Renewable energy generation fell in 2016 but thanks to gas, greenhouse gas emissions declined dramatically.
Carbon dioxide emissions arising from electricity generation in Great Britain dropped very significantly in 2016, not because of the continuing deployment of subsidised renewable energy generation capacity, but because of a large-scale switch from coal to gas fired power. In fact, in spite of rising capacities, the share of electricity generation from wind and hydro actually decreased in 2016 compared to 2015.
The installed capacity of large-scale, grid-connected wind generators increased by about 800 MW in 2016, but wind speeds over the year were lower than 2015 resulting in wind generated electricity being 10% lower than the 2015 figure. Lower annual wind speeds tend to be accompanied by reduced rainfall, and it is therefore unsurprising that hydro generation was also 18% lower in 2016 compared with 2015.
However,electricity generation from biomass increased by 25%, which offset the reduced output from hydro and wind, resulting in an overall minor decrease in renewable generation of about 0.5% in 2016 compared with 2015.
The big success story for 2016 was the very significant decrease in carbon dioxide emissions per unit of electricity (MWh). This fell from around 0.33 tonnes of CO2 per MWh of electricity supplied in 2015 to approximately 0.26 tonnes of CO2 per MWh. This large decrease is almost entirely due to switching from coal to gas in fossil-fuelled generation. The overall proportion of GB electricity supplied by coal and gas was steady at 56% but whereas coal supplied about half of that share in 2015, it dropped to less than a fifth in 2016, with gas making up the shortfall. Coal emits nearly two and a half times the amount of greenhouse gases per unit of electricity compared with gas, so the switch from coal to gas-fired generation resulted in the saving of more than 24 million tonnes of CO2.
To put this figure into context, this is about one quarter of the total emissions from electricity generation in 2015.
The overall demand for electricity in GB continued the downward trend of recent years with 2% less being supplied in 2016 compared with 2015. This reduction also contributed to a saving of approximately 1.6 million tonnes of CO2. A reduction in demand will doubtless be claimed as a victory for energy efficiency leading to conservation, and some part of the fall may be the result of that effect, but we remain concerned that the fall may in fact reflect fundamental economic problems.
The reduced output of wind and hydro stations in 2016, and decrease in emissions from power generation means that both wind and hydro power stations saved less greenhouse gas in 2016 than the year before; wind generation saved roughly 2.5 million tonnes less in 2016 than in 2015 and hydro, about 0.5 million tonnes less. The increase in biomass generation helped biomass to offset the fall in average grid emissions.
As we noted in a previous blog, a reduction in emission factor for the GB electricity grid means that renewables become a more expensive means of cutting emissions. To put this differently, subsidy to renewables needs to decrease rapidly for emission savings to be cost-effective. The 2016 figures reveal that reducing emissions by onshore wind costs consumers around £169 per tonne of CO2, while offshore wind costs approximately double that amount, and the roof-mounted solar panels receiving the first Feed-in Tariffs about ten times that amount. These costs are very much in excess of the EUR 30 that the OECD estimates is the cost of the climate change damage arising from emitting a tonne of carbon dioxide. As we have stated in previous publications, such figures mean that, bizarre as it seems, it would be rational for the general public to prefer the damage of climate change to the economic harms they are exposed to in meeting the current subsidy costs of reducing emissions through renewable energy. Government surely did not intend this outcome.