Renewable power accounted for 70% of net additions to global power generating capacity in 2017, the largest such increase in modern history, a report said on Monday.

But the heating, cooling and transport sectors, which together account for about four-fifths of global final energy demand, continue to lag far behind the power sector.

According to the REN21's Renewables 2018 Global Status Report, solar photovoltaic (PV) capacity reached record levels.

Solar PV additions were up 29% relative to 2016, to 98 GW. More solar PV generating capacity was added to the electricity system than net capacity additions of coal, natural gas and nuclear power combined, said the report.

Wind power also drove the uptake of renewables with 52 GW added globally.

Investment in new renewable power capacity was more than twice that of net, new fossil fuel and nuclear power capacity combined, despite large, ongoing subsidies for fossil fuel generation.

More than two-thirds of investments in power generation were in renewables in 2017 owing to increasing cost-competitiveness and the share of renewables in the power sector is expected to only continue to rise.

China, Europe and the US accounted for nearly 75% of global investment in renewables in 2017.

However, when measured per unit of gross domestic product (GDP), the Marshall Islands, Rwanda, the Solomon Islands, Guinea-Bissau, and many other developing countries are investing as much as or more in renewables than developed and emerging economies.

Both energy demand and energy-related carbon dioxide emissions rose substantially for the first time in four years.

In the power sector, the transition to renewables is under way but is progressing more slowly than is possible or desirable.

A commitment made under the 2015 Paris climate agreement to limit global temperature rise to "well below" 2 degrees Celsius above pre-industrial levels makes the nature of the challenge much clearer.

If the world is to achieve the target set in the Paris agreement, then heating, cooling and transport will need to follow the same path as the power sector and fast, the report warned.

Small changes are underway. In India, for example, installations of solar thermal collectors rose approximately 25% in 2017 as compared to 2016.