By Tristan Edis
The chart below details PPA prices inclusive of a bundle of wholesale electricity and renewable energy certificates (which count towards state government renewable energy targets common across the US) struck by wind farm developers across four regions of the United States (the quality of the wind resource varies by region).
Yet in spite of declining wind speeds projects built in recent times achieve levels of power generation per unit of capacity, or ‘capacity factors’, similar to those of earlier projects that had access to higher wind speeds.
What’s also interesting from this recent report is that wind continues to expand its level of power generation market share in a range of countries to levels the naysayers said weren’t possible.
Now while this is still noticeably higher than prices prevailing around 2002, you need to recognise the current-generation turbines achieve vastly better power output from a given wind speed.
Now this doesn’t mean the all-inclusive cost of power from wind farms in the United States is now $US25 per megawatt-hour, because one also needs to add on the value of federal government tax credits (worth about $US20/MWh) and other government incentives which act to subsidise wind farm output.
So when the first lot of wind turbines wear out we’ll be able to replace them with the more advanced turbines – and considerably expand the amount of power we can extract from the high quality wind sites.
Nonetheless, this decline in costs reflects underlying and considerable improvements in wind turbine technology which have allowed costs to decline in spite of a move towards lower wind speed sites.
Even though the report concentrates on the US market it provides one of the most insightful reference documents into how wind power technology and its economics are evolving over time on a global basis.
Each year, Ryan Wiser and Mark Bolinger from the Lawrence Berkeley National Laboratory put out a superb report documenting developments in the US wind power market.
Our charts of the week are taken from Wiser and Bolinger’s latest report, which finds that wind farms in 2013 are signing long-term power purchase agreements at rock-bottom lows.
By being allowed to employ turbines with larger rotors, which will often require a higher hub height than older designs, it should substantially improve the economics of these Victorian wind farms.
For many Victorian wind farm development sites, their planning approvals were based on turbine designs that are now as much as four years old.
What has driven this improvement is partly going higher – placing the turbine on taller towers – as wind speeds tend to improve the further above ground you go.
Projects being built in 2011 and 2012 were making use of resources with wind speeds 85 per cent of the levels employed in projects built in 1998-99.
These advancements in turbine technology are a key reason for why the Victorian Government’s recent decision to allow developers to adjust wind turbine layout without obtaining a new planning approval was so important.
Read more here: Business Spectator