Photovoltaic Cells generate electricity directly from natural sunlight.
Between 2003 and 2008 we installed 4.4KWp of PV cells on our south facing roof and west facing wall. The array consists of 27 Isofoton 165Wp monocrystalline modules. The images below illustrate installation of the 22 modules on the south facing roof and 5 mounted on a west facing wall.
How much energy do they generate?
Electricity Usage and Generation Profile per month (January 2009 to January 2011)
The table to the left displays how much electricity (in KWh)
- we consume each month (Electricity Usage/KWh)
- how much we generate on-site from our PV array (PV Generation/KWh)
- how much we import from the grid (Electricity Imported/KWh)
- how much we export to the grid (Electricity Exported/KWh)
- where we generated more than we used each month (Generated more than used ?)
In 2010 we consumed 3928KWh and generated 2994KWh. This equates to 76% of our total usage.
However during both years we experienced some failures of our inverter (the unit which converts from DC to AC) which degraded the potential energy available.
This table will be updated on a regular basis so that figures for recent months are available.
How much did they cost?
With assistance from a grant which was widely available at the time, the total capital and installation costs are comparable with that of a modest hatchback car. The lifetime of the panels is expected to be 30 years+