Is it right for me
There are very few criteria that determine your suitability for Solar PV:
- Is your roof facing South, East, or West?
- Do you have more than 3sq meters of roof or ground space?
- Is your roof in good condition?
- Is your roof free from significant shading?
- Has your house got an Energy Performance Certificate rated “D” or above
If you answered yes to all these questions then you are suitable!
Orientation and Tilt Angle
The ideal orientation for Solar PV in the UK is South facing and the ideal tilt angle is between 30 and 45 degrees from the horizontal axis.
However, facing an Easterly or Westerly direction, or being at an angle of 65 degrees will still generate significant volumes of electricity but not a such as south facing at 30 degrees.
The following table shows performance levels for all types of system installations.
Use the table to estimate your returns based on your orientation tilt angle.
Even a small section of a panel is shaded by the branch of a tree or telephone pole then there will be a large reduction in power output from the panel. This is because a PV solar panel is made up of a string of individual solar cells connected with one another.
The output of the whole panel is limited to the output passing through the weakest cell. If one cell (out of 36 in a panel) is completely shaded, the power output from the panel will fall to zero, or if one cell is 50% shaded, then the power output from the whole panel will fall by 50%.
In addition to a loss of power output, shade can have much more serious effects on photovoltaic solar panels – hot spot damage to cells in which a shaded cell or cells overheat and potentially burn out.
EPC – Energy Performance Certificate
Solar Photovoltaic systems after 1st April 2012 on domestic properties will eligible for a lower feed-in-tariff payment if the property has an EPC rating of below level D.
The official statement from DECC explains that the government “wants to ensure that solar PV is considered as part of a holistic approach to carbon reductions in buildings that prioritises energy efficiency.”
The EPC rating level will apply to both domestic and commercial buildings but not farms for all new Solar PV installations on or after the 1st April 2012. Properties which do not meet an EPC of level D or above will be eligible for a lower tariff rate, currently proposed at 0.57p.
Whilst this may be of concern to some, according to government statistics there is an estimated 51% of UK domestic properties and 65% of non-domestic buildings which already have an EPC rating of D or above, meaning that even before any energy efficiency measures are taken, a large proportion of properties will already be eligible for the standard tariffs. An exemption to energy efficiency requirements may be available if it can be demonstrated that it is not possible for an EPC certificate to be obtained for that building or property.
A new Solar PV installation can contribute to increasing the EPC level of a property.