Although Solar PV would seem to many to be the ideal ‘free’ source of energy, one of the main arguments against it has been that the manufacture of the panels comes at significant environmental cost, in terms of extracting and processing the minerals and materials needed to make the panels; and then shipping both the materials and the panels themselves halfway round the world to distribute them.
Critics argue that this embodied energy is greater than the energy that the panels will ever generate, thus wiping out any benefit that they may have had.
This was something that was in my mind when I looked at solar pv, but after reading around, I’m happy to say that I’m pretty well convinced that actually solar pv comes out on top, even after taking embodied energy into account.
The reasons for this? Well, the primary reason is that *even if* the payback time (the time taken for the energy produced by the panels to equal the energy used in their creation), was very large, there is at least a point when the panels will be ‘in credit’ in energy terms. Once made, they don’t continue to use resources, unlike, say generating electricity with a gas fired power station, which because it has to use natural resources over its entire life, has no chance of making that payback in energy terms.
The secondary reason is that modern panel manufacture means that it is likely that payback times will be far less than was previously thought to be the case – as little as 4 years. Given a lifespan of over 25 years, this is good news from an energy point of view.
There have been a lot of studies into the subject, but I found this abstract from Colin Bankier and Steve Gale very useful, as it summarizes many reports in the once place.
All that remains is to see just how much useful electricity PV panels can produce here in Northern Ireland. Not a vast amount, given the relatively tiny panels (160w) that will be used, but then our energy requirements are similarly small, so it should all balance out.