I have noticed that wind power delivered to the grid is always less than 6 GW, no matter how windy it gets. This was clearly demonstrated on October 21st when wind speeds across the country reached around 50 mph for most of the day. The wind output was simply bumping along always under 6 GW. Something fishy is going on – What is it?
The heart of the problem becomes clearer once you start looking at the constraint payments made to wind farms under the Grid’s ‘balancing mechanism’ (see: ref.org.uk). Large wind farms were paid a staggering £2 million on 21st October to disconnect from the grid. These payments were priced at over £90 for each MWh of generated wind energy which is then simply thrown away !
Nor is this an isolated incident. Over the past year constraint payments have been increasing as more capacity is added. We can see similar periods over weekends in August and April. All these hidden costs for wind are passed on to the consumer through their bills.
The UK installed wind capacity is 11.2 GW but the effective load capacity on a perfect day of wind is apparently only around a maximum of 60 %. The Grid simply cannot handle more than 6GW of instantaneous wind power, whereas it has no problem with 30GW of coal or Gas. I think the problem lies in the Grid topology which is based on large power lines to central generators. The high voltage connections to dispersed wind farms cannot handle large power, made worse by unpredictability. There is really no point adding new wind capacity until the underlying infrastructure is upgraded.
This message of course is not what the green Wind lobby want to hear. They want to instal as much as possible because they can’t lose. They get paid whatever happens.
Finally lets look at the headline wind energy statistics that are often quoted. Renewable Energy UK quote that the fleet of UK wind farms generate 27,263,077 MWh of Energy Produced each year. This is based on DECCs own DUKES review of on-shore and off-shore capacity factors (27.82%). Lets now look at the actual electrical energy supplied to the Grid in 1 year of operations. I have integrated the total energy supplied to the grid over the last 13 months based on hourly monitoring.
The average daily electrical energy supplied to the Grid by Wind farms between 1st September 2013 and 1st October 2014 was 22,833,000 MWh. The total energy generated in a 12 month period was 20,217,523,383 MWh. This means that up to 26% of the reported energy paid out to wind farms is simply thrown away. This fact is hidden from public scrutiny because we pay for this wastage on our electricity bills. DECC and the Wind industry would prefer you not to know because it undermines their economic case for green energy.
So for example the real ‘savings’ of CO2 emissions from wind were 3 million tonnes less than the official figures of 11.7 million tonnes. The real capacity load factor was 20.6% and not the quoted 28.7% if you take into account the discarded excess wind energy.
The real costs of Wind electricity should really be revised upwards by 35%. Only if and when the Grid gets upgraded to handle multiple power lines to such a dispersed energy source as wind can the current DECC and wind industry figures be believed. The costs of upgrading the Grid are enormous and must be factored into the real costs of expending wind energy. Until the Grid is upgraded it makes hardly any sense at all to add any new UK wind capacity. That is unless you are a wind operator with guaranteed 20% return on investment underwritten by the UK government.