We're submitting a project where we have 42% of electricity and 58% of gas consumption. And out of 42% of electricity consumption, 9.2% is generated on-site.

Do we have to purchase 35% over a 2-year period for the 100% of energy consumption (including both electricity and gas)? Or do we have to buy 35% over a 2-year period for the 42% of electricity consumption minus the energy generated on-site? 

Thanks in advance for your answers.