The Paris Agreement aims to reduce carbon emissions to zero by 2050, which has sped up the growth of "zero-carbon" business worldwide. Part 3 of Zero Carbon Ahead looks at this trend. The world's biggest solar power station is currently being built in the deserts of the United Arab Emirates -- the power it generates will be far cheaper than coal. Dramatic decreases like this in the cost of renewable energy mean that many businesses hope to eventually use renewables for 100% of their energy needs.