around , with an average load factor of 72% (i.e. 3.6×1011/(8,760 × 57×106). Decarbonisation The national grid has a stretch target to be carbon neutral or negative by 2033, well ahead of the UK's national target to achieve this by 2050. It also aims to have the capability to be 'zero carbon' as early as 2025, meaning that if energy suppliers are able to produce sufficient green power, the grid could theoretically run without any greenhouse gas emissions at all (i.e. no carbon capture or offsetting would be needed as is the case with 'net zero'). In 2020 about 40% of the grid's energy came from burning natural gas, and it is not expected that anywhere close to sufficient green power will be available to run the grid on zero carbon in 2025, except perhaps on the very windiest days. Analysts such as Hartree Solutions considered in 2020 that getting to 'net zero' by 2050 would be challenging, even more so to reach 'net zero' by 2033. There has, however, been sustained progress towards carbon neutrality, with carbon intensity falling by 53% in the five years to 2020. The phase out of coal is progressing rapidly with only 1.6% of the UK's electricity coming from coal in 2020, compared with about 25% in 2015. 2020 saw the UK go more than two months without needing to burn any coal for electricity, the longest period since the industrial revolution. Losses Figures are again from the 2005 Seven Year Statement. Joule heating in cables: 857.8 MW Fixed losses: 266 MW (consists of corona and iron loss; can be 100 MW higher in adverse weather) Substation transformer heating losses: 142.4 MW Generator transformer heating losses: 157.3 MW Total losses: 1,423.5 MW (2.29% of peak demand) Although overall losses in the national grid are low, there are significant further losses in onward electricity distribution to the consumer, causing a total distribution loss of about 7.7%. Losses differ significantly for customers connected at different voltages; connected at high voltage the total losses are about 2.6%, at medium voltage 6.4% and at low voltage 12.2%. Generated power entering the grid is metered at the high-voltage side of the generator transformer. Any power losses in the generator transformer are therefore accounted to the generating company, not to the grid system. The power loss in the generator transformer does not contribute to the grid losses. Power flow In