A new energy source is not like a new technology that can be developed. It needs to be discovered - as in a scientific break-through. A plan can not assume that break-throughs occur.

GDP measures the total production of an economy. That is mostly equivalent to energy_consumption * p_efficiency.

Investing in new technologies that increase efficiency has always been a good decision. Maybe you can improve solar panels by a further 5% and batteries by 10%?

Realistically, energy_consumption will need to decrease, but that isn't actually that terrible.