The reality behind China's 'green power'

Upgrade costs

The IEA estimates that in general, China’s will need to invest approximately US$1.5 trillion in new grids and upgrades by 2030.

The solution is coal

China’s wind farm operators want to install an additional 80GW to 85GW of coal fired power generation not previously included in official forecasts. This will be the equivalent of an estimated 5 per cent to 6 per cent increase in total generating capacity.

Coal fired back up power

By mid 2008, Beijing was under pressure from developers of a new high profile large-scale wind farm, as well as a number of investors and major operators seeking approval for the construction of coal fired power stations to supply backup power during low wind conditions.

Operators want coal fired backup plants to supply 65 per cent to 75 per cent of the capacity of the wind generating facility. They have the full support of local officials and grid operators who claim that these backup systems maintain a reliable supply of power and will prevent disruption and possible damage to the grid system and loss of power to consumers.

The problems with dedicated backup coal fired power generation

In theory, during ideal wind generating conditions, backup power is shut down. When wind speed drops off, backup power is restarted. Coal fired power stations are base load supply systems, not suited for intermittent and unscheduled stop-start cycles. These intermittent operations incur higher operational, maintenance and production charges, as well as higher coal consumption, raising the cost per kilowatt of electricity produced above that of normal base load operations.

Each new start cycle also releases higher pollutant levels prior to reaching normal operating temperatures.

Unlike gas turbine peaking systems, coal fired systems can take in excess of 24 hours to bring back on line from time of shut down, depending upon cold, warm or hot starts.

Operating and managing such a complex combined generating facility is challenging and costly, and would normally require one boiler/turbine/generator train on line at all times, adding varying degrees of carbon emissions to the renewable facility zero carbon footprint.

Success has created problems of looming overcapacity for China’s booming wind generation industry, and State Council will introduce restrictions in early 2010.