KJ Tait

PV News

4 August 2023

At KJ Tait, we continue to invest in new software to assist our Engineers in developing strategies to reduce carbon emissions.  PVSol is the most comprehensive solar PV software currently on the market.  It can help our Engineers assess how much energy generated would be used by the building and whether batteries would be technically and economically feasible.    


We have recently completed an assessment for a building in Edinburgh that investigated two layout scenarios: 

  • South facing, this would produce more energy per m2 
  • East/west facing, more panels could be installed. 


The current Tenant’s utility rate is comparatively low, when their current deal ends the utility rate will revert to normal market rates which are currently circa 40p/kWh. 


Using the half hourly data supplied by the Tenant, we were able to calculate how much energy would be exported to the grid: this normally occurs on summer days when the generated power is greater than the power demand of the building.  The south facing array would export 5% of the energy generated to the grid, whilst the bigger the east/west facing array would export 11%.


Under each scenario, exported energy would receive no payments owing to their size being greater than 50kW, therefore, to reduce the amount of energy exported, we subsequently investigated the economic feasibility of battery storage.  This assessment found the payback for each scenario would lengthen and the return on investment over 25 years would reduce. 


We recommended that the Client install the east/west system without battery storage on the building as this represented the greatest return on investment and contributed the most to reducing carbon emissions.