Keen followers of the Blom UK blog might recall that in early 2011 we announced a new partnership with German company Sun Area, which enabled us to offer city wide solar potential assessment surveys quickly, accurately and cost effectively. It wasn’t long before we teamed up with our first customer of the new offering; Bristol City Council.
Bristol City Council has long been seen as one of the UK’s most innovative and dynamic local authorities, and the ‘UK’s leading green city’s’ stance on renewable energies is proving no exception. Being the first local authority outside of London to setup its own energy services company, and the first to be building its own wind turbines, it came as perhaps no surprise that they would be the first council within the UK to commission a city wide solar potential assessment survey.
What does this mean for you?
Bristol Council has now gone ‘live’ and published the data to a mapping portal. What does this mean for us? Residents from across Bristol can now quickly and easily see the solar potential of their property at a glance. Not only is the map free, but can also provide more detailed information such as roof size & aspect, suitable PV system size, annual generation, Feed in Tariff (FIT) payback and term of Return on Investment (ROI).
Surprisingly, a third of all houses in the Bristol area provide enough undisturbed roof space to be suitable for solar generation. This is approximately 420 hectares which, to give this some bearing, is as large as 600 premiership football pitches. Readers of the Blom UK blog familiar with the Bristol area can also note that this is enough to cover The Downs twice over in solar panels!
Even more surprising is that the previous solar assessment methodology used by the government underestimated the solar potential of Bristol by approximately 75%.
Interested in generating your own electricity? Find out more on Bristol Council’s Bristol Solar Map.
In March 2011 Blom captured LiDAR across the City of Bristol with an Optech 3033 LiDAR sensor mounted in a fixed wing platform. At two points/m2 resolution, this LiDAR data would provide increased survey accuracy when compared with any solar assessment carried out with data of a broader resolution. The insolation (a measure of solar radiation energy received on a given surface area) for each point is then calculated using this data. This calculation takes into consideration the daily and annual transit of the sun and shadowing effect of any features that may comes between the two, and expressed as kWh/m2 per yr. Building rooftops are then generated and a value for each building is created. Unshaded areas are joined up to give the total roof resource and average insolation figure for each building.
Weighing up the financial viability of installing PV panels meant establishing a minimum baseline figure, under which any installation would be considered unsuitable. The remaining buildings were then assigned a solar potential ranking of ‘Reasonable’, ‘Good’ and ‘Very good’.
In total the survey assessed the solar potential of just under 240,000 buildings in Bristol, with a surprising 66.2% considered financially viable of supporting a system of at least 10m2.
Across Bristol there were:
- 80,924 rooftops unsuited to solar generation (34%)
- 4,642 rooftops with reasonable insolation (2%)
- 64,854 rooftops with good insolation (27%)
- 88,650 rooftops with very good insolation (34%)