symptoms just because they expect to. ‘Wind turbine syndrome’ may well be an example.

In contrast, the direct health risks of coal mining and power generation are well documented and understood. In the big picture, a major co-benefit of solar power is that it displaces the use of polluting fossil fuel fired power. As Ben Harris-Roxas puts it, “Without a doubt, the biggest health risk our children will face is climate change.

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Tanya Ha is an expert environmentalist and author. To ask a question for her next column, email askg@gmagazine.com.au