Efficiency first. Fabric second. Bolt-on’s last?2.5kWp ground-mounted PV array

I admit it’s a little hypocritical to install PV’s at this stage, since I can get a bit preachy about the urgent need for a general fabric-first approach. With the general state of the UK housing stock the Feed-in Tariff scheme for PV does not make economic sense.

Our decision was certainly driven in part by the rapidly falling FiT rates coinciding with an almost equal drop in the installed cost of PV.

On October 20th our PV array was commissioned. This is our second bolt-on after the solar hot water panels in 2009. In 2006 we got planning permission for a 2.5kW wind turbine, and a fat copper cable was laid to where we planned to install a 2.5kWp tracking PV array. Money ran out and both the PV array and a wind turbine were postponed indefinitely.

In late 2012 Dulas in Machynlleth made us an offer we couldn’t refuse for a small fixed array. The 110m cable was rediscovered under a fallen willow at the bottom f the 2x2m hole for the footings of the planned PV tracker. The cable passed the integrity tests and we went ahead with clearing the site and making the foundation pads. We had a lovely time with the engineers from Dulas and got our first kWh’s on October 20th.

Updated on April 5th 2013:

The word “risible” still rings in my ears from an article by George Monbiot on the UK PV FiT folly. Well, so far our small array has produced 33% of our non-heating winter electricity, and 18.5% of the total. Particularly surprising is the energy captured on days with full cloud coverage (most days really…).moonshine

Tests in recent days have shown that the actual conversion efficiency of the array is 19% of the solar insolation on the panels when in direct sunlight.  Overall the performance is significantly better than manufacturers published data would lead one to believe. I’m surprised. But it’s early days. Let’s see what the rest of the year brings.

The jury is still out, but I’m pleading not guilty to the charge of folly. However, would PV in our context still make sense without the FiT?