Proportion of energy self-generated - This measures the percentage of our electricity and gas use that is accounted for by our own renewable generation.
The renewable energy in this calculation includes:
- Electricity from combined heat and power fueled by sewage sludge biogas
- Exported biomethane expressed as the electricity that it would have produced if the source biogas had been converted into electricity instead
- Electricity from hydropower installations
- Renewable electricity from other on-site generation that is consumed by a regulated activity (i.e. water treatment, distribution, sewerage, sewage treatment or sludge treatment). In our case this includes electrical output of food waste digestion and solar power.
The denominator for this performance commitment is total electricity demand. We use electricity as the single common unit to avoid combining electrical and thermal energy output, which could lead to confusion and disparities.
We are targeting an increase in the amount we generate over time, starting at 21% in 2015-16 and rising to 25% by 2019-20. If we miss the target in any year, we will refund customers £99k for every percent we are below this target.
Our renewable electricity generation for this year was 26%, better than our target. We have met this target in each of the five years of this regulatory period.